quote requests are paused while the payout amount is being edited

Reviewed-on: #209

api/fx/oracle/internal/service/oracle/service.go

@@ -130,7 +130,7 @@ func (s *Service) getQuoteResponder(ctx context.Context, req *oraclev1.GetQuoteR
 	if err != nil {
 		switch {
 		case errors.Is(err, merrors.ErrNoData):
-			logger.Warn("pair not supported", zap.String("pair", pairKey.Base+"/"+pairKey.Quote))
+			logger.Warn("Pair not supported", zap.String("pair", pairKey.Base+"/"+pairKey.Quote))
 			return gsresponse.InvalidArgument[oraclev1.GetQuoteResponse](s.logger, mservice.FXOracle, merrors.InvalidArgument("pair_not_supported"))
 		default:
 			logger.Warn("GetQuote failed to load pair", zap.Error(err))
@@ -150,7 +150,7 @@ func (s *Service) getQuoteResponder(ctx context.Context, req *oraclev1.GetQuoteR
 	if err != nil {
 		switch {
 		case errors.Is(err, merrors.ErrNoData):
-			logger.Warn("rate not found", zap.String("pair", pairKey.Base+"/"+pairKey.Quote), zap.String("provider", provider))
+			logger.Warn("Rate not found", zap.String("pair", pairKey.Base+"/"+pairKey.Quote), zap.String("provider", provider))
 			return gsresponse.FailedPrecondition[oraclev1.GetQuoteResponse](s.logger, mservice.FXOracle, "rate_not_found", err)
 		default:
 			logger.Warn("GetQuote failed to load rate", zap.Error(err), zap.String("pair", pairKey.Base+"/"+pairKey.Quote), zap.String("provider", provider))

api/fx/storage/mongo/repository.go

@@ -50,28 +50,28 @@ func New(logger mlogger.Logger, conn *db.MongoConnection) (*Store, error) {
 	defer cancel()
 
 	if err := s.Ping(ctx); err != nil {
-		s.logger.Error("mongo ping failed during store init", zap.Error(err))
+		s.logger.Error("Mongo ping failed during store init", zap.Error(err))
 		return nil, err
 	}
 
 	ratesStore, err := store.NewRates(s.logger, db)
 	if err != nil {
-		s.logger.Error("failed to initialize rates store", zap.Error(err))
+		s.logger.Error("Failed to initialize rates store", zap.Error(err))
 		return nil, err
 	}
 	quotesStore, err := store.NewQuotes(s.logger, db, txFactory)
 	if err != nil {
-		s.logger.Error("failed to initialize quotes store", zap.Error(err))
+		s.logger.Error("Failed to initialize quotes store", zap.Error(err))
 		return nil, err
 	}
 	pairsStore, err := store.NewPair(s.logger, db)
 	if err != nil {
-		s.logger.Error("failed to initialize pair store", zap.Error(err))
+		s.logger.Error("Failed to initialize pair store", zap.Error(err))
 		return nil, err
 	}
 	currencyStore, err := store.NewCurrency(s.logger, db)
 	if err != nil {
-		s.logger.Error("failed to initialize currency store", zap.Error(err))
+		s.logger.Error("Failed to initialize currency store", zap.Error(err))
 		return nil, err
 	}
 
@@ -80,7 +80,7 @@ func New(logger mlogger.Logger, conn *db.MongoConnection) (*Store, error) {
 	s.pairs = pairsStore
 	s.currencies = currencyStore
 
-	s.logger.Info("mongo storage ready")
+	s.logger.Info("Mongo storage ready")
 	return s, nil
 }
 

api/fx/storage/mongo/store/currency.go

@@ -29,11 +29,11 @@ func NewCurrency(logger mlogger.Logger, db *mongo.Database) (storage.CurrencySto
 		Unique: true,
 	}
 	if err := repo.CreateIndex(index); err != nil {
-		logger.Error("failed to ensure currencies index", zap.Error(err))
+		logger.Error("Failed to ensure currencies index", zap.Error(err))
 		return nil, err
 	}
 	childLogger := logger.Named(model.CurrenciesCollection)
-	childLogger.Debug("currency store initialised", zap.String("collection", model.CurrenciesCollection))
+	childLogger.Debug("Currency store initialised", zap.String("collection", model.CurrenciesCollection))
 
 	return &currencyStore{
 		logger: childLogger,
@@ -43,17 +43,17 @@ func NewCurrency(logger mlogger.Logger, db *mongo.Database) (storage.CurrencySto
 
 func (c *currencyStore) Get(ctx context.Context, code string) (*model.Currency, error) {
 	if code == "" {
-		c.logger.Warn("attempt to fetch currency with empty code")
+		c.logger.Warn("Attempt to fetch currency with empty code")
 		return nil, merrors.InvalidArgument("currencyStore: empty code")
 	}
 	result := &model.Currency{}
 	if err := c.repo.FindOneByFilter(ctx, repository.Filter("code", code), result); err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.logger.Debug("currency not found", zap.String("code", code))
+			c.logger.Debug("Currency not found", zap.String("code", code))
 		}
 		return nil, err
 	}
-	c.logger.Debug("currency loaded", zap.String("code", code))
+	c.logger.Debug("Currency loaded", zap.String("code", code))
 	return result, nil
 }
 
@@ -77,20 +77,20 @@ func (c *currencyStore) List(ctx context.Context, codes ...string) ([]*model.Cur
 		return nil
 	})
 	if err != nil {
-		c.logger.Error("failed to list currencies", zap.Error(err))
+		c.logger.Warn("Failed to list currencies", zap.Error(err))
 		return nil, err
 	}
-	c.logger.Debug("listed currencies", zap.Int("count", len(currencies)))
+	c.logger.Debug("Listed currencies", zap.Int("count", len(currencies)))
 	return currencies, nil
 }
 
 func (c *currencyStore) Upsert(ctx context.Context, currency *model.Currency) error {
 	if currency == nil {
-		c.logger.Warn("attempt to upsert nil currency")
+		c.logger.Warn("Attempt to upsert nil currency")
 		return merrors.InvalidArgument("currencyStore: nil currency")
 	}
 	if currency.Code == "" {
-		c.logger.Warn("attempt to upsert currency with empty code")
+		c.logger.Warn("Attempt to upsert currency with empty code")
 		return merrors.InvalidArgument("currencyStore: empty code")
 	}
 
@@ -98,16 +98,16 @@ func (c *currencyStore) Upsert(ctx context.Context, currency *model.Currency) er
 	filter := repository.Filter("code", currency.Code)
 	if err := c.repo.FindOneByFilter(ctx, filter, existing); err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.logger.Debug("inserting new currency", zap.String("code", currency.Code))
+			c.logger.Debug("Inserting new currency", zap.String("code", currency.Code))
 			return c.repo.Insert(ctx, currency, filter)
 		}
-		c.logger.Error("failed to fetch currency", zap.Error(err), zap.String("code", currency.Code))
+		c.logger.Warn("Failed to fetch currency", zap.Error(err), zap.String("code", currency.Code))
 		return err
 	}
 
 	if existing.GetID() != nil {
 		currency.SetID(*existing.GetID())
 	}
-	c.logger.Debug("updating currency", zap.String("code", currency.Code))
+	c.logger.Debug("Updating currency", zap.String("code", currency.Code))
 	return c.repo.Update(ctx, currency)
 }

api/fx/storage/mongo/store/pair.go

@@ -29,10 +29,10 @@ func NewPair(logger mlogger.Logger, db *mongo.Database) (storage.PairStore, erro
 		Unique: true,
 	}
 	if err := repo.CreateIndex(index); err != nil {
-		logger.Error("failed to ensure pairs index", zap.Error(err))
+		logger.Error("Failed to ensure pairs index", zap.Error(err))
 		return nil, err
 	}
-	logger.Debug("pair store initialised", zap.String("collection", model.PairsCollection))
+	logger.Debug("Pair store initialised", zap.String("collection", model.PairsCollection))
 
 	return &pairStore{
 		logger: logger.Named(model.PairsCollection),
@@ -53,16 +53,16 @@ func (p *pairStore) ListEnabled(ctx context.Context) ([]*model.Pair, error) {
 		return nil
 	})
 	if err != nil {
-		p.logger.Error("failed to list enabled pairs", zap.Error(err))
+		p.logger.Warn("Failed to list enabled pairs", zap.Error(err))
 		return nil, err
 	}
-	p.logger.Debug("listed enabled pairs", zap.Int("count", len(pairs)))
+	p.logger.Debug("Listed enabled pairs", zap.Int("count", len(pairs)))
 	return pairs, nil
 }
 
 func (p *pairStore) Get(ctx context.Context, pair model.CurrencyPair) (*model.Pair, error) {
 	if pair.Base == "" || pair.Quote == "" {
-		p.logger.Warn("attempt to fetch pair with empty currency", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
+		p.logger.Warn("Attempt to fetch pair with empty currency", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
 		return nil, merrors.InvalidArgument("pairStore: incomplete pair")
 	}
 	result := &model.Pair{}
@@ -71,21 +71,21 @@ func (p *pairStore) Get(ctx context.Context, pair model.CurrencyPair) (*model.Pa
 		Filter(repository.Field("pair").Dot("quote"), pair.Quote)
 	if err := p.repo.FindOneByFilter(ctx, query, result); err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			p.logger.Debug("pair not found", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
+			p.logger.Debug("Pair not found", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
 		}
 		return nil, err
 	}
-	p.logger.Debug("pair loaded", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
+	p.logger.Debug("Pair loaded", zap.String("base", pair.Base), zap.String("quote", pair.Quote))
 	return result, nil
 }
 
 func (p *pairStore) Upsert(ctx context.Context, pair *model.Pair) error {
 	if pair == nil {
-		p.logger.Warn("attempt to upsert nil pair")
+		p.logger.Warn("Attempt to upsert nil pair")
 		return merrors.InvalidArgument("pairStore: nil pair")
 	}
 	if pair.Pair.Base == "" || pair.Pair.Quote == "" {
-		p.logger.Warn("attempt to upsert pair with empty currency", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
+		p.logger.Warn("Attempt to upsert pair with empty currency", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
 		return merrors.InvalidArgument("pairStore: incomplete pair")
 	}
 
@@ -96,16 +96,16 @@ func (p *pairStore) Upsert(ctx context.Context, pair *model.Pair) error {
 	err := p.repo.FindOneByFilter(ctx, query, existing)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			p.logger.Debug("inserting new pair", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
+			p.logger.Debug("Inserting new pair", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
 			return p.repo.Insert(ctx, pair, query)
 		}
-		p.logger.Error("failed to fetch pair", zap.Error(err), zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
+		p.logger.Warn("Failed to fetch pair", zap.Error(err), zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
 		return err
 	}
 
 	if existing.GetID() != nil {
 		pair.SetID(*existing.GetID())
 	}
-	p.logger.Debug("updating pair", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
+	p.logger.Debug("Updating pair", zap.String("base", pair.Pair.Base), zap.String("quote", pair.Pair.Quote))
 	return p.repo.Update(ctx, pair)
 }

api/fx/storage/mongo/store/quotes.go

@@ -56,12 +56,12 @@ func NewQuotes(logger mlogger.Logger, db *mongo.Database, txFactory transaction.
 
 	for _, def := range indexes {
 		if err := repo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure quotes index", zap.Error(err))
+			logger.Error("Failed to ensure quotes index", zap.Error(err))
 			return nil, err
 		}
 	}
 	childLogger := logger.Named(model.QuotesCollection)
-	childLogger.Debug("quotes store initialised", zap.String("collection", model.QuotesCollection))
+	childLogger.Debug("Quotes store initialised", zap.String("collection", model.QuotesCollection))
 
 	return &quotesStore{
 		logger:    childLogger,
@@ -72,11 +72,11 @@ func NewQuotes(logger mlogger.Logger, db *mongo.Database, txFactory transaction.
 
 func (q *quotesStore) Issue(ctx context.Context, quote *model.Quote) error {
 	if quote == nil {
-		q.logger.Warn("attempt to issue nil quote")
+		q.logger.Warn("Attempt to issue nil quote")
 		return merrors.InvalidArgument("quotesStore: nil quote")
 	}
 	if quote.QuoteRef == "" {
-		q.logger.Warn("attempt to issue quote with empty ref")
+		q.logger.Warn("Attempt to issue quote with empty ref")
 		return merrors.InvalidArgument("quotesStore: empty quoteRef")
 	}
 
@@ -89,32 +89,32 @@ func (q *quotesStore) Issue(ctx context.Context, quote *model.Quote) error {
 	quote.ConsumedByLedgerTxnRef = ""
 	quote.ConsumedAtUnixMs = nil
 	if err := q.repo.Insert(ctx, quote, repository.Filter("quoteRef", quote.QuoteRef)); err != nil {
-		q.logger.Error("failed to insert quote", zap.Error(err), zap.String("quote_ref", quote.QuoteRef))
+		q.logger.Warn("Failed to insert quote", zap.Error(err), zap.String("quote_ref", quote.QuoteRef))
 		return err
 	}
-	q.logger.Debug("quote issued", zap.String("quote_ref", quote.QuoteRef), zap.Bool("firm", quote.Firm))
+	q.logger.Debug("Quote issued", zap.String("quote_ref", quote.QuoteRef), zap.Bool("firm", quote.Firm))
 	return nil
 }
 
 func (q *quotesStore) GetByRef(ctx context.Context, quoteRef string) (*model.Quote, error) {
 	if quoteRef == "" {
-		q.logger.Warn("attempt to fetch quote with empty ref")
+		q.logger.Warn("Attempt to fetch quote with empty ref")
 		return nil, merrors.InvalidArgument("quotesStore: empty quoteRef")
 	}
 	quote := &model.Quote{}
 	if err := q.repo.FindOneByFilter(ctx, repository.Filter("quoteRef", quoteRef), quote); err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			q.logger.Debug("quote not found", zap.String("quote_ref", quoteRef))
+			q.logger.Debug("Quote not found", zap.String("quote_ref", quoteRef))
 		}
 		return nil, err
 	}
-	q.logger.Debug("quote loaded", zap.String("quote_ref", quoteRef), zap.String("status", string(quote.Status)))
+	q.logger.Debug("Quote loaded", zap.String("quote_ref", quoteRef), zap.String("status", string(quote.Status)))
 	return quote, nil
 }
 
 func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string, when time.Time) (*model.Quote, error) {
 	if quoteRef == "" || ledgerTxnRef == "" {
-		q.logger.Warn("attempt to consume quote with missing identifiers", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
+		q.logger.Warn("Attempt to consume quote with missing identifiers", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
 		return nil, merrors.InvalidArgument("quotesStore: missing identifiers")
 	}
 
@@ -122,7 +122,7 @@ func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string
 		when = time.Now()
 	}
 
-	q.logger.Debug("consuming quote", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
+	q.logger.Debug("Consuming quote", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
 	txn := q.txFactory.CreateTransaction()
 	result, err := txn.Execute(ctx, func(txCtx context.Context) (any, error) {
 		quote := &model.Quote{}
@@ -131,7 +131,7 @@ func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string
 		}
 
 		if !quote.Firm {
-			q.logger.Warn("quote not firm", zap.String("quote_ref", quoteRef))
+			q.logger.Warn("Quote not firm", zap.String("quote_ref", quoteRef))
 			return nil, storage.ErrQuoteNotFirm
 		}
 
@@ -140,16 +140,16 @@ func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string
 			if err := q.repo.Update(txCtx, quote); err != nil {
 				return nil, err
 			}
-			q.logger.Info("quote expired during consume", zap.String("quote_ref", quoteRef))
+			q.logger.Info("Quote expired during consume", zap.String("quote_ref", quoteRef))
 			return nil, storage.ErrQuoteExpired
 		}
 
 		if quote.Status == model.QuoteStatusConsumed {
 			if quote.ConsumedByLedgerTxnRef == ledgerTxnRef {
-				q.logger.Debug("quote already consumed by ledger", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
+				q.logger.Debug("Quote already consumed by ledger", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
 				return quote, nil
 			}
-			q.logger.Warn("quote consumed by different ledger", zap.String("quote_ref", quoteRef), zap.String("existing_ledger_ref", quote.ConsumedByLedgerTxnRef))
+			q.logger.Warn("Quote consumed by different ledger", zap.String("quote_ref", quoteRef), zap.String("existing_ledger_ref", quote.ConsumedByLedgerTxnRef))
 			return nil, storage.ErrQuoteConsumed
 		}
 
@@ -157,11 +157,11 @@ func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string
 		if err := q.repo.Update(txCtx, quote); err != nil {
 			return nil, err
 		}
-		q.logger.Info("quote consumed", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
+		q.logger.Info("Quote consumed", zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
 		return quote, nil
 	})
 	if err != nil {
-		q.logger.Error("quote consumption failed", zap.Error(err), zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
+		q.logger.Warn("Quote consumption failed", zap.Error(err), zap.String("quote_ref", quoteRef), zap.String("ledger_ref", ledgerTxnRef))
 		return nil, err
 	}
 	quote, _ := result.(*model.Quote)
@@ -173,7 +173,7 @@ func (q *quotesStore) Consume(ctx context.Context, quoteRef, ledgerTxnRef string
 
 func (q *quotesStore) ExpireIssuedBefore(ctx context.Context, cutoff time.Time) (int, error) {
 	if cutoff.IsZero() {
-		q.logger.Warn("attempt to expire quotes with zero cutoff")
+		q.logger.Warn("Attempt to expire quotes with zero cutoff")
 		return 0, merrors.InvalidArgument("quotesStore: cutoff time is zero")
 	}
 
@@ -188,11 +188,11 @@ func (q *quotesStore) ExpireIssuedBefore(ctx context.Context, cutoff time.Time)
 
 	updated, err := q.repo.PatchMany(ctx, filter, patch)
 	if err != nil {
-		q.logger.Error("failed to expire quotes", zap.Error(err))
+		q.logger.Warn("Failed to expire quotes", zap.Error(err))
 		return 0, err
 	}
 	if updated > 0 {
-		q.logger.Info("quotes expired", zap.Int("count", updated))
+		q.logger.Info("Quotes expired", zap.Int("count", updated))
 	}
 	return updated, nil
 }

api/fx/storage/mongo/store/rates.go

@@ -51,11 +51,11 @@ func NewRates(logger mlogger.Logger, db *mongo.Database) (storage.RatesStore, er
 
 	for _, def := range indexes {
 		if err := repo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure rates index", zap.Error(err))
+			logger.Error("Failed to ensure rates index", zap.Error(err))
 			return nil, err
 		}
 	}
-	logger.Debug("rates store initialised", zap.String("collection", model.RatesCollection))
+	logger.Debug("Rates store initialised", zap.String("collection", model.RatesCollection))
 	return &ratesStore{
 		logger: logger.Named(model.RatesCollection),
 		repo:   repo,
@@ -64,11 +64,11 @@ func NewRates(logger mlogger.Logger, db *mongo.Database) (storage.RatesStore, er
 
 func (r *ratesStore) UpsertSnapshot(ctx context.Context, snapshot *model.RateSnapshot) error {
 	if snapshot == nil {
-		r.logger.Warn("attempt to upsert nil snapshot")
+		r.logger.Warn("Attempt to upsert nil snapshot")
 		return merrors.InvalidArgument("ratesStore: nil snapshot")
 	}
 	if snapshot.RateRef == "" {
-		r.logger.Warn("attempt to upsert snapshot with empty rate_ref")
+		r.logger.Warn("Attempt to upsert snapshot with empty rate_ref")
 		return merrors.InvalidArgument("ratesStore: empty rateRef")
 	}
 
@@ -82,17 +82,17 @@ func (r *ratesStore) UpsertSnapshot(ctx context.Context, snapshot *model.RateSna
 	err := r.repo.FindOneByFilter(ctx, filter, existing)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			r.logger.Debug("inserting new rate snapshot", zap.String("rate_ref", snapshot.RateRef))
+			r.logger.Debug("Inserting new rate snapshot", zap.String("rate_ref", snapshot.RateRef))
 			return r.repo.Insert(ctx, snapshot, filter)
 		}
-		r.logger.Error("failed to query rate snapshot", zap.Error(err), zap.String("rate_ref", snapshot.RateRef))
+		r.logger.Warn("Failed to query rate snapshot", zap.Error(err), zap.String("rate_ref", snapshot.RateRef))
 		return err
 	}
 
 	if existing.GetID() != nil {
 		snapshot.SetID(*existing.GetID())
 	}
-	r.logger.Debug("updating rate snapshot", zap.String("rate_ref", snapshot.RateRef))
+	r.logger.Debug("Updating rate snapshot", zap.String("rate_ref", snapshot.RateRef))
 	return r.repo.Update(ctx, snapshot)
 }
 

api/gateway/chain/client/client.go

@@ -24,6 +24,8 @@ type Client interface {
 	GetTransfer(ctx context.Context, req *chainv1.GetTransferRequest) (*chainv1.GetTransferResponse, error)
 	ListTransfers(ctx context.Context, req *chainv1.ListTransfersRequest) (*chainv1.ListTransfersResponse, error)
 	EstimateTransferFee(ctx context.Context, req *chainv1.EstimateTransferFeeRequest) (*chainv1.EstimateTransferFeeResponse, error)
+	ComputeGasTopUp(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error)
+	EnsureGasTopUp(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error)
 	Close() error
 }
 
@@ -36,6 +38,8 @@ type grpcGatewayClient interface {
 	GetTransfer(ctx context.Context, in *chainv1.GetTransferRequest, opts ...grpc.CallOption) (*chainv1.GetTransferResponse, error)
 	ListTransfers(ctx context.Context, in *chainv1.ListTransfersRequest, opts ...grpc.CallOption) (*chainv1.ListTransfersResponse, error)
 	EstimateTransferFee(ctx context.Context, in *chainv1.EstimateTransferFeeRequest, opts ...grpc.CallOption) (*chainv1.EstimateTransferFeeResponse, error)
+	ComputeGasTopUp(ctx context.Context, in *chainv1.ComputeGasTopUpRequest, opts ...grpc.CallOption) (*chainv1.ComputeGasTopUpResponse, error)
+	EnsureGasTopUp(ctx context.Context, in *chainv1.EnsureGasTopUpRequest, opts ...grpc.CallOption) (*chainv1.EnsureGasTopUpResponse, error)
 }
 
 type chainGatewayClient struct {
@@ -139,6 +143,18 @@ func (c *chainGatewayClient) EstimateTransferFee(ctx context.Context, req *chain
 	return c.client.EstimateTransferFee(ctx, req)
 }
 
+func (c *chainGatewayClient) ComputeGasTopUp(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error) {
+	ctx, cancel := c.callContext(ctx)
+	defer cancel()
+	return c.client.ComputeGasTopUp(ctx, req)
+}
+
+func (c *chainGatewayClient) EnsureGasTopUp(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error) {
+	ctx, cancel := c.callContext(ctx)
+	defer cancel()
+	return c.client.EnsureGasTopUp(ctx, req)
+}
+
 func (c *chainGatewayClient) callContext(ctx context.Context) (context.Context, context.CancelFunc) {
 	timeout := c.cfg.CallTimeout
 	if timeout <= 0 {

api/gateway/chain/client/fake.go

@@ -16,6 +16,8 @@ type Fake struct {
 	GetTransferFn         func(ctx context.Context, req *chainv1.GetTransferRequest) (*chainv1.GetTransferResponse, error)
 	ListTransfersFn       func(ctx context.Context, req *chainv1.ListTransfersRequest) (*chainv1.ListTransfersResponse, error)
 	EstimateTransferFeeFn func(ctx context.Context, req *chainv1.EstimateTransferFeeRequest) (*chainv1.EstimateTransferFeeResponse, error)
+	ComputeGasTopUpFn     func(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error)
+	EnsureGasTopUpFn      func(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error)
 	CloseFn               func() error
 }
 
@@ -75,6 +77,20 @@ func (f *Fake) EstimateTransferFee(ctx context.Context, req *chainv1.EstimateTra
 	return &chainv1.EstimateTransferFeeResponse{}, nil
 }
 
+func (f *Fake) ComputeGasTopUp(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error) {
+	if f.ComputeGasTopUpFn != nil {
+		return f.ComputeGasTopUpFn(ctx, req)
+	}
+	return &chainv1.ComputeGasTopUpResponse{}, nil
+}
+
+func (f *Fake) EnsureGasTopUp(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error) {
+	if f.EnsureGasTopUpFn != nil {
+		return f.EnsureGasTopUpFn(ctx, req)
+	}
+	return &chainv1.EnsureGasTopUpResponse{}, nil
+}
+
 func (f *Fake) Close() error {
 	if f.CloseFn != nil {
 		return f.CloseFn()

api/gateway/chain/config.yml

@@ -38,6 +38,11 @@ chains:
     chain_id: 728126428 # 0x2b6653dc
     native_token: TRX
     rpc_url_env: CHAIN_GATEWAY_RPC_URL
+    gas_topup_policy:
+      buffer_percent: 0.10
+      min_native_balance_trx: 10
+      rounding_unit_trx: 1
+      max_topup_trx: 100
     tokens:
       - symbol: USDT
         contract: "0xa614f803b6fd780986a42c78ec9c7f77e6ded13c"

api/gateway/chain/go.mod

@@ -22,7 +22,7 @@ require (
 
 require (
 	github.com/Microsoft/go-winio v0.6.2 // indirect
-	github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251223223124-03e3cef63e04 // indirect
+	github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251229120209-a0d175451f7b // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bits-and-blooms/bitset v1.24.4 // indirect
 	github.com/bmatcuk/doublestar/v4 v4.9.1 // indirect

api/gateway/chain/go.sum

@@ -6,8 +6,8 @@ github.com/DataDog/zstd v1.4.5 h1:EndNeuB0l9syBZhut0wns3gV1hL8zX8LIu6ZiVHWLIQ=
 github.com/DataDog/zstd v1.4.5/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
 github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
-github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251223223124-03e3cef63e04 h1:wCr/SrKzMrtW9wG85ApPfncRr7ajzkRevhsWnCkl2sE=
-github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251223223124-03e3cef63e04/go.mod h1:ioLG6R+5bUSO1oeGSDxOV3FADARuMoytZCSX6MEMQkI=
+github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251229120209-a0d175451f7b h1:g/wCbvJGhOAqfGBjWnqtD6CVsXdr3G4GCbjLR6z9kNw=
+github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251229120209-a0d175451f7b/go.mod h1:ioLG6R+5bUSO1oeGSDxOV3FADARuMoytZCSX6MEMQkI=
 github.com/VictoriaMetrics/fastcache v1.13.0 h1:AW4mheMR5Vd9FkAPUv+NH6Nhw+fmbTMGMsNAoA/+4G0=
 github.com/VictoriaMetrics/fastcache v1.13.0/go.mod h1:hHXhl4DA2fTL2HTZDJFXWgW0LNjo6B+4aj2Wmng3TjU=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=

api/gateway/chain/internal/keymanager/vault/manager.go

@@ -45,22 +45,22 @@ func New(logger mlogger.Logger, cfg Config) (*Manager, error) {
 	}
 	address := strings.TrimSpace(cfg.Address)
 	if address == "" {
-		logger.Error("vault address missing")
+		logger.Error("Vault address missing")
 		return nil, merrors.InvalidArgument("vault key manager: address is required")
 	}
 	tokenEnv := strings.TrimSpace(cfg.TokenEnv)
 	if tokenEnv == "" {
-		logger.Error("vault token env missing")
+		logger.Error("Vault token env missing")
 		return nil, merrors.InvalidArgument("vault key manager: token_env is required")
 	}
 	token := strings.TrimSpace(os.Getenv(tokenEnv))
 	if token == "" {
-		logger.Error("vault token missing; expected Vault Agent to export token", zap.String("env", tokenEnv))
+		logger.Error("Vault token missing; expected Vault Agent to export token", zap.String("env", tokenEnv))
 		return nil, merrors.InvalidArgument("vault key manager: token env " + tokenEnv + " is not set (expected Vault Agent sink to populate it)")
 	}
 	mountPath := strings.Trim(strings.TrimSpace(cfg.MountPath), "/")
 	if mountPath == "" {
-		logger.Error("vault mount path missing")
+		logger.Error("Vault mount path missing")
 		return nil, merrors.InvalidArgument("vault key manager: mount_path is required")
 	}
 	keyPrefix := strings.Trim(strings.TrimSpace(cfg.KeyPrefix), "/")
@@ -73,7 +73,7 @@ func New(logger mlogger.Logger, cfg Config) (*Manager, error) {
 
 	client, err := api.NewClient(clientCfg)
 	if err != nil {
-		logger.Error("failed to create vault client", zap.Error(err))
+		logger.Error("Failed to create vault client", zap.Error(err))
 		return nil, merrors.Internal("vault key manager: failed to create client: " + err.Error())
 	}
 	client.SetToken(token)
@@ -94,17 +94,17 @@ func New(logger mlogger.Logger, cfg Config) (*Manager, error) {
 // CreateManagedWalletKey creates a new managed wallet key and stores it in Vault.
 func (m *Manager) CreateManagedWalletKey(ctx context.Context, walletRef string, network string) (*keymanager.ManagedWalletKey, error) {
 	if strings.TrimSpace(walletRef) == "" {
-		m.logger.Warn("walletRef missing for managed key creation", zap.String("network", network))
+		m.logger.Warn("WalletRef missing for managed key creation", zap.String("network", network))
 		return nil, merrors.InvalidArgument("vault key manager: walletRef is required")
 	}
 	if strings.TrimSpace(network) == "" {
-		m.logger.Warn("network missing for managed key creation", zap.String("wallet_ref", walletRef))
+		m.logger.Warn("Network missing for managed key creation", zap.String("wallet_ref", walletRef))
 		return nil, merrors.InvalidArgument("vault key manager: network is required")
 	}
 
 	privateKey, err := ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
 	if err != nil {
-		m.logger.Warn("failed to generate managed wallet key", zap.String("wallet_ref", walletRef), zap.String("network", network), zap.Error(err))
+		m.logger.Warn("Failed to generate managed wallet key", zap.String("wallet_ref", walletRef), zap.String("network", network), zap.Error(err))
 		return nil, merrors.Internal("vault key manager: failed to generate key: " + err.Error())
 	}
 	privateKeyBytes := crypto.FromECDSA(privateKey)
@@ -115,7 +115,7 @@ func (m *Manager) CreateManagedWalletKey(ctx context.Context, walletRef string,
 
 	err = m.persistKey(ctx, walletRef, network, privateKeyBytes, publicKeyBytes, address)
 	if err != nil {
-		m.logger.Warn("failed to persist managed wallet key", zap.String("wallet_ref", walletRef), zap.String("network", network), zap.Error(err))
+		m.logger.Warn("Failed to persist managed wallet key", zap.String("wallet_ref", walletRef), zap.String("network", network), zap.Error(err))
 		zeroBytes(privateKeyBytes)
 		zeroBytes(publicKeyBytes)
 		return nil, err
@@ -123,7 +123,7 @@ func (m *Manager) CreateManagedWalletKey(ctx context.Context, walletRef string,
 	zeroBytes(privateKeyBytes)
 	zeroBytes(publicKeyBytes)
 
-	m.logger.Info("managed wallet key created",
+	m.logger.Info("Managed wallet key created",
 		zap.String("wallet_ref", walletRef),
 		zap.String("network", network),
 		zap.String("address", strings.ToLower(address)),
@@ -158,43 +158,43 @@ func (m *Manager) buildKeyID(network, walletRef string) string {
 // SignTransaction loads the key material from Vault and signs the transaction.
 func (m *Manager) SignTransaction(ctx context.Context, keyID string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
 	if strings.TrimSpace(keyID) == "" {
-		m.logger.Warn("signing failed: empty key id")
+		m.logger.Warn("Signing failed: empty key id")
 		return nil, merrors.InvalidArgument("vault key manager: keyID is required")
 	}
 	if tx == nil {
-		m.logger.Warn("signing failed: nil transaction", zap.String("key_id", keyID))
+		m.logger.Warn("Signing failed: nil transaction", zap.String("key_id", keyID))
 		return nil, merrors.InvalidArgument("vault key manager: transaction is nil")
 	}
 	if chainID == nil {
-		m.logger.Warn("signing failed: nil chain id", zap.String("key_id", keyID))
+		m.logger.Warn("Signing failed: nil chain id", zap.String("key_id", keyID))
 		return nil, merrors.InvalidArgument("vault key manager: chainID is nil")
 	}
 
 	material, err := m.loadKey(ctx, keyID)
 	if err != nil {
-		m.logger.Warn("failed to load key material", zap.String("key_id", keyID), zap.Error(err))
+		m.logger.Warn("Failed to load key material", zap.String("key_id", keyID), zap.Error(err))
 		return nil, err
 	}
 
 	keyBytes, err := hex.DecodeString(material.PrivateKey)
 	if err != nil {
-		m.logger.Warn("invalid key material", zap.String("key_id", keyID), zap.Error(err))
+		m.logger.Warn("Invalid key material", zap.String("key_id", keyID), zap.Error(err))
 		return nil, merrors.Internal("vault key manager: invalid key material: " + err.Error())
 	}
 	defer zeroBytes(keyBytes)
 
 	privateKey, err := crypto.ToECDSA(keyBytes)
 	if err != nil {
-		m.logger.Warn("failed to construct private key", zap.String("key_id", keyID), zap.Error(err))
+		m.logger.Warn("Failed to construct private key", zap.String("key_id", keyID), zap.Error(err))
 		return nil, merrors.Internal("vault key manager: failed to construct private key: " + err.Error())
 	}
 
 	signed, err := types.SignTx(tx, types.LatestSignerForChainID(chainID), privateKey)
 	if err != nil {
-		m.logger.Warn("failed to sign transaction", zap.String("key_id", keyID), zap.Error(err))
+		m.logger.Warn("Failed to sign transaction", zap.String("key_id", keyID), zap.Error(err))
 		return nil, merrors.Internal("vault key manager: failed to sign transaction: " + err.Error())
 	}
-	m.logger.Info("transaction signed with managed key",
+	m.logger.Info("Transaction signed with managed key",
 		zap.String("key_id", keyID),
 		zap.String("network", material.Network),
 		zap.String("tx_hash", signed.Hash().Hex()),
@@ -213,23 +213,23 @@ func (m *Manager) loadKey(ctx context.Context, keyID string) (*keyMaterial, erro
 	secretPath := strings.Trim(strings.TrimPrefix(keyID, "/"), "/")
 	secret, err := m.store.Get(ctx, secretPath)
 	if err != nil {
-		m.logger.Warn("failed to read secret", zap.String("path", secretPath), zap.Error(err))
+		m.logger.Warn("Failed to read secret", zap.String("path", secretPath), zap.Error(err))
 		return nil, merrors.Internal("vault key manager: failed to read secret at " + secretPath + ": " + err.Error())
 	}
 	if secret == nil || secret.Data == nil {
-		m.logger.Warn("secret not found", zap.String("path", secretPath))
+		m.logger.Warn("Secret not found", zap.String("path", secretPath))
 		return nil, merrors.NoData("vault key manager: secret " + secretPath + " not found")
 	}
 
 	getString := func(key string) (string, error) {
 		val, ok := secret.Data[key]
 		if !ok {
-			m.logger.Warn("secret missing field", zap.String("path", secretPath), zap.String("field", key))
+			m.logger.Warn("Secret missing field", zap.String("path", secretPath), zap.String("field", key))
 			return "", merrors.Internal("vault key manager: secret " + secretPath + " missing " + key)
 		}
 		str, ok := val.(string)
 		if !ok || strings.TrimSpace(str) == "" {
-			m.logger.Warn("secret field invalid", zap.String("path", secretPath), zap.String("field", key))
+			m.logger.Warn("Secret field invalid", zap.String("path", secretPath), zap.String("field", key))
 			return "", merrors.Internal("vault key manager: secret " + secretPath + " invalid " + key)
 		}
 		return str, nil

api/gateway/chain/internal/server/internal/serverimp.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/mitchellh/mapstructure"
+	"github.com/shopspring/decimal"
 	"github.com/tech/sendico/gateway/chain/internal/keymanager"
 	vaultmanager "github.com/tech/sendico/gateway/chain/internal/keymanager/vault"
 	gatewayservice "github.com/tech/sendico/gateway/chain/internal/service/gateway"
@@ -46,11 +47,12 @@ type config struct {
 }
 
 type chainConfig struct {
-	Name        string        `yaml:"name"`
-	RPCURLEnv   string        `yaml:"rpc_url_env"`
-	ChainID     uint64        `yaml:"chain_id"`
-	NativeToken string        `yaml:"native_token"`
-	Tokens      []tokenConfig `yaml:"tokens"`
+	Name           string                `yaml:"name"`
+	RPCURLEnv      string                `yaml:"rpc_url_env"`
+	ChainID        uint64                `yaml:"chain_id"`
+	NativeToken    string                `yaml:"native_token"`
+	Tokens         []tokenConfig         `yaml:"tokens"`
+	GasTopUpPolicy *gasTopUpPolicyConfig `yaml:"gas_topup_policy"`
 }
 
 type serviceWalletConfig struct {
@@ -66,6 +68,19 @@ type tokenConfig struct {
 	ContractEnv string `yaml:"contract_env"`
 }
 
+type gasTopUpPolicyConfig struct {
+	gasTopUpRuleConfig `yaml:",inline"`
+	Native             *gasTopUpRuleConfig `yaml:"native"`
+	Contract           *gasTopUpRuleConfig `yaml:"contract"`
+}
+
+type gasTopUpRuleConfig struct {
+	BufferPercent       float64 `yaml:"buffer_percent"`
+	MinNativeBalanceTRX float64 `yaml:"min_native_balance_trx"`
+	RoundingUnitTRX     float64 `yaml:"rounding_unit_trx"`
+	MaxTopUpTRX         float64 `yaml:"max_topup_trx"`
+}
+
 // Create initialises the chain gateway server implementation.
 func Create(logger mlogger.Logger, file string, debug bool) (*Imp, error) {
 	return &Imp{
@@ -108,12 +123,12 @@ func (i *Imp) Start() error {
 	cl := i.logger.Named("config")
 	networkConfigs, err := resolveNetworkConfigs(cl.Named("network"), cfg.Chains)
 	if err != nil {
-		i.logger.Error("invalid chain network configuration", zap.Error(err))
+		i.logger.Error("Invalid chain network configuration", zap.Error(err))
 		return err
 	}
 	rpcClients, err := rpcclient.Prepare(context.Background(), i.logger.Named("rpc"), networkConfigs)
 	if err != nil {
-		i.logger.Error("failed to prepare rpc clients", zap.Error(err))
+		i.logger.Error("Failed to prepare rpc clients", zap.Error(err))
 		return err
 	}
 	i.rpcClients = rpcClients
@@ -151,7 +166,7 @@ func (i *Imp) Start() error {
 func (i *Imp) loadConfig() (*config, error) {
 	data, err := os.ReadFile(i.file)
 	if err != nil {
-		i.logger.Error("could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
+		i.logger.Error("Could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
 		return nil, err
 	}
 
@@ -159,7 +174,7 @@ func (i *Imp) loadConfig() (*config, error) {
 		Config: &grpcapp.Config{},
 	}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
-		i.logger.Error("failed to parse configuration", zap.Error(err))
+		i.logger.Error("Failed to parse configuration", zap.Error(err))
 		return nil, err
 	}
 
@@ -183,7 +198,7 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) ([]gatew
 	result := make([]gatewayshared.Network, 0, len(chains))
 	for _, chain := range chains {
 		if strings.TrimSpace(chain.Name) == "" {
-			logger.Warn("skipping unnamed chain configuration")
+			logger.Warn("Skipping unnamed chain configuration")
 			continue
 		}
 		rpcURL := strings.TrimSpace(os.Getenv(chain.RPCURLEnv))
@@ -195,7 +210,7 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) ([]gatew
 		for _, token := range chain.Tokens {
 			symbol := strings.TrimSpace(token.Symbol)
 			if symbol == "" {
-				logger.Warn("skipping token with empty symbol", zap.String("chain", chain.Name))
+				logger.Warn("Skipping token with empty symbol", zap.String("chain", chain.Name))
 				continue
 			}
 			addr := strings.TrimSpace(token.Contract)
@@ -205,9 +220,9 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) ([]gatew
 			}
 			if addr == "" {
 				if env != "" {
-					logger.Warn("token contract not configured", zap.String("token", symbol), zap.String("env", env), zap.String("chain", chain.Name))
+					logger.Warn("Token contract not configured", zap.String("token", symbol), zap.String("env", env), zap.String("chain", chain.Name))
 				} else {
-					logger.Warn("token contract not configured", zap.String("token", symbol), zap.String("chain", chain.Name))
+					logger.Warn("Token contract not configured", zap.String("token", symbol), zap.String("chain", chain.Name))
 				}
 				continue
 			}
@@ -217,17 +232,86 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) ([]gatew
 			})
 		}
 
+		gasPolicy, err := buildGasTopUpPolicy(chain.Name, chain.GasTopUpPolicy)
+		if err != nil {
+			logger.Error("Invalid gas top-up policy", zap.String("chain", chain.Name), zap.Error(err))
+			return nil, err
+		}
+
 		result = append(result, gatewayshared.Network{
-			Name:         chain.Name,
-			RPCURL:       rpcURL,
-			ChainID:      chain.ChainID,
-			NativeToken:  chain.NativeToken,
-			TokenConfigs: contracts,
+			Name:           chain.Name,
+			RPCURL:         rpcURL,
+			ChainID:        chain.ChainID,
+			NativeToken:    chain.NativeToken,
+			TokenConfigs:   contracts,
+			GasTopUpPolicy: gasPolicy,
 		})
 	}
 	return result, nil
 }
 
+func buildGasTopUpPolicy(chainName string, cfg *gasTopUpPolicyConfig) (*gatewayshared.GasTopUpPolicy, error) {
+	if cfg == nil {
+		return nil, nil
+	}
+	defaultRule, defaultSet, err := parseGasTopUpRule(chainName, "default", cfg.gasTopUpRuleConfig)
+	if err != nil {
+		return nil, err
+	}
+	if !defaultSet {
+		return nil, merrors.InvalidArgument(fmt.Sprintf("chain %s gas_topup_policy is required", chainName))
+	}
+
+	policy := &gatewayshared.GasTopUpPolicy{
+		Default: defaultRule,
+	}
+
+	if cfg.Native != nil {
+		rule, set, err := parseGasTopUpRule(chainName, "native", *cfg.Native)
+		if err != nil {
+			return nil, err
+		}
+		if set {
+			policy.Native = &rule
+		}
+	}
+	if cfg.Contract != nil {
+		rule, set, err := parseGasTopUpRule(chainName, "contract", *cfg.Contract)
+		if err != nil {
+			return nil, err
+		}
+		if set {
+			policy.Contract = &rule
+		}
+	}
+
+	return policy, nil
+}
+
+func parseGasTopUpRule(chainName, label string, cfg gasTopUpRuleConfig) (gatewayshared.GasTopUpRule, bool, error) {
+	if cfg.BufferPercent == 0 && cfg.MinNativeBalanceTRX == 0 && cfg.RoundingUnitTRX == 0 && cfg.MaxTopUpTRX == 0 {
+		return gatewayshared.GasTopUpRule{}, false, nil
+	}
+	if cfg.BufferPercent < 0 {
+		return gatewayshared.GasTopUpRule{}, true, merrors.InvalidArgument(fmt.Sprintf("chain %s gas_topup_policy %s buffer_percent must be >= 0", chainName, label))
+	}
+	if cfg.MinNativeBalanceTRX < 0 {
+		return gatewayshared.GasTopUpRule{}, true, merrors.InvalidArgument(fmt.Sprintf("chain %s gas_topup_policy %s min_native_balance_trx must be >= 0", chainName, label))
+	}
+	if cfg.RoundingUnitTRX <= 0 {
+		return gatewayshared.GasTopUpRule{}, true, merrors.InvalidArgument(fmt.Sprintf("chain %s gas_topup_policy %s rounding_unit_trx must be > 0", chainName, label))
+	}
+	if cfg.MaxTopUpTRX <= 0 {
+		return gatewayshared.GasTopUpRule{}, true, merrors.InvalidArgument(fmt.Sprintf("chain %s gas_topup_policy %s max_topup_trx must be > 0", chainName, label))
+	}
+	return gatewayshared.GasTopUpRule{
+		BufferPercent:    decimal.NewFromFloat(cfg.BufferPercent),
+		MinNativeBalance: decimal.NewFromFloat(cfg.MinNativeBalanceTRX),
+		RoundingUnit:     decimal.NewFromFloat(cfg.RoundingUnitTRX),
+		MaxTopUp:         decimal.NewFromFloat(cfg.MaxTopUpTRX),
+	}, true, nil
+}
+
 func resolveServiceWallet(logger mlogger.Logger, cfg serviceWalletConfig) gatewayshared.ServiceWallet {
 	address := strings.TrimSpace(cfg.Address)
 	if address == "" && cfg.AddressEnv != "" {
@@ -238,13 +322,13 @@ func resolveServiceWallet(logger mlogger.Logger, cfg serviceWalletConfig) gatewa
 
 	if address == "" {
 		if cfg.AddressEnv != "" {
-			logger.Warn("service wallet address not configured", zap.String("env", cfg.AddressEnv))
+			logger.Warn("Service wallet address not configured", zap.String("env", cfg.AddressEnv))
 		} else {
-			logger.Warn("service wallet address not configured", zap.String("chain", cfg.Chain))
+			logger.Warn("Service wallet address not configured", zap.String("chain", cfg.Chain))
 		}
 	}
 	if privateKey == "" {
-		logger.Warn("service wallet private key not configured", zap.String("env", cfg.PrivateKeyEnv))
+		logger.Warn("Service wallet private key not configured", zap.String("env", cfg.PrivateKeyEnv))
 	}
 
 	return gatewayshared.ServiceWallet{
@@ -258,7 +342,7 @@ func resolveKeyManager(logger mlogger.Logger, cfg keymanager.Config) (keymanager
 	driver := strings.ToLower(strings.TrimSpace(string(cfg.Driver)))
 	if driver == "" {
 		err := merrors.InvalidArgument("key management driver is not configured")
-		logger.Error("key management driver missing")
+		logger.Error("Key management driver missing")
 		return nil, err
 	}
 
@@ -267,19 +351,19 @@ func resolveKeyManager(logger mlogger.Logger, cfg keymanager.Config) (keymanager
 		settings := vaultmanager.Config{}
 		if len(cfg.Settings) > 0 {
 			if err := mapstructure.Decode(cfg.Settings, &settings); err != nil {
-				logger.Error("failed to decode vault key manager settings", zap.Error(err), zap.Any("settings", cfg.Settings))
+				logger.Error("Failed to decode vault key manager settings", zap.Error(err), zap.Any("settings", cfg.Settings))
 				return nil, merrors.InvalidArgument("invalid vault key manager settings: " + err.Error())
 			}
 		}
 		manager, err := vaultmanager.New(logger, settings)
 		if err != nil {
-			logger.Error("failed to initialise vault key manager", zap.Error(err))
+			logger.Error("Failed to initialise vault key manager", zap.Error(err))
 			return nil, err
 		}
 		return manager, nil
 	default:
 		err := merrors.InvalidArgument("unsupported key management driver: " + driver)
-		logger.Error("unsupported key management driver", zap.String("driver", driver))
+		logger.Error("Unsupported key management driver", zap.String("driver", driver))
 		return nil, err
 	}
 }

api/gateway/chain/internal/service/gateway/commands/registry.go

@@ -23,6 +23,8 @@ type Registry struct {
 	GetTransfer      Unary[chainv1.GetTransferRequest, chainv1.GetTransferResponse]
 	ListTransfers    Unary[chainv1.ListTransfersRequest, chainv1.ListTransfersResponse]
 	EstimateTransfer Unary[chainv1.EstimateTransferFeeRequest, chainv1.EstimateTransferFeeResponse]
+	ComputeGasTopUp  Unary[chainv1.ComputeGasTopUpRequest, chainv1.ComputeGasTopUpResponse]
+	EnsureGasTopUp   Unary[chainv1.EnsureGasTopUpRequest, chainv1.EnsureGasTopUpResponse]
 }
 
 type RegistryDeps struct {
@@ -40,5 +42,7 @@ func NewRegistry(deps RegistryDeps) Registry {
 		GetTransfer:         transfer.NewGetTransfer(deps.Transfer.WithLogger("transfer.get")),
 		ListTransfers:       transfer.NewListTransfers(deps.Transfer.WithLogger("transfer.list")),
 		EstimateTransfer:    transfer.NewEstimateTransfer(deps.Transfer.WithLogger("transfer.estimate_fee")),
+		ComputeGasTopUp:     transfer.NewComputeGasTopUp(deps.Transfer.WithLogger("gas_topup.compute")),
+		EnsureGasTopUp:      transfer.NewEnsureGasTopUp(deps.Transfer.WithLogger("gas_topup.ensure")),
 	}
 }

api/gateway/chain/internal/service/gateway/commands/transfer/destination.go

@@ -17,21 +17,21 @@ func resolveDestination(ctx context.Context, deps Deps, dest *chainv1.TransferDe
 	managedRef := strings.TrimSpace(dest.GetManagedWalletRef())
 	external := strings.TrimSpace(dest.GetExternalAddress())
 	if managedRef != "" && external != "" {
-		deps.Logger.Warn("both managed and external destination provided")
+		deps.Logger.Warn("Both managed and external destination provided")
 		return model.TransferDestination{}, merrors.InvalidArgument("destination must be managed_wallet_ref or external_address")
 	}
 	if managedRef != "" {
 		wallet, err := deps.Storage.Wallets().Get(ctx, managedRef)
 		if err != nil {
-			deps.Logger.Warn("destination wallet lookup failed", zap.Error(err), zap.String("managed_wallet_ref", managedRef))
+			deps.Logger.Warn("Destination wallet lookup failed", zap.Error(err), zap.String("managed_wallet_ref", managedRef))
 			return model.TransferDestination{}, err
 		}
 		if !strings.EqualFold(wallet.Network, source.Network) {
-			deps.Logger.Warn("destination wallet network mismatch", zap.String("source_network", source.Network), zap.String("dest_network", wallet.Network))
+			deps.Logger.Warn("Destination wallet network mismatch", zap.String("source_network", source.Network), zap.String("dest_network", wallet.Network))
 			return model.TransferDestination{}, merrors.InvalidArgument("destination wallet network mismatch")
 		}
 		if strings.TrimSpace(wallet.DepositAddress) == "" {
-			deps.Logger.Warn("destination wallet missing deposit address", zap.String("managed_wallet_ref", managedRef))
+			deps.Logger.Warn("Destination wallet missing deposit address", zap.String("managed_wallet_ref", managedRef))
 			return model.TransferDestination{}, merrors.InvalidArgument("destination wallet missing deposit address")
 		}
 		return model.TransferDestination{
@@ -40,25 +40,26 @@ func resolveDestination(ctx context.Context, deps Deps, dest *chainv1.TransferDe
 		}, nil
 	}
 	if external == "" {
-		deps.Logger.Warn("destination external address missing")
+		deps.Logger.Warn("Destination external address missing")
 		return model.TransferDestination{}, merrors.InvalidArgument("destination is required")
 	}
 	if deps.Drivers == nil {
-		deps.Logger.Warn("chain drivers missing", zap.String("network", source.Network))
+		deps.Logger.Warn("Chain drivers missing", zap.String("network", source.Network))
 		return model.TransferDestination{}, merrors.Internal("chain drivers not configured")
 	}
 	chainDriver, err := deps.Drivers.Driver(source.Network)
 	if err != nil {
-		deps.Logger.Warn("unsupported chain driver", zap.String("network", source.Network), zap.Error(err))
+		deps.Logger.Warn("Unsupported chain driver", zap.String("network", source.Network), zap.Error(err))
 		return model.TransferDestination{}, merrors.InvalidArgument("unsupported chain for wallet")
 	}
 	normalized, err := chainDriver.NormalizeAddress(external)
 	if err != nil {
-		deps.Logger.Warn("invalid external address", zap.Error(err))
+		deps.Logger.Warn("Invalid external address", zap.Error(err))
 		return model.TransferDestination{}, err
 	}
 	return model.TransferDestination{
-		ExternalAddress: normalized,
-		Memo:            strings.TrimSpace(dest.GetMemo()),
+		ExternalAddress:         normalized,
+		ExternalAddressOriginal: external,
+		Memo:                    strings.TrimSpace(dest.GetMemo()),
 	}, nil
 }

api/gateway/chain/internal/service/gateway/commands/transfer/fee.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/pkg/api/routers/gsresponse"
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mservice"
@@ -23,81 +24,94 @@ func NewEstimateTransfer(deps Deps) *estimateTransferFeeCommand {
 
 func (c *estimateTransferFeeCommand) Execute(ctx context.Context, req *chainv1.EstimateTransferFeeRequest) gsresponse.Responder[chainv1.EstimateTransferFeeResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Empty request received")
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("request is required"))
 	}
 
 	sourceWalletRef := strings.TrimSpace(req.GetSourceWalletRef())
 	if sourceWalletRef == "" {
-		c.deps.Logger.Warn("source wallet ref missing")
+		c.deps.Logger.Warn("Source wallet ref missing")
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("source_wallet_ref is required"))
 	}
 	amount := req.GetAmount()
 	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
-		c.deps.Logger.Warn("amount missing or incomplete")
+		c.deps.Logger.Warn("Amount missing or incomplete")
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("amount is required"))
 	}
 
 	sourceWallet, err := c.deps.Storage.Wallets().Get(ctx, sourceWalletRef)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("source wallet not found", zap.String("source_wallet_ref", sourceWalletRef))
+			c.deps.Logger.Warn("Source wallet not found", zap.String("source_wallet_ref", sourceWalletRef))
 			return gsresponse.NotFound[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("storage get wallet failed", zap.Error(err), zap.String("source_wallet_ref", sourceWalletRef))
+		c.deps.Logger.Warn("Storage get wallet failed", zap.Error(err), zap.String("source_wallet_ref", sourceWalletRef))
 		return gsresponse.Auto[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
 	networkKey := strings.ToLower(strings.TrimSpace(sourceWallet.Network))
 	networkCfg, ok := c.deps.Networks.Network(networkKey)
 	if !ok {
-		c.deps.Logger.Warn("unsupported chain", zap.String("network", networkKey))
+		c.deps.Logger.Warn("Unsupported chain", zap.String("network", networkKey))
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain for wallet"))
 	}
 	if c.deps.Drivers == nil {
-		c.deps.Logger.Warn("chain drivers missing", zap.String("network", networkKey))
+		c.deps.Logger.Warn("Chain drivers missing", zap.String("network", networkKey))
 		return gsresponse.Internal[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.Internal("chain drivers not configured"))
 	}
 	chainDriver, err := c.deps.Drivers.Driver(networkKey)
 	if err != nil {
-		c.deps.Logger.Warn("unsupported chain driver", zap.String("network", networkKey), zap.Error(err))
+		c.deps.Logger.Warn("Unsupported chain driver", zap.String("network", networkKey), zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain for wallet"))
 	}
 
 	dest, err := resolveDestination(ctx, c.deps, req.GetDestination(), sourceWallet)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("destination not found", zap.String("destination_wallet_ref", req.GetDestination().GetManagedWalletRef()))
+			c.deps.Logger.Warn("Destination not found", zap.String("destination_wallet_ref", req.GetDestination().GetManagedWalletRef()))
 			return gsresponse.NotFound[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("invalid destination", zap.Error(err))
+		c.deps.Logger.Warn("Invalid destination", zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
 	destinationAddress, err := destinationAddress(ctx, c.deps, chainDriver, dest)
 	if err != nil {
-		c.deps.Logger.Warn("failed to resolve destination address", zap.Error(err))
+		c.deps.Logger.Warn("Failed to resolve destination address", zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
+	walletForFee := sourceWallet
+	nativeCurrency := shared.NativeCurrency(networkCfg)
+	if nativeCurrency != "" && strings.EqualFold(nativeCurrency, amount.GetCurrency()) {
+		copyWallet := *sourceWallet
+		copyWallet.ContractAddress = ""
+		copyWallet.TokenSymbol = nativeCurrency
+		walletForFee = &copyWallet
+	}
+
 	driverDeps := driver.Deps{
 		Logger:     c.deps.Logger,
 		Registry:   c.deps.Networks,
 		RPCTimeout: c.deps.RPCTimeout,
 	}
-	feeMoney, err := chainDriver.EstimateFee(ctx, driverDeps, networkCfg, sourceWallet, destinationAddress, amount)
+	feeMoney, err := chainDriver.EstimateFee(ctx, driverDeps, networkCfg, walletForFee, destinationAddress, amount)
 	if err != nil {
-		c.deps.Logger.Warn("fee estimation failed", zap.Error(err))
+		c.deps.Logger.Warn("Fee estimation failed", zap.Error(err))
 		return gsresponse.Auto[chainv1.EstimateTransferFeeResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
+	contextLabel := "erc20_transfer"
+	if strings.TrimSpace(walletForFee.ContractAddress) == "" {
+		contextLabel = "native_transfer"
+	}
 	resp := &chainv1.EstimateTransferFeeResponse{
 		NetworkFee:        feeMoney,
-		EstimationContext: "erc20_transfer",
+		EstimationContext: contextLabel,
 	}
 	return gsresponse.Success(resp)
 }

api/gateway/chain/internal/service/gateway/commands/transfer/gas_topup.go

@@ -0,0 +1,290 @@
+package transfer
+
+import (
+	"context"
+	"strings"
+
+	"github.com/shopspring/decimal"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/commands/wallet"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/evm"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/tron"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/api/routers/gsresponse"
+	"github.com/tech/sendico/pkg/merrors"
+	"github.com/tech/sendico/pkg/mlogger"
+	"github.com/tech/sendico/pkg/mservice"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
+	"go.uber.org/zap"
+)
+
+type computeGasTopUpCommand struct {
+	deps Deps
+}
+
+func NewComputeGasTopUp(deps Deps) *computeGasTopUpCommand {
+	return &computeGasTopUpCommand{deps: deps}
+}
+
+func (c *computeGasTopUpCommand) Execute(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) gsresponse.Responder[chainv1.ComputeGasTopUpResponse] {
+	if err := c.deps.EnsureRepository(ctx); err != nil {
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
+		return gsresponse.Unavailable[chainv1.ComputeGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, err)
+	}
+	if req == nil {
+		c.deps.Logger.Warn("Nil request")
+		return gsresponse.InvalidArgument[chainv1.ComputeGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("request is required"))
+	}
+
+	walletRef := strings.TrimSpace(req.GetWalletRef())
+	if walletRef == "" {
+		c.deps.Logger.Warn("Wallet ref missing")
+		return gsresponse.InvalidArgument[chainv1.ComputeGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("wallet_ref is required"))
+	}
+	estimatedFee := req.GetEstimatedTotalFee()
+	if estimatedFee == nil || strings.TrimSpace(estimatedFee.GetAmount()) == "" || strings.TrimSpace(estimatedFee.GetCurrency()) == "" {
+		c.deps.Logger.Warn("Estimated fee missing")
+		return gsresponse.InvalidArgument[chainv1.ComputeGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("estimated_total_fee is required"))
+	}
+
+	topUp, capHit, decision, nativeBalance, walletModel, err := computeGasTopUp(ctx, c.deps, walletRef, estimatedFee)
+	if err != nil {
+		return gsresponse.Auto[chainv1.ComputeGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, err)
+	}
+
+	logDecision(c.deps.Logger, walletRef, estimatedFee, nativeBalance, topUp, capHit, decision, walletModel)
+
+	return gsresponse.Success(&chainv1.ComputeGasTopUpResponse{
+		TopupAmount: topUp,
+		CapHit:      capHit,
+	})
+}
+
+type ensureGasTopUpCommand struct {
+	deps Deps
+}
+
+func NewEnsureGasTopUp(deps Deps) *ensureGasTopUpCommand {
+	return &ensureGasTopUpCommand{deps: deps}
+}
+
+func (c *ensureGasTopUpCommand) Execute(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) gsresponse.Responder[chainv1.EnsureGasTopUpResponse] {
+	if err := c.deps.EnsureRepository(ctx); err != nil {
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
+		return gsresponse.Unavailable[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, err)
+	}
+	if req == nil {
+		c.deps.Logger.Warn("Nil request")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("request is required"))
+	}
+
+	idempotencyKey := strings.TrimSpace(req.GetIdempotencyKey())
+	if idempotencyKey == "" {
+		c.deps.Logger.Warn("Idempotency key missing")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("idempotency_key is required"))
+	}
+	organizationRef := strings.TrimSpace(req.GetOrganizationRef())
+	if organizationRef == "" {
+		c.deps.Logger.Warn("Organization ref missing")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("organization_ref is required"))
+	}
+	sourceWalletRef := strings.TrimSpace(req.GetSourceWalletRef())
+	if sourceWalletRef == "" {
+		c.deps.Logger.Warn("Source wallet ref missing")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("source_wallet_ref is required"))
+	}
+	targetWalletRef := strings.TrimSpace(req.GetTargetWalletRef())
+	if targetWalletRef == "" {
+		c.deps.Logger.Warn("Target wallet ref missing")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("target_wallet_ref is required"))
+	}
+	estimatedFee := req.GetEstimatedTotalFee()
+	if estimatedFee == nil || strings.TrimSpace(estimatedFee.GetAmount()) == "" || strings.TrimSpace(estimatedFee.GetCurrency()) == "" {
+		c.deps.Logger.Warn("Estimated fee missing")
+		return gsresponse.InvalidArgument[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("estimated_total_fee is required"))
+	}
+
+	topUp, capHit, decision, nativeBalance, walletModel, err := computeGasTopUp(ctx, c.deps, targetWalletRef, estimatedFee)
+	if err != nil {
+		return gsresponse.Auto[chainv1.EnsureGasTopUpResponse](c.deps.Logger, mservice.ChainGateway, err)
+	}
+
+	logDecision(c.deps.Logger, targetWalletRef, estimatedFee, nativeBalance, topUp, capHit, decision, walletModel)
+
+	if topUp == nil || strings.TrimSpace(topUp.GetAmount()) == "" {
+		return gsresponse.Success(&chainv1.EnsureGasTopUpResponse{
+			TopupAmount: nil,
+			CapHit:      capHit,
+		})
+	}
+
+	submitReq := &chainv1.SubmitTransferRequest{
+		IdempotencyKey:  idempotencyKey,
+		OrganizationRef: organizationRef,
+		SourceWalletRef: sourceWalletRef,
+		Destination: &chainv1.TransferDestination{
+			Destination: &chainv1.TransferDestination_ManagedWalletRef{ManagedWalletRef: targetWalletRef},
+		},
+		Amount:          topUp,
+		Metadata:        shared.CloneMetadata(req.GetMetadata()),
+		ClientReference: strings.TrimSpace(req.GetClientReference()),
+	}
+
+	submitResponder := NewSubmitTransfer(c.deps.WithLogger("transfer.submit")).Execute(ctx, submitReq)
+	return func(ctx context.Context) (*chainv1.EnsureGasTopUpResponse, error) {
+		submitResp, err := submitResponder(ctx)
+		if err != nil {
+			return nil, err
+		}
+		return &chainv1.EnsureGasTopUpResponse{
+			TopupAmount: topUp,
+			CapHit:      capHit,
+			Transfer:    submitResp.GetTransfer(),
+		}, nil
+	}
+}
+
+func computeGasTopUp(ctx context.Context, deps Deps, walletRef string, estimatedFee *moneyv1.Money) (*moneyv1.Money, bool, *tron.GasTopUpDecision, *moneyv1.Money, *model.ManagedWallet, error) {
+	walletRef = strings.TrimSpace(walletRef)
+	estimatedFee = shared.CloneMoney(estimatedFee)
+	walletModel, err := deps.Storage.Wallets().Get(ctx, walletRef)
+	if err != nil {
+		return nil, false, nil, nil, nil, err
+	}
+
+	networkKey := strings.ToLower(strings.TrimSpace(walletModel.Network))
+	networkCfg, ok := deps.Networks.Network(networkKey)
+	if !ok {
+		return nil, false, nil, nil, nil, merrors.InvalidArgument("unsupported chain for wallet")
+	}
+
+	nativeBalance, err := nativeBalanceForWallet(ctx, deps, walletModel)
+	if err != nil {
+		return nil, false, nil, nil, nil, err
+	}
+
+	if strings.HasPrefix(networkKey, "tron") {
+		topUp, decision, err := tron.ComputeGasTopUp(networkCfg, walletModel, estimatedFee, nativeBalance)
+		if err != nil {
+			return nil, false, nil, nil, nil, err
+		}
+		return topUp, decision.CapHit, &decision, nativeBalance, walletModel, nil
+	}
+
+	if networkCfg.GasTopUpPolicy != nil {
+		topUp, capHit, err := evm.ComputeGasTopUp(networkCfg, walletModel, estimatedFee, nativeBalance)
+		if err != nil {
+			return nil, false, nil, nil, nil, err
+		}
+		return topUp, capHit, nil, nativeBalance, walletModel, nil
+	}
+
+	topUp, err := defaultGasTopUp(estimatedFee, nativeBalance)
+	if err != nil {
+		return nil, false, nil, nil, nil, err
+	}
+	return topUp, false, nil, nativeBalance, walletModel, nil
+}
+
+func nativeBalanceForWallet(ctx context.Context, deps Deps, walletModel *model.ManagedWallet) (*moneyv1.Money, error) {
+	if walletModel == nil {
+		return nil, merrors.InvalidArgument("wallet is required")
+	}
+	walletDeps := wallet.Deps{
+		Logger:           deps.Logger.Named("wallet"),
+		Drivers:          deps.Drivers,
+		Networks:         deps.Networks,
+		KeyManager:       nil,
+		Storage:          deps.Storage,
+		Clock:            deps.Clock,
+		BalanceCacheTTL:  0,
+		RPCTimeout:       deps.RPCTimeout,
+		EnsureRepository: deps.EnsureRepository,
+	}
+	_, nativeBalance, err := wallet.OnChainWalletBalances(ctx, walletDeps, walletModel)
+	if err != nil {
+		return nil, err
+	}
+	if nativeBalance == nil || strings.TrimSpace(nativeBalance.GetAmount()) == "" || strings.TrimSpace(nativeBalance.GetCurrency()) == "" {
+		return nil, merrors.InvalidArgument("native balance is unavailable")
+	}
+	return nativeBalance, nil
+}
+
+func defaultGasTopUp(estimatedFee *moneyv1.Money, currentBalance *moneyv1.Money) (*moneyv1.Money, error) {
+	if estimatedFee == nil || strings.TrimSpace(estimatedFee.GetAmount()) == "" || strings.TrimSpace(estimatedFee.GetCurrency()) == "" {
+		return nil, merrors.InvalidArgument("estimated fee is required")
+	}
+	if currentBalance == nil || strings.TrimSpace(currentBalance.GetAmount()) == "" || strings.TrimSpace(currentBalance.GetCurrency()) == "" {
+		return nil, merrors.InvalidArgument("native balance is required")
+	}
+	if !strings.EqualFold(estimatedFee.GetCurrency(), currentBalance.GetCurrency()) {
+		return nil, merrors.InvalidArgument("native balance currency mismatch")
+	}
+
+	estimated, err := decimal.NewFromString(strings.TrimSpace(estimatedFee.GetAmount()))
+	if err != nil {
+		return nil, err
+	}
+	current, err := decimal.NewFromString(strings.TrimSpace(currentBalance.GetAmount()))
+	if err != nil {
+		return nil, err
+	}
+	required := estimated.Sub(current)
+	if !required.IsPositive() {
+		return nil, nil
+	}
+	return &moneyv1.Money{
+		Currency: strings.ToUpper(strings.TrimSpace(estimatedFee.GetCurrency())),
+		Amount:   required.String(),
+	}, nil
+}
+
+func logDecision(logger mlogger.Logger, walletRef string, estimatedFee *moneyv1.Money, nativeBalance *moneyv1.Money, topUp *moneyv1.Money, capHit bool, decision *tron.GasTopUpDecision, walletModel *model.ManagedWallet) {
+	if logger == nil {
+		return
+	}
+	fields := []zap.Field{
+		zap.String("wallet_ref", walletRef),
+		zap.String("estimated_total_fee", amountString(estimatedFee)),
+		zap.String("current_native_balance", amountString(nativeBalance)),
+		zap.String("topup_amount", amountString(topUp)),
+		zap.Bool("cap_hit", capHit),
+	}
+	if walletModel != nil {
+		fields = append(fields, zap.String("network", strings.TrimSpace(walletModel.Network)))
+	}
+	if decision != nil {
+		fields = append(fields,
+			zap.String("estimated_total_fee_trx", decision.EstimatedFeeTRX.String()),
+			zap.String("current_native_balance_trx", decision.CurrentBalanceTRX.String()),
+			zap.String("required_trx", decision.RequiredTRX.String()),
+			zap.String("buffered_required_trx", decision.BufferedRequiredTRX.String()),
+			zap.String("min_balance_topup_trx", decision.MinBalanceTopUpTRX.String()),
+			zap.String("raw_topup_trx", decision.RawTopUpTRX.String()),
+			zap.String("rounded_topup_trx", decision.RoundedTopUpTRX.String()),
+			zap.String("topup_trx", decision.TopUpTRX.String()),
+			zap.String("operation_type", decision.OperationType),
+		)
+	}
+	logger.Info("Gas top-up decision", fields...)
+}
+
+func amountString(m *moneyv1.Money) string {
+	if m == nil {
+		return ""
+	}
+	amount := strings.TrimSpace(m.GetAmount())
+	currency := strings.TrimSpace(m.GetCurrency())
+	if amount == "" && currency == "" {
+		return ""
+	}
+	if currency == "" {
+		return amount
+	}
+	if amount == "" {
+		return currency
+	}
+	return amount + " " + currency
+}

api/gateway/chain/internal/service/gateway/commands/transfer/get.go

@@ -22,25 +22,25 @@ func NewGetTransfer(deps Deps) *getTransferCommand {
 
 func (c *getTransferCommand) Execute(ctx context.Context, req *chainv1.GetTransferRequest) gsresponse.Responder[chainv1.GetTransferResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.GetTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Nil request")
 		return gsresponse.InvalidArgument[chainv1.GetTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("nil request"))
 	}
 	transferRef := strings.TrimSpace(req.GetTransferRef())
 	if transferRef == "" {
-		c.deps.Logger.Warn("transfer_ref missing")
+		c.deps.Logger.Warn("Transfer_ref missing")
 		return gsresponse.InvalidArgument[chainv1.GetTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("transfer_ref is required"))
 	}
 	transfer, err := c.deps.Storage.Transfers().Get(ctx, transferRef)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("not found", zap.String("transfer_ref", transferRef))
+			c.deps.Logger.Warn("Not found", zap.String("transfer_ref", transferRef))
 			return gsresponse.NotFound[chainv1.GetTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("storage get failed", zap.Error(err), zap.String("transfer_ref", transferRef))
+		c.deps.Logger.Warn("Storage get failed", zap.Error(err), zap.String("transfer_ref", transferRef))
 		return gsresponse.Auto[chainv1.GetTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	return gsresponse.Success(&chainv1.GetTransferResponse{Transfer: toProtoTransfer(transfer)})

api/gateway/chain/internal/service/gateway/commands/transfer/list.go

@@ -23,7 +23,7 @@ func NewListTransfers(deps Deps) *listTransfersCommand {
 
 func (c *listTransfersCommand) Execute(ctx context.Context, req *chainv1.ListTransfersRequest) gsresponse.Responder[chainv1.ListTransfersResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.ListTransfersResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	filter := model.TransferFilter{}
@@ -41,7 +41,7 @@ func (c *listTransfersCommand) Execute(ctx context.Context, req *chainv1.ListTra
 
 	result, err := c.deps.Storage.Transfers().List(ctx, filter)
 	if err != nil {
-		c.deps.Logger.Warn("storage list failed", zap.Error(err))
+		c.deps.Logger.Warn("Storage list failed", zap.Error(err))
 		return gsresponse.Auto[chainv1.ListTransfersResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 

api/gateway/chain/internal/service/gateway/commands/transfer/submit.go

@@ -25,94 +25,102 @@ func NewSubmitTransfer(deps Deps) *submitTransferCommand {
 
 func (c *submitTransferCommand) Execute(ctx context.Context, req *chainv1.SubmitTransferRequest) gsresponse.Responder[chainv1.SubmitTransferResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Nil request")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("nil request"))
 	}
 
 	idempotencyKey := strings.TrimSpace(req.GetIdempotencyKey())
 	if idempotencyKey == "" {
-		c.deps.Logger.Warn("missing idempotency key")
+		c.deps.Logger.Warn("Missing idempotency key")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("idempotency_key is required"))
 	}
 	organizationRef := strings.TrimSpace(req.GetOrganizationRef())
 	if organizationRef == "" {
-		c.deps.Logger.Warn("missing organization ref")
+		c.deps.Logger.Warn("Missing organization ref")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("organization_ref is required"))
 	}
 	sourceWalletRef := strings.TrimSpace(req.GetSourceWalletRef())
 	if sourceWalletRef == "" {
-		c.deps.Logger.Warn("missing source wallet ref")
+		c.deps.Logger.Warn("Missing source wallet ref")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("source_wallet_ref is required"))
 	}
 	amount := req.GetAmount()
 	if amount == nil {
-		c.deps.Logger.Warn("missing amount")
+		c.deps.Logger.Warn("Missing amount")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("amount is required"))
 	}
 	amountCurrency := strings.ToUpper(strings.TrimSpace(amount.GetCurrency()))
 	if amountCurrency == "" {
-		c.deps.Logger.Warn("missing amount currency")
+		c.deps.Logger.Warn("Missing amount currency")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("amount.currency is required"))
 	}
 	amountValue := strings.TrimSpace(amount.GetAmount())
 	if amountValue == "" {
-		c.deps.Logger.Warn("missing amount value")
+		c.deps.Logger.Warn("Missing amount value")
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("amount.amount is required"))
 	}
 
 	sourceWallet, err := c.deps.Storage.Wallets().Get(ctx, sourceWalletRef)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("source wallet not found", zap.String("source_wallet_ref", sourceWalletRef))
+			c.deps.Logger.Warn("Source wallet not found", zap.String("source_wallet_ref", sourceWalletRef))
 			return gsresponse.NotFound[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("storage get wallet failed", zap.Error(err), zap.String("source_wallet_ref", sourceWalletRef))
+		c.deps.Logger.Warn("Storage get wallet failed", zap.Error(err), zap.String("source_wallet_ref", sourceWalletRef))
 		return gsresponse.Auto[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if !strings.EqualFold(sourceWallet.OrganizationRef, organizationRef) {
-		c.deps.Logger.Warn("organization mismatch", zap.String("wallet_org", sourceWallet.OrganizationRef), zap.String("req_org", organizationRef))
+		c.deps.Logger.Warn("Organization mismatch", zap.String("wallet_org", sourceWallet.OrganizationRef), zap.String("req_org", organizationRef))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("organization_ref mismatch with wallet"))
 	}
 	networkKey := strings.ToLower(strings.TrimSpace(sourceWallet.Network))
 	networkCfg, ok := c.deps.Networks.Network(networkKey)
 	if !ok {
-		c.deps.Logger.Warn("unsupported chain", zap.String("network", networkKey))
+		c.deps.Logger.Warn("Unsupported chain", zap.String("network", networkKey))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain for wallet"))
 	}
 
 	destination, err := resolveDestination(ctx, c.deps, req.GetDestination(), sourceWallet)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("destination not found", zap.String("destination_wallet_ref", req.GetDestination().GetManagedWalletRef()))
+			c.deps.Logger.Warn("Destination not found", zap.String("destination_wallet_ref", req.GetDestination().GetManagedWalletRef()))
 			return gsresponse.NotFound[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("invalid destination", zap.Error(err))
+		c.deps.Logger.Warn("Invalid destination", zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
 	fees, feeSum, err := convertFees(req.GetFees(), amountCurrency)
 	if err != nil {
-		c.deps.Logger.Warn("fee conversion failed", zap.Error(err))
+		c.deps.Logger.Warn("Fee conversion failed", zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	amountDec, err := decimal.NewFromString(amountValue)
 	if err != nil {
-		c.deps.Logger.Warn("invalid amount", zap.Error(err))
+		c.deps.Logger.Warn("Invalid amount", zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("invalid amount"))
 	}
 	netDec := amountDec.Sub(feeSum)
 	if netDec.IsNegative() {
-		c.deps.Logger.Warn("fees exceed amount", zap.String("amount", amountValue), zap.String("fee_sum", feeSum.String()))
+		c.deps.Logger.Warn("Fees exceed amount", zap.String("amount", amountValue), zap.String("fee_sum", feeSum.String()))
 		return gsresponse.InvalidArgument[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("fees exceed amount"))
 	}
 
 	netAmount := shared.CloneMoney(amount)
 	netAmount.Amount = netDec.String()
 
+	effectiveTokenSymbol := sourceWallet.TokenSymbol
+	effectiveContractAddress := sourceWallet.ContractAddress
+	nativeCurrency := shared.NativeCurrency(networkCfg)
+	if nativeCurrency != "" && strings.EqualFold(nativeCurrency, amountCurrency) {
+		effectiveTokenSymbol = nativeCurrency
+		effectiveContractAddress = ""
+	}
+
 	transfer := &model.Transfer{
 		IdempotencyKey:  idempotencyKey,
 		TransferRef:     shared.GenerateTransferRef(),
@@ -120,8 +128,8 @@ func (c *submitTransferCommand) Execute(ctx context.Context, req *chainv1.Submit
 		SourceWalletRef: sourceWalletRef,
 		Destination:     destination,
 		Network:         sourceWallet.Network,
-		TokenSymbol:     sourceWallet.TokenSymbol,
-		ContractAddress: sourceWallet.ContractAddress,
+		TokenSymbol:     effectiveTokenSymbol,
+		ContractAddress: effectiveContractAddress,
 		RequestedAmount: shared.CloneMoney(amount),
 		NetAmount:       netAmount,
 		Fees:            fees,
@@ -133,10 +141,10 @@ func (c *submitTransferCommand) Execute(ctx context.Context, req *chainv1.Submit
 	saved, err := c.deps.Storage.Transfers().Create(ctx, transfer)
 	if err != nil {
 		if errors.Is(err, merrors.ErrDataConflict) {
-			c.deps.Logger.Debug("transfer already exists", zap.String("transfer_ref", transfer.TransferRef), zap.String("idempotency_key", idempotencyKey))
+			c.deps.Logger.Debug("Transfer already exists", zap.String("transfer_ref", transfer.TransferRef), zap.String("idempotency_key", idempotencyKey))
 			return gsresponse.Success(&chainv1.SubmitTransferResponse{Transfer: toProtoTransfer(saved)})
 		}
-		c.deps.Logger.Warn("storage create failed", zap.Error(err), zap.String("transfer_ref", transfer.TransferRef))
+		c.deps.Logger.Warn("Storage create failed", zap.Error(err), zap.String("transfer_ref", transfer.TransferRef))
 		return gsresponse.Auto[chainv1.SubmitTransferResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 

api/gateway/chain/internal/service/gateway/commands/wallet/balance.go

@@ -29,41 +29,41 @@ func NewGetWalletBalance(deps Deps) *getWalletBalanceCommand {
 
 func (c *getWalletBalanceCommand) Execute(ctx context.Context, req *chainv1.GetWalletBalanceRequest) gsresponse.Responder[chainv1.GetWalletBalanceResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Nil request")
 		return gsresponse.InvalidArgument[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("nil request"))
 	}
 	walletRef := strings.TrimSpace(req.GetWalletRef())
 	if walletRef == "" {
-		c.deps.Logger.Warn("wallet_ref missing")
+		c.deps.Logger.Warn("Wallet_ref missing")
 		return gsresponse.InvalidArgument[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("wallet_ref is required"))
 	}
 	wallet, err := c.deps.Storage.Wallets().Get(ctx, walletRef)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("not found", zap.String("wallet_ref", walletRef))
+			c.deps.Logger.Warn("Not found", zap.String("wallet_ref", walletRef))
 			return gsresponse.NotFound[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("storage get failed", zap.Error(err), zap.String("wallet_ref", walletRef))
+		c.deps.Logger.Warn("Storage get failed", zap.Error(err), zap.String("wallet_ref", walletRef))
 		return gsresponse.Auto[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
-	balance, chainErr := onChainWalletBalance(ctx, c.deps, wallet)
+	tokenBalance, nativeBalance, chainErr := OnChainWalletBalances(ctx, c.deps, wallet)
 	if chainErr != nil {
-		c.deps.Logger.Warn("on-chain balance fetch failed, attempting cached balance", zap.Error(chainErr), zap.String("wallet_ref", walletRef))
+		c.deps.Logger.Warn("On-chain balance fetch failed, attempting cached balance", zap.Error(chainErr), zap.String("wallet_ref", walletRef))
 		stored, err := c.deps.Storage.Wallets().GetBalance(ctx, walletRef)
 		if err != nil {
 			if errors.Is(err, merrors.ErrNoData) {
-				c.deps.Logger.Warn("cached balance not found", zap.String("wallet_ref", walletRef))
+				c.deps.Logger.Warn("Cached balance not found", zap.String("wallet_ref", walletRef))
 				return gsresponse.Auto[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, chainErr)
 			}
 			return gsresponse.Auto[chainv1.GetWalletBalanceResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
 		if c.isCachedBalanceStale(stored) {
-			c.deps.Logger.Warn("cached balance is stale",
+			c.deps.Logger.Info("Cached balance is stale",
 				zap.String("wallet_ref", walletRef),
 				zap.Time("calculated_at", stored.CalculatedAt),
 				zap.Duration("ttl", c.cacheTTL()),
@@ -74,39 +74,49 @@ func (c *getWalletBalanceCommand) Execute(ctx context.Context, req *chainv1.GetW
 	}
 
 	calculatedAt := c.now()
-	c.persistCachedBalance(ctx, walletRef, balance, calculatedAt)
+	c.persistCachedBalance(ctx, walletRef, tokenBalance, nativeBalance, calculatedAt)
 
 	return gsresponse.Success(&chainv1.GetWalletBalanceResponse{
-		Balance: onChainBalanceToProto(balance, calculatedAt),
+		Balance: onChainBalanceToProto(tokenBalance, nativeBalance, calculatedAt),
 	})
 }
 
-func onChainBalanceToProto(balance *moneyv1.Money, calculatedAt time.Time) *chainv1.WalletBalance {
-	if balance == nil {
+func onChainBalanceToProto(balance *moneyv1.Money, native *moneyv1.Money, calculatedAt time.Time) *chainv1.WalletBalance {
+	if balance == nil && native == nil {
 		return nil
 	}
-	zero := zeroMoney(balance.Currency)
+	currency := ""
+	if balance != nil {
+		currency = balance.Currency
+	}
+	zero := zeroMoney(currency)
 	return &chainv1.WalletBalance{
 		Available:       balance,
+		NativeAvailable: native,
 		PendingInbound:  zero,
 		PendingOutbound: zero,
 		CalculatedAt:    timestamppb.New(calculatedAt.UTC()),
 	}
 }
 
-func (c *getWalletBalanceCommand) persistCachedBalance(ctx context.Context, walletRef string, available *moneyv1.Money, calculatedAt time.Time) {
-	if available == nil {
+func (c *getWalletBalanceCommand) persistCachedBalance(ctx context.Context, walletRef string, available *moneyv1.Money, nativeAvailable *moneyv1.Money, calculatedAt time.Time) {
+	if available == nil && nativeAvailable == nil {
 		return
 	}
 	record := &model.WalletBalance{
 		WalletRef:       walletRef,
 		Available:       shared.CloneMoney(available),
-		PendingInbound:  zeroMoney(available.Currency),
-		PendingOutbound: zeroMoney(available.Currency),
+		NativeAvailable: shared.CloneMoney(nativeAvailable),
 		CalculatedAt:    calculatedAt,
 	}
+	currency := ""
+	if available != nil {
+		currency = available.Currency
+	}
+	record.PendingInbound = zeroMoney(currency)
+	record.PendingOutbound = zeroMoney(currency)
 	if err := c.deps.Storage.Wallets().SaveBalance(ctx, record); err != nil {
-		c.deps.Logger.Warn("failed to cache wallet balance", zap.String("wallet_ref", walletRef), zap.Error(err))
+		c.deps.Logger.Warn("Failed to cache wallet balance", zap.String("wallet_ref", walletRef), zap.Error(err))
 	}
 }
 

api/gateway/chain/internal/service/gateway/commands/wallet/create.go

@@ -25,88 +25,90 @@ func NewCreateManagedWallet(deps Deps) *createManagedWalletCommand {
 
 func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.CreateManagedWalletRequest) gsresponse.Responder[chainv1.CreateManagedWalletResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Nil request")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("nil request"))
 	}
 
 	idempotencyKey := strings.TrimSpace(req.GetIdempotencyKey())
 	if idempotencyKey == "" {
-		c.deps.Logger.Warn("missing idempotency key")
+		c.deps.Logger.Warn("Missing idempotency key")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("idempotency_key is required"))
 	}
 	organizationRef := strings.TrimSpace(req.GetOrganizationRef())
 	if organizationRef == "" {
-		c.deps.Logger.Warn("missing organization ref")
+		c.deps.Logger.Warn("Missing organization ref")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("organization_ref is required"))
 	}
 	ownerRef := strings.TrimSpace(req.GetOwnerRef())
 	if ownerRef == "" {
-		c.deps.Logger.Warn("missing owner ref")
+		c.deps.Logger.Warn("Missing owner ref")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("owner_ref is required"))
 	}
 
 	asset := req.GetAsset()
 	if asset == nil {
-		c.deps.Logger.Warn("missing asset")
+		c.deps.Logger.Warn("Missing asset")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("asset is required"))
 	}
 
 	chainKey, _ := shared.ChainKeyFromEnum(asset.GetChain())
 	if chainKey == "" {
-		c.deps.Logger.Warn("unsupported chain", zap.Any("chain", asset.GetChain()))
+		c.deps.Logger.Warn("Unsupported chain", zap.Any("chain", asset.GetChain()))
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain"))
 	}
 	networkCfg, ok := c.deps.Networks.Network(chainKey)
 	if !ok {
-		c.deps.Logger.Warn("unsupported chain in config", zap.String("chain", chainKey))
+		c.deps.Logger.Warn("Unsupported chain in config", zap.String("chain", chainKey))
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain"))
 	}
 	if c.deps.Drivers == nil {
-		c.deps.Logger.Warn("chain drivers missing", zap.String("chain", chainKey))
+		c.deps.Logger.Warn("Chain drivers missing", zap.String("chain", chainKey))
 		return gsresponse.Internal[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.Internal("chain drivers not configured"))
 	}
 	chainDriver, err := c.deps.Drivers.Driver(chainKey)
 	if err != nil {
-		c.deps.Logger.Warn("unsupported chain driver", zap.String("chain", chainKey), zap.Error(err))
+		c.deps.Logger.Warn("Unsupported chain driver", zap.String("chain", chainKey), zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain"))
 	}
 
 	tokenSymbol := strings.ToUpper(strings.TrimSpace(asset.GetTokenSymbol()))
 	if tokenSymbol == "" {
-		c.deps.Logger.Warn("missing token symbol")
+		c.deps.Logger.Warn("Missing token symbol")
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("asset.token_symbol is required"))
 	}
 	contractAddress := strings.ToLower(strings.TrimSpace(asset.GetContractAddress()))
 	if contractAddress == "" {
-		contractAddress = shared.ResolveContractAddress(networkCfg.TokenConfigs, tokenSymbol)
-		if contractAddress == "" {
-			c.deps.Logger.Warn("unsupported token", zap.String("token", tokenSymbol), zap.String("chain", chainKey))
-			return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported token for chain"))
+		if !strings.EqualFold(tokenSymbol, networkCfg.NativeToken) {
+			contractAddress = shared.ResolveContractAddress(networkCfg.TokenConfigs, tokenSymbol)
+			if contractAddress == "" {
+				c.deps.Logger.Warn("Unsupported token", zap.String("token", tokenSymbol), zap.String("chain", chainKey))
+				return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported token for chain"))
+			}
 		}
 	}
 
 	walletRef := shared.GenerateWalletRef()
 	if c.deps.KeyManager == nil {
-		c.deps.Logger.Warn("key manager missing")
+		c.deps.Logger.Warn("Key manager missing")
 		return gsresponse.Internal[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.Internal("key manager not configured"))
 	}
 
 	keyInfo, err := c.deps.KeyManager.CreateManagedWalletKey(ctx, walletRef, chainKey)
 	if err != nil {
-		c.deps.Logger.Warn("key manager error", zap.Error(err))
+		c.deps.Logger.Warn("Key manager error", zap.Error(err))
 		return gsresponse.Auto[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if keyInfo == nil || strings.TrimSpace(keyInfo.Address) == "" {
-		c.deps.Logger.Warn("key manager returned empty address")
+		c.deps.Logger.Warn("Key manager returned empty address")
 		return gsresponse.Internal[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.Internal("key manager returned empty address"))
 	}
 	depositAddress, err := chainDriver.FormatAddress(keyInfo.Address)
 	if err != nil {
-		c.deps.Logger.Warn("invalid derived deposit address", zap.String("wallet_ref", walletRef), zap.Error(err))
+		c.deps.Logger.Warn("Invalid derived deposit address", zap.String("wallet_ref", walletRef), zap.Error(err))
 		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 
@@ -154,10 +156,10 @@ func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.C
 	created, err := c.deps.Storage.Wallets().Create(ctx, wallet)
 	if err != nil {
 		if errors.Is(err, merrors.ErrDataConflict) {
-			c.deps.Logger.Debug("wallet already exists", zap.String("wallet_ref", walletRef), zap.String("idempotency_key", idempotencyKey))
+			c.deps.Logger.Debug("Wallet already exists", zap.String("wallet_ref", walletRef), zap.String("idempotency_key", idempotencyKey))
 			return gsresponse.Success(&chainv1.CreateManagedWalletResponse{Wallet: toProtoManagedWallet(created)})
 		}
-		c.deps.Logger.Warn("storage create failed", zap.Error(err), zap.String("wallet_ref", walletRef))
+		c.deps.Logger.Warn("Storage create failed", zap.Error(err), zap.String("wallet_ref", walletRef))
 		return gsresponse.Auto[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 

api/gateway/chain/internal/service/gateway/commands/wallet/get.go

@@ -22,25 +22,25 @@ func NewGetManagedWallet(deps Deps) *getManagedWalletCommand {
 
 func (c *getManagedWalletCommand) Execute(ctx context.Context, req *chainv1.GetManagedWalletRequest) gsresponse.Responder[chainv1.GetManagedWalletResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.GetManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	if req == nil {
-		c.deps.Logger.Warn("nil request")
+		c.deps.Logger.Warn("Nil request")
 		return gsresponse.InvalidArgument[chainv1.GetManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("nil request"))
 	}
 	walletRef := strings.TrimSpace(req.GetWalletRef())
 	if walletRef == "" {
-		c.deps.Logger.Warn("wallet_ref missing")
+		c.deps.Logger.Warn("Wallet_ref missing")
 		return gsresponse.InvalidArgument[chainv1.GetManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("wallet_ref is required"))
 	}
 	wallet, err := c.deps.Storage.Wallets().Get(ctx, walletRef)
 	if err != nil {
 		if errors.Is(err, merrors.ErrNoData) {
-			c.deps.Logger.Warn("not found", zap.String("wallet_ref", walletRef))
+			c.deps.Logger.Warn("Not found", zap.String("wallet_ref", walletRef))
 			return gsresponse.NotFound[chainv1.GetManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 		}
-		c.deps.Logger.Warn("storage get failed", zap.Error(err), zap.String("wallet_ref", walletRef))
+		c.deps.Logger.Warn("Storage get failed", zap.Error(err), zap.String("wallet_ref", walletRef))
 		return gsresponse.Auto[chainv1.GetManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	return gsresponse.Success(&chainv1.GetManagedWalletResponse{Wallet: toProtoManagedWallet(wallet)})

api/gateway/chain/internal/service/gateway/commands/wallet/list.go

@@ -23,7 +23,7 @@ func NewListManagedWallets(deps Deps) *listManagedWalletsCommand {
 
 func (c *listManagedWalletsCommand) Execute(ctx context.Context, req *chainv1.ListManagedWalletsRequest) gsresponse.Responder[chainv1.ListManagedWalletsResponse] {
 	if err := c.deps.EnsureRepository(ctx); err != nil {
-		c.deps.Logger.Warn("repository unavailable", zap.Error(err))
+		c.deps.Logger.Warn("Repository unavailable", zap.Error(err))
 		return gsresponse.Unavailable[chainv1.ListManagedWalletsResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 	filter := model.ManagedWalletFilter{}
@@ -42,7 +42,7 @@ func (c *listManagedWalletsCommand) Execute(ctx context.Context, req *chainv1.Li
 
 	result, err := c.deps.Storage.Wallets().List(ctx, filter)
 	if err != nil {
-		c.deps.Logger.Warn("storage list failed", zap.Error(err))
+		c.deps.Logger.Warn("Storage list failed", zap.Error(err))
 		return gsresponse.Auto[chainv1.ListManagedWalletsResponse](c.deps.Logger, mservice.ChainGateway, err)
 	}
 

api/gateway/chain/internal/service/gateway/commands/wallet/onchain_balance.go

@@ -12,16 +12,16 @@ import (
 	"go.uber.org/zap"
 )
 
-func onChainWalletBalance(ctx context.Context, deps Deps, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
+func OnChainWalletBalances(ctx context.Context, deps Deps, wallet *model.ManagedWallet) (*moneyv1.Money, *moneyv1.Money, error) {
 	logger := deps.Logger
 	if wallet == nil {
-		return nil, merrors.InvalidArgument("wallet is required")
+		return nil, nil, merrors.InvalidArgument("wallet is required")
 	}
 	if deps.Networks == nil {
-		return nil, merrors.Internal("rpc clients not initialised")
+		return nil, nil, merrors.Internal("rpc clients not initialised")
 	}
 	if deps.Drivers == nil {
-		return nil, merrors.Internal("chain drivers not configured")
+		return nil, nil, merrors.Internal("chain drivers not configured")
 	}
 
 	networkKey := strings.ToLower(strings.TrimSpace(wallet.Network))
@@ -31,7 +31,7 @@ func onChainWalletBalance(ctx context.Context, deps Deps, wallet *model.ManagedW
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", networkKey),
 		)
-		return nil, merrors.Internal(fmt.Sprintf("Requested network '%s' is not configured", networkKey))
+		return nil, nil, merrors.Internal(fmt.Sprintf("Requested network '%s' is not configured", networkKey))
 	}
 
 	chainDriver, err := deps.Drivers.Driver(networkKey)
@@ -41,7 +41,7 @@ func onChainWalletBalance(ctx context.Context, deps Deps, wallet *model.ManagedW
 			zap.String("network", networkKey),
 			zap.Error(err),
 		)
-		return nil, merrors.InvalidArgument("unsupported chain")
+		return nil, nil, merrors.InvalidArgument("unsupported chain")
 	}
 
 	driverDeps := driver.Deps{
@@ -50,5 +50,13 @@ func onChainWalletBalance(ctx context.Context, deps Deps, wallet *model.ManagedW
 		KeyManager: deps.KeyManager,
 		RPCTimeout: deps.RPCTimeout,
 	}
-	return chainDriver.Balance(ctx, driverDeps, network, wallet)
+	tokenBalance, err := chainDriver.Balance(ctx, driverDeps, network, wallet)
+	if err != nil {
+		return nil, nil, err
+	}
+	nativeBalance, err := chainDriver.NativeBalance(ctx, driverDeps, network, wallet)
+	if err != nil {
+		return nil, nil, err
+	}
+	return tokenBalance, nativeBalance, nil
 }

api/gateway/chain/internal/service/gateway/commands/wallet/proto.go

@@ -58,6 +58,7 @@ func toProtoWalletBalance(balance *model.WalletBalance) *chainv1.WalletBalance {
 	}
 	return &chainv1.WalletBalance{
 		Available:       shared.CloneMoney(balance.Available),
+		NativeAvailable: shared.CloneMoney(balance.NativeAvailable),
 		PendingInbound:  shared.CloneMoney(balance.PendingInbound),
 		PendingOutbound: shared.CloneMoney(balance.PendingOutbound),
 		CalculatedAt:    timestamppb.New(balance.CalculatedAt.UTC()),

api/gateway/chain/internal/service/gateway/driver/arbitrum/driver.go

@@ -27,25 +27,25 @@ func (d *Driver) Name() string {
 }
 
 func (d *Driver) FormatAddress(address string) (string, error) {
-	d.logger.Debug("format address", zap.String("address", address))
+	d.logger.Debug("Format address", zap.String("address", address))
 	normalized, err := evm.NormalizeAddress(address)
 	if err != nil {
-		d.logger.Warn("format address failed", zap.String("address", address), zap.Error(err))
+		d.logger.Warn("Format address failed", zap.String("address", address), zap.Error(err))
 	}
 	return normalized, err
 }
 
 func (d *Driver) NormalizeAddress(address string) (string, error) {
-	d.logger.Debug("normalize address", zap.String("address", address))
+	d.logger.Debug("Normalize address", zap.String("address", address))
 	normalized, err := evm.NormalizeAddress(address)
 	if err != nil {
-		d.logger.Warn("normalize address failed", zap.String("address", address), zap.Error(err))
+		d.logger.Warn("Normalize address failed", zap.String("address", address), zap.Error(err))
 	}
 	return normalized, err
 }
 
 func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
-	d.logger.Debug("balance request",
+	d.logger.Debug("Balance request",
 		zap.String("wallet_ref", wallet.WalletRef),
 		zap.String("network", network.Name),
 	)
@@ -53,13 +53,38 @@ func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.N
 	driverDeps.Logger = d.logger
 	result, err := evm.Balance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
 	if err != nil {
-		d.logger.Warn("balance failed",
+		d.logger.Warn("Balance failed",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if result != nil {
-		d.logger.Debug("balance result",
+		d.logger.Debug("Balance result",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.String("amount", result.Amount),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+func (d *Driver) NativeBalance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
+	d.logger.Debug("Native balance request",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	result, err := evm.NativeBalance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
+	if err != nil {
+		d.logger.Warn("Native balance failed",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else if result != nil {
+		d.logger.Debug("Native balance result",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.String("amount", result.Amount),
@@ -70,7 +95,7 @@ func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.N
 }
 
 func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, destination string, amount *moneyv1.Money) (*moneyv1.Money, error) {
-	d.logger.Debug("estimate fee request",
+	d.logger.Debug("Estimate fee request",
 		zap.String("wallet_ref", wallet.WalletRef),
 		zap.String("network", network.Name),
 		zap.String("destination", destination),
@@ -79,13 +104,13 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 	driverDeps.Logger = d.logger
 	result, err := evm.EstimateFee(ctx, driverDeps, network, wallet, wallet.DepositAddress, destination, amount)
 	if err != nil {
-		d.logger.Warn("estimate fee failed",
+		d.logger.Warn("Estimate fee failed",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if result != nil {
-		d.logger.Debug("estimate fee result",
+		d.logger.Debug("Estimate fee result",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.String("amount", result.Amount),
@@ -96,7 +121,7 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 }
 
 func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Network, transfer *model.Transfer, source *model.ManagedWallet, destination string) (string, error) {
-	d.logger.Debug("submit transfer request",
+	d.logger.Debug("Submit transfer request",
 		zap.String("transfer_ref", transfer.TransferRef),
 		zap.String("network", network.Name),
 		zap.String("destination", destination),
@@ -105,13 +130,13 @@ func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network s
 	driverDeps.Logger = d.logger
 	txHash, err := evm.SubmitTransfer(ctx, driverDeps, network, transfer, source, source.DepositAddress, destination)
 	if err != nil {
-		d.logger.Warn("submit transfer failed",
+		d.logger.Warn("Submit transfer failed",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else {
-		d.logger.Debug("submit transfer result",
+		d.logger.Debug("Submit transfer result",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 			zap.String("tx_hash", txHash),
@@ -121,7 +146,7 @@ func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network s
 }
 
 func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
-	d.logger.Debug("await confirmation",
+	d.logger.Debug("Await confirmation",
 		zap.String("tx_hash", txHash),
 		zap.String("network", network.Name),
 	)
@@ -129,13 +154,13 @@ func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, networ
 	driverDeps.Logger = d.logger
 	receipt, err := evm.AwaitConfirmation(ctx, driverDeps, network, txHash)
 	if err != nil {
-		d.logger.Warn("await confirmation failed",
+		d.logger.Warn("Await confirmation failed",
 			zap.String("tx_hash", txHash),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if receipt != nil {
-		d.logger.Debug("await confirmation result",
+		d.logger.Debug("Await confirmation result",
 			zap.String("tx_hash", txHash),
 			zap.String("network", network.Name),
 			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),

api/gateway/chain/internal/service/gateway/driver/driver.go

@@ -27,6 +27,7 @@ type Driver interface {
 	FormatAddress(address string) (string, error)
 	NormalizeAddress(address string) (string, error)
 	Balance(ctx context.Context, deps Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error)
+	NativeBalance(ctx context.Context, deps Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error)
 	EstimateFee(ctx context.Context, deps Deps, network shared.Network, wallet *model.ManagedWallet, destination string, amount *moneyv1.Money) (*moneyv1.Money, error)
 	SubmitTransfer(ctx context.Context, deps Deps, network shared.Network, transfer *model.Transfer, source *model.ManagedWallet, destination string) (string, error)
 	AwaitConfirmation(ctx context.Context, deps Deps, network shared.Network, txHash string) (*types.Receipt, error)

api/gateway/chain/internal/service/gateway/driver/ethereum/driver.go

@@ -27,25 +27,25 @@ func (d *Driver) Name() string {
 }
 
 func (d *Driver) FormatAddress(address string) (string, error) {
-	d.logger.Debug("format address", zap.String("address", address))
+	d.logger.Debug("Format address", zap.String("address", address))
 	normalized, err := evm.NormalizeAddress(address)
 	if err != nil {
-		d.logger.Warn("format address failed", zap.String("address", address), zap.Error(err))
+		d.logger.Warn("Format address failed", zap.String("address", address), zap.Error(err))
 	}
 	return normalized, err
 }
 
 func (d *Driver) NormalizeAddress(address string) (string, error) {
-	d.logger.Debug("normalize address", zap.String("address", address))
+	d.logger.Debug("Normalize address", zap.String("address", address))
 	normalized, err := evm.NormalizeAddress(address)
 	if err != nil {
-		d.logger.Warn("normalize address failed", zap.String("address", address), zap.Error(err))
+		d.logger.Warn("Normalize address failed", zap.String("address", address), zap.Error(err))
 	}
 	return normalized, err
 }
 
 func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
-	d.logger.Debug("balance request",
+	d.logger.Debug("Balance request",
 		zap.String("wallet_ref", wallet.WalletRef),
 		zap.String("network", network.Name),
 	)
@@ -53,13 +53,38 @@ func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.N
 	driverDeps.Logger = d.logger
 	result, err := evm.Balance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
 	if err != nil {
-		d.logger.Warn("balance failed",
+		d.logger.Warn("Balance failed",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if result != nil {
-		d.logger.Debug("balance result",
+		d.logger.Debug("Balance result",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.String("amount", result.Amount),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+func (d *Driver) NativeBalance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
+	d.logger.Debug("Native balance request",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	result, err := evm.NativeBalance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
+	if err != nil {
+		d.logger.Warn("Native balance failed",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else if result != nil {
+		d.logger.Debug("Native balance result",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.String("amount", result.Amount),
@@ -70,7 +95,7 @@ func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.N
 }
 
 func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, destination string, amount *moneyv1.Money) (*moneyv1.Money, error) {
-	d.logger.Debug("estimate fee request",
+	d.logger.Debug("Estimate fee request",
 		zap.String("wallet_ref", wallet.WalletRef),
 		zap.String("network", network.Name),
 		zap.String("destination", destination),
@@ -79,13 +104,13 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 	driverDeps.Logger = d.logger
 	result, err := evm.EstimateFee(ctx, driverDeps, network, wallet, wallet.DepositAddress, destination, amount)
 	if err != nil {
-		d.logger.Warn("estimate fee failed",
+		d.logger.Warn("Estimate fee failed",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if result != nil {
-		d.logger.Debug("estimate fee result",
+		d.logger.Debug("Estimate fee result",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.String("amount", result.Amount),
@@ -96,7 +121,7 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 }
 
 func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Network, transfer *model.Transfer, source *model.ManagedWallet, destination string) (string, error) {
-	d.logger.Debug("submit transfer request",
+	d.logger.Debug("Submit transfer request",
 		zap.String("transfer_ref", transfer.TransferRef),
 		zap.String("network", network.Name),
 		zap.String("destination", destination),
@@ -105,13 +130,13 @@ func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network s
 	driverDeps.Logger = d.logger
 	txHash, err := evm.SubmitTransfer(ctx, driverDeps, network, transfer, source, source.DepositAddress, destination)
 	if err != nil {
-		d.logger.Warn("submit transfer failed",
+		d.logger.Warn("Submit transfer failed",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else {
-		d.logger.Debug("submit transfer result",
+		d.logger.Debug("Submit transfer result",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 			zap.String("tx_hash", txHash),
@@ -121,7 +146,7 @@ func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network s
 }
 
 func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
-	d.logger.Debug("await confirmation",
+	d.logger.Debug("Await confirmation",
 		zap.String("tx_hash", txHash),
 		zap.String("network", network.Name),
 	)
@@ -129,13 +154,13 @@ func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, networ
 	driverDeps.Logger = d.logger
 	receipt, err := evm.AwaitConfirmation(ctx, driverDeps, network, txHash)
 	if err != nil {
-		d.logger.Warn("await confirmation failed",
+		d.logger.Warn("Await confirmation failed",
 			zap.String("tx_hash", txHash),
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
 	} else if receipt != nil {
-		d.logger.Debug("await confirmation result",
+		d.logger.Debug("Await confirmation result",
 			zap.String("tx_hash", txHash),
 			zap.String("network", network.Name),
 			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),

api/gateway/chain/internal/service/gateway/driver/evm/estimate_gas_test.go

@@ -0,0 +1,31 @@
+package evm
+
+import (
+	"math/big"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTronEstimateCallUsesData(t *testing.T) {
+	from := common.HexToAddress("0xfa89b4d534bdeb2713d4ffd893e79d6535fb58f8")
+	to := common.HexToAddress("0xa614f803b6fd780986a42c78ec9c7f77e6ded13c")
+	callMsg := ethereum.CallMsg{
+		From:     from,
+		To:       &to,
+		GasPrice: big.NewInt(100),
+		Data:     []byte{0xa9, 0x05, 0x9c, 0xbb},
+	}
+
+	call := tronEstimateCall(callMsg)
+
+	require.Equal(t, strings.ToLower(from.Hex()), call["from"])
+	require.Equal(t, strings.ToLower(to.Hex()), call["to"])
+	require.Equal(t, "0x64", call["gasPrice"])
+	require.Equal(t, "0xa9059cbb", call["data"])
+	_, hasInput := call["input"]
+	require.False(t, hasInput)
+}

api/gateway/chain/internal/service/gateway/driver/evm/evm.go

@@ -10,6 +10,7 @@ import (
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/shopspring/decimal"
@@ -70,9 +71,32 @@ func NormalizeAddress(address string) (string, error) {
 	return strings.ToLower(common.HexToAddress(trimmed).Hex()), nil
 }
 
+func nativeCurrency(network shared.Network) string {
+	currency := strings.ToUpper(strings.TrimSpace(network.NativeToken))
+	if currency == "" {
+		currency = strings.ToUpper(network.Name)
+	}
+	return currency
+}
+
+func parseBaseUnitAmount(amount string) (*big.Int, error) {
+	trimmed := strings.TrimSpace(amount)
+	if trimmed == "" {
+		return nil, merrors.InvalidArgument("amount is required")
+	}
+	value, ok := new(big.Int).SetString(trimmed, 10)
+	if !ok {
+		return nil, merrors.InvalidArgument("invalid amount")
+	}
+	if value.Sign() < 0 {
+		return nil, merrors.InvalidArgument("amount must be non-negative")
+	}
+	return value, nil
+}
+
 // Balance fetches ERC20 token balance for the provided address.
 func Balance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, address string) (*moneyv1.Money, error) {
-	logger := deps.Logger
+	logger := deps.Logger.Named("evm")
 	registry := deps.Registry
 
 	if registry == nil {
@@ -101,7 +125,11 @@ func Balance(ctx context.Context, deps driver.Deps, network shared.Network, wall
 	}
 
 	contract := strings.TrimSpace(wallet.ContractAddress)
-	if contract == "" || !common.IsHexAddress(contract) {
+	if contract == "" {
+		logger.Debug("Native balance requested", logFields...)
+		return NativeBalance(ctx, deps, network, wallet, normalizedAddress)
+	}
+	if !common.IsHexAddress(contract) {
 		logger.Warn("Invalid contract address for balance fetch", logFields...)
 		return nil, merrors.InvalidArgument("invalid contract address")
 	}
@@ -146,9 +174,67 @@ func Balance(ctx context.Context, deps driver.Deps, network shared.Network, wall
 	return &moneyv1.Money{Currency: wallet.TokenSymbol, Amount: dec.String()}, nil
 }
 
+// NativeBalance fetches native token balance for the provided address.
+func NativeBalance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, address string) (*moneyv1.Money, error) {
+	logger := deps.Logger.Named("evm")
+	registry := deps.Registry
+
+	if registry == nil {
+		return nil, merrors.Internal("rpc clients not initialised")
+	}
+	if wallet == nil {
+		return nil, merrors.InvalidArgument("wallet is required")
+	}
+
+	normalizedAddress, err := NormalizeAddress(address)
+	if err != nil {
+		return nil, err
+	}
+
+	rpcURL := strings.TrimSpace(network.RPCURL)
+	logFields := []zap.Field{
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", strings.ToLower(strings.TrimSpace(network.Name))),
+		zap.String("wallet_address", normalizedAddress),
+	}
+	if rpcURL == "" {
+		logger.Warn("Network rpc url is not configured", logFields...)
+		return nil, merrors.Internal("network rpc url is not configured")
+	}
+
+	client, err := registry.Client(network.Name)
+	if err != nil {
+		logger.Warn("Failed to fetch rpc client", append(logFields, zap.Error(err))...)
+		return nil, err
+	}
+
+	timeout := deps.RPCTimeout
+	if timeout <= 0 {
+		timeout = 10 * time.Second
+	}
+	timeoutCtx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	bal, err := client.BalanceAt(timeoutCtx, common.HexToAddress(normalizedAddress), nil)
+	if err != nil {
+		logger.Warn("Native balance call failed", append(logFields, zap.Error(err))...)
+		return nil, err
+	}
+
+	logger.Info("On-chain native balance fetched",
+		append(logFields,
+			zap.String("balance_raw", bal.String()),
+		)...,
+	)
+	return &moneyv1.Money{
+		Currency: nativeCurrency(network),
+		Amount:   bal.String(),
+	}, nil
+}
+
 // EstimateFee estimates ERC20 transfer fees for the given parameters.
 func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, fromAddress, destination string, amount *moneyv1.Money) (*moneyv1.Money, error) {
-	logger := deps.Logger
+	logger := deps.Logger.Named("evm")
 	registry := deps.Registry
 
 	if registry == nil {
@@ -165,12 +251,6 @@ func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network,
 	if rpcURL == "" {
 		return nil, merrors.InvalidArgument("network rpc url not configured")
 	}
-	if strings.TrimSpace(wallet.ContractAddress) == "" {
-		return nil, merrors.NotImplemented("native token transfers not supported")
-	}
-	if !common.IsHexAddress(wallet.ContractAddress) {
-		return nil, merrors.InvalidArgument("invalid token contract address")
-	}
 	if _, err := NormalizeAddress(fromAddress); err != nil {
 		return nil, merrors.InvalidArgument("invalid source wallet address")
 	}
@@ -180,10 +260,12 @@ func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network,
 
 	client, err := registry.Client(network.Name)
 	if err != nil {
+		logger.Warn("Failed to resolve client", zap.Error(err), zap.String("network_name", network.Name))
 		return nil, err
 	}
 	rpcClient, err := registry.RPCClient(network.Name)
 	if err != nil {
+		logger.Warn("Failed to resolve RPC client", zap.Error(err), zap.String("network_name", network.Name))
 		return nil, err
 	}
 
@@ -194,10 +276,46 @@ func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network,
 	timeoutCtx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
-	tokenAddr := common.HexToAddress(wallet.ContractAddress)
+	contract := strings.TrimSpace(wallet.ContractAddress)
 	toAddr := common.HexToAddress(destination)
 	fromAddr := common.HexToAddress(fromAddress)
 
+	if contract == "" {
+		amountBase, err := parseBaseUnitAmount(amount.GetAmount())
+		if err != nil {
+			logger.Warn("Failed to parse base unit amount", zap.Error(err), zap.String("amount", amount.GetAmount()))
+			return nil, err
+		}
+		gasPrice, err := client.SuggestGasPrice(timeoutCtx)
+		if err != nil {
+			logger.Warn("Failed to suggest gas price", zap.Error(err))
+			return nil, merrors.Internal("failed to suggest gas price: " + err.Error())
+		}
+		callMsg := ethereum.CallMsg{
+			From:     fromAddr,
+			To:       &toAddr,
+			GasPrice: gasPrice,
+			Value:    amountBase,
+		}
+		gasLimit, err := estimateGas(timeoutCtx, network, client, rpcClient, callMsg)
+		if err != nil {
+			logger.Warn("Failed to estimate gas", zap.Error(err), zap.Any("call_mesasge", callMsg))
+			return nil, merrors.Internal("failed to estimate gas: " + err.Error())
+		}
+		fee := new(big.Int).Mul(gasPrice, new(big.Int).SetUint64(gasLimit))
+		feeDec := decimal.NewFromBigInt(fee, 0)
+		return &moneyv1.Money{
+			Currency: nativeCurrency(network),
+			Amount:   feeDec.String(),
+		}, nil
+	}
+	if !common.IsHexAddress(contract) {
+		logger.Warn("Failed to validate contract", zap.String("contract", contract))
+		return nil, merrors.InvalidArgument("invalid token contract address")
+	}
+
+	tokenAddr := common.HexToAddress(contract)
+
 	decimals, err := erc20Decimals(timeoutCtx, rpcClient, tokenAddr)
 	if err != nil {
 		logger.Warn("Failed to read token decimals", zap.Error(err))
@@ -211,11 +329,13 @@ func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network,
 
 	input, err := erc20ABI.Pack("transfer", toAddr, amountBase)
 	if err != nil {
+		logger.Warn("Failed to encode transfer call", zap.Error(err))
 		return nil, merrors.Internal("failed to encode transfer call: " + err.Error())
 	}
 
 	gasPrice, err := client.SuggestGasPrice(timeoutCtx)
 	if err != nil {
+		logger.Warn("Failed to suggest gas price", zap.Error(err))
 		return nil, merrors.Internal("failed to suggest gas price: " + err.Error())
 	}
 
@@ -225,28 +345,24 @@ func EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network,
 		GasPrice: gasPrice,
 		Data:     input,
 	}
-	gasLimit, err := client.EstimateGas(timeoutCtx, callMsg)
+	gasLimit, err := estimateGas(timeoutCtx, network, client, rpcClient, callMsg)
 	if err != nil {
+		logger.Warn("Failed to estimate gas", zap.Error(err), zap.Any("call_message", callMsg))
 		return nil, merrors.Internal("failed to estimate gas: " + err.Error())
 	}
 
 	fee := new(big.Int).Mul(gasPrice, new(big.Int).SetUint64(gasLimit))
 	feeDec := decimal.NewFromBigInt(fee, 0)
 
-	currency := strings.ToUpper(strings.TrimSpace(network.NativeToken))
-	if currency == "" {
-		currency = strings.ToUpper(network.Name)
-	}
-
 	return &moneyv1.Money{
-		Currency: currency,
+		Currency: nativeCurrency(network),
 		Amount:   feeDec.String(),
 	}, nil
 }
 
 // SubmitTransfer submits an ERC20 transfer on an EVM-compatible chain.
 func SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Network, transfer *model.Transfer, source *model.ManagedWallet, fromAddress, destination string) (string, error) {
-	logger := deps.Logger
+	logger := deps.Logger.Named("evm")
 	registry := deps.Registry
 
 	if deps.KeyManager == nil {
@@ -278,7 +394,7 @@ func SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Networ
 		return "", executorInvalid("invalid destination address " + destination)
 	}
 
-	logger.Info("submitting transfer",
+	logger.Info("Submitting transfer",
 		zap.String("transfer_ref", transfer.TransferRef),
 		zap.String("source_wallet_ref", source.WalletRef),
 		zap.String("network", network.Name),
@@ -287,12 +403,12 @@ func SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Networ
 
 	client, err := registry.Client(network.Name)
 	if err != nil {
-		logger.Warn("Failed to initialise rpc client", zap.Error(err), zap.String("network", network.Name))
+		logger.Warn("Failed to initialise RPC client", zap.Error(err), zap.String("network", network.Name))
 		return "", err
 	}
 	rpcClient, err := registry.RPCClient(network.Name)
 	if err != nil {
-		logger.Warn("failed to initialise rpc client", zap.String("network", network.Name))
+		logger.Warn("Failed to initialise RPC client", zap.String("network", network.Name))
 		return "", err
 	}
 
@@ -322,66 +438,86 @@ func SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Networ
 
 	chainID := new(big.Int).SetUint64(network.ChainID)
 
-	if strings.TrimSpace(transfer.ContractAddress) == "" {
-		logger.Warn("Native token transfer requested but not supported", zap.String("transfer_ref", transfer.TransferRef))
-		return "", merrors.NotImplemented("executor: native token transfers not yet supported")
-	}
-
-	if !common.IsHexAddress(transfer.ContractAddress) {
-		logger.Warn("Invalid token contract address",
-			zap.String("transfer_ref", transfer.TransferRef),
-			zap.String("contract", transfer.ContractAddress),
-		)
-		return "", executorInvalid("invalid token contract address " + transfer.ContractAddress)
-	}
-	tokenAddress := common.HexToAddress(transfer.ContractAddress)
-
-	decimals, err := erc20Decimals(ctx, rpcClient, tokenAddress)
-	if err != nil {
-		logger.Warn("Failed to read token decimals", zap.Error(err),
-			zap.String("transfer_ref", transfer.TransferRef),
-			zap.String("contract", transfer.ContractAddress),
-		)
-		return "", err
-	}
-
+	contract := strings.TrimSpace(transfer.ContractAddress)
 	amount := transfer.NetAmount
 	if amount == nil || strings.TrimSpace(amount.Amount) == "" {
 		logger.Warn("Transfer missing net amount", zap.String("transfer_ref", transfer.TransferRef))
 		return "", executorInvalid("transfer missing net amount")
 	}
-	amountInt, err := toBaseUnits(amount.Amount, decimals)
-	if err != nil {
-		logger.Warn("Failed to convert amount to base units", zap.Error(err),
-			zap.String("transfer_ref", transfer.TransferRef),
-			zap.String("amount", amount.Amount),
-		)
-		return "", err
-	}
 
-	input, err := erc20ABI.Pack("transfer", destinationAddr, amountInt)
-	if err != nil {
-		logger.Warn("Failed to encode transfer call", zap.Error(err),
-			zap.String("transfer_ref", transfer.TransferRef),
-		)
-		return "", executorInternal("failed to encode transfer call", err)
-	}
+	var tx *types.Transaction
+	if contract == "" {
+		amountInt, err := parseBaseUnitAmount(amount.Amount)
+		if err != nil {
+			logger.Warn("Invalid native amount", zap.Error(err), zap.String("transfer_ref", transfer.TransferRef))
+			return "", err
+		}
+		callMsg := ethereum.CallMsg{
+			From:     sourceAddress,
+			To:       &destinationAddr,
+			GasPrice: gasPrice,
+			Value:    amountInt,
+		}
+		gasLimit, err := estimateGas(ctx, network, client, rpcClient, callMsg)
+		if err != nil {
+			logger.Warn("Failed to estimate gas", zap.Error(err),
+				zap.String("transfer_ref", transfer.TransferRef),
+			)
+			return "", executorInternal("failed to estimate gas", err)
+		}
+		tx = types.NewTransaction(nonce, destinationAddr, amountInt, gasLimit, gasPrice, nil)
+	} else {
+		if !common.IsHexAddress(contract) {
+			logger.Warn("Invalid token contract address",
+				zap.String("transfer_ref", transfer.TransferRef),
+				zap.String("contract", contract),
+			)
+			return "", executorInvalid("invalid token contract address " + contract)
+		}
+		tokenAddress := common.HexToAddress(contract)
 
-	callMsg := ethereum.CallMsg{
-		From:     sourceAddress,
-		To:       &tokenAddress,
-		GasPrice: gasPrice,
-		Data:     input,
-	}
-	gasLimit, err := client.EstimateGas(ctx, callMsg)
-	if err != nil {
-		logger.Warn("Failed to estimate gas", zap.Error(err),
-			zap.String("transfer_ref", transfer.TransferRef),
-		)
-		return "", executorInternal("failed to estimate gas", err)
-	}
+		decimals, err := erc20Decimals(ctx, rpcClient, tokenAddress)
+		if err != nil {
+			logger.Warn("Failed to read token decimals", zap.Error(err),
+				zap.String("transfer_ref", transfer.TransferRef),
+				zap.String("contract", contract),
+			)
+			return "", err
+		}
 
-	tx := types.NewTransaction(nonce, tokenAddress, big.NewInt(0), gasLimit, gasPrice, input)
+		amountInt, err := toBaseUnits(amount.Amount, decimals)
+		if err != nil {
+			logger.Warn("Failed to convert amount to base units", zap.Error(err),
+				zap.String("transfer_ref", transfer.TransferRef),
+				zap.String("amount", amount.Amount),
+			)
+			return "", err
+		}
+
+		input, err := erc20ABI.Pack("transfer", destinationAddr, amountInt)
+		if err != nil {
+			logger.Warn("Failed to encode transfer call", zap.Error(err),
+				zap.String("transfer_ref", transfer.TransferRef),
+			)
+			return "", executorInternal("failed to encode transfer call", err)
+		}
+
+		callMsg := ethereum.CallMsg{
+			From:     sourceAddress,
+			To:       &tokenAddress,
+			GasPrice: gasPrice,
+			Data:     input,
+		}
+		gasLimit, err := estimateGas(ctx, network, client, rpcClient, callMsg)
+		if err != nil {
+			logger.Warn("Failed to estimate gas", zap.Error(err),
+				zap.String("transfer_ref", transfer.TransferRef),
+			)
+			return "", executorInternal("failed to estimate gas", err)
+		}
+
+		tx = types.NewTransaction(nonce, tokenAddress, big.NewInt(0), gasLimit, gasPrice, input)
+	}
 
 	signedTx, err := deps.KeyManager.SignTransaction(ctx, source.KeyReference, tx, chainID)
 	if err != nil {
@@ -411,7 +547,7 @@ func SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Networ
 
 // AwaitConfirmation waits for the transaction receipt.
 func AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
-	logger := deps.Logger
+	logger := deps.Logger.Named("evm")
 	registry := deps.Registry
 
 	if strings.TrimSpace(txHash) == "" {
@@ -526,6 +662,63 @@ func erc20Decimals(ctx context.Context, client *rpc.Client, token common.Address
 	return val, nil
 }
 
+type gasEstimator interface {
+	EstimateGas(ctx context.Context, msg ethereum.CallMsg) (uint64, error)
+}
+
+func estimateGas(ctx context.Context, network shared.Network, client gasEstimator, rpcClient *rpc.Client, callMsg ethereum.CallMsg) (uint64, error) {
+	if isTronNetwork(network) {
+		if rpcClient == nil {
+			return 0, merrors.Internal("rpc client not initialised")
+		}
+		return estimateGasTron(ctx, rpcClient, callMsg)
+	}
+	return client.EstimateGas(ctx, callMsg)
+}
+
+func estimateGasTron(ctx context.Context, rpcClient *rpc.Client, callMsg ethereum.CallMsg) (uint64, error) {
+	call := tronEstimateCall(callMsg)
+	var hexResp string
+	if err := rpcClient.CallContext(ctx, &hexResp, "eth_estimateGas", call); err != nil {
+		return 0, err
+	}
+	val, err := shared.DecodeHexBig(hexResp)
+	if err != nil {
+		return 0, err
+	}
+	if val == nil {
+		return 0, merrors.Internal("failed to decode gas estimate")
+	}
+	return val.Uint64(), nil
+}
+
+func tronEstimateCall(callMsg ethereum.CallMsg) map[string]string {
+	call := make(map[string]string)
+	if callMsg.From != (common.Address{}) {
+		call["from"] = strings.ToLower(callMsg.From.Hex())
+	}
+	if callMsg.To != nil {
+		call["to"] = strings.ToLower(callMsg.To.Hex())
+	}
+	if callMsg.Gas > 0 {
+		call["gas"] = hexutil.EncodeUint64(callMsg.Gas)
+	}
+	if callMsg.GasPrice != nil {
+		call["gasPrice"] = hexutil.EncodeBig(callMsg.GasPrice)
+	}
+	if callMsg.Value != nil {
+		call["value"] = hexutil.EncodeBig(callMsg.Value)
+	}
+	if len(callMsg.Data) > 0 {
+		call["data"] = hexutil.Encode(callMsg.Data)
+	}
+	return call
+}
+
+func isTronNetwork(network shared.Network) bool {
+	return strings.HasPrefix(strings.ToLower(strings.TrimSpace(network.Name)), "tron")
+}
+
 func toBaseUnits(amount string, decimals uint8) (*big.Int, error) {
 	value, err := decimal.NewFromString(strings.TrimSpace(amount))
 	if err != nil {

api/gateway/chain/internal/service/gateway/driver/evm/gas_topup.go

@@ -0,0 +1,108 @@
+package evm
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/shopspring/decimal"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/merrors"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+)
+
+var evmBaseUnitFactor = decimal.NewFromInt(1_000_000_000_000_000_000)
+
+// ComputeGasTopUp applies the network policy to decide an EVM native-token top-up amount.
+func ComputeGasTopUp(network shared.Network, wallet *model.ManagedWallet, estimatedFee *moneyv1.Money, currentBalance *moneyv1.Money) (*moneyv1.Money, bool, error) {
+	if wallet == nil {
+		return nil, false, merrors.InvalidArgument("wallet is required")
+	}
+	if estimatedFee == nil || strings.TrimSpace(estimatedFee.GetAmount()) == "" || strings.TrimSpace(estimatedFee.GetCurrency()) == "" {
+		return nil, false, merrors.InvalidArgument("estimated fee is required")
+	}
+	if currentBalance == nil || strings.TrimSpace(currentBalance.GetAmount()) == "" || strings.TrimSpace(currentBalance.GetCurrency()) == "" {
+		return nil, false, merrors.InvalidArgument("current native balance is required")
+	}
+	if network.GasTopUpPolicy == nil {
+		return nil, false, merrors.InvalidArgument("gas top-up policy is not configured")
+	}
+
+	nativeCurrency := strings.TrimSpace(network.NativeToken)
+	if nativeCurrency == "" {
+		nativeCurrency = strings.ToUpper(strings.TrimSpace(network.Name))
+	}
+	if !strings.EqualFold(nativeCurrency, estimatedFee.GetCurrency()) {
+		return nil, false, merrors.InvalidArgument(fmt.Sprintf("estimated fee currency mismatch (expected %s)", nativeCurrency))
+	}
+	if !strings.EqualFold(nativeCurrency, currentBalance.GetCurrency()) {
+		return nil, false, merrors.InvalidArgument(fmt.Sprintf("native balance currency mismatch (expected %s)", nativeCurrency))
+	}
+
+	estimatedNative, err := evmToNative(estimatedFee)
+	if err != nil {
+		return nil, false, err
+	}
+	currentNative, err := evmToNative(currentBalance)
+	if err != nil {
+		return nil, false, err
+	}
+
+	isContract := strings.TrimSpace(wallet.ContractAddress) != ""
+	rule, ok := network.GasTopUpPolicy.Rule(isContract)
+	if !ok {
+		return nil, false, merrors.InvalidArgument("gas top-up policy is not configured")
+	}
+	if rule.RoundingUnit.LessThanOrEqual(decimal.Zero) {
+		return nil, false, merrors.InvalidArgument("gas top-up rounding unit must be > 0")
+	}
+	if rule.MaxTopUp.LessThanOrEqual(decimal.Zero) {
+		return nil, false, merrors.InvalidArgument("gas top-up max top-up must be > 0")
+	}
+
+	required := estimatedNative.Sub(currentNative)
+	if required.IsNegative() {
+		required = decimal.Zero
+	}
+	bufferedRequired := required.Mul(decimal.NewFromInt(1).Add(rule.BufferPercent))
+
+	minBalanceTopUp := rule.MinNativeBalance.Sub(currentNative)
+	if minBalanceTopUp.IsNegative() {
+		minBalanceTopUp = decimal.Zero
+	}
+
+	rawTopUp := bufferedRequired
+	if minBalanceTopUp.GreaterThan(rawTopUp) {
+		rawTopUp = minBalanceTopUp
+	}
+
+	roundedTopUp := decimal.Zero
+	if rawTopUp.IsPositive() {
+		roundedTopUp = rawTopUp.Div(rule.RoundingUnit).Ceil().Mul(rule.RoundingUnit)
+	}
+
+	topUp := roundedTopUp
+	capHit := false
+	if topUp.GreaterThan(rule.MaxTopUp) {
+		topUp = rule.MaxTopUp
+		capHit = true
+	}
+
+	if !topUp.IsPositive() {
+		return nil, capHit, nil
+	}
+
+	baseUnits := topUp.Mul(evmBaseUnitFactor).Ceil().Truncate(0)
+	return &moneyv1.Money{
+		Currency: strings.ToUpper(nativeCurrency),
+		Amount:   baseUnits.StringFixed(0),
+	}, capHit, nil
+}
+
+func evmToNative(amount *moneyv1.Money) (decimal.Decimal, error) {
+	value, err := decimal.NewFromString(strings.TrimSpace(amount.GetAmount()))
+	if err != nil {
+		return decimal.Zero, err
+	}
+	return value.Div(evmBaseUnitFactor), nil
+}

api/gateway/chain/internal/service/gateway/driver/evm/gas_topup_test.go

@@ -0,0 +1,146 @@
+package evm
+
+import (
+	"testing"
+
+	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/require"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+)
+
+func TestComputeGasTopUp_BalanceSufficient(t *testing.T) {
+	network := ethNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("5"), ethMoney("30"))
+	require.NoError(t, err)
+	require.Nil(t, topUp)
+	require.False(t, capHit)
+}
+
+func TestComputeGasTopUp_BufferedRequired(t *testing.T) {
+	network := ethNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("50"), ethMoney("10"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.False(t, capHit)
+	require.Equal(t, "46000000000000000000", topUp.GetAmount())
+	require.Equal(t, "ETH", topUp.GetCurrency())
+}
+
+func TestComputeGasTopUp_MinBalanceBinding(t *testing.T) {
+	network := ethNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("5"), ethMoney("1"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.False(t, capHit)
+	require.Equal(t, "19000000000000000000", topUp.GetAmount())
+}
+
+func TestComputeGasTopUp_RoundsUp(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0),
+			MinNativeBalance: decimal.NewFromFloat(0),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+	}
+	network := ethNetwork(&policy)
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("1.1"), ethMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.False(t, capHit)
+	require.Equal(t, "2000000000000000000", topUp.GetAmount())
+}
+
+func TestComputeGasTopUp_CapHit(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0),
+			MinNativeBalance: decimal.NewFromFloat(0),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(10),
+		},
+	}
+	network := ethNetwork(&policy)
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("100"), ethMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.True(t, capHit)
+	require.Equal(t, "10000000000000000000", topUp.GetAmount())
+}
+
+func TestComputeGasTopUp_MinBalanceWhenRequiredZero(t *testing.T) {
+	network := ethNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("0"), ethMoney("5"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.False(t, capHit)
+	require.Equal(t, "15000000000000000000", topUp.GetAmount())
+}
+
+func TestComputeGasTopUp_ContractPolicyOverride(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.1),
+			MinNativeBalance: decimal.NewFromFloat(10),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+		Contract: &shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.5),
+			MinNativeBalance: decimal.NewFromFloat(5),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+	}
+	network := ethNetwork(&policy)
+	wallet := &model.ManagedWallet{ContractAddress: "0xcontract"}
+
+	topUp, capHit, err := ComputeGasTopUp(network, wallet, ethMoney("10"), ethMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.False(t, capHit)
+	require.Equal(t, "15000000000000000000", topUp.GetAmount())
+}
+
+func defaultPolicy() *shared.GasTopUpPolicy {
+	return &shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.15),
+			MinNativeBalance: decimal.NewFromFloat(20),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(500),
+		},
+	}
+}
+
+func ethNetwork(policy *shared.GasTopUpPolicy) shared.Network {
+	return shared.Network{
+		Name:           "ethereum_mainnet",
+		NativeToken:    "ETH",
+		GasTopUpPolicy: policy,
+	}
+}
+
+func ethMoney(eth string) *moneyv1.Money {
+	value, _ := decimal.NewFromString(eth)
+	baseUnits := value.Mul(evmBaseUnitFactor).Truncate(0)
+	return &moneyv1.Money{
+		Currency: "ETH",
+		Amount:   baseUnits.StringFixed(0),
+	}
+}

api/gateway/chain/internal/service/gateway/driver/tron/driver.go

@@ -2,6 +2,7 @@ package tron
 
 import (
 	"context"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
@@ -40,7 +41,7 @@ func (d *Driver) NormalizeAddress(address string) (string, error) {
 	d.logger.Debug("Normalize address", zap.String("address", address))
 	normalized, err := normalizeAddress(address)
 	if err != nil {
-		d.logger.Warn("normalize address failed", zap.String("address", address), zap.Error(err))
+		d.logger.Warn("Normalize address failed", zap.String("address", address), zap.Error(err))
 	}
 	return normalized, err
 }
@@ -67,7 +68,39 @@ func (d *Driver) Balance(ctx context.Context, deps driver.Deps, network shared.N
 			zap.String("network", network.Name),
 		)
 	} else if result != nil {
-		d.logger.Debug("balance result",
+		d.logger.Debug("Balance result",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.String("amount", result.Amount),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+func (d *Driver) NativeBalance(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet) (*moneyv1.Money, error) {
+	if wallet == nil {
+		return nil, merrors.InvalidArgument("wallet is required")
+	}
+	d.logger.Debug("Native balance request", zap.String("wallet_ref", wallet.WalletRef), zap.String("network", network.Name))
+	rpcAddr, err := rpcAddress(wallet.DepositAddress)
+	if err != nil {
+		d.logger.Warn("Native balance address conversion failed", zap.Error(err),
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("address", wallet.DepositAddress),
+		)
+		return nil, err
+	}
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	result, err := evm.NativeBalance(ctx, driverDeps, network, wallet, rpcAddr)
+	if err != nil {
+		d.logger.Warn("Native balance failed", zap.Error(err),
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+		)
+	} else if result != nil {
+		d.logger.Debug("Native balance result",
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
 			zap.String("amount", result.Amount),
@@ -81,6 +114,9 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 	if wallet == nil {
 		return nil, merrors.InvalidArgument("wallet is required")
 	}
+	if amount == nil {
+		return nil, merrors.InvalidArgument("amount is required")
+	}
 	d.logger.Debug("Estimate fee request",
 		zap.String("wallet_ref", wallet.WalletRef),
 		zap.String("network", network.Name),
@@ -102,6 +138,12 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 		)
 		return nil, err
 	}
+	if rpcFrom == rpcTo {
+		return &moneyv1.Money{
+			Currency: nativeCurrency(network),
+			Amount:   "0",
+		}, nil
+	}
 	driverDeps := deps
 	driverDeps.Logger = d.logger
 	result, err := evm.EstimateFee(ctx, driverDeps, network, wallet, rpcFrom, rpcTo, amount)
@@ -109,6 +151,10 @@ func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shar
 		d.logger.Warn("Estimate fee failed", zap.Error(err),
 			zap.String("wallet_ref", wallet.WalletRef),
 			zap.String("network", network.Name),
+			zap.String("from_address", wallet.DepositAddress),
+			zap.String("from_rpc", rpcFrom),
+			zap.String("to_address", destination),
+			zap.String("to_rpc", rpcTo),
 		)
 	} else if result != nil {
 		d.logger.Debug("Estimate fee result",
@@ -150,7 +196,7 @@ func (d *Driver) SubmitTransfer(ctx context.Context, deps driver.Deps, network s
 	driverDeps.Logger = d.logger
 	txHash, err := evm.SubmitTransfer(ctx, driverDeps, network, transfer, source, rpcFrom, rpcTo)
 	if err != nil {
-		d.logger.Warn("submit transfer failed", zap.Error(err),
+		d.logger.Warn("Submit transfer failed", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 		)
@@ -188,4 +234,12 @@ func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, networ
 	return receipt, err
 }
 
+func nativeCurrency(network shared.Network) string {
+	currency := strings.ToUpper(strings.TrimSpace(network.NativeToken))
+	if currency == "" {
+		currency = strings.ToUpper(strings.TrimSpace(network.Name))
+	}
+	return currency
+}
+
 var _ driver.Driver = (*Driver)(nil)

api/gateway/chain/internal/service/gateway/driver/tron/driver_test.go

@@ -0,0 +1,33 @@
+package tron
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"go.uber.org/zap"
+)
+
+func TestEstimateFeeSelfTransferReturnsZero(t *testing.T) {
+	logger := zap.NewNop()
+	d := New(logger)
+	wallet := &model.ManagedWallet{
+		WalletRef:      "wallet_ref",
+		DepositAddress: "TGBDXEg9rxSqGFJDcb889zqTjDwx1bmLRF",
+	}
+	network := shared.Network{
+		Name:        "tron_mainnet",
+		NativeToken: "TRX",
+	}
+	amount := &moneyv1.Money{Currency: "TRX", Amount: "1000000"}
+
+	fee, err := d.EstimateFee(context.Background(), driver.Deps{}, network, wallet, wallet.DepositAddress, amount)
+	require.NoError(t, err)
+	require.NotNil(t, fee)
+	require.Equal(t, "TRX", fee.GetCurrency())
+	require.Equal(t, "0", fee.GetAmount())
+}

api/gateway/chain/internal/service/gateway/driver/tron/gas_topup.go

@@ -0,0 +1,143 @@
+package tron
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/shopspring/decimal"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/merrors"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+)
+
+var tronBaseUnitFactor = decimal.NewFromInt(1_000_000)
+
+// GasTopUpDecision captures the applied policy inputs and outputs (in TRX units).
+type GasTopUpDecision struct {
+	CurrentBalanceTRX   decimal.Decimal
+	EstimatedFeeTRX     decimal.Decimal
+	RequiredTRX         decimal.Decimal
+	BufferedRequiredTRX decimal.Decimal
+	MinBalanceTopUpTRX  decimal.Decimal
+	RawTopUpTRX         decimal.Decimal
+	RoundedTopUpTRX     decimal.Decimal
+	TopUpTRX            decimal.Decimal
+	CapHit              bool
+	OperationType       string
+}
+
+// ComputeGasTopUp applies the network policy to decide a TRX top-up amount.
+func ComputeGasTopUp(network shared.Network, wallet *model.ManagedWallet, estimatedFee *moneyv1.Money, currentBalance *moneyv1.Money) (*moneyv1.Money, GasTopUpDecision, error) {
+	decision := GasTopUpDecision{}
+	if wallet == nil {
+		return nil, decision, merrors.InvalidArgument("wallet is required")
+	}
+	if estimatedFee == nil || strings.TrimSpace(estimatedFee.GetAmount()) == "" || strings.TrimSpace(estimatedFee.GetCurrency()) == "" {
+		return nil, decision, merrors.InvalidArgument("estimated fee is required")
+	}
+	if currentBalance == nil || strings.TrimSpace(currentBalance.GetAmount()) == "" || strings.TrimSpace(currentBalance.GetCurrency()) == "" {
+		return nil, decision, merrors.InvalidArgument("current native balance is required")
+	}
+	if network.GasTopUpPolicy == nil {
+		return nil, decision, merrors.InvalidArgument("gas top-up policy is not configured")
+	}
+
+	nativeCurrency := strings.TrimSpace(network.NativeToken)
+	if nativeCurrency == "" {
+		nativeCurrency = strings.ToUpper(strings.TrimSpace(network.Name))
+	}
+	if !strings.EqualFold(nativeCurrency, estimatedFee.GetCurrency()) {
+		return nil, decision, merrors.InvalidArgument(fmt.Sprintf("estimated fee currency mismatch (expected %s)", nativeCurrency))
+	}
+	if !strings.EqualFold(nativeCurrency, currentBalance.GetCurrency()) {
+		return nil, decision, merrors.InvalidArgument(fmt.Sprintf("native balance currency mismatch (expected %s)", nativeCurrency))
+	}
+
+	estimatedTRX, err := tronToTRX(estimatedFee)
+	if err != nil {
+		return nil, decision, err
+	}
+	currentTRX, err := tronToTRX(currentBalance)
+	if err != nil {
+		return nil, decision, err
+	}
+
+	isContract := strings.TrimSpace(wallet.ContractAddress) != ""
+	rule, ok := network.GasTopUpPolicy.Rule(isContract)
+	if !ok {
+		return nil, decision, merrors.InvalidArgument("gas top-up policy is not configured")
+	}
+	if rule.RoundingUnit.LessThanOrEqual(decimal.Zero) {
+		return nil, decision, merrors.InvalidArgument("gas top-up rounding unit must be > 0")
+	}
+	if rule.MaxTopUp.LessThanOrEqual(decimal.Zero) {
+		return nil, decision, merrors.InvalidArgument("gas top-up max top-up must be > 0")
+	}
+
+	required := estimatedTRX.Sub(currentTRX)
+	if required.IsNegative() {
+		required = decimal.Zero
+	}
+	bufferedRequired := required.Mul(decimal.NewFromInt(1).Add(rule.BufferPercent))
+
+	minBalanceTopUp := rule.MinNativeBalance.Sub(currentTRX)
+	if minBalanceTopUp.IsNegative() {
+		minBalanceTopUp = decimal.Zero
+	}
+
+	rawTopUp := bufferedRequired
+	if minBalanceTopUp.GreaterThan(rawTopUp) {
+		rawTopUp = minBalanceTopUp
+	}
+
+	roundedTopUp := decimal.Zero
+	if rawTopUp.IsPositive() {
+		roundedTopUp = rawTopUp.Div(rule.RoundingUnit).Ceil().Mul(rule.RoundingUnit)
+	}
+
+	topUp := roundedTopUp
+	capHit := false
+	if topUp.GreaterThan(rule.MaxTopUp) {
+		topUp = rule.MaxTopUp
+		capHit = true
+	}
+
+	decision = GasTopUpDecision{
+		CurrentBalanceTRX:   currentTRX,
+		EstimatedFeeTRX:     estimatedTRX,
+		RequiredTRX:         required,
+		BufferedRequiredTRX: bufferedRequired,
+		MinBalanceTopUpTRX:  minBalanceTopUp,
+		RawTopUpTRX:         rawTopUp,
+		RoundedTopUpTRX:     roundedTopUp,
+		TopUpTRX:            topUp,
+		CapHit:              capHit,
+		OperationType:       operationType(isContract),
+	}
+
+	if !topUp.IsPositive() {
+		return nil, decision, nil
+	}
+
+	baseUnits := topUp.Mul(tronBaseUnitFactor).Ceil().Truncate(0)
+	return &moneyv1.Money{
+		Currency: strings.ToUpper(nativeCurrency),
+		Amount:   baseUnits.StringFixed(0),
+	}, decision, nil
+}
+
+func tronToTRX(amount *moneyv1.Money) (decimal.Decimal, error) {
+	value, err := decimal.NewFromString(strings.TrimSpace(amount.GetAmount()))
+	if err != nil {
+		return decimal.Zero, err
+	}
+	return value.Div(tronBaseUnitFactor), nil
+}
+
+func operationType(contract bool) string {
+	if contract {
+		return "trc20"
+	}
+	return "native"
+}

api/gateway/chain/internal/service/gateway/driver/tron/gas_topup_test.go

@@ -0,0 +1,147 @@
+package tron
+
+import (
+	"testing"
+
+	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/require"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+)
+
+func TestComputeGasTopUp_BalanceSufficient(t *testing.T) {
+	network := tronNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("5"), tronMoney("30"))
+	require.NoError(t, err)
+	require.Nil(t, topUp)
+	require.True(t, decision.TopUpTRX.IsZero())
+}
+
+func TestComputeGasTopUp_BufferedRequired(t *testing.T) {
+	network := tronNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("50"), tronMoney("10"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "46000000", topUp.GetAmount())
+	require.Equal(t, "TRX", topUp.GetCurrency())
+	require.Equal(t, "46", decision.TopUpTRX.String())
+}
+
+func TestComputeGasTopUp_MinBalanceBinding(t *testing.T) {
+	network := tronNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("5"), tronMoney("1"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "19000000", topUp.GetAmount())
+	require.Equal(t, "19", decision.TopUpTRX.String())
+}
+
+func TestComputeGasTopUp_RoundsUp(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0),
+			MinNativeBalance: decimal.NewFromFloat(0),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+	}
+	network := tronNetwork(&policy)
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("1.1"), tronMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "2000000", topUp.GetAmount())
+	require.Equal(t, "2", decision.TopUpTRX.String())
+}
+
+func TestComputeGasTopUp_CapHit(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0),
+			MinNativeBalance: decimal.NewFromFloat(0),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(10),
+		},
+	}
+	network := tronNetwork(&policy)
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("100"), tronMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "10000000", topUp.GetAmount())
+	require.True(t, decision.CapHit)
+}
+
+func TestComputeGasTopUp_MinBalanceWhenRequiredZero(t *testing.T) {
+	network := tronNetwork(defaultPolicy())
+	wallet := &model.ManagedWallet{}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("0"), tronMoney("5"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "15000000", topUp.GetAmount())
+	require.Equal(t, "15", decision.TopUpTRX.String())
+}
+
+func TestComputeGasTopUp_ContractPolicyOverride(t *testing.T) {
+	policy := shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.1),
+			MinNativeBalance: decimal.NewFromFloat(10),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+		Contract: &shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.5),
+			MinNativeBalance: decimal.NewFromFloat(5),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(100),
+		},
+	}
+	network := tronNetwork(&policy)
+	wallet := &model.ManagedWallet{ContractAddress: "0xcontract"}
+
+	topUp, decision, err := ComputeGasTopUp(network, wallet, tronMoney("10"), tronMoney("0"))
+	require.NoError(t, err)
+	require.NotNil(t, topUp)
+	require.Equal(t, "15000000", topUp.GetAmount())
+	require.Equal(t, "15", decision.TopUpTRX.String())
+	require.Equal(t, "trc20", decision.OperationType)
+}
+
+func defaultPolicy() *shared.GasTopUpPolicy {
+	return &shared.GasTopUpPolicy{
+		Default: shared.GasTopUpRule{
+			BufferPercent:    decimal.NewFromFloat(0.15),
+			MinNativeBalance: decimal.NewFromFloat(20),
+			RoundingUnit:     decimal.NewFromFloat(1),
+			MaxTopUp:         decimal.NewFromFloat(500),
+		},
+	}
+}
+
+func tronNetwork(policy *shared.GasTopUpPolicy) shared.Network {
+	return shared.Network{
+		Name:           "tron_mainnet",
+		NativeToken:    "TRX",
+		GasTopUpPolicy: policy,
+	}
+}
+
+func tronMoney(trx string) *moneyv1.Money {
+	value, _ := decimal.NewFromString(trx)
+	baseUnits := value.Mul(tronBaseUnitFactor).Truncate(0)
+	return &moneyv1.Money{
+		Currency: "TRX",
+		Amount:   baseUnits.StringFixed(0),
+	}
+}

api/gateway/chain/internal/service/gateway/drivers/registry.go

@@ -32,7 +32,7 @@ func NewRegistry(logger mlogger.Logger, networks []shared.Network) (*Registry, e
 		}
 		chainDriver, err := resolveDriver(logger, name)
 		if err != nil {
-			logger.Error("unsupported chain driver", zap.String("network", name), zap.Error(err))
+			logger.Error("Unsupported chain driver", zap.String("network", name), zap.Error(err))
 			return nil, err
 		}
 		result.byNetwork[name] = chainDriver
@@ -40,7 +40,7 @@ func NewRegistry(logger mlogger.Logger, networks []shared.Network) (*Registry, e
 	if len(result.byNetwork) == 0 {
 		return nil, merrors.InvalidArgument("driver registry: no supported networks configured")
 	}
-	logger.Info("chain drivers configured", zap.Int("count", len(result.byNetwork)))
+	logger.Info("Chain drivers configured", zap.Int("count", len(result.byNetwork)))
 	return result, nil
 }
 

api/gateway/chain/internal/service/gateway/executor.go

@@ -47,32 +47,32 @@ type onChainExecutor struct {
 
 func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Transfer, source *model.ManagedWallet, destinationAddress string, network shared.Network) (string, error) {
 	if o.keyManager == nil {
-		o.logger.Warn("key manager not configured")
+		o.logger.Warn("Key manager not configured")
 		return "", executorInternal("key manager is not configured", nil)
 	}
 	rpcURL := strings.TrimSpace(network.RPCURL)
 	if rpcURL == "" {
-		o.logger.Warn("network rpc url missing", zap.String("network", network.Name))
+		o.logger.Warn("Network rpc url missing", zap.String("network", network.Name))
 		return "", executorInvalid("network rpc url is not configured")
 	}
 	if source == nil || transfer == nil {
-		o.logger.Warn("transfer context missing")
+		o.logger.Warn("Transfer context missing")
 		return "", executorInvalid("transfer context missing")
 	}
 	if strings.TrimSpace(source.KeyReference) == "" {
-		o.logger.Warn("source wallet missing key reference", zap.String("wallet_ref", source.WalletRef))
+		o.logger.Warn("Source wallet missing key reference", zap.String("wallet_ref", source.WalletRef))
 		return "", executorInvalid("source wallet missing key reference")
 	}
 	if strings.TrimSpace(source.DepositAddress) == "" {
-		o.logger.Warn("source wallet missing deposit address", zap.String("wallet_ref", source.WalletRef))
+		o.logger.Warn("Source wallet missing deposit address", zap.String("wallet_ref", source.WalletRef))
 		return "", executorInvalid("source wallet missing deposit address")
 	}
 	if !common.IsHexAddress(destinationAddress) {
-		o.logger.Warn("invalid destination address", zap.String("transfer_ref", transfer.TransferRef), zap.String("address", destinationAddress))
+		o.logger.Warn("Invalid destination address", zap.String("transfer_ref", transfer.TransferRef), zap.String("address", destinationAddress))
 		return "", executorInvalid("invalid destination address " + destinationAddress)
 	}
 
-	o.logger.Info("submitting transfer",
+	o.logger.Info("Submitting transfer",
 		zap.String("transfer_ref", transfer.TransferRef),
 		zap.String("source_wallet_ref", source.WalletRef),
 		zap.String("network", network.Name),
@@ -81,12 +81,12 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	client, err := o.clients.Client(network.Name)
 	if err != nil {
-		o.logger.Warn("failed to initialise rpc client", zap.Error(err), zap.String("network", network.Name))
+		o.logger.Warn("Failed to initialise RPC client", zap.Error(err), zap.String("network", network.Name))
 		return "", err
 	}
 	rpcClient, err := o.clients.RPCClient(network.Name)
 	if err != nil {
-		o.logger.Warn("failed to initialise rpc client",
+		o.logger.Warn("Failed to initialise RPC client",
 			zap.String("network", network.Name),
 			zap.Error(err),
 		)
@@ -101,7 +101,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	nonce, err := client.PendingNonceAt(ctx, sourceAddress)
 	if err != nil {
-		o.logger.Warn("failed to fetch nonce", zap.Error(err),
+		o.logger.Warn("Failed to fetch nonce", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("wallet_ref", source.WalletRef),
 		)
@@ -110,7 +110,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	gasPrice, err := client.SuggestGasPrice(ctx)
 	if err != nil {
-		o.logger.Warn("failed to suggest gas price",
+		o.logger.Warn("Failed to suggest gas price",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("network", network.Name),
 			zap.Error(err),
@@ -124,12 +124,12 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 	chainID := new(big.Int).SetUint64(network.ChainID)
 
 	if strings.TrimSpace(transfer.ContractAddress) == "" {
-		o.logger.Warn("native token transfer requested but not supported", zap.String("transfer_ref", transfer.TransferRef))
+		o.logger.Warn("Native token transfer requested but not supported", zap.String("transfer_ref", transfer.TransferRef))
 		return "", merrors.NotImplemented("executor: native token transfers not yet supported")
 	}
 
 	if !common.IsHexAddress(transfer.ContractAddress) {
-		o.logger.Warn("invalid token contract address",
+		o.logger.Warn("Invalid token contract address",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("contract", transfer.ContractAddress),
 		)
@@ -139,7 +139,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	decimals, err := erc20Decimals(ctx, rpcClient, tokenAddress)
 	if err != nil {
-		o.logger.Warn("failed to read token decimals", zap.Error(err),
+		o.logger.Warn("Failed to read token decimals", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("contract", transfer.ContractAddress),
 		)
@@ -148,12 +148,12 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	amount := transfer.NetAmount
 	if amount == nil || strings.TrimSpace(amount.Amount) == "" {
-		o.logger.Warn("transfer missing net amount", zap.String("transfer_ref", transfer.TransferRef))
+		o.logger.Warn("Transfer missing net amount", zap.String("transfer_ref", transfer.TransferRef))
 		return "", executorInvalid("transfer missing net amount")
 	}
 	amountInt, err := toBaseUnits(amount.Amount, decimals)
 	if err != nil {
-		o.logger.Warn("failed to convert amount to base units", zap.Error(err),
+		o.logger.Warn("Failed to convert amount to base units", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("amount", amount.Amount),
 		)
@@ -162,7 +162,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	input, err := erc20ABI.Pack("transfer", destination, amountInt)
 	if err != nil {
-		o.logger.Warn("failed to encode transfer call",
+		o.logger.Warn("Failed to encode transfer call",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.Error(err),
 		)
@@ -177,7 +177,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 	}
 	gasLimit, err := client.EstimateGas(ctx, callMsg)
 	if err != nil {
-		o.logger.Warn("failed to estimate gas",
+		o.logger.Warn("Failed to estimate gas",
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.Error(err),
 		)
@@ -188,7 +188,7 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 	signedTx, err := o.keyManager.SignTransaction(ctx, source.KeyReference, tx, chainID)
 	if err != nil {
-		o.logger.Warn("failed to sign transaction", zap.Error(err),
+		o.logger.Warn("Failed to sign transaction", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("wallet_ref", source.WalletRef),
 		)
@@ -196,14 +196,14 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 	}
 
 	if err := client.SendTransaction(ctx, signedTx); err != nil {
-		o.logger.Warn("failed to send transaction", zap.Error(err),
+		o.logger.Warn("Failed to send transaction", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 		)
 		return "", executorInternal("failed to send transaction", err)
 	}
 
 	txHash = signedTx.Hash().Hex()
-	o.logger.Info("transaction submitted",
+	o.logger.Info("Transaction submitted",
 		zap.String("transfer_ref", transfer.TransferRef),
 		zap.String("tx_hash", txHash),
 		zap.String("network", network.Name),
@@ -214,12 +214,12 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 
 func (o *onChainExecutor) AwaitConfirmation(ctx context.Context, network shared.Network, txHash string) (*types.Receipt, error) {
 	if strings.TrimSpace(txHash) == "" {
-		o.logger.Warn("missing transaction hash for confirmation", zap.String("network", network.Name))
+		o.logger.Warn("Missing transaction hash for confirmation", zap.String("network", network.Name))
 		return nil, executorInvalid("tx hash is required")
 	}
 	rpcURL := strings.TrimSpace(network.RPCURL)
 	if rpcURL == "" {
-		o.logger.Warn("network rpc url missing while awaiting confirmation", zap.String("tx_hash", txHash))
+		o.logger.Warn("Network RPC url missing while awaiting confirmation", zap.String("tx_hash", txHash))
 		return nil, executorInvalid("network rpc url is not configured")
 	}
 
@@ -238,27 +238,27 @@ func (o *onChainExecutor) AwaitConfirmation(ctx context.Context, network shared.
 			if errors.Is(err, ethereum.NotFound) {
 				select {
 				case <-ticker.C:
-					o.logger.Debug("transaction not yet mined",
+					o.logger.Debug("Transaction not yet mined",
 						zap.String("tx_hash", txHash),
 						zap.String("network", network.Name),
 					)
 					continue
 				case <-ctx.Done():
-					o.logger.Warn("context cancelled while awaiting confirmation",
+					o.logger.Warn("Context cancelled while awaiting confirmation",
 						zap.String("tx_hash", txHash),
 						zap.String("network", network.Name),
 					)
 					return nil, ctx.Err()
 				}
 			}
-			o.logger.Warn("failed to fetch transaction receipt",
+			o.logger.Warn("Failed to fetch transaction receipt",
 				zap.String("tx_hash", txHash),
 				zap.String("network", network.Name),
 				zap.Error(err),
 			)
 			return nil, executorInternal("failed to fetch transaction receipt", err)
 		}
-		o.logger.Info("transaction confirmed",
+		o.logger.Info("Transaction confirmed",
 			zap.String("tx_hash", txHash),
 			zap.String("network", network.Name),
 			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),

api/gateway/chain/internal/service/gateway/rpcclient/clients.go

@@ -2,6 +2,7 @@ package rpcclient
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -48,14 +49,14 @@ func Prepare(ctx context.Context, logger mlogger.Logger, networks []shared.Netwo
 		if rpcURL == "" {
 			result.Close()
 			err := merrors.InvalidArgument(fmt.Sprintf("rpc url not configured for network %s", name))
-			clientLogger.Warn("rpc url missing", zap.String("network", name))
+			clientLogger.Warn("Rpc url missing", zap.String("network", name))
 			return nil, err
 		}
 
 		fields := []zap.Field{
 			zap.String("network", name),
 		}
-		clientLogger.Info("initialising rpc client", fields...)
+		clientLogger.Info("Initialising rpc client", fields...)
 
 		dialCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
 		httpClient := &http.Client{
@@ -70,7 +71,7 @@ func Prepare(ctx context.Context, logger mlogger.Logger, networks []shared.Netwo
 		cancel()
 		if err != nil {
 			result.Close()
-			clientLogger.Warn("failed to dial rpc endpoint", append(fields, zap.Error(err))...)
+			clientLogger.Warn("Failed to dial rpc endpoint", append(fields, zap.Error(err))...)
 			return nil, merrors.Internal(fmt.Sprintf("rpc dial failed for %s: %s", name, err.Error()))
 		}
 		client := ethclient.NewClient(rpcCli)
@@ -78,7 +79,7 @@ func Prepare(ctx context.Context, logger mlogger.Logger, networks []shared.Netwo
 			eth: client,
 			rpc: rpcCli,
 		}
-		clientLogger.Info("rpc client ready", fields...)
+		clientLogger.Info("RPC client ready", fields...)
 	}
 
 	if len(result.clients) == 0 {
@@ -94,12 +95,12 @@ func Prepare(ctx context.Context, logger mlogger.Logger, networks []shared.Netwo
 // Client returns a prepared client for the given network name.
 func (c *Clients) Client(network string) (*ethclient.Client, error) {
 	if c == nil {
-		return nil, merrors.Internal("rpc clients not initialised")
+		return nil, merrors.Internal("RPC clients not initialised")
 	}
 	name := strings.ToLower(strings.TrimSpace(network))
 	entry, ok := c.clients[name]
 	if !ok || entry.eth == nil {
-		return nil, merrors.InvalidArgument(fmt.Sprintf("rpc client not configured for network %s", name))
+		return nil, merrors.InvalidArgument(fmt.Sprintf("RPC client not configured for network %s", name))
 	}
 	return entry.eth, nil
 }
@@ -129,7 +130,7 @@ func (c *Clients) Close() {
 			entry.eth.Close()
 		}
 		if c.logger != nil {
-			c.logger.Info("rpc client closed", zap.String("network", name))
+			c.logger.Info("RPC client closed", zap.String("network", name))
 		}
 	}
 }
@@ -155,16 +156,15 @@ func (l *loggingRoundTripper) RoundTrip(req *http.Request) (*http.Response, erro
 
 	fields := []zap.Field{
 		zap.String("network", l.network),
-		zap.String("rpc_endpoint", l.endpoint),
 	}
 	if len(reqBody) > 0 {
 		fields = append(fields, zap.String("rpc_request", truncate(string(reqBody), 2048)))
 	}
-	l.logger.Debug("rpc request", fields...)
+	l.logger.Debug("RPC request", fields...)
 
 	resp, err := l.base.RoundTrip(req)
 	if err != nil {
-		l.logger.Warn("rpc http request failed", append(fields, zap.Error(err))...)
+		l.logger.Warn("RPC http request failed", append(fields, zap.Error(err))...)
 		return nil, err
 	}
 
@@ -175,11 +175,19 @@ func (l *loggingRoundTripper) RoundTrip(req *http.Request) (*http.Response, erro
 	respFields := append(fields,
 		zap.Int("status_code", resp.StatusCode),
 	)
+	if contentType := strings.TrimSpace(resp.Header.Get("Content-Type")); contentType != "" {
+		respFields = append(respFields, zap.String("content_type", contentType))
+	}
 	if len(bodyBytes) > 0 {
 		respFields = append(respFields, zap.String("rpc_response", truncate(string(bodyBytes), 2048)))
 	}
+	l.logger.Debug("RPC response", respFields...)
 	if resp.StatusCode >= 400 {
 		l.logger.Warn("RPC response error", respFields...)
+	} else if len(bodyBytes) == 0 {
+		l.logger.Warn("RPC response empty body", respFields...)
+	} else if len(bodyBytes) > 0 && !json.Valid(bodyBytes) {
+		l.logger.Warn("RPC response invalid JSON", respFields...)
 	}
 
 	return resp, nil

api/gateway/chain/internal/service/gateway/service.go

@@ -126,6 +126,14 @@ func (s *Service) EstimateTransferFee(ctx context.Context, req *chainv1.Estimate
 	return executeUnary(ctx, s, "EstimateTransferFee", s.commands.EstimateTransfer.Execute, req)
 }
 
+func (s *Service) ComputeGasTopUp(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error) {
+	return executeUnary(ctx, s, "ComputeGasTopUp", s.commands.ComputeGasTopUp.Execute, req)
+}
+
+func (s *Service) EnsureGasTopUp(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error) {
+	return executeUnary(ctx, s, "EnsureGasTopUp", s.commands.EnsureGasTopUp.Execute, req)
+}
+
 func (s *Service) ensureRepository(ctx context.Context) error {
 	if s.storage == nil {
 		return errStorageUnavailable

api/gateway/chain/internal/service/gateway/service_test.go

@@ -66,6 +66,25 @@ func TestCreateManagedWallet_Idempotent(t *testing.T) {
 	require.Equal(t, 1, repo.wallets.count())
 }
 
+func TestCreateManagedWallet_NativeTokenWithoutContract(t *testing.T) {
+	svc, _ := newTestService(t)
+	ctx := context.Background()
+
+	resp, err := svc.CreateManagedWallet(ctx, &ichainv1.CreateManagedWalletRequest{
+		IdempotencyKey:  "idem-native",
+		OrganizationRef: "org-1",
+		OwnerRef:        "owner-1",
+		Asset: &ichainv1.Asset{
+			Chain:       ichainv1.ChainNetwork_CHAIN_NETWORK_ETHEREUM_MAINNET,
+			TokenSymbol: "ETH",
+		},
+	})
+	require.NoError(t, err)
+	require.NotNil(t, resp.GetWallet())
+	require.Equal(t, "ETH", resp.GetWallet().GetAsset().GetTokenSymbol())
+	require.Empty(t, resp.GetWallet().GetAsset().GetContractAddress())
+}
+
 func TestSubmitTransfer_ManagedDestination(t *testing.T) {
 	svc, repo := newTestService(t)
 	ctx := context.Background()
@@ -144,6 +163,37 @@ func TestGetWalletBalance_NotFound(t *testing.T) {
 	require.Equal(t, codes.NotFound, st.Code())
 }
 
+func TestGetWalletBalance_ReturnsCachedNativeAvailable(t *testing.T) {
+	svc, repo := newTestService(t)
+	ctx := context.Background()
+
+	createResp, err := svc.CreateManagedWallet(ctx, &ichainv1.CreateManagedWalletRequest{
+		IdempotencyKey:  "idem-balance",
+		OrganizationRef: "org-1",
+		OwnerRef:        "owner-1",
+		Asset: &ichainv1.Asset{
+			Chain:       ichainv1.ChainNetwork_CHAIN_NETWORK_ETHEREUM_MAINNET,
+			TokenSymbol: "USDC",
+		},
+	})
+	require.NoError(t, err)
+	walletRef := createResp.GetWallet().GetWalletRef()
+
+	err = repo.wallets.SaveBalance(ctx, &model.WalletBalance{
+		WalletRef:       walletRef,
+		Available:       &moneyv1.Money{Currency: "USDC", Amount: "25"},
+		NativeAvailable: &moneyv1.Money{Currency: "ETH", Amount: "0.5"},
+		CalculatedAt:    time.Now().UTC(),
+	})
+	require.NoError(t, err)
+
+	resp, err := svc.GetWalletBalance(ctx, &ichainv1.GetWalletBalanceRequest{WalletRef: walletRef})
+	require.NoError(t, err)
+	require.NotNil(t, resp.GetBalance())
+	require.Equal(t, "0.5", resp.GetBalance().GetNativeAvailable().GetAmount())
+	require.Equal(t, "ETH", resp.GetBalance().GetNativeAvailable().GetCurrency())
+}
+
 // ---- in-memory storage implementation ----
 
 type inMemoryRepository struct {
@@ -531,7 +581,8 @@ func newTestService(t *testing.T) (*Service, *inMemoryRepository) {
 	repo := newInMemoryRepository()
 	logger := zap.NewNop()
 	networks := []shared.Network{{
-		Name: "ethereum_mainnet",
+		Name:        "ethereum_mainnet",
+		NativeToken: "ETH",
 		TokenConfigs: []shared.TokenContract{
 			{Symbol: "USDC", ContractAddress: "0xusdc"},
 		},

api/gateway/chain/internal/service/gateway/shared/gas_topup.go

@@ -0,0 +1,32 @@
+package shared
+
+import "github.com/shopspring/decimal"
+
+// GasTopUpRule defines buffer, minimum, rounding, and cap behavior for native gas top-ups.
+type GasTopUpRule struct {
+	BufferPercent    decimal.Decimal
+	MinNativeBalance decimal.Decimal
+	RoundingUnit     decimal.Decimal
+	MaxTopUp         decimal.Decimal
+}
+
+// GasTopUpPolicy captures default and optional overrides for native vs contract transfers.
+type GasTopUpPolicy struct {
+	Default  GasTopUpRule
+	Native   *GasTopUpRule
+	Contract *GasTopUpRule
+}
+
+// Rule selects the policy rule for the transfer type.
+func (p *GasTopUpPolicy) Rule(contractTransfer bool) (GasTopUpRule, bool) {
+	if p == nil {
+		return GasTopUpRule{}, false
+	}
+	if contractTransfer && p.Contract != nil {
+		return *p.Contract, true
+	}
+	if !contractTransfer && p.Native != nil {
+		return *p.Native, true
+	}
+	return p.Default, true
+}

api/gateway/chain/internal/service/gateway/shared/helpers.go

@@ -119,13 +119,23 @@ func TransferStatusToProto(status model.TransferStatus) chainv1.TransferStatus {
 	}
 }
 
+// NativeCurrency returns the canonical native token symbol for a network.
+func NativeCurrency(network Network) string {
+	currency := strings.ToUpper(strings.TrimSpace(network.NativeToken))
+	if currency == "" {
+		currency = strings.ToUpper(strings.TrimSpace(network.Name))
+	}
+	return currency
+}
+
 // Network describes a supported blockchain network and known token contracts.
 type Network struct {
-	Name         string
-	RPCURL       string
-	ChainID      uint64
-	NativeToken  string
-	TokenConfigs []TokenContract
+	Name           string
+	RPCURL         string
+	ChainID        uint64
+	NativeToken    string
+	TokenConfigs   []TokenContract
+	GasTopUpPolicy *GasTopUpPolicy
 }
 
 // TokenContract captures the metadata needed to work with a specific on-chain token.

api/gateway/chain/internal/service/gateway/transfer_execution.go

@@ -24,7 +24,7 @@ func (s *Service) launchTransferExecution(transferRef, sourceWalletRef string, n
 		defer cancel()
 
 		if err := s.executeTransfer(ctx, ref, walletRef, net); err != nil {
-			s.logger.Warn("failed to execute transfer", zap.String("transfer_ref", ref), zap.Error(err))
+			s.logger.Warn("Failed to execute transfer", zap.String("transfer_ref", ref), zap.Error(err))
 		}
 	}(transferRef, sourceWalletRef, network)
 }
@@ -41,7 +41,7 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 	}
 
 	if _, err := s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusSigning, "", ""); err != nil {
-		s.logger.Warn("failed to update transfer status to signing", zap.String("transfer_ref", transferRef), zap.Error(err))
+		s.logger.Warn("Failed to update transfer status to signing", zap.String("transfer_ref", transferRef), zap.Error(err))
 	}
 
 	driverDeps := s.driverDeps()
@@ -57,6 +57,23 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 		return err
 	}
 
+	sourceAddress, err := chainDriver.NormalizeAddress(sourceWallet.DepositAddress)
+	if err != nil {
+		_, _ = s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusFailed, err.Error(), "")
+		return err
+	}
+	if chainDriver.Name() == "tron" && sourceAddress == destinationAddress {
+		s.logger.Info("Self transfer detected; skipping submission",
+			zap.String("transfer_ref", transferRef),
+			zap.String("wallet_ref", sourceWalletRef),
+			zap.String("network", network.Name),
+		)
+		if _, err := s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusConfirmed, "", ""); err != nil {
+			s.logger.Warn("Failed to update transfer status to confirmed", zap.String("transfer_ref", transferRef), zap.Error(err))
+		}
+		return nil
+	}
+
 	txHash, err := chainDriver.SubmitTransfer(ctx, driverDeps, network, transfer, sourceWallet, destinationAddress)
 	if err != nil {
 		_, _ = s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusFailed, err.Error(), "")
@@ -64,7 +81,7 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 	}
 
 	if _, err := s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusSubmitted, "", txHash); err != nil {
-		s.logger.Warn("failed to update transfer status to submitted", zap.String("transfer_ref", transferRef), zap.Error(err))
+		s.logger.Warn("Failed to update transfer status to submitted", zap.String("transfer_ref", transferRef), zap.Error(err))
 	}
 
 	receiptCtx, cancel := context.WithTimeout(ctx, 10*time.Minute)
@@ -72,20 +89,20 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 	receipt, err := chainDriver.AwaitConfirmation(receiptCtx, driverDeps, network, txHash)
 	if err != nil {
 		if !errors.Is(err, context.DeadlineExceeded) && !errors.Is(err, context.Canceled) {
-			s.logger.Warn("failed to await transfer confirmation", zap.String("transfer_ref", transferRef), zap.Error(err))
+			s.logger.Warn("Failed to await transfer confirmation", zap.String("transfer_ref", transferRef), zap.Error(err))
 		}
 		return err
 	}
 
 	if receipt != nil && receipt.Status == types.ReceiptStatusSuccessful {
 		if _, err := s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusConfirmed, "", txHash); err != nil {
-			s.logger.Warn("failed to update transfer status to confirmed", zap.String("transfer_ref", transferRef), zap.Error(err))
+			s.logger.Warn("Failed to update transfer status to confirmed", zap.String("transfer_ref", transferRef), zap.Error(err))
 		}
 		return nil
 	}
 
 	if _, err := s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusFailed, "transaction reverted", txHash); err != nil {
-		s.logger.Warn("failed to update transfer status to failed", zap.String("transfer_ref", transferRef), zap.Error(err))
+		s.logger.Warn("Failed to update transfer status to failed", zap.String("transfer_ref", transferRef), zap.Error(err))
 	}
 	return nil
 }

api/gateway/chain/storage/model/transfer.go

@@ -28,9 +28,10 @@ type ServiceFee struct {
 }
 
 type TransferDestination struct {
-	ManagedWalletRef string `bson:"managedWalletRef,omitempty" json:"managedWalletRef,omitempty"`
-	ExternalAddress  string `bson:"externalAddress,omitempty" json:"externalAddress,omitempty"`
-	Memo             string `bson:"memo,omitempty" json:"memo,omitempty"`
+	ManagedWalletRef        string `bson:"managedWalletRef,omitempty" json:"managedWalletRef,omitempty"`
+	ExternalAddress         string `bson:"externalAddress,omitempty" json:"externalAddress,omitempty"`
+	ExternalAddressOriginal string `bson:"externalAddressOriginal,omitempty" json:"externalAddressOriginal,omitempty"`
+	Memo                    string `bson:"memo,omitempty" json:"memo,omitempty"`
 }
 
 // Transfer models an on-chain transfer orchestrated by the gateway.
@@ -85,7 +86,8 @@ func (t *Transfer) Normalize() {
 	t.TokenSymbol = strings.TrimSpace(strings.ToUpper(t.TokenSymbol))
 	t.ContractAddress = strings.TrimSpace(strings.ToLower(t.ContractAddress))
 	t.Destination.ManagedWalletRef = strings.TrimSpace(t.Destination.ManagedWalletRef)
-	t.Destination.ExternalAddress = strings.TrimSpace(strings.ToLower(t.Destination.ExternalAddress))
+	t.Destination.ExternalAddress = normalizeWalletAddress(t.Destination.ExternalAddress)
+	t.Destination.ExternalAddressOriginal = strings.TrimSpace(t.Destination.ExternalAddressOriginal)
 	t.Destination.Memo = strings.TrimSpace(t.Destination.Memo)
 	t.ClientReference = strings.TrimSpace(t.ClientReference)
 }

api/gateway/chain/storage/model/transfer_test.go

@@ -0,0 +1,50 @@
+package model
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestTransferNormalizePreservesBase58ExternalAddress(t *testing.T) {
+	address := "TGBDXEg9rxSqGFJDcb889zqTjDwx1bmLRF"
+	transfer := &Transfer{
+		IdempotencyKey:  "idemp",
+		TransferRef:     "ref",
+		OrganizationRef: "org",
+		SourceWalletRef: "wallet",
+		Network:         "tron_mainnet",
+		TokenSymbol:     "USDT",
+		Destination: TransferDestination{
+			ExternalAddress:         address,
+			ExternalAddressOriginal: address,
+		},
+	}
+
+	transfer.Normalize()
+
+	if transfer.Destination.ExternalAddress != address {
+		t.Fatalf("expected external address to preserve case, got %q", transfer.Destination.ExternalAddress)
+	}
+	if transfer.Destination.ExternalAddressOriginal != address {
+		t.Fatalf("expected external address original to preserve case, got %q", transfer.Destination.ExternalAddressOriginal)
+	}
+}
+
+func TestTransferNormalizeLowercasesHexExternalAddress(t *testing.T) {
+	address := "0xAABBCCDDEEFF00112233445566778899AABBCCDD"
+	transfer := &Transfer{
+		Destination: TransferDestination{
+			ExternalAddress:         address,
+			ExternalAddressOriginal: address,
+		},
+	}
+
+	transfer.Normalize()
+
+	if transfer.Destination.ExternalAddress != strings.ToLower(address) {
+		t.Fatalf("expected hex external address to be lowercased, got %q", transfer.Destination.ExternalAddress)
+	}
+	if transfer.Destination.ExternalAddressOriginal != address {
+		t.Fatalf("expected external address original to preserve case, got %q", transfer.Destination.ExternalAddressOriginal)
+	}
+}

api/gateway/chain/storage/model/wallet.go

@@ -47,6 +47,7 @@ type WalletBalance struct {
 
 	WalletRef       string         `bson:"walletRef" json:"walletRef"`
 	Available       *moneyv1.Money `bson:"available" json:"available"`
+	NativeAvailable *moneyv1.Money `bson:"nativeAvailable,omitempty" json:"nativeAvailable,omitempty"`
 	PendingInbound  *moneyv1.Money `bson:"pendingInbound,omitempty" json:"pendingInbound,omitempty"`
 	PendingOutbound *moneyv1.Money `bson:"pendingOutbound,omitempty" json:"pendingOutbound,omitempty"`
 	CalculatedAt    time.Time      `bson:"calculatedAt" json:"calculatedAt"`

api/gateway/chain/storage/mongo/repository.go

@@ -44,23 +44,23 @@ func New(logger mlogger.Logger, conn *db.MongoConnection) (*Store, error) {
 	defer cancel()
 
 	if err := result.Ping(ctx); err != nil {
-		result.logger.Error("mongo ping failed during repository initialisation", zap.Error(err))
+		result.logger.Error("Mongo ping failed during repository initialisation", zap.Error(err))
 		return nil, err
 	}
 
 	walletsStore, err := store.NewWallets(result.logger, result.db)
 	if err != nil {
-		result.logger.Error("failed to initialise wallets store", zap.Error(err))
+		result.logger.Error("Failed to initialise wallets store", zap.Error(err))
 		return nil, err
 	}
 	transfersStore, err := store.NewTransfers(result.logger, result.db)
 	if err != nil {
-		result.logger.Error("failed to initialise transfers store", zap.Error(err))
+		result.logger.Error("Failed to initialise transfers store", zap.Error(err))
 		return nil, err
 	}
 	depositsStore, err := store.NewDeposits(result.logger, result.db)
 	if err != nil {
-		result.logger.Error("failed to initialise deposits store", zap.Error(err))
+		result.logger.Error("Failed to initialise deposits store", zap.Error(err))
 		return nil, err
 	}
 

api/gateway/chain/storage/mongo/store/deposits.go

@@ -48,13 +48,13 @@ func NewDeposits(logger mlogger.Logger, db *mongo.Database) (*Deposits, error) {
 	}
 	for _, def := range indexes {
 		if err := repo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure deposit index", zap.Error(err), zap.String("collection", repo.Collection()))
+			logger.Error("Failed to ensure deposit index", zap.Error(err), zap.String("collection", repo.Collection()))
 			return nil, err
 		}
 	}
 
 	childLogger := logger.Named("deposits")
-	childLogger.Debug("deposits store initialised")
+	childLogger.Debug("Deposits store initialised")
 
 	return &Deposits{logger: childLogger, repo: repo}, nil
 }

api/gateway/chain/storage/mongo/store/transfers.go

@@ -53,13 +53,13 @@ func NewTransfers(logger mlogger.Logger, db *mongo.Database) (*Transfers, error)
 	}
 	for _, def := range indexes {
 		if err := repo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure transfer index", zap.Error(err), zap.String("collection", repo.Collection()))
+			logger.Error("Failed to ensure transfer index", zap.Error(err), zap.String("collection", repo.Collection()))
 			return nil, err
 		}
 	}
 
 	childLogger := logger.Named("transfers")
-	childLogger.Debug("transfers store initialised")
+	childLogger.Debug("Transfers store initialised")
 
 	return &Transfers{
 		logger: childLogger,
@@ -89,12 +89,12 @@ func (t *Transfers) Create(ctx context.Context, transfer *model.Transfer) (*mode
 	}
 	if err := t.repo.Insert(ctx, transfer, repository.Filter("idempotencyKey", transfer.IdempotencyKey)); err != nil {
 		if errors.Is(err, merrors.ErrDataConflict) {
-			t.logger.Debug("transfer already exists", zap.String("transfer_ref", transfer.TransferRef), zap.String("idempotency_key", transfer.IdempotencyKey))
+			t.logger.Debug("Transfer already exists", zap.String("transfer_ref", transfer.TransferRef), zap.String("idempotency_key", transfer.IdempotencyKey))
 			return transfer, nil
 		}
 		return nil, err
 	}
-	t.logger.Debug("transfer created", zap.String("transfer_ref", transfer.TransferRef))
+	t.logger.Debug("Transfer created", zap.String("transfer_ref", transfer.TransferRef))
 	return transfer, nil
 }
 
@@ -126,7 +126,7 @@ func (t *Transfers) List(ctx context.Context, filter model.TransferFilter) (*mod
 		if oid, err := primitive.ObjectIDFromHex(cursor); err == nil {
 			query = query.Comparison(repository.IDField(), builder.Gt, oid)
 		} else {
-			t.logger.Warn("ignoring invalid transfer cursor", zap.String("cursor", cursor), zap.Error(err))
+			t.logger.Warn("Ignoring invalid transfer cursor", zap.String("cursor", cursor), zap.Error(err))
 		}
 	}
 

api/gateway/chain/storage/mongo/store/wallets.go

@@ -56,7 +56,7 @@ func NewWallets(logger mlogger.Logger, db *mongo.Database) (*Wallets, error) {
 	}
 	for _, def := range walletIndexes {
 		if err := walletRepo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure wallet index", zap.String("collection", walletRepo.Collection()), zap.Error(err))
+			logger.Error("Failed to ensure wallet index", zap.String("collection", walletRepo.Collection()), zap.Error(err))
 			return nil, err
 		}
 	}
@@ -70,13 +70,13 @@ func NewWallets(logger mlogger.Logger, db *mongo.Database) (*Wallets, error) {
 	}
 	for _, def := range balanceIndexes {
 		if err := balanceRepo.CreateIndex(def); err != nil {
-			logger.Error("failed to ensure wallet balance index", zap.String("collection", balanceRepo.Collection()), zap.Error(err))
+			logger.Error("Failed to ensure wallet balance index", zap.String("collection", balanceRepo.Collection()), zap.Error(err))
 			return nil, err
 		}
 	}
 
 	childLogger := logger.Named("wallets")
-	childLogger.Debug("wallet stores initialised")
+	childLogger.Debug("Wallet stores initialised")
 
 	return &Wallets{
 		logger:      childLogger,
@@ -99,24 +99,49 @@ func (w *Wallets) Create(ctx context.Context, wallet *model.ManagedWallet) (*mod
 	if strings.TrimSpace(wallet.IdempotencyKey) == "" {
 		return nil, merrors.InvalidArgument("walletsStore: empty idempotencyKey")
 	}
+	fields := []zap.Field{
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("idempotency_key", wallet.IdempotencyKey),
+	}
+	if wallet.OrganizationRef != "" {
+		fields = append(fields, zap.String("organization_ref", wallet.OrganizationRef))
+	}
+	if wallet.OwnerRef != "" {
+		fields = append(fields, zap.String("owner_ref", wallet.OwnerRef))
+	}
+	if wallet.Network != "" {
+		fields = append(fields, zap.String("network", wallet.Network))
+	}
+	if wallet.TokenSymbol != "" {
+		fields = append(fields, zap.String("token_symbol", wallet.TokenSymbol))
+	}
 	if err := w.walletRepo.Insert(ctx, wallet, repository.Filter("idempotencyKey", wallet.IdempotencyKey)); err != nil {
 		if errors.Is(err, merrors.ErrDataConflict) {
-			w.logger.Debug("wallet already exists", zap.String("wallet_ref", wallet.WalletRef), zap.String("idempotency_key", wallet.IdempotencyKey))
+			w.logger.Debug("Wallet already exists", fields...)
 			return wallet, nil
 		}
+		w.logger.Warn("Wallet create failed", append(fields, zap.Error(err))...)
 		return nil, err
 	}
-	w.logger.Debug("wallet created", zap.String("wallet_ref", wallet.WalletRef))
+	w.logger.Debug("Wallet created", fields...)
 	return wallet, nil
 }
 
-func (w *Wallets) Get(ctx context.Context, walletRef string) (*model.ManagedWallet, error) {
-	walletRef = strings.TrimSpace(walletRef)
-	if walletRef == "" {
+func (w *Wallets) Get(ctx context.Context, walletID string) (*model.ManagedWallet, error) {
+	walletID = strings.TrimSpace(walletID)
+	if walletID == "" {
 		return nil, merrors.InvalidArgument("walletsStore: empty walletRef")
 	}
+	fields := []zap.Field{
+		zap.String("wallet_id", walletID),
+	}
 	wallet := &model.ManagedWallet{}
-	if err := w.walletRepo.FindOneByFilter(ctx, repository.Filter("walletRef", walletRef), wallet); err != nil {
+	if err := w.walletRepo.FindOneByFilter(ctx, repository.Filter("walletRef", walletID), wallet); err != nil {
+		if errors.Is(err, merrors.ErrNoData) {
+			w.logger.Debug("Wallet not found", fields...)
+		} else {
+			w.logger.Warn("Wallet lookup failed", append(fields, zap.Error(err))...)
+		}
 		return nil, err
 	}
 	return wallet, nil
@@ -124,29 +149,38 @@ func (w *Wallets) Get(ctx context.Context, walletRef string) (*model.ManagedWall
 
 func (w *Wallets) List(ctx context.Context, filter model.ManagedWalletFilter) (*model.ManagedWalletList, error) {
 	query := repository.Query()
+	fields := make([]zap.Field, 0, 6)
 
 	if org := strings.TrimSpace(filter.OrganizationRef); org != "" {
 		query = query.Filter(repository.Field("organizationRef"), org)
+		fields = append(fields, zap.String("organization_ref", org))
 	}
 	if owner := strings.TrimSpace(filter.OwnerRef); owner != "" {
 		query = query.Filter(repository.Field("ownerRef"), owner)
+		fields = append(fields, zap.String("owner_ref", owner))
 	}
 	if network := strings.TrimSpace(filter.Network); network != "" {
-		query = query.Filter(repository.Field("network"), strings.ToLower(network))
+		normalized := strings.ToLower(network)
+		query = query.Filter(repository.Field("network"), normalized)
+		fields = append(fields, zap.String("network", normalized))
 	}
 	if token := strings.TrimSpace(filter.TokenSymbol); token != "" {
-		query = query.Filter(repository.Field("tokenSymbol"), strings.ToUpper(token))
+		normalized := strings.ToUpper(token)
+		query = query.Filter(repository.Field("tokenSymbol"), normalized)
+		fields = append(fields, zap.String("token_symbol", normalized))
 	}
 
 	if cursor := strings.TrimSpace(filter.Cursor); cursor != "" {
 		if oid, err := primitive.ObjectIDFromHex(cursor); err == nil {
 			query = query.Comparison(repository.IDField(), builder.Gt, oid)
+			fields = append(fields, zap.String("cursor", cursor))
 		} else {
-			w.logger.Warn("ignoring invalid wallet cursor", zap.String("cursor", cursor), zap.Error(err))
+			w.logger.Warn("Ignoring invalid wallet cursor", zap.String("cursor", cursor), zap.Error(err))
 		}
 	}
 
 	limit := sanitizeWalletLimit(filter.Limit)
+	fields = append(fields, zap.Int64("limit", limit))
 	fetchLimit := limit + 1
 	query = query.Sort(repository.IDField(), true).Limit(&fetchLimit)
 
@@ -160,8 +194,10 @@ func (w *Wallets) List(ctx context.Context, filter model.ManagedWalletFilter) (*
 		return nil
 	}
 
-	if err := w.walletRepo.FindManyByFilter(ctx, query, decoder); err != nil && !errors.Is(err, merrors.ErrNoData) {
-		return nil, err
+	listErr := w.walletRepo.FindManyByFilter(ctx, query, decoder)
+	if listErr != nil && !errors.Is(listErr, merrors.ErrNoData) {
+		w.logger.Warn("Wallet list failed", append(fields, zap.Error(listErr))...)
+		return nil, listErr
 	}
 
 	nextCursor := ""
@@ -171,10 +207,21 @@ func (w *Wallets) List(ctx context.Context, filter model.ManagedWalletFilter) (*
 		wallets = wallets[:len(wallets)-1]
 	}
 
-	return &model.ManagedWalletList{
+	result := &model.ManagedWalletList{
 		Items:      wallets,
 		NextCursor: nextCursor,
-	}, nil
+	}
+
+	fields = append(fields,
+		zap.Int("count", len(result.Items)),
+		zap.String("next_cursor", result.NextCursor),
+	)
+	if errors.Is(listErr, merrors.ErrNoData) {
+		w.logger.Debug("Wallet list empty", fields...)
+	} else {
+		w.logger.Debug("Wallet list fetched", fields...)
+	}
+	return result, nil
 }
 
 func (w *Wallets) SaveBalance(ctx context.Context, balance *model.WalletBalance) error {
@@ -188,6 +235,7 @@ func (w *Wallets) SaveBalance(ctx context.Context, balance *model.WalletBalance)
 	if balance.CalculatedAt.IsZero() {
 		balance.CalculatedAt = time.Now().UTC()
 	}
+	fields := []zap.Field{zap.String("wallet_ref", balance.WalletRef)}
 
 	existing := &model.WalletBalance{}
 	err := w.balanceRepo.FindOneByFilter(ctx, repository.Filter("walletRef", balance.WalletRef), existing)
@@ -198,28 +246,40 @@ func (w *Wallets) SaveBalance(ctx context.Context, balance *model.WalletBalance)
 		existing.PendingOutbound = balance.PendingOutbound
 		existing.CalculatedAt = balance.CalculatedAt
 		if err := w.balanceRepo.Update(ctx, existing); err != nil {
+			w.logger.Warn("Wallet balance update failed", append(fields, zap.Error(err))...)
 			return err
 		}
+		w.logger.Debug("Wallet balance updated", fields...)
 		return nil
 	case errors.Is(err, merrors.ErrNoData):
 		if err := w.balanceRepo.Insert(ctx, balance, repository.Filter("walletRef", balance.WalletRef)); err != nil {
+			w.logger.Warn("Wallet balance create failed", append(fields, zap.Error(err))...)
 			return err
 		}
+		w.logger.Debug("Wallet balance created", fields...)
 		return nil
 	default:
+		w.logger.Warn("Wallet balance lookup failed", append(fields, zap.Error(err))...)
 		return err
 	}
 }
 
-func (w *Wallets) GetBalance(ctx context.Context, walletRef string) (*model.WalletBalance, error) {
-	walletRef = strings.TrimSpace(walletRef)
-	if walletRef == "" {
+func (w *Wallets) GetBalance(ctx context.Context, walletID string) (*model.WalletBalance, error) {
+	walletID = strings.TrimSpace(walletID)
+	if walletID == "" {
 		return nil, merrors.InvalidArgument("walletsStore: empty walletRef")
 	}
+	fields := []zap.Field{zap.String("wallet_ref", walletID)}
 	balance := &model.WalletBalance{}
-	if err := w.balanceRepo.FindOneByFilter(ctx, repository.Filter("walletRef", walletRef), balance); err != nil {
+	if err := w.balanceRepo.FindOneByFilter(ctx, repository.Filter("walletRef", walletID), balance); err != nil {
+		if errors.Is(err, merrors.ErrNoData) {
+			w.logger.Debug("Wallet balance not found", fields...)
+		} else {
+			w.logger.Warn("Wallet balance lookup failed", append(fields, zap.Error(err))...)
+		}
 		return nil, err
 	}
+	w.logger.Debug("Wallet balance fetched", fields...)
 	return balance, nil
 }
 

api/gateway/mntx/config.yml

@@ -26,7 +26,7 @@ monetix:
   base_url_env: MONETIX_BASE_URL
   project_id_env: MONETIX_PROJECT_ID
   secret_key_env: MONETIX_SECRET_KEY
-  allowed_currencies: ["USD", "EUR"]
+  allowed_currencies: ["RUB"]
   require_customer_address: false
   request_timeout_seconds: 15
   status_success: "success"

api/gateway/mntx/internal/server/internal/serverimp.go

@@ -95,22 +95,49 @@ func (i *Imp) Shutdown() {
 }
 
 func (i *Imp) Start() error {
+	i.logger.Info("Starting Monetix gateway", zap.String("config_file", i.file), zap.Bool("debug", i.debug))
+
 	cfg, err := i.loadConfig()
 	if err != nil {
 		return err
 	}
 	i.config = cfg
 
+	i.logger.Info("Configuration loaded",
+		zap.String("grpc_address", cfg.GRPC.Address),
+		zap.String("metrics_address", cfg.Metrics.Address),
+	)
+
 	monetixCfg, err := i.resolveMonetixConfig(cfg.Monetix)
 	if err != nil {
+		i.logger.Error("Failed to resolve Monetix configuration", zap.Error(err))
 		return err
 	}
 
 	callbackCfg, err := i.resolveCallbackConfig(cfg.HTTP.Callback)
 	if err != nil {
+		i.logger.Error("Failed to resolve callback configuration", zap.Error(err))
 		return err
 	}
 
+	i.logger.Info("Monetix configuration resolved",
+		zap.Bool("base_url_set", strings.TrimSpace(monetixCfg.BaseURL) != ""),
+		zap.Int64("project_id", monetixCfg.ProjectID),
+		zap.Bool("secret_key_set", strings.TrimSpace(monetixCfg.SecretKey) != ""),
+		zap.Int("allowed_currencies", len(monetixCfg.AllowedCurrencies)),
+		zap.Bool("require_customer_address", monetixCfg.RequireCustomerAddress),
+		zap.Duration("request_timeout", monetixCfg.RequestTimeout),
+		zap.String("status_success", monetixCfg.SuccessStatus()),
+		zap.String("status_processing", monetixCfg.ProcessingStatus()),
+	)
+
+	i.logger.Info("Callback configuration resolved",
+		zap.String("address", callbackCfg.Address),
+		zap.String("path", callbackCfg.Path),
+		zap.Int("allowed_cidrs", len(callbackCfg.AllowedCIDRs)),
+		zap.Int64("max_body_bytes", callbackCfg.MaxBodyBytes),
+	)
+
 	serviceFactory := func(logger mlogger.Logger, _ struct{}, producer msg.Producer) (grpcapp.Service, error) {
 		svc := mntxservice.NewService(logger,
 			mntxservice.WithProducer(producer),
@@ -137,7 +164,7 @@ func (i *Imp) Start() error {
 func (i *Imp) loadConfig() (*config, error) {
 	data, err := os.ReadFile(i.file)
 	if err != nil {
-		i.logger.Error("could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
+		i.logger.Error("Could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
 		return nil, err
 	}
 
@@ -145,7 +172,7 @@ func (i *Imp) loadConfig() (*config, error) {
 		Config: &grpcapp.Config{},
 	}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
-		i.logger.Error("failed to parse configuration", zap.Error(err))
+		i.logger.Error("Failed to parse configuration", zap.Error(err))
 		return nil, err
 	}
 
@@ -245,7 +272,7 @@ func (i *Imp) resolveCallbackConfig(cfg callbackConfig) (callbackRuntimeConfig,
 		}
 		_, block, err := net.ParseCIDR(clean)
 		if err != nil {
-			i.logger.Warn("invalid callback allowlist CIDR skipped", zap.String("cidr", clean), zap.Error(err))
+			i.logger.Warn("Invalid callback allowlist CIDR skipped", zap.String("cidr", clean), zap.Error(err))
 			continue
 		}
 		cidrs = append(cidrs, block)
@@ -270,20 +297,36 @@ func (i *Imp) startHTTPCallbackServer(svc *mntxservice.Service, cfg callbackRunt
 
 	router := chi.NewRouter()
 	router.Post(cfg.Path, func(w http.ResponseWriter, r *http.Request) {
+		log := i.logger.Named("callback_http")
+		log.Debug("Callback request received",
+			zap.String("remote_addr", strings.TrimSpace(r.RemoteAddr)),
+			zap.String("path", r.URL.Path),
+			zap.String("method", r.Method),
+		)
+
 		if len(cfg.AllowedCIDRs) > 0 && !clientAllowed(r, cfg.AllowedCIDRs) {
+			ip := clientIPFromRequest(r)
+			remoteIP := ""
+			if ip != nil {
+				remoteIP = ip.String()
+			}
+			log.Warn("Callback rejected by CIDR allowlist", zap.String("remote_ip", remoteIP))
 			http.Error(w, "forbidden", http.StatusForbidden)
 			return
 		}
 		body, err := io.ReadAll(io.LimitReader(r.Body, cfg.MaxBodyBytes))
 		if err != nil {
+			log.Warn("Callback body read failed", zap.Error(err))
 			http.Error(w, "failed to read body", http.StatusBadRequest)
 			return
 		}
 		status, err := svc.ProcessMonetixCallback(r.Context(), body)
 		if err != nil {
+			log.Warn("Callback processing failed", zap.Error(err), zap.Int("status", status))
 			http.Error(w, err.Error(), status)
 			return
 		}
+		log.Debug("Callback processed", zap.Int("status", status))
 		w.WriteHeader(status)
 	})
 
@@ -301,7 +344,7 @@ func (i *Imp) startHTTPCallbackServer(svc *mntxservice.Service, cfg callbackRunt
 
 	go func() {
 		if err := server.Serve(ln); err != nil && !errors.Is(err, http.ErrServerClosed) {
-			i.logger.Error("Monetix callback server stopped with error", zap.Error(err))
+			i.logger.Warn("Monetix callback server stopped with error", zap.Error(err))
 		}
 	}()
 

api/gateway/mntx/internal/server/internal/serverimp_test.go

@@ -0,0 +1,52 @@
+package serverimp
+
+import (
+	"net"
+	"net/http"
+	"testing"
+)
+
+func TestClientIPFromRequest(t *testing.T) {
+	req := &http.Request{
+		Header:     http.Header{"X-Forwarded-For": []string{"1.2.3.4, 5.6.7.8"}},
+		RemoteAddr: "9.8.7.6:1234",
+	}
+	ip := clientIPFromRequest(req)
+	if ip == nil || ip.String() != "1.2.3.4" {
+		t.Fatalf("expected forwarded ip, got %v", ip)
+	}
+
+	req = &http.Request{RemoteAddr: "9.8.7.6:1234"}
+	ip = clientIPFromRequest(req)
+	if ip == nil || ip.String() != "9.8.7.6" {
+		t.Fatalf("expected remote addr ip, got %v", ip)
+	}
+
+	req = &http.Request{RemoteAddr: "invalid"}
+	ip = clientIPFromRequest(req)
+	if ip != nil {
+		t.Fatalf("expected nil ip, got %v", ip)
+	}
+}
+
+func TestClientAllowed(t *testing.T) {
+	_, cidr, err := net.ParseCIDR("10.0.0.0/8")
+	if err != nil {
+		t.Fatalf("failed to parse cidr: %v", err)
+	}
+
+	allowedReq := &http.Request{RemoteAddr: "10.1.2.3:1234"}
+	if !clientAllowed(allowedReq, []*net.IPNet{cidr}) {
+		t.Fatalf("expected allowed request")
+	}
+
+	deniedReq := &http.Request{RemoteAddr: "8.8.8.8:1234"}
+	if clientAllowed(deniedReq, []*net.IPNet{cidr}) {
+		t.Fatalf("expected denied request")
+	}
+
+	openReq := &http.Request{RemoteAddr: "8.8.8.8:1234"}
+	if !clientAllowed(openReq, nil) {
+		t.Fatalf("expected allow when no cidrs are configured")
+	}
+}

api/gateway/mntx/internal/service/gateway/callback.go

@@ -10,6 +10,7 @@ import (
 	clockpkg "github.com/tech/sendico/pkg/clock"
 	"github.com/tech/sendico/pkg/merrors"
 	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	"go.uber.org/zap"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
@@ -66,9 +67,12 @@ type monetixCallback struct {
 
 // ProcessMonetixCallback ingests Monetix provider callbacks and updates payout state.
 func (s *Service) ProcessMonetixCallback(ctx context.Context, payload []byte) (int, error) {
+	log := s.logger.Named("callback")
 	if s.card == nil {
+		log.Warn("Card payout processor not initialised")
 		return http.StatusInternalServerError, merrors.Internal("card payout processor not initialised")
 	}
+	log.Debug("Callback processing requested", zap.Int("payload_bytes", len(payload)))
 	return s.card.ProcessCallback(ctx, payload)
 }
 

api/gateway/mntx/internal/service/gateway/callback_test.go

@@ -0,0 +1,130 @@
+package gateway
+
+import (
+	"testing"
+	"time"
+
+	"github.com/tech/sendico/gateway/mntx/internal/service/monetix"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+)
+
+type fixedClock struct {
+	now time.Time
+}
+
+func (f fixedClock) Now() time.Time {
+	return f.now
+}
+
+func baseCallback() monetixCallback {
+	cb := monetixCallback{
+		ProjectID: 42,
+	}
+	cb.Payment.ID = "payout-1"
+	cb.Payment.Status = "success"
+	cb.Payment.Sum.Amount = 5000
+	cb.Payment.Sum.Currency = "usd"
+	cb.Customer.ID = "cust-1"
+	cb.Operation.Status = "success"
+	cb.Operation.Code = ""
+	cb.Operation.Message = "ok"
+	cb.Operation.RequestID = "req-1"
+	cb.Operation.Provider.PaymentID = "prov-1"
+	return cb
+}
+
+func TestMapCallbackToState_StatusMapping(t *testing.T) {
+	now := time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC)
+	cfg := monetix.DefaultConfig()
+
+	cases := []struct {
+		name           string
+		paymentStatus  string
+		operationStatus string
+		code           string
+		expectedStatus mntxv1.PayoutStatus
+		expectedOutcome string
+	}{
+		{
+			name:            "success",
+			paymentStatus:   "success",
+			operationStatus: "success",
+			code:            "0",
+			expectedStatus:  mntxv1.PayoutStatus_PAYOUT_STATUS_PROCESSED,
+			expectedOutcome: monetix.OutcomeSuccess,
+		},
+		{
+			name:            "processing",
+			paymentStatus:   "processing",
+			operationStatus: "success",
+			code:            "",
+			expectedStatus:  mntxv1.PayoutStatus_PAYOUT_STATUS_PENDING,
+			expectedOutcome: monetix.OutcomeProcessing,
+		},
+		{
+			name:            "decline",
+			paymentStatus:   "failed",
+			operationStatus: "failed",
+			code:            "1",
+			expectedStatus:  mntxv1.PayoutStatus_PAYOUT_STATUS_FAILED,
+			expectedOutcome: monetix.OutcomeDecline,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			cb := baseCallback()
+			cb.Payment.Status = tc.paymentStatus
+			cb.Operation.Status = tc.operationStatus
+			cb.Operation.Code = tc.code
+
+			state, outcome := mapCallbackToState(fixedClock{now: now}, cfg, cb)
+			if state.Status != tc.expectedStatus {
+				t.Fatalf("expected status %v, got %v", tc.expectedStatus, state.Status)
+			}
+			if outcome != tc.expectedOutcome {
+				t.Fatalf("expected outcome %q, got %q", tc.expectedOutcome, outcome)
+			}
+			if state.Currency != "USD" {
+				t.Fatalf("expected currency USD, got %q", state.Currency)
+			}
+			if !state.UpdatedAt.AsTime().Equal(now) {
+				t.Fatalf("expected updated_at %v, got %v", now, state.UpdatedAt.AsTime())
+			}
+		})
+	}
+}
+
+func TestFallbackProviderPaymentID(t *testing.T) {
+	cb := baseCallback()
+	if got := fallbackProviderPaymentID(cb); got != "prov-1" {
+		t.Fatalf("expected provider payment id, got %q", got)
+	}
+	cb.Operation.Provider.PaymentID = ""
+	if got := fallbackProviderPaymentID(cb); got != "req-1" {
+		t.Fatalf("expected request id fallback, got %q", got)
+	}
+	cb.Operation.RequestID = ""
+	if got := fallbackProviderPaymentID(cb); got != "payout-1" {
+		t.Fatalf("expected payment id fallback, got %q", got)
+	}
+}
+
+func TestVerifyCallbackSignature(t *testing.T) {
+	secret := "secret"
+	cb := baseCallback()
+
+	sig, err := monetix.SignPayload(cb, secret)
+	if err != nil {
+		t.Fatalf("failed to sign payload: %v", err)
+	}
+	cb.Signature = sig
+	if err := verifyCallbackSignature(cb, secret); err != nil {
+		t.Fatalf("expected valid signature, got %v", err)
+	}
+
+	cb.Signature = "invalid"
+	if err := verifyCallbackSignature(cb, secret); err == nil {
+		t.Fatalf("expected signature mismatch error")
+	}
+}

api/gateway/mntx/internal/service/gateway/card_payout_handlers.go

@@ -9,6 +9,7 @@ import (
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mservice"
 	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	"go.uber.org/zap"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -17,14 +18,24 @@ func (s *Service) CreateCardPayout(ctx context.Context, req *mntxv1.CardPayoutRe
 }
 
 func (s *Service) handleCreateCardPayout(ctx context.Context, req *mntxv1.CardPayoutRequest) gsresponse.Responder[mntxv1.CardPayoutResponse] {
+	log := s.logger.Named("card_payout")
+	log.Info("Create card payout request received",
+		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+		zap.Int64("amount_minor", req.GetAmountMinor()),
+		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
+	)
 	if s.card == nil {
+		log.Warn("Card payout processor not initialised")
 		return gsresponse.Internal[mntxv1.CardPayoutResponse](s.logger, mservice.MntxGateway, merrors.Internal("card payout processor not initialised"))
 	}
 
 	resp, err := s.card.Submit(ctx, req)
 	if err != nil {
+		log.Warn("Card payout submission failed", zap.Error(err))
 		return gsresponse.Auto[mntxv1.CardPayoutResponse](s.logger, mservice.MntxGateway, err)
 	}
+	log.Info("Card payout submission completed", zap.String("payout_id", resp.GetPayout().GetPayoutId()), zap.Bool("accepted", resp.GetAccepted()))
 	return gsresponse.Success(resp)
 }
 
@@ -33,14 +44,24 @@ func (s *Service) CreateCardTokenPayout(ctx context.Context, req *mntxv1.CardTok
 }
 
 func (s *Service) handleCreateCardTokenPayout(ctx context.Context, req *mntxv1.CardTokenPayoutRequest) gsresponse.Responder[mntxv1.CardTokenPayoutResponse] {
+	log := s.logger.Named("card_token_payout")
+	log.Info("Create card token payout request received",
+		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+		zap.Int64("amount_minor", req.GetAmountMinor()),
+		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
+	)
 	if s.card == nil {
+		log.Warn("Card payout processor not initialised")
 		return gsresponse.Internal[mntxv1.CardTokenPayoutResponse](s.logger, mservice.MntxGateway, merrors.Internal("card payout processor not initialised"))
 	}
 
 	resp, err := s.card.SubmitToken(ctx, req)
 	if err != nil {
+		log.Warn("Card token payout submission failed", zap.Error(err))
 		return gsresponse.Auto[mntxv1.CardTokenPayoutResponse](s.logger, mservice.MntxGateway, err)
 	}
+	log.Info("Card token payout submission completed", zap.String("payout_id", resp.GetPayout().GetPayoutId()), zap.Bool("accepted", resp.GetAccepted()))
 	return gsresponse.Success(resp)
 }
 
@@ -49,14 +70,22 @@ func (s *Service) CreateCardToken(ctx context.Context, req *mntxv1.CardTokenizeR
 }
 
 func (s *Service) handleCreateCardToken(ctx context.Context, req *mntxv1.CardTokenizeRequest) gsresponse.Responder[mntxv1.CardTokenizeResponse] {
+	log := s.logger.Named("card_tokenize")
+	log.Info("Create card token request received",
+		zap.String("request_id", strings.TrimSpace(req.GetRequestId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+	)
 	if s.card == nil {
+		log.Warn("Card payout processor not initialised")
 		return gsresponse.Internal[mntxv1.CardTokenizeResponse](s.logger, mservice.MntxGateway, merrors.Internal("card payout processor not initialised"))
 	}
 
 	resp, err := s.card.Tokenize(ctx, req)
 	if err != nil {
+		log.Warn("Card tokenization failed", zap.Error(err))
 		return gsresponse.Auto[mntxv1.CardTokenizeResponse](s.logger, mservice.MntxGateway, err)
 	}
+	log.Info("Card tokenization completed", zap.String("request_id", resp.GetRequestId()), zap.Bool("success", resp.GetSuccess()))
 	return gsresponse.Success(resp)
 }
 
@@ -65,14 +94,19 @@ func (s *Service) GetCardPayoutStatus(ctx context.Context, req *mntxv1.GetCardPa
 }
 
 func (s *Service) handleGetCardPayoutStatus(_ context.Context, req *mntxv1.GetCardPayoutStatusRequest) gsresponse.Responder[mntxv1.GetCardPayoutStatusResponse] {
+	log := s.logger.Named("card_payout_status")
+	log.Info("Get card payout status request received", zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())))
 	if s.card == nil {
+		log.Warn("Card payout processor not initialised")
 		return gsresponse.Internal[mntxv1.GetCardPayoutStatusResponse](s.logger, mservice.MntxGateway, merrors.Internal("card payout processor not initialised"))
 	}
 
 	state, err := s.card.Status(context.Background(), req.GetPayoutId())
 	if err != nil {
+		log.Warn("Card payout status lookup failed", zap.Error(err))
 		return gsresponse.Auto[mntxv1.GetCardPayoutStatusResponse](s.logger, mservice.MntxGateway, err)
 	}
+	log.Info("Card payout status retrieved", zap.String("payout_id", state.GetPayoutId()), zap.String("status", state.GetStatus().String()))
 	return gsresponse.Success(&mntxv1.GetCardPayoutStatusResponse{Payout: state})
 }
 

api/gateway/mntx/internal/service/gateway/card_payout_validation_test.go

@@ -0,0 +1,103 @@
+package gateway
+
+import (
+	"testing"
+
+	"github.com/tech/sendico/gateway/mntx/internal/service/monetix"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+)
+
+func TestValidateCardPayoutRequest_Valid(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardPayoutRequest()
+	if err := validateCardPayoutRequest(req, cfg); err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+}
+
+func TestValidateCardPayoutRequest_Errors(t *testing.T) {
+	baseCfg := testMonetixConfig()
+	cases := []struct {
+		name     string
+		mutate   func(*mntxv1.CardPayoutRequest)
+		config   func(monetix.Config) monetix.Config
+		expected string
+	}{
+		{
+			name:     "missing_payout_id",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.PayoutId = "" },
+			expected: "missing_payout_id",
+		},
+		{
+			name:     "missing_customer_id",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CustomerId = "" },
+			expected: "missing_customer_id",
+		},
+		{
+			name:     "missing_customer_ip",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CustomerIp = "" },
+			expected: "missing_customer_ip",
+		},
+		{
+			name:     "invalid_amount",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.AmountMinor = 0 },
+			expected: "invalid_amount",
+		},
+		{
+			name:     "missing_currency",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.Currency = "" },
+			expected: "missing_currency",
+		},
+		{
+			name:   "unsupported_currency",
+			mutate: func(r *mntxv1.CardPayoutRequest) { r.Currency = "EUR" },
+			config: func(cfg monetix.Config) monetix.Config {
+				cfg.AllowedCurrencies = []string{"USD"}
+				return cfg
+			},
+			expected: "unsupported_currency",
+		},
+		{
+			name:     "missing_card_pan",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CardPan = "" },
+			expected: "missing_card_pan",
+		},
+		{
+			name:     "missing_card_holder",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CardHolder = "" },
+			expected: "missing_card_holder",
+		},
+		{
+			name:     "invalid_expiry_month",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CardExpMonth = 13 },
+			expected: "invalid_expiry_month",
+		},
+		{
+			name:     "invalid_expiry_year",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.CardExpYear = 0 },
+			expected: "invalid_expiry_year",
+		},
+		{
+			name:   "missing_customer_country_when_required",
+			mutate: func(r *mntxv1.CardPayoutRequest) { r.CustomerCountry = "" },
+			config: func(cfg monetix.Config) monetix.Config {
+				cfg.RequireCustomerAddress = true
+				return cfg
+			},
+			expected: "missing_customer_country",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			req := validCardPayoutRequest()
+			tc.mutate(req)
+			cfg := baseCfg
+			if tc.config != nil {
+				cfg = tc.config(cfg)
+			}
+			err := validateCardPayoutRequest(req, cfg)
+			requireReason(t, err, tc.expected)
+		})
+	}
+}

api/gateway/mntx/internal/service/gateway/card_processor.go

@@ -45,14 +45,20 @@ func (p *cardPayoutProcessor) Submit(ctx context.Context, req *mntxv1.CardPayout
 	if p == nil {
 		return nil, merrors.Internal("card payout processor not initialised")
 	}
+	p.logger.Info("Submitting card payout",
+		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+		zap.Int64("amount_minor", req.GetAmountMinor()),
+		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
+	)
 	if strings.TrimSpace(p.config.BaseURL) == "" || strings.TrimSpace(p.config.SecretKey) == "" {
-		p.logger.Warn("monetix configuration is incomplete for payout submission")
+		p.logger.Warn("Monetix configuration is incomplete for payout submission")
 		return nil, merrors.Internal("monetix configuration is incomplete")
 	}
 
 	req = sanitizeCardPayoutRequest(req)
 	if err := validateCardPayoutRequest(req, p.config); err != nil {
-		p.logger.Warn("card payout validation failed",
+		p.logger.Warn("Card payout validation failed",
 			zap.String("payout_id", req.GetPayoutId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -65,7 +71,7 @@ func (p *cardPayoutProcessor) Submit(ctx context.Context, req *mntxv1.CardPayout
 		projectID = p.config.ProjectID
 	}
 	if projectID == 0 {
-		p.logger.Warn("monetix project_id is not configured", zap.String("payout_id", req.GetPayoutId()))
+		p.logger.Warn("Monetix project_id is not configured", zap.String("payout_id", req.GetPayoutId()))
 		return nil, merrors.Internal("monetix project_id is not configured")
 	}
 
@@ -95,7 +101,7 @@ func (p *cardPayoutProcessor) Submit(ctx context.Context, req *mntxv1.CardPayout
 		state.ProviderMessage = err.Error()
 		state.UpdatedAt = timestamppb.New(p.clock.Now())
 		p.store.Save(state)
-		p.logger.Warn("monetix payout submission failed",
+		p.logger.Warn("Monetix payout submission failed",
 			zap.String("payout_id", req.GetPayoutId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -122,6 +128,13 @@ func (p *cardPayoutProcessor) Submit(ctx context.Context, req *mntxv1.CardPayout
 		ErrorMessage:      result.ErrorMessage,
 	}
 
+	p.logger.Info("Card payout submission stored",
+		zap.String("payout_id", state.GetPayoutId()),
+		zap.String("status", state.GetStatus().String()),
+		zap.Bool("accepted", result.Accepted),
+		zap.String("provider_request_id", result.ProviderRequestID),
+	)
+
 	return resp, nil
 }
 
@@ -129,14 +142,20 @@ func (p *cardPayoutProcessor) SubmitToken(ctx context.Context, req *mntxv1.CardT
 	if p == nil {
 		return nil, merrors.Internal("card payout processor not initialised")
 	}
+	p.logger.Info("Submitting card token payout",
+		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+		zap.Int64("amount_minor", req.GetAmountMinor()),
+		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
+	)
 	if strings.TrimSpace(p.config.BaseURL) == "" || strings.TrimSpace(p.config.SecretKey) == "" {
-		p.logger.Warn("monetix configuration is incomplete for token payout submission")
+		p.logger.Warn("Monetix configuration is incomplete for token payout submission")
 		return nil, merrors.Internal("monetix configuration is incomplete")
 	}
 
 	req = sanitizeCardTokenPayoutRequest(req)
 	if err := validateCardTokenPayoutRequest(req, p.config); err != nil {
-		p.logger.Warn("card token payout validation failed",
+		p.logger.Warn("Card token payout validation failed",
 			zap.String("payout_id", req.GetPayoutId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -149,7 +168,7 @@ func (p *cardPayoutProcessor) SubmitToken(ctx context.Context, req *mntxv1.CardT
 		projectID = p.config.ProjectID
 	}
 	if projectID == 0 {
-		p.logger.Warn("monetix project_id is not configured", zap.String("payout_id", req.GetPayoutId()))
+		p.logger.Warn("Monetix project_id is not configured", zap.String("payout_id", req.GetPayoutId()))
 		return nil, merrors.Internal("monetix project_id is not configured")
 	}
 
@@ -179,7 +198,7 @@ func (p *cardPayoutProcessor) SubmitToken(ctx context.Context, req *mntxv1.CardT
 		state.ProviderMessage = err.Error()
 		state.UpdatedAt = timestamppb.New(p.clock.Now())
 		p.store.Save(state)
-		p.logger.Warn("monetix token payout submission failed",
+		p.logger.Warn("Monetix token payout submission failed",
 			zap.String("payout_id", req.GetPayoutId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -206,6 +225,13 @@ func (p *cardPayoutProcessor) SubmitToken(ctx context.Context, req *mntxv1.CardT
 		ErrorMessage:      result.ErrorMessage,
 	}
 
+	p.logger.Info("Card token payout submission stored",
+		zap.String("payout_id", state.GetPayoutId()),
+		zap.String("status", state.GetStatus().String()),
+		zap.Bool("accepted", result.Accepted),
+		zap.String("provider_request_id", result.ProviderRequestID),
+	)
+
 	return resp, nil
 }
 
@@ -213,9 +239,13 @@ func (p *cardPayoutProcessor) Tokenize(ctx context.Context, req *mntxv1.CardToke
 	if p == nil {
 		return nil, merrors.Internal("card payout processor not initialised")
 	}
+	p.logger.Info("Submitting card tokenization",
+		zap.String("request_id", strings.TrimSpace(req.GetRequestId())),
+		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
+	)
 	cardInput, err := validateCardTokenizeRequest(req, p.config)
 	if err != nil {
-		p.logger.Warn("card tokenization validation failed",
+		p.logger.Warn("Card tokenization validation failed",
 			zap.String("request_id", req.GetRequestId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -228,7 +258,7 @@ func (p *cardPayoutProcessor) Tokenize(ctx context.Context, req *mntxv1.CardToke
 		projectID = p.config.ProjectID
 	}
 	if projectID == 0 {
-		p.logger.Warn("monetix project_id is not configured", zap.String("request_id", req.GetRequestId()))
+		p.logger.Warn("Monetix project_id is not configured", zap.String("request_id", req.GetRequestId()))
 		return nil, merrors.Internal("monetix project_id is not configured")
 	}
 
@@ -238,7 +268,7 @@ func (p *cardPayoutProcessor) Tokenize(ctx context.Context, req *mntxv1.CardToke
 	apiReq := buildCardTokenizeRequest(projectID, req, cardInput)
 	result, err := client.CreateCardTokenization(ctx, apiReq)
 	if err != nil {
-		p.logger.Warn("monetix tokenization request failed",
+		p.logger.Warn("Monetix tokenization request failed",
 			zap.String("request_id", req.GetRequestId()),
 			zap.String("customer_id", req.GetCustomerId()),
 			zap.Error(err),
@@ -258,6 +288,12 @@ func (p *cardPayoutProcessor) Tokenize(ctx context.Context, req *mntxv1.CardToke
 	resp.ExpiryYear = result.ExpiryYear
 	resp.CardBrand = result.CardBrand
 
+	p.logger.Info("Card tokenization completed",
+		zap.String("request_id", resp.GetRequestId()),
+		zap.Bool("success", resp.GetSuccess()),
+		zap.String("provider_request_id", result.ProviderRequestID),
+	)
+
 	return resp, nil
 }
 
@@ -267,16 +303,18 @@ func (p *cardPayoutProcessor) Status(_ context.Context, payoutID string) (*mntxv
 	}
 
 	id := strings.TrimSpace(payoutID)
+	p.logger.Info("Card payout status requested", zap.String("payout_id", id))
 	if id == "" {
-		p.logger.Warn("payout status requested with empty payout_id")
+		p.logger.Warn("Payout status requested with empty payout_id")
 		return nil, merrors.InvalidArgument("payout_id is required", "payout_id")
 	}
 
 	state, ok := p.store.Get(id)
 	if !ok || state == nil {
-		p.logger.Warn("payout status not found", zap.String("payout_id", id))
+		p.logger.Warn("Payout status not found", zap.String("payout_id", id))
 		return nil, merrors.NoData("payout not found")
 	}
+	p.logger.Info("Card payout status resolved", zap.String("payout_id", state.GetPayoutId()), zap.String("status", state.GetStatus().String()))
 	return state, nil
 }
 
@@ -284,18 +322,19 @@ func (p *cardPayoutProcessor) ProcessCallback(ctx context.Context, payload []byt
 	if p == nil {
 		return http.StatusInternalServerError, merrors.Internal("card payout processor not initialised")
 	}
+	p.logger.Debug("Processing Monetix callback", zap.Int("payload_bytes", len(payload)))
 	if len(payload) == 0 {
-		p.logger.Warn("received empty Monetix callback payload")
+		p.logger.Warn("Received empty Monetix callback payload")
 		return http.StatusBadRequest, merrors.InvalidArgument("callback body is empty")
 	}
 	if strings.TrimSpace(p.config.SecretKey) == "" {
-		p.logger.Warn("monetix secret key is not configured; cannot verify callback")
+		p.logger.Warn("Monetix secret key is not configured; cannot verify callback")
 		return http.StatusInternalServerError, merrors.Internal("monetix secret key is not configured")
 	}
 
 	var cb monetixCallback
 	if err := json.Unmarshal(payload, &cb); err != nil {
-		p.logger.Warn("failed to unmarshal Monetix callback", zap.Error(err))
+		p.logger.Warn("Failed to unmarshal Monetix callback", zap.Error(err))
 		return http.StatusBadRequest, err
 	}
 
@@ -337,16 +376,16 @@ func (p *cardPayoutProcessor) emitCardPayoutEvent(state *mntxv1.CardPayoutState)
 	event := &mntxv1.CardPayoutStatusChangedEvent{Payout: state}
 	payload, err := protojson.Marshal(event)
 	if err != nil {
-		p.logger.Warn("failed to marshal payout callback event", zap.Error(err))
+		p.logger.Warn("Failed to marshal payout callback event", zap.Error(err))
 		return
 	}
 
 	env := messaging.CreateEnvelope(string(mservice.MntxGateway), model.NewNotification(mservice.MntxGateway, nm.NAUpdated))
 	if _, err := env.Wrap(payload); err != nil {
-		p.logger.Warn("failed to wrap payout callback event payload", zap.Error(err))
+		p.logger.Warn("Failed to wrap payout callback event payload", zap.Error(err))
 		return
 	}
 	if err := p.producer.SendMessage(env); err != nil {
-		p.logger.Warn("failed to publish payout callback event", zap.Error(err))
+		p.logger.Warn("Failed to publish payout callback event", zap.Error(err))
 	}
 }

api/gateway/mntx/internal/service/gateway/card_processor_test.go

@@ -0,0 +1,149 @@
+package gateway
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/tech/sendico/gateway/mntx/internal/service/monetix"
+	clockpkg "github.com/tech/sendico/pkg/clock"
+	"github.com/tech/sendico/pkg/merrors"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	"go.uber.org/zap"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+type roundTripperFunc func(*http.Request) (*http.Response, error)
+
+func (f roundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return f(r)
+}
+
+type staticClock struct {
+	now time.Time
+}
+
+func (s staticClock) Now() time.Time {
+	return s.now
+}
+
+func TestCardPayoutProcessor_Submit_Success(t *testing.T) {
+	cfg := monetix.Config{
+		BaseURL:           "https://monetix.test",
+		SecretKey:         "secret",
+		ProjectID:         99,
+		AllowedCurrencies: []string{"RUB"},
+	}
+
+	existingCreated := timestamppb.New(time.Date(2020, 2, 3, 0, 0, 0, 0, time.UTC))
+	store := newCardPayoutStore()
+	store.Save(&mntxv1.CardPayoutState{
+		PayoutId:  "payout-1",
+		CreatedAt: existingCreated,
+	})
+
+	httpClient := &http.Client{
+		Transport: roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+			resp := monetix.APIResponse{}
+			resp.Operation.RequestID = "req-123"
+			body, _ := json.Marshal(resp)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewReader(body)),
+				Header:     http.Header{"Content-Type": []string{"application/json"}},
+			}, nil
+		}),
+	}
+
+	now := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
+	processor := newCardPayoutProcessor(zap.NewNop(), cfg, staticClock{now: now}, store, httpClient, nil)
+
+	req := validCardPayoutRequest()
+	req.ProjectId = 0
+
+	resp, err := processor.Submit(context.Background(), req)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if !resp.GetAccepted() {
+		t.Fatalf("expected accepted payout response")
+	}
+	if resp.GetPayout().GetProjectId() != cfg.ProjectID {
+		t.Fatalf("expected project id %d, got %d", cfg.ProjectID, resp.GetPayout().GetProjectId())
+	}
+	if resp.GetPayout().GetStatus() != mntxv1.PayoutStatus_PAYOUT_STATUS_PENDING {
+		t.Fatalf("expected pending status, got %v", resp.GetPayout().GetStatus())
+	}
+	if !resp.GetPayout().GetCreatedAt().AsTime().Equal(existingCreated.AsTime()) {
+		t.Fatalf("expected created_at preserved, got %v", resp.GetPayout().GetCreatedAt().AsTime())
+	}
+
+	stored, ok := store.Get(req.GetPayoutId())
+	if !ok || stored == nil {
+		t.Fatalf("expected payout state stored")
+	}
+	if stored.GetProviderPaymentId() == "" {
+		t.Fatalf("expected provider payment id")
+	}
+}
+
+func TestCardPayoutProcessor_Submit_MissingConfig(t *testing.T) {
+	cfg := monetix.Config{
+		AllowedCurrencies: []string{"RUB"},
+	}
+	processor := newCardPayoutProcessor(zap.NewNop(), cfg, clockpkg.NewSystem(), newCardPayoutStore(), &http.Client{}, nil)
+
+	_, err := processor.Submit(context.Background(), validCardPayoutRequest())
+	if err == nil {
+		t.Fatalf("expected error")
+	}
+	if !errors.Is(err, merrors.ErrInternal) {
+		t.Fatalf("expected internal error, got %v", err)
+	}
+}
+
+func TestCardPayoutProcessor_ProcessCallback(t *testing.T) {
+	cfg := monetix.Config{
+		SecretKey:         "secret",
+		StatusSuccess:     "success",
+		StatusProcessing:  "processing",
+		AllowedCurrencies: []string{"RUB"},
+	}
+	store := newCardPayoutStore()
+	processor := newCardPayoutProcessor(zap.NewNop(), cfg, staticClock{now: time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC)}, store, &http.Client{}, nil)
+
+	cb := baseCallback()
+	cb.Payment.Sum.Currency = "RUB"
+	cb.Signature = ""
+	sig, err := monetix.SignPayload(cb, cfg.SecretKey)
+	if err != nil {
+		t.Fatalf("failed to sign callback: %v", err)
+	}
+	cb.Signature = sig
+
+	payload, err := json.Marshal(cb)
+	if err != nil {
+		t.Fatalf("failed to marshal callback: %v", err)
+	}
+
+	status, err := processor.ProcessCallback(context.Background(), payload)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if status != http.StatusOK {
+		t.Fatalf("expected status ok, got %d", status)
+	}
+
+	state, ok := store.Get(cb.Payment.ID)
+	if !ok || state == nil {
+		t.Fatalf("expected payout state stored")
+	}
+	if state.GetStatus() != mntxv1.PayoutStatus_PAYOUT_STATUS_PROCESSED {
+		t.Fatalf("expected processed status, got %v", state.GetStatus())
+	}
+}

api/gateway/mntx/internal/service/gateway/card_token_validation_test.go

@@ -0,0 +1,93 @@
+package gateway
+
+import (
+	"testing"
+
+	"github.com/tech/sendico/gateway/mntx/internal/service/monetix"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+)
+
+func TestValidateCardTokenPayoutRequest_Valid(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenPayoutRequest()
+	if err := validateCardTokenPayoutRequest(req, cfg); err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+}
+
+func TestValidateCardTokenPayoutRequest_Errors(t *testing.T) {
+	baseCfg := testMonetixConfig()
+	cases := []struct {
+		name     string
+		mutate   func(*mntxv1.CardTokenPayoutRequest)
+		config   func(monetix.Config) monetix.Config
+		expected string
+	}{
+		{
+			name:     "missing_payout_id",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.PayoutId = "" },
+			expected: "missing_payout_id",
+		},
+		{
+			name:     "missing_customer_id",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.CustomerId = "" },
+			expected: "missing_customer_id",
+		},
+		{
+			name:     "missing_customer_ip",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.CustomerIp = "" },
+			expected: "missing_customer_ip",
+		},
+		{
+			name:     "invalid_amount",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.AmountMinor = 0 },
+			expected: "invalid_amount",
+		},
+		{
+			name:     "missing_currency",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.Currency = "" },
+			expected: "missing_currency",
+		},
+		{
+			name:   "unsupported_currency",
+			mutate: func(r *mntxv1.CardTokenPayoutRequest) { r.Currency = "EUR" },
+			config: func(cfg monetix.Config) monetix.Config {
+				cfg.AllowedCurrencies = []string{"USD"}
+				return cfg
+			},
+			expected: "unsupported_currency",
+		},
+		{
+			name:     "missing_card_token",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.CardToken = "" },
+			expected: "missing_card_token",
+		},
+		{
+			name:   "missing_customer_city_when_required",
+			mutate: func(r *mntxv1.CardTokenPayoutRequest) {
+				r.CustomerCountry = "US"
+				r.CustomerCity = ""
+				r.CustomerAddress = "Main St"
+				r.CustomerZip = "12345"
+			},
+			config: func(cfg monetix.Config) monetix.Config {
+				cfg.RequireCustomerAddress = true
+				return cfg
+			},
+			expected: "missing_customer_city",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			req := validCardTokenPayoutRequest()
+			tc.mutate(req)
+			cfg := baseCfg
+			if tc.config != nil {
+				cfg = tc.config(cfg)
+			}
+			err := validateCardTokenPayoutRequest(req, cfg)
+			requireReason(t, err, tc.expected)
+		})
+	}
+}

api/gateway/mntx/internal/service/gateway/card_tokenize_validation_test.go

@@ -0,0 +1,76 @@
+package gateway
+
+import (
+	"testing"
+	"time"
+
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+)
+
+func TestValidateCardTokenizeRequest_ValidTopLevel(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenizeRequest()
+	if _, err := validateCardTokenizeRequest(req, cfg); err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+}
+
+func TestValidateCardTokenizeRequest_ValidNestedCard(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenizeRequest()
+	req.Card = &mntxv1.CardDetails{
+		Pan:        "4111111111111111",
+		ExpMonth:   req.CardExpMonth,
+		ExpYear:    req.CardExpYear,
+		CardHolder: req.CardHolder,
+		Cvv:        req.CardCvv,
+	}
+	req.CardPan = ""
+	req.CardExpMonth = 0
+	req.CardExpYear = 0
+	req.CardHolder = ""
+	req.CardCvv = ""
+
+	if _, err := validateCardTokenizeRequest(req, cfg); err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+}
+
+func TestValidateCardTokenizeRequest_Expired(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenizeRequest()
+	now := time.Now().UTC()
+	req.CardExpMonth = uint32(now.Month())
+	req.CardExpYear = uint32(now.Year() - 1)
+
+	_, err := validateCardTokenizeRequest(req, cfg)
+	requireReason(t, err, "expired_card")
+}
+
+func TestValidateCardTokenizeRequest_MissingCvv(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenizeRequest()
+	req.CardCvv = ""
+
+	_, err := validateCardTokenizeRequest(req, cfg)
+	requireReason(t, err, "missing_cvv")
+}
+
+func TestValidateCardTokenizeRequest_MissingCardPan(t *testing.T) {
+	cfg := testMonetixConfig()
+	req := validCardTokenizeRequest()
+	req.CardPan = ""
+
+	_, err := validateCardTokenizeRequest(req, cfg)
+	requireReason(t, err, "missing_card_pan")
+}
+
+func TestValidateCardTokenizeRequest_AddressRequired(t *testing.T) {
+	cfg := testMonetixConfig()
+	cfg.RequireCustomerAddress = true
+	req := validCardTokenizeRequest()
+	req.CustomerCountry = ""
+
+	_, err := validateCardTokenizeRequest(req, cfg)
+	requireReason(t, err, "missing_customer_country")
+}

api/gateway/mntx/internal/service/gateway/metrics.go

@@ -164,11 +164,3 @@ func statusLabel(err error) string {
 		return "error"
 	}
 }
-
-func normalizeCallbackStatus(status string) string {
-	status = strings.TrimSpace(status)
-	if status == "" {
-		return "unknown"
-	}
-	return strings.ToLower(status)
-}

api/gateway/mntx/internal/service/gateway/payout_get.go

@@ -9,6 +9,7 @@ import (
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mservice"
 	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	"go.uber.org/zap"
 )
 
 func (s *Service) GetPayout(ctx context.Context, req *mntxv1.GetPayoutRequest) (*mntxv1.GetPayoutResponse, error) {
@@ -17,14 +18,19 @@ func (s *Service) GetPayout(ctx context.Context, req *mntxv1.GetPayoutRequest) (
 
 func (s *Service) handleGetPayout(_ context.Context, req *mntxv1.GetPayoutRequest) gsresponse.Responder[mntxv1.GetPayoutResponse] {
 	ref := strings.TrimSpace(req.GetPayoutRef())
+	log := s.logger.Named("payout")
+	log.Info("Get payout request received", zap.String("payout_ref", ref))
 	if ref == "" {
+		log.Warn("Get payout request missing payout_ref")
 		return gsresponse.InvalidArgument[mntxv1.GetPayoutResponse](s.logger, mservice.MntxGateway, merrors.InvalidArgument("payout_ref is required", "payout_ref"))
 	}
 
 	payout, ok := s.store.Get(ref)
 	if !ok {
+		log.Warn("Payout not found", zap.String("payout_ref", ref))
 		return gsresponse.NotFound[mntxv1.GetPayoutResponse](s.logger, mservice.MntxGateway, merrors.NoData(fmt.Sprintf("payout %s not found", ref)))
 	}
 
+	log.Info("Payout retrieved", zap.String("payout_ref", ref), zap.String("status", payout.GetStatus().String()))
 	return gsresponse.Success(&mntxv1.GetPayoutResponse{Payout: payout})
 }

api/gateway/mntx/internal/service/gateway/payout_submit.go

@@ -22,8 +22,17 @@ func (s *Service) SubmitPayout(ctx context.Context, req *mntxv1.SubmitPayoutRequ
 }
 
 func (s *Service) handleSubmitPayout(_ context.Context, req *mntxv1.SubmitPayoutRequest) gsresponse.Responder[mntxv1.SubmitPayoutResponse] {
+	log := s.logger.Named("payout")
+	log.Info("Submit payout request received",
+		zap.String("idempotency_key", strings.TrimSpace(req.GetIdempotencyKey())),
+		zap.String("organization_ref", strings.TrimSpace(req.GetOrganizationRef())),
+		zap.String("currency", strings.TrimSpace(req.GetAmount().GetCurrency())),
+		zap.String("amount", strings.TrimSpace(req.GetAmount().GetAmount())),
+	)
+
 	payout, err := s.buildPayout(req)
 	if err != nil {
+		log.Warn("Submit payout validation failed", zap.Error(err))
 		return gsresponse.Auto[mntxv1.SubmitPayoutResponse](s.logger, mservice.MntxGateway, err)
 	}
 
@@ -31,6 +40,7 @@ func (s *Service) handleSubmitPayout(_ context.Context, req *mntxv1.SubmitPayout
 	s.emitEvent(payout, nm.NAPending)
 	go s.completePayout(payout, strings.TrimSpace(req.GetSimulatedFailureReason()))
 
+	log.Info("Payout accepted", zap.String("payout_ref", payout.GetPayoutRef()), zap.String("status", payout.GetStatus().String()))
 	return gsresponse.Success(&mntxv1.SubmitPayoutResponse{Payout: payout})
 }
 
@@ -79,6 +89,7 @@ func (s *Service) buildPayout(req *mntxv1.SubmitPayoutRequest) (*mntxv1.Payout,
 }
 
 func (s *Service) completePayout(original *mntxv1.Payout, simulatedFailure string) {
+	log := s.logger.Named("payout")
 	outcome := clonePayout(original)
 	if outcome == nil {
 		return
@@ -95,6 +106,7 @@ func (s *Service) completePayout(original *mntxv1.Payout, simulatedFailure strin
 		observePayoutError(simulatedFailure, outcome.Amount)
 		s.store.Save(outcome)
 		s.emitEvent(outcome, nm.NAUpdated)
+		log.Info("Payout completed", zap.String("payout_ref", outcome.GetPayoutRef()), zap.String("status", outcome.GetStatus().String()), zap.String("failure_reason", simulatedFailure))
 		return
 	}
 
@@ -102,6 +114,7 @@ func (s *Service) completePayout(original *mntxv1.Payout, simulatedFailure strin
 	observePayoutSuccess(outcome.Amount)
 	s.store.Save(outcome)
 	s.emitEvent(outcome, nm.NAUpdated)
+	log.Info("Payout completed", zap.String("payout_ref", outcome.GetPayoutRef()), zap.String("status", outcome.GetStatus().String()))
 }
 
 func (s *Service) emitEvent(payout *mntxv1.Payout, action nm.NotificationAction) {
@@ -111,18 +124,18 @@ func (s *Service) emitEvent(payout *mntxv1.Payout, action nm.NotificationAction)
 
 	payload, err := protojson.Marshal(&mntxv1.PayoutStatusChangedEvent{Payout: payout})
 	if err != nil {
-		s.logger.Warn("failed to marshal payout event", zapError(err))
+		s.logger.Warn("Failed to marshal payout event", zapError(err))
 		return
 	}
 
 	env := messaging.CreateEnvelope(string(mservice.MntxGateway), model.NewNotification(mservice.MntxGateway, action))
 	if _, err := env.Wrap(payload); err != nil {
-		s.logger.Warn("failed to wrap payout event payload", zapError(err))
+		s.logger.Warn("Failed to wrap payout event payload", zapError(err))
 		return
 	}
 
 	if err := s.producer.SendMessage(env); err != nil {
-		s.logger.Warn("failed to publish payout event", zapError(err))
+		s.logger.Warn("Failed to publish payout event", zapError(err))
 	}
 }
 

api/gateway/mntx/internal/service/gateway/service.go

@@ -14,6 +14,7 @@ import (
 	"github.com/tech/sendico/pkg/mlogger"
 	"github.com/tech/sendico/pkg/mservice"
 	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	"go.uber.org/zap"
 	"google.golang.org/grpc"
 )
 
@@ -97,9 +98,19 @@ func (s *Service) Register(router routers.GRPC) error {
 }
 
 func executeUnary[TReq any, TResp any](ctx context.Context, svc *Service, method string, handler func(context.Context, *TReq) gsresponse.Responder[TResp], req *TReq) (*TResp, error) {
+	log := svc.logger.Named("rpc")
+	log.Info("RPC request started", zap.String("method", method))
+
 	start := svc.clock.Now()
 	resp, err := gsresponse.Unary(svc.logger, mservice.MntxGateway, handler)(ctx, req)
-	observeRPC(method, err, svc.clock.Now().Sub(start))
+	duration := svc.clock.Now().Sub(start)
+	observeRPC(method, err, duration)
+
+	if err != nil {
+		log.Warn("RPC request failed", zap.String("method", method), zap.Duration("duration", duration), zap.Error(err))
+	} else {
+		log.Info("RPC request completed", zap.String("method", method), zap.Duration("duration", duration))
+	}
 	return resp, err
 }
 

api/gateway/mntx/internal/service/gateway/testhelpers_test.go

@@ -0,0 +1,84 @@
+package gateway
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/tech/sendico/gateway/mntx/internal/service/monetix"
+	"github.com/tech/sendico/pkg/merrors"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+)
+
+func requireReason(t *testing.T, err error, reason string) {
+	t.Helper()
+	if err == nil {
+		t.Fatalf("expected error")
+	}
+	if !errors.Is(err, merrors.ErrInvalidArg) {
+		t.Fatalf("expected invalid argument error, got %v", err)
+	}
+	reasoned, ok := err.(payoutFailure)
+	if !ok {
+		t.Fatalf("expected payout failure reason, got %T", err)
+	}
+	if reasoned.Reason() != reason {
+		t.Fatalf("expected reason %q, got %q", reason, reasoned.Reason())
+	}
+}
+
+func testMonetixConfig() monetix.Config {
+	return monetix.Config{
+		AllowedCurrencies: []string{"RUB", "USD"},
+	}
+}
+
+func validCardPayoutRequest() *mntxv1.CardPayoutRequest {
+	return &mntxv1.CardPayoutRequest{
+		PayoutId:          "payout-1",
+		CustomerId:        "cust-1",
+		CustomerFirstName: "Jane",
+		CustomerLastName:  "Doe",
+		CustomerIp:        "203.0.113.10",
+		AmountMinor:       1500,
+		Currency:          "RUB",
+		CardPan:           "4111111111111111",
+		CardHolder:        "JANE DOE",
+		CardExpMonth:      12,
+		CardExpYear:       2035,
+	}
+}
+
+func validCardTokenPayoutRequest() *mntxv1.CardTokenPayoutRequest {
+	return &mntxv1.CardTokenPayoutRequest{
+		PayoutId:          "payout-1",
+		CustomerId:        "cust-1",
+		CustomerFirstName: "Jane",
+		CustomerLastName:  "Doe",
+		CustomerIp:        "203.0.113.11",
+		AmountMinor:       2500,
+		Currency:          "USD",
+		CardToken:         "tok_123",
+	}
+}
+
+func validCardTokenizeRequest() *mntxv1.CardTokenizeRequest {
+	month, year := futureExpiry()
+	return &mntxv1.CardTokenizeRequest{
+		RequestId:         "req-1",
+		CustomerId:        "cust-1",
+		CustomerFirstName: "Jane",
+		CustomerLastName:  "Doe",
+		CustomerIp:        "203.0.113.12",
+		CardPan:           "4111111111111111",
+		CardHolder:        "JANE DOE",
+		CardCvv:           "123",
+		CardExpMonth:      month,
+		CardExpYear:       year,
+	}
+}
+
+func futureExpiry() (uint32, uint32) {
+	now := time.Now().UTC()
+	return uint32(now.Month()), uint32(now.Year() + 1)
+}

api/gateway/mntx/internal/service/monetix/client.go

@@ -2,10 +2,6 @@ package monetix
 
 import (
 	"context"
-	"crypto/hmac"
-	"crypto/sha256"
-	"encoding/hex"
-	"encoding/json"
 	"net/http"
 
 	"github.com/tech/sendico/pkg/mlogger"
@@ -45,21 +41,3 @@ func (c *Client) CreateCardTokenPayout(ctx context.Context, req CardTokenPayoutR
 func (c *Client) CreateCardTokenization(ctx context.Context, req CardTokenizeRequest) (*TokenizationResult, error) {
 	return c.sendTokenization(ctx, req)
 }
-
-func signPayload(payload any, secret string) (string, error) {
-	data, err := json.Marshal(payload)
-	if err != nil {
-		return "", err
-	}
-
-	h := hmac.New(sha256.New, []byte(secret))
-	if _, err := h.Write(data); err != nil {
-		return "", err
-	}
-	return hex.EncodeToString(h.Sum(nil)), nil
-}
-
-// SignPayload exposes signature calculation for callback verification.
-func SignPayload(payload any, secret string) (string, error) {
-	return signPayload(payload, secret)
-}

api/gateway/mntx/internal/service/monetix/mask_test.go

@@ -0,0 +1,23 @@
+package monetix
+
+import "testing"
+
+func TestMaskPAN(t *testing.T) {
+	cases := []struct {
+		input    string
+		expected string
+	}{
+		{input: "1234", expected: "****"},
+		{input: "1234567890", expected: "12******90"},
+		{input: "1234567890123456", expected: "123456******3456"},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.input, func(t *testing.T) {
+			got := MaskPAN(tc.input)
+			if got != tc.expected {
+				t.Fatalf("expected %q, got %q", tc.expected, got)
+			}
+		})
+	}
+}

api/gateway/mntx/internal/service/monetix/sender.go

@@ -24,7 +24,7 @@ func (c *Client) sendCardPayout(ctx context.Context, req CardPayoutRequest) (*Ca
 	maskedPAN := MaskPAN(req.Card.PAN)
 	return c.send(ctx, &req, "/v2/payment/card/payout",
 		func() {
-			c.logger.Info("dispatching Monetix card payout",
+			c.logger.Info("Dispatching Monetix card payout",
 				zap.String("payout_id", req.General.PaymentID),
 				zap.Int64("amount_minor", req.Payment.Amount),
 				zap.String("currency", req.Payment.Currency),
@@ -47,7 +47,7 @@ func (c *Client) sendCardPayout(ctx context.Context, req CardPayoutRequest) (*Ca
 func (c *Client) sendCardTokenPayout(ctx context.Context, req CardTokenPayoutRequest) (*CardPayoutSendResult, error) {
 	return c.send(ctx, &req, "/v2/payment/card/payout/token",
 		func() {
-			c.logger.Info("dispatching Monetix card token payout",
+			c.logger.Info("Dispatching Monetix card token payout",
 				zap.String("payout_id", req.General.PaymentID),
 				zap.Int64("amount_minor", req.Payment.Amount),
 				zap.String("currency", req.Payment.Currency),
@@ -101,7 +101,7 @@ func (c *Client) sendTokenization(ctx context.Context, req CardTokenizeRequest)
 	httpReq.Header.Set("Content-Type", "application/json")
 	httpReq.Header.Set("Accept", "application/json")
 
-	c.logger.Info("dispatching Monetix card tokenization",
+	c.logger.Info("Dispatching Monetix card tokenization",
 		zap.String("request_id", req.General.PaymentID),
 		zap.String("masked_pan", MaskPAN(req.Card.PAN)),
 	)
@@ -111,7 +111,7 @@ func (c *Client) sendTokenization(ctx context.Context, req CardTokenizeRequest)
 	duration := time.Since(start)
 	if err != nil {
 		observeRequest(outcomeNetworkError, duration)
-		c.logger.Warn("monetix tokenization request failed", zap.Error(err))
+		c.logger.Warn("Monetix tokenization request failed", zap.Error(err))
 		return nil, merrors.Internal("monetix tokenization request failed: " + err.Error())
 	}
 	defer resp.Body.Close()
@@ -133,7 +133,7 @@ func (c *Client) sendTokenization(ctx context.Context, req CardTokenizeRequest)
 	var apiResp APIResponse
 	if len(body) > 0 {
 		if err := json.Unmarshal(body, &apiResp); err != nil {
-			c.logger.Warn("failed to decode Monetix tokenization response", zap.String("request_id", req.General.PaymentID), zap.Int("status_code", resp.StatusCode), zap.Error(err))
+			c.logger.Warn("Failed to decode Monetix tokenization response", zap.String("request_id", req.General.PaymentID), zap.Int("status_code", resp.StatusCode), zap.Error(err))
 		} else {
 			var tokenData struct {
 				Token       string `json:"token"`
@@ -245,7 +245,7 @@ func (c *Client) send(ctx context.Context, req any, path string, dispatchLog fun
 	var apiResp APIResponse
 	if len(body) > 0 {
 		if err := json.Unmarshal(body, &apiResp); err != nil {
-			c.logger.Warn("failed to decode Monetix response", zap.Int("status_code", resp.StatusCode), zap.Error(err))
+			c.logger.Warn("Failed to decode Monetix response", zap.Int("status_code", resp.StatusCode), zap.Error(err))
 		}
 	}
 

api/gateway/mntx/internal/service/monetix/sender_test.go

@@ -0,0 +1,128 @@
+package monetix
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"go.uber.org/zap"
+)
+
+type roundTripperFunc func(*http.Request) (*http.Response, error)
+
+func (f roundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return f(r)
+}
+
+func TestSendCardPayout_SignsPayload(t *testing.T) {
+	secret := "secret"
+	var captured CardPayoutRequest
+
+	httpClient := &http.Client{
+		Transport: roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+			if r.URL.Path != "/v2/payment/card/payout" {
+				t.Fatalf("expected payout path, got %q", r.URL.Path)
+			}
+			body, _ := io.ReadAll(r.Body)
+			if err := json.Unmarshal(body, &captured); err != nil {
+				t.Fatalf("failed to decode request: %v", err)
+			}
+			resp := APIResponse{}
+			resp.Operation.RequestID = "req-1"
+			payload, _ := json.Marshal(resp)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewReader(payload)),
+				Header:     http.Header{"Content-Type": []string{"application/json"}},
+			}, nil
+		}),
+	}
+
+	cfg := Config{
+		BaseURL:   "https://monetix.test",
+		SecretKey: secret,
+	}
+	client := NewClient(cfg, httpClient, zap.NewNop())
+
+	req := CardPayoutRequest{
+		General: General{ProjectID: 1, PaymentID: "payout-1"},
+		Customer: Customer{
+			ID:        "cust-1",
+			FirstName: "Jane",
+			LastName:  "Doe",
+			IP:        "203.0.113.10",
+		},
+		Payment: Payment{Amount: 1000, Currency: "RUB"},
+		Card:    Card{PAN: "4111111111111111", Year: 2030, Month: 12, CardHolder: "JANE DOE"},
+	}
+
+	result, err := client.CreateCardPayout(context.Background(), req)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if !result.Accepted {
+		t.Fatalf("expected accepted response")
+	}
+	if captured.General.Signature == "" {
+		t.Fatalf("expected signature in request")
+	}
+
+	signed := captured
+	signed.General.Signature = ""
+	expectedSig, err := SignPayload(signed, secret)
+	if err != nil {
+		t.Fatalf("failed to compute signature: %v", err)
+	}
+	if captured.General.Signature != expectedSig {
+		t.Fatalf("expected signature %q, got %q", expectedSig, captured.General.Signature)
+	}
+}
+
+func TestSendCardPayout_HTTPError(t *testing.T) {
+	httpClient := &http.Client{
+		Transport: roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+			body := `{"code":"E100","message":"denied"}`
+			return &http.Response{
+				StatusCode: http.StatusBadRequest,
+				Body:       io.NopCloser(strings.NewReader(body)),
+				Header:     http.Header{"Content-Type": []string{"application/json"}},
+			}, nil
+		}),
+	}
+
+	cfg := Config{
+		BaseURL:   "https://monetix.test",
+		SecretKey: "secret",
+	}
+	client := NewClient(cfg, httpClient, zap.NewNop())
+
+	req := CardPayoutRequest{
+		General: General{ProjectID: 1, PaymentID: "payout-1"},
+		Customer: Customer{
+			ID:        "cust-1",
+			FirstName: "Jane",
+			LastName:  "Doe",
+			IP:        "203.0.113.10",
+		},
+		Payment: Payment{Amount: 1000, Currency: "RUB"},
+		Card:    Card{PAN: "4111111111111111", Year: 2030, Month: 12, CardHolder: "JANE DOE"},
+	}
+
+	result, err := client.CreateCardPayout(context.Background(), req)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if result.Accepted {
+		t.Fatalf("expected rejected response")
+	}
+	if result.ErrorCode != "E100" {
+		t.Fatalf("expected error code E100, got %q", result.ErrorCode)
+	}
+	if result.ErrorMessage != "denied" {
+		t.Fatalf("expected error message denied, got %q", result.ErrorMessage)
+	}
+}

api/gateway/mntx/internal/service/monetix/signature.go

@@ -0,0 +1,112 @@
+package monetix
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha512"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func signPayload(payload any, secret string) (string, error) {
+	canonical, err := signaturePayloadString(payload)
+	if err != nil {
+		return "", err
+	}
+
+	mac := hmac.New(sha512.New, []byte(secret))
+	if _, err := mac.Write([]byte(canonical)); err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(mac.Sum(nil)), nil
+}
+
+// SignPayload exposes signature calculation for callback verification.
+func SignPayload(payload any, secret string) (string, error) {
+	return signPayload(payload, secret)
+}
+
+func signaturePayloadString(payload any) (string, error) {
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return "", err
+	}
+
+	var root any
+	decoder := json.NewDecoder(bytes.NewReader(data))
+	decoder.UseNumber()
+	if err := decoder.Decode(&root); err != nil {
+		return "", err
+	}
+
+	lines := make([]string, 0)
+	collectSignatureLines(nil, root, &lines)
+	sort.Strings(lines)
+
+	return strings.Join(lines, ";"), nil
+}
+
+func collectSignatureLines(path []string, value any, lines *[]string) {
+	switch v := value.(type) {
+	case map[string]any:
+		for key, child := range v {
+			if strings.EqualFold(key, "signature") {
+				continue
+			}
+			collectSignatureLines(append(path, key), child, lines)
+		}
+	case []any:
+		if len(v) == 0 {
+			return
+		}
+		for idx, child := range v {
+			collectSignatureLines(append(path, strconv.Itoa(idx)), child, lines)
+		}
+	default:
+		line := formatSignatureLine(path, v)
+		if line != "" {
+			*lines = append(*lines, line)
+		}
+	}
+}
+
+func formatSignatureLine(path []string, value any) string {
+	if len(path) == 0 {
+		return ""
+	}
+	val := signatureValueString(value)
+	segments := append(append([]string{}, path...), val)
+	return strings.Join(segments, ":")
+}
+
+func signatureValueString(value any) string {
+	switch v := value.(type) {
+	case nil:
+		return "null"
+	case string:
+		return v
+	case json.Number:
+		return v.String()
+	case bool:
+		if v {
+			return "1"
+		}
+		return "0"
+	case float64:
+		return strconv.FormatFloat(v, 'f', -1, 64)
+	case float32:
+		return strconv.FormatFloat(float64(v), 'f', -1, 32)
+	case int:
+		return strconv.Itoa(v)
+	case int8, int16, int32, int64:
+		return fmt.Sprint(v)
+	case uint, uint8, uint16, uint32, uint64:
+		return fmt.Sprint(v)
+	default:
+		return fmt.Sprint(v)
+	}
+}

api/gateway/mntx/internal/service/monetix/signature_test.go

@@ -0,0 +1,148 @@
+package monetix
+
+import "testing"
+
+func TestSignaturePayloadString_Example(t *testing.T) {
+	payload := map[string]any{
+		"general": map[string]any{
+			"project_id": 3254,
+			"payment_id": "id_38202316",
+			"signature":  "<ignored>",
+		},
+		"customer": map[string]any{
+			"id":         "585741",
+			"email":      "johndoe@example.com",
+			"first_name": "John",
+			"last_name":  "Doe",
+			"address":    "Downing str., 23",
+			"identify": map[string]any{
+				"doc_number": "54122312544",
+			},
+			"ip_address": "198.51.100.47",
+		},
+		"payment": map[string]any{
+			"amount":      10800,
+			"currency":    "USD",
+			"description": "Computer keyboards",
+		},
+		"receipt_data": map[string]any{
+			"positions": []any{
+				map[string]any{
+					"quantity":    "10",
+					"amount":      "108",
+					"description": "Computer keyboard",
+				},
+			},
+		},
+		"return_url": map[string]any{
+			"success": "https://paymentpage.example.com/complete-redirect?id=success",
+			"decline": "https://paymentpage.example.com/complete-redirect?id=decline",
+		},
+	}
+
+	got, err := signaturePayloadString(payload)
+	if err != nil {
+		t.Fatalf("failed to build signature string: %v", err)
+	}
+
+	expected := "customer:address:Downing str., 23;customer:email:johndoe@example.com;customer:first_name:John;customer:id:585741;customer:identify:doc_number:54122312544;customer:ip_address:198.51.100.47;customer:last_name:Doe;general:payment_id:id_38202316;general:project_id:3254;payment:amount:10800;payment:currency:USD;payment:description:Computer keyboards;receipt_data:positions:0:amount:108;receipt_data:positions:0:description:Computer keyboard;receipt_data:positions:0:quantity:10;return_url:decline:https://paymentpage.example.com/complete-redirect?id=decline;return_url:success:https://paymentpage.example.com/complete-redirect?id=success"
+	if got != expected {
+		t.Fatalf("unexpected signature string\nexpected: %s\ngot: %s", expected, got)
+	}
+}
+
+func TestSignPayload_Example(t *testing.T) {
+	payload := map[string]any{
+		"general": map[string]any{
+			"project_id": 3254,
+			"payment_id": "id_38202316",
+			"signature":  "<ignored>",
+		},
+		"customer": map[string]any{
+			"id":         "585741",
+			"email":      "johndoe@example.com",
+			"first_name": "John",
+			"last_name":  "Doe",
+			"address":    "Downing str., 23",
+			"identify": map[string]any{
+				"doc_number": "54122312544",
+			},
+			"ip_address": "198.51.100.47",
+		},
+		"payment": map[string]any{
+			"amount":      10800,
+			"currency":    "USD",
+			"description": "Computer keyboards",
+		},
+		"receipt_data": map[string]any{
+			"positions": []any{
+				map[string]any{
+					"quantity":    "10",
+					"amount":      "108",
+					"description": "Computer keyboard",
+				},
+			},
+		},
+		"return_url": map[string]any{
+			"success": "https://paymentpage.example.com/complete-redirect?id=success",
+			"decline": "https://paymentpage.example.com/complete-redirect?id=decline",
+		},
+	}
+
+	got, err := SignPayload(payload, "secret")
+	if err != nil {
+		t.Fatalf("failed to sign payload: %v", err)
+	}
+	expected := "lagSnuspAn+F6XkmQISqwtBg0PsiTy62fF9x33TM+278mnufIDZyi1yP0BQALuCxyikkIxIMbodBn2F8hMdRwA=="
+	if got != expected {
+		t.Fatalf("unexpected signature\nexpected: %s\ngot: %s", expected, got)
+	}
+}
+
+func TestSignaturePayloadString_BooleansAndArrays(t *testing.T) {
+	payload := map[string]any{
+		"flag":       true,
+		"false_flag": false,
+		"empty":      "",
+		"zero":       0,
+		"nested": map[string]any{
+			"list":  []any{},
+			"items": []any{"alpha", "beta"},
+		},
+	}
+
+	got, err := signaturePayloadString(payload)
+	if err != nil {
+		t.Fatalf("failed to build signature string: %v", err)
+	}
+
+	expected := "empty:;false_flag:0;flag:1;nested:items:0:alpha;nested:items:1:beta;zero:0"
+	if got != expected {
+		t.Fatalf("unexpected signature string\nexpected: %s\ngot: %s", expected, got)
+	}
+}
+
+func TestSignPayload_EthEstimateGasExample(t *testing.T) {
+	payload := map[string]any{
+		"jsonrpc": "2.0",
+		"id":      3,
+		"method":  "eth_estimateGas",
+		"params": []any{
+			map[string]any{
+				"from":     "0xfa89b4d534bdeb2713d4ffd893e79d6535fb58f8",
+				"to":       "0x44162e39eefd9296231e772663a92e72958e182f",
+				"gasPrice": "0x64",
+				"data":     "0xa9059cbb00000000000000000000000044162e39eefd9296231e772663a92e72958e182f00000000000000000000000000000000000000000000000000000000000f4240",
+			},
+		},
+	}
+
+	got, err := SignPayload(payload, "1")
+	if err != nil {
+		t.Fatalf("failed to sign payload: %v", err)
+	}
+	expected := "C4WbSvXKSMyX8yLamQcUe/Nzr6nSt9m3HYn4jHSyA7yi/FaTiqk0r8BlfIzfxSCoDaRgrSd82ihgZW+DxELhdQ=="
+	if got != expected {
+		t.Fatalf("unexpected signature\nexpected: %s\ngot: %s", expected, got)
+	}
+}

api/payments/orchestrator/config.yml

@@ -51,6 +51,12 @@ gateway:
   call_timeout_seconds: 3
   insecure: true
 
+mntx:
+  address: "sendico_mntx_gateway:50075"
+  dial_timeout_seconds: 5
+  call_timeout_seconds: 3
+  insecure: true
+
 oracle:
   address: "sendico_fx_oracle:50051"
   dial_timeout_seconds: 5
@@ -59,8 +65,8 @@ oracle:
 
 card_gateways:
   monetix:
-    funding_address: "wallet_funding_monetix"
-    fee_address: "wallet_fee_monetix"
+    funding_address: "TGBDXEg9rxSqGFJDcb889zqTjDwx1bmLRF"
+    fee_wallet_ref: "694c124ed76f9f811ac57133"
 
 fee_ledger_accounts:
   monetix: "ledger:fees:monetix"

api/payments/orchestrator/internal/server/internal/serverimp.go

@@ -9,6 +9,7 @@ import (
 
 	oracleclient "github.com/tech/sendico/fx/oracle/client"
 	chainclient "github.com/tech/sendico/gateway/chain/client"
+	mntxclient "github.com/tech/sendico/gateway/mntx/client"
 	ledgerclient "github.com/tech/sendico/ledger/client"
 	"github.com/tech/sendico/payments/orchestrator/internal/service/orchestrator"
 	"github.com/tech/sendico/payments/orchestrator/storage"
@@ -36,6 +37,7 @@ type Imp struct {
 	feesConn      *grpc.ClientConn
 	ledgerClient  ledgerclient.Client
 	gatewayClient chainclient.Client
+	mntxClient    mntxclient.Client
 	oracleClient  oracleclient.Client
 }
 
@@ -44,6 +46,7 @@ type config struct {
 	Fees            clientConfig                      `yaml:"fees"`
 	Ledger          clientConfig                      `yaml:"ledger"`
 	Gateway         clientConfig                      `yaml:"gateway"`
+	Mntx            clientConfig                      `yaml:"mntx"`
 	Oracle          clientConfig                      `yaml:"oracle"`
 	CardGateways    map[string]cardGatewayRouteConfig `yaml:"card_gateways"`
 	FeeAccounts     map[string]string                 `yaml:"fee_ledger_accounts"`
@@ -59,6 +62,7 @@ type clientConfig struct {
 type cardGatewayRouteConfig struct {
 	FundingAddress string `yaml:"funding_address"`
 	FeeAddress     string `yaml:"fee_address"`
+	FeeWalletRef   string `yaml:"fee_wallet_ref"`
 }
 
 func (c clientConfig) address() string {
@@ -104,6 +108,9 @@ func (i *Imp) Shutdown() {
 	if i.gatewayClient != nil {
 		_ = i.gatewayClient.Close()
 	}
+	if i.mntxClient != nil {
+		_ = i.mntxClient.Close()
+	}
 	if i.oracleClient != nil {
 		_ = i.oracleClient.Close()
 	}
@@ -138,6 +145,11 @@ func (i *Imp) Start() error {
 		i.gatewayClient = gatewayClient
 	}
 
+	mntxClient := i.initMntxClient(cfg.Mntx)
+	if mntxClient != nil {
+		i.mntxClient = mntxClient
+	}
+
 	oracleClient := i.initOracleClient(cfg.Oracle)
 	if oracleClient != nil {
 		i.oracleClient = oracleClient
@@ -154,6 +166,9 @@ func (i *Imp) Start() error {
 		if gatewayClient != nil {
 			opts = append(opts, orchestrator.WithChainGatewayClient(gatewayClient))
 		}
+		if mntxClient != nil {
+			opts = append(opts, orchestrator.WithMntxGateway(mntxClient))
+		}
 		if oracleClient != nil {
 			opts = append(opts, orchestrator.WithOracleClient(oracleClient))
 		}
@@ -191,11 +206,11 @@ func (i *Imp) initFeesClient(cfg clientConfig) (feesv1.FeeEngineClient, *grpc.Cl
 
 	conn, err := grpc.DialContext(dialCtx, addr, grpc.WithTransportCredentials(creds))
 	if err != nil {
-		i.logger.Warn("failed to connect to fees service", zap.String("address", addr), zap.Error(err))
+		i.logger.Warn("Failed to connect to fees service", zap.String("address", addr), zap.Error(err))
 		return nil, nil
 	}
 
-	i.logger.Info("connected to fees service", zap.String("address", addr))
+	i.logger.Info("Connected to fees service", zap.String("address", addr))
 	return feesv1.NewFeeEngineClient(conn), conn
 }
 
@@ -215,10 +230,10 @@ func (i *Imp) initLedgerClient(cfg clientConfig) ledgerclient.Client {
 		Insecure:    cfg.InsecureTransport,
 	})
 	if err != nil {
-		i.logger.Warn("failed to connect to ledger service", zap.String("address", addr), zap.Error(err))
+		i.logger.Warn("Failed to connect to ledger service", zap.String("address", addr), zap.Error(err))
 		return nil
 	}
-	i.logger.Info("connected to ledger service", zap.String("address", addr))
+	i.logger.Info("Connected to ledger service", zap.String("address", addr))
 	return client
 }
 
@@ -245,6 +260,28 @@ func (i *Imp) initGatewayClient(cfg clientConfig) chainclient.Client {
 	return client
 }
 
+func (i *Imp) initMntxClient(cfg clientConfig) mntxclient.Client {
+	addr := cfg.address()
+	if addr == "" {
+		return nil
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), cfg.dialTimeout())
+	defer cancel()
+
+	client, err := mntxclient.New(ctx, mntxclient.Config{
+		Address:     addr,
+		DialTimeout: cfg.dialTimeout(),
+		CallTimeout: cfg.callTimeout(),
+	})
+	if err != nil {
+		i.logger.Warn("Failed to connect to mntx gateway service", zap.String("address", addr), zap.Error(err))
+		return nil
+	}
+	i.logger.Info("Connected to mntx gateway service", zap.String("address", addr))
+	return client
+}
+
 func (i *Imp) initOracleClient(cfg clientConfig) oracleclient.Client {
 	addr := cfg.address()
 	if addr == "" {
@@ -261,10 +298,10 @@ func (i *Imp) initOracleClient(cfg clientConfig) oracleclient.Client {
 		Insecure:    cfg.InsecureTransport,
 	})
 	if err != nil {
-		i.logger.Warn("failed to connect to oracle service", zap.String("address", addr), zap.Error(err))
+		i.logger.Warn("Failed to connect to oracle service", zap.String("address", addr), zap.Error(err))
 		return nil
 	}
-	i.logger.Info("connected to oracle service", zap.String("address", addr))
+	i.logger.Info("Connected to oracle service", zap.String("address", addr))
 	return client
 }
 
@@ -323,6 +360,7 @@ func buildCardGatewayRoutes(src map[string]cardGatewayRouteConfig) map[string]or
 		result[trimmedKey] = orchestrator.CardGatewayRoute{
 			FundingAddress: strings.TrimSpace(route.FundingAddress),
 			FeeAddress:     strings.TrimSpace(route.FeeAddress),
+			FeeWalletRef:   strings.TrimSpace(route.FeeWalletRef),
 		}
 	}
 	return result

api/payments/orchestrator/internal/service/orchestrator/card_payout.go

@@ -7,13 +7,21 @@ import (
 	"github.com/shopspring/decimal"
 	"github.com/tech/sendico/payments/orchestrator/storage/model"
 	"github.com/tech/sendico/pkg/merrors"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
 	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
 	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 	"go.uber.org/zap"
 )
 
-const defaultCardGateway = "monetix"
+const (
+	defaultCardGateway = "monetix"
+
+	stepCodeGasTopUp        = "gas_top_up"
+	stepCodeFundingTransfer = "funding_transfer"
+	stepCodeCardPayout      = "card_payout"
+	stepCodeFeeTransfer     = "fee_transfer"
+)
 
 func (s *Service) cardRoute(gateway string) (CardGatewayRoute, error) {
 	if len(s.deps.cardRoutes) == 0 {
@@ -54,24 +62,214 @@ func (s *Service) submitCardFundingTransfers(ctx context.Context, payment *model
 	if err != nil {
 		return err
 	}
+	sourceWalletRef := strings.TrimSpace(source.ManagedWalletRef)
+	fundingAddress := strings.TrimSpace(route.FundingAddress)
+	feeWalletRef := strings.TrimSpace(route.FeeWalletRef)
 
 	amount := cloneMoney(intent.Amount)
-	if amount == nil {
+	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
 		return merrors.InvalidArgument("card funding: amount is required")
 	}
 
+	payoutAmount, err := cardPayoutAmount(payment)
+	if err != nil {
+		return err
+	}
+
+	feeMoney := (*moneyv1.Money)(nil)
+	if quote != nil {
+		feeMoney = quote.GetExpectedFeeTotal()
+	}
+	if feeMoney == nil && payment.LastQuote != nil {
+		feeMoney = payment.LastQuote.ExpectedFeeTotal
+	}
+	feeDecimal := decimal.Zero
+	if feeMoney != nil && strings.TrimSpace(feeMoney.GetAmount()) != "" {
+		if strings.TrimSpace(feeMoney.GetCurrency()) == "" {
+			return merrors.InvalidArgument("card funding: fee currency is required")
+		}
+		feeDecimal, err = decimalFromMoney(feeMoney)
+		if err != nil {
+			return err
+		}
+	}
+	feeRequired := feeDecimal.IsPositive()
+
+	fundingDest := &chainv1.TransferDestination{
+		Destination: &chainv1.TransferDestination_ExternalAddress{ExternalAddress: fundingAddress},
+	}
+	fundingFee, err := s.estimateTransferNetworkFee(ctx, sourceWalletRef, fundingDest, amount)
+	if err != nil {
+		return err
+	}
+
+	var feeTransferFee *moneyv1.Money
+	if feeRequired {
+		if feeWalletRef == "" {
+			return merrors.InvalidArgument("card funding: fee wallet ref is required when fee exists")
+		}
+		feeDest := &chainv1.TransferDestination{
+			Destination: &chainv1.TransferDestination_ManagedWalletRef{ManagedWalletRef: feeWalletRef},
+		}
+		feeTransferFee, err = s.estimateTransferNetworkFee(ctx, sourceWalletRef, feeDest, feeMoney)
+		if err != nil {
+			return err
+		}
+	}
+
+	totalFee, gasCurrency, err := sumNetworkFees(fundingFee, feeTransferFee)
+	if err != nil {
+		return err
+	}
+
+	var estimatedTotalFee *moneyv1.Money
+	if gasCurrency != "" && !totalFee.IsNegative() {
+		estimatedTotalFee = makeMoney(gasCurrency, totalFee)
+	}
+
+	var topUpMoney *moneyv1.Money
+	var topUpFee *moneyv1.Money
+	topUpPositive := false
+	if estimatedTotalFee != nil {
+		computeResp, err := s.deps.gateway.client.ComputeGasTopUp(ctx, &chainv1.ComputeGasTopUpRequest{
+			WalletRef:         sourceWalletRef,
+			EstimatedTotalFee: estimatedTotalFee,
+		})
+		if err != nil {
+			s.logger.Warn("card funding gas top-up compute failed", zap.Error(err), zap.String("payment_ref", payment.PaymentRef))
+			return err
+		}
+		if computeResp != nil {
+			topUpMoney = computeResp.GetTopupAmount()
+		}
+		if topUpMoney != nil && strings.TrimSpace(topUpMoney.GetAmount()) != "" {
+			amountDec, err := decimalFromMoney(topUpMoney)
+			if err != nil {
+				return err
+			}
+			topUpPositive = amountDec.IsPositive()
+		}
+		if topUpMoney != nil && topUpPositive {
+			if strings.TrimSpace(topUpMoney.GetCurrency()) == "" {
+				return merrors.InvalidArgument("card funding: gas top-up currency is required")
+			}
+			if feeWalletRef == "" {
+				return merrors.InvalidArgument("card funding: fee wallet ref is required for gas top-up")
+			}
+			topUpDest := &chainv1.TransferDestination{
+				Destination: &chainv1.TransferDestination_ManagedWalletRef{ManagedWalletRef: sourceWalletRef},
+			}
+			topUpFee, err = s.estimateTransferNetworkFee(ctx, feeWalletRef, topUpDest, topUpMoney)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	plan := ensureExecutionPlan(payment)
+	var gasStep *model.ExecutionStep
+	if topUpMoney != nil && topUpPositive {
+		gasStep = ensureExecutionStep(plan, stepCodeGasTopUp)
+		gasStep.Description = "Top up native gas from fee wallet"
+		gasStep.Amount = cloneMoney(topUpMoney)
+		gasStep.NetworkFee = cloneMoney(topUpFee)
+		gasStep.SourceWalletRef = feeWalletRef
+		gasStep.DestinationRef = sourceWalletRef
+	}
+
+	fundStep := ensureExecutionStep(plan, stepCodeFundingTransfer)
+	fundStep.Description = "Transfer payout amount to card funding wallet"
+	fundStep.Amount = cloneMoney(amount)
+	fundStep.NetworkFee = cloneMoney(fundingFee)
+	fundStep.SourceWalletRef = sourceWalletRef
+	fundStep.DestinationRef = fundingAddress
+
+	cardStep := ensureExecutionStep(plan, stepCodeCardPayout)
+	cardStep.Description = "Submit card payout"
+	cardStep.Amount = cloneMoney(payoutAmount)
+	if card := intent.Destination.Card; card != nil {
+		if masked := strings.TrimSpace(card.MaskedPan); masked != "" {
+			cardStep.DestinationRef = masked
+		}
+	}
+
+	if feeRequired {
+		step := ensureExecutionStep(plan, stepCodeFeeTransfer)
+		step.Description = "Transfer fee to fee wallet"
+		step.Amount = cloneMoney(feeMoney)
+		step.NetworkFee = cloneMoney(feeTransferFee)
+		step.SourceWalletRef = sourceWalletRef
+		step.DestinationRef = feeWalletRef
+	}
+
+	updateExecutionPlanTotalNetworkFee(plan)
+
 	exec := payment.Execution
 	if exec == nil {
 		exec = &model.ExecutionRefs{}
 	}
 
+	if topUpMoney != nil && topUpPositive {
+		ensureResp, gasErr := s.deps.gateway.client.EnsureGasTopUp(ctx, &chainv1.EnsureGasTopUpRequest{
+			IdempotencyKey:    payment.IdempotencyKey + ":card:gas",
+			OrganizationRef:   payment.OrganizationRef.Hex(),
+			SourceWalletRef:   feeWalletRef,
+			TargetWalletRef:   sourceWalletRef,
+			EstimatedTotalFee: estimatedTotalFee,
+			Metadata:          cloneMetadata(payment.Metadata),
+			ClientReference:   payment.PaymentRef,
+		})
+		if gasErr != nil {
+			s.logger.Warn("card gas top-up transfer failed", zap.Error(gasErr), zap.String("payment_ref", payment.PaymentRef))
+			return gasErr
+		}
+		if gasStep != nil {
+			actual := (*moneyv1.Money)(nil)
+			if ensureResp != nil {
+				actual = ensureResp.GetTopupAmount()
+				if transfer := ensureResp.GetTransfer(); transfer != nil {
+					gasStep.TransferRef = strings.TrimSpace(transfer.GetTransferRef())
+				}
+			}
+			actualPositive := false
+			if actual != nil && strings.TrimSpace(actual.GetAmount()) != "" {
+				actualDec, err := decimalFromMoney(actual)
+				if err != nil {
+					return err
+				}
+				actualPositive = actualDec.IsPositive()
+			}
+			if actual != nil && actualPositive {
+				gasStep.Amount = cloneMoney(actual)
+				if strings.TrimSpace(actual.GetCurrency()) == "" {
+					return merrors.InvalidArgument("card funding: gas top-up currency is required")
+				}
+				topUpDest := &chainv1.TransferDestination{
+					Destination: &chainv1.TransferDestination_ManagedWalletRef{ManagedWalletRef: sourceWalletRef},
+				}
+				topUpFee, err = s.estimateTransferNetworkFee(ctx, feeWalletRef, topUpDest, actual)
+				if err != nil {
+					return err
+				}
+				gasStep.NetworkFee = cloneMoney(topUpFee)
+			} else {
+				gasStep.Amount = nil
+				gasStep.NetworkFee = nil
+			}
+		}
+		if gasStep != nil {
+			s.logger.Info("card gas top-up transfer submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("transfer_ref", gasStep.TransferRef))
+		}
+		updateExecutionPlanTotalNetworkFee(plan)
+	}
+
 	// Transfer payout amount to funding wallet.
 	fundReq := &chainv1.SubmitTransferRequest{
 		IdempotencyKey:  payment.IdempotencyKey + ":card:fund",
 		OrganizationRef: payment.OrganizationRef.Hex(),
-		SourceWalletRef: strings.TrimSpace(source.ManagedWalletRef),
+		SourceWalletRef: sourceWalletRef,
 		Destination: &chainv1.TransferDestination{
-			Destination: &chainv1.TransferDestination_ExternalAddress{ExternalAddress: strings.TrimSpace(route.FundingAddress)},
+			Destination: &chainv1.TransferDestination_ExternalAddress{ExternalAddress: fundingAddress},
 		},
 		Amount:          amount,
 		Metadata:        cloneMetadata(payment.Metadata),
@@ -84,42 +282,10 @@ func (s *Service) submitCardFundingTransfers(ctx context.Context, payment *model
 	}
 	if fundResp != nil && fundResp.GetTransfer() != nil {
 		exec.ChainTransferRef = strings.TrimSpace(fundResp.GetTransfer().GetTransferRef())
+		fundStep.TransferRef = exec.ChainTransferRef
 	}
 	s.logger.Info("card funding transfer submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("transfer_ref", exec.ChainTransferRef))
 
-	feeMoney := quote.GetExpectedFeeTotal()
-	if feeMoney != nil && strings.TrimSpace(feeMoney.GetAmount()) != "" {
-		if strings.TrimSpace(route.FeeAddress) == "" {
-			return merrors.InvalidArgument("card funding: fee address is required when fee exists")
-		}
-		feeDecimal, err := decimalFromMoney(feeMoney)
-		if err != nil {
-			return err
-		}
-		if feeDecimal.IsPositive() {
-			feeReq := &chainv1.SubmitTransferRequest{
-				IdempotencyKey:  payment.IdempotencyKey + ":card:fee",
-				OrganizationRef: payment.OrganizationRef.Hex(),
-				SourceWalletRef: strings.TrimSpace(source.ManagedWalletRef),
-				Destination: &chainv1.TransferDestination{
-					Destination: &chainv1.TransferDestination_ExternalAddress{ExternalAddress: strings.TrimSpace(route.FeeAddress)},
-				},
-				Amount:          feeMoney,
-				Metadata:        cloneMetadata(payment.Metadata),
-				ClientReference: payment.PaymentRef,
-			}
-			feeResp, feeErr := s.deps.gateway.client.SubmitTransfer(ctx, feeReq)
-			if feeErr != nil {
-				s.logger.Warn("card fee transfer failed", zap.Error(feeErr), zap.String("payment_ref", payment.PaymentRef))
-				return feeErr
-			}
-			if feeResp != nil && feeResp.GetTransfer() != nil {
-				exec.FeeTransferRef = strings.TrimSpace(feeResp.GetTransfer().GetTransferRef())
-			}
-			s.logger.Info("card fee transfer submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("transfer_ref", exec.FeeTransferRef))
-		}
-	}
-
 	payment.Execution = exec
 	return nil
 }
@@ -133,9 +299,9 @@ func (s *Service) submitCardPayout(ctx context.Context, payment *model.Payment)
 	if card == nil {
 		return merrors.InvalidArgument("card payout: card endpoint is required")
 	}
-	amount := cloneMoney(intent.Amount)
-	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
-		return merrors.InvalidArgument("card payout: amount is required")
+	amount, err := cardPayoutAmount(payment)
+	if err != nil {
+		return err
 	}
 	amtDec, err := decimalFromMoney(amount)
 	if err != nil {
@@ -147,6 +313,47 @@ func (s *Service) submitCardPayout(ctx context.Context, payment *model.Payment)
 	currency := strings.TrimSpace(amount.GetCurrency())
 	holder := strings.TrimSpace(card.Cardholder)
 	meta := cloneMetadata(payment.Metadata)
+	customer := intent.Customer
+	customerID := ""
+	customerFirstName := ""
+	customerMiddleName := ""
+	customerLastName := ""
+	customerIP := ""
+	customerZip := ""
+	customerCountry := ""
+	customerState := ""
+	customerCity := ""
+	customerAddress := ""
+	if customer != nil {
+		customerID = strings.TrimSpace(customer.ID)
+		customerFirstName = strings.TrimSpace(customer.FirstName)
+		customerMiddleName = strings.TrimSpace(customer.MiddleName)
+		customerLastName = strings.TrimSpace(customer.LastName)
+		customerIP = strings.TrimSpace(customer.IP)
+		customerZip = strings.TrimSpace(customer.Zip)
+		customerCountry = strings.TrimSpace(customer.Country)
+		customerState = strings.TrimSpace(customer.State)
+		customerCity = strings.TrimSpace(customer.City)
+		customerAddress = strings.TrimSpace(customer.Address)
+	}
+	if customerFirstName == "" {
+		customerFirstName = strings.TrimSpace(card.Cardholder)
+	}
+	if customerLastName == "" {
+		customerLastName = strings.TrimSpace(card.CardholderSurname)
+	}
+	if customerID == "" {
+		return merrors.InvalidArgument("card payout: customer id is required")
+	}
+	if customerFirstName == "" {
+		return merrors.InvalidArgument("card payout: customer first name is required")
+	}
+	if customerLastName == "" {
+		return merrors.InvalidArgument("card payout: customer last name is required")
+	}
+	if customerIP == "" {
+		return merrors.InvalidArgument("card payout: customer ip is required")
+	}
 
 	var (
 		state *mntxv1.CardPayoutState
@@ -154,13 +361,23 @@ func (s *Service) submitCardPayout(ctx context.Context, payment *model.Payment)
 
 	if token := strings.TrimSpace(card.Token); token != "" {
 		req := &mntxv1.CardTokenPayoutRequest{
-			PayoutId:    payoutID,
-			AmountMinor: minor,
-			Currency:    currency,
-			CardToken:   token,
-			CardHolder:  holder,
-			MaskedPan:   strings.TrimSpace(card.MaskedPan),
-			Metadata:    meta,
+			PayoutId:           payoutID,
+			CustomerId:         customerID,
+			CustomerFirstName:  customerFirstName,
+			CustomerMiddleName: customerMiddleName,
+			CustomerLastName:   customerLastName,
+			CustomerIp:         customerIP,
+			CustomerZip:        customerZip,
+			CustomerCountry:    customerCountry,
+			CustomerState:      customerState,
+			CustomerCity:       customerCity,
+			CustomerAddress:    customerAddress,
+			AmountMinor:        minor,
+			Currency:           currency,
+			CardToken:          token,
+			CardHolder:         holder,
+			MaskedPan:          strings.TrimSpace(card.MaskedPan),
+			Metadata:           meta,
 		}
 		resp, err := s.deps.mntx.client.CreateCardTokenPayout(ctx, req)
 		if err != nil {
@@ -170,14 +387,24 @@ func (s *Service) submitCardPayout(ctx context.Context, payment *model.Payment)
 		state = resp.GetPayout()
 	} else if pan := strings.TrimSpace(card.Pan); pan != "" {
 		req := &mntxv1.CardPayoutRequest{
-			PayoutId:     payoutID,
-			AmountMinor:  minor,
-			Currency:     currency,
-			CardPan:      pan,
-			CardExpYear:  card.ExpYear,
-			CardExpMonth: card.ExpMonth,
-			CardHolder:   holder,
-			Metadata:     meta,
+			PayoutId:           payoutID,
+			CustomerId:         customerID,
+			CustomerFirstName:  customerFirstName,
+			CustomerMiddleName: customerMiddleName,
+			CustomerLastName:   customerLastName,
+			CustomerIp:         customerIP,
+			CustomerZip:        customerZip,
+			CustomerCountry:    customerCountry,
+			CustomerState:      customerState,
+			CustomerCity:       customerCity,
+			CustomerAddress:    customerAddress,
+			AmountMinor:        minor,
+			Currency:           currency,
+			CardPan:            pan,
+			CardExpYear:        card.ExpYear,
+			CardExpMonth:       card.ExpMonth,
+			CardHolder:         holder,
+			Metadata:           meta,
 		}
 		resp, err := s.deps.mntx.client.CreateCardPayout(ctx, req)
 		if err != nil {
@@ -193,13 +420,92 @@ func (s *Service) submitCardPayout(ctx context.Context, payment *model.Payment)
 		return merrors.Internal("card payout: missing payout state")
 	}
 	recordCardPayoutState(payment, state)
-	if payment.Execution == nil {
-		payment.Execution = &model.ExecutionRefs{}
+	exec := payment.Execution
+	if exec == nil {
+		exec = &model.ExecutionRefs{}
 	}
-	if payment.Execution.CardPayoutRef == "" {
-		payment.Execution.CardPayoutRef = strings.TrimSpace(state.GetPayoutId())
+	if exec.CardPayoutRef == "" {
+		exec.CardPayoutRef = strings.TrimSpace(state.GetPayoutId())
 	}
-	s.logger.Info("card payout submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("payout_id", payment.Execution.CardPayoutRef))
+	payment.Execution = exec
+
+	plan := ensureExecutionPlan(payment)
+	if plan != nil {
+		step := ensureExecutionStep(plan, stepCodeCardPayout)
+		step.Description = "Submit card payout"
+		step.Amount = cloneMoney(amount)
+		if masked := strings.TrimSpace(card.MaskedPan); masked != "" {
+			step.DestinationRef = masked
+		}
+		if exec.CardPayoutRef != "" {
+			step.TransferRef = exec.CardPayoutRef
+		}
+		updateExecutionPlanTotalNetworkFee(plan)
+	}
+
+	feeMoney := (*moneyv1.Money)(nil)
+	if payment.LastQuote != nil {
+		feeMoney = payment.LastQuote.ExpectedFeeTotal
+	}
+	if feeMoney != nil && strings.TrimSpace(feeMoney.GetAmount()) != "" {
+		if strings.TrimSpace(feeMoney.GetCurrency()) == "" {
+			return merrors.InvalidArgument("card payout: fee currency is required")
+		}
+		feeDecimal, err := decimalFromMoney(feeMoney)
+		if err != nil {
+			return err
+		}
+		if feeDecimal.IsPositive() {
+			if !s.deps.gateway.available() {
+				s.logger.Warn("card fee aborted: chain gateway unavailable")
+				return merrors.InvalidArgument("card payout: chain gateway unavailable")
+			}
+			sourceWallet := intent.Source.ManagedWallet
+			if sourceWallet == nil || strings.TrimSpace(sourceWallet.ManagedWalletRef) == "" {
+				return merrors.InvalidArgument("card payout: source managed wallet is required")
+			}
+			route, err := s.cardRoute(defaultCardGateway)
+			if err != nil {
+				return err
+			}
+			feeWalletRef := strings.TrimSpace(route.FeeWalletRef)
+			if feeWalletRef == "" {
+				return merrors.InvalidArgument("card payout: fee wallet ref is required when fee exists")
+			}
+			feeReq := &chainv1.SubmitTransferRequest{
+				IdempotencyKey:  payment.IdempotencyKey + ":card:fee",
+				OrganizationRef: payment.OrganizationRef.Hex(),
+				SourceWalletRef: strings.TrimSpace(sourceWallet.ManagedWalletRef),
+				Destination: &chainv1.TransferDestination{
+					Destination: &chainv1.TransferDestination_ManagedWalletRef{ManagedWalletRef: feeWalletRef},
+				},
+				Amount:          feeMoney,
+				Metadata:        cloneMetadata(payment.Metadata),
+				ClientReference: payment.PaymentRef,
+			}
+			feeResp, feeErr := s.deps.gateway.client.SubmitTransfer(ctx, feeReq)
+			if feeErr != nil {
+				s.logger.Warn("card fee transfer failed", zap.Error(feeErr), zap.String("payment_ref", payment.PaymentRef))
+				return feeErr
+			}
+			if feeResp != nil && feeResp.GetTransfer() != nil {
+				exec.FeeTransferRef = strings.TrimSpace(feeResp.GetTransfer().GetTransferRef())
+			}
+			s.logger.Info("card fee transfer submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("transfer_ref", exec.FeeTransferRef))
+
+			if plan != nil {
+				step := ensureExecutionStep(plan, stepCodeFeeTransfer)
+				step.Description = "Transfer fee to fee wallet"
+				step.Amount = cloneMoney(feeMoney)
+				step.SourceWalletRef = strings.TrimSpace(sourceWallet.ManagedWalletRef)
+				step.DestinationRef = feeWalletRef
+				step.TransferRef = exec.FeeTransferRef
+				updateExecutionPlanTotalNetworkFee(plan)
+			}
+		}
+	}
+
+	s.logger.Info("card payout submitted", zap.String("payment_ref", payment.PaymentRef), zap.String("payout_id", exec.CardPayoutRef))
 
 	return nil
 }
@@ -250,3 +556,147 @@ func applyCardPayoutUpdate(payment *model.Payment, payout *mntxv1.CardPayoutStat
 		// leave as-is for pending/unspecified
 	}
 }
+
+func cardPayoutAmount(payment *model.Payment) (*moneyv1.Money, error) {
+	if payment == nil {
+		return nil, merrors.InvalidArgument("payment is required")
+	}
+	amount := cloneMoney(payment.Intent.Amount)
+	if payment.LastQuote != nil {
+		settlement := payment.LastQuote.ExpectedSettlementAmount
+		if settlement != nil && strings.TrimSpace(settlement.GetAmount()) != "" && strings.TrimSpace(settlement.GetCurrency()) != "" {
+			amount = cloneMoney(settlement)
+		}
+	}
+	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
+		return nil, merrors.InvalidArgument("card payout: amount is required")
+	}
+	return amount, nil
+}
+
+func (s *Service) estimateTransferNetworkFee(ctx context.Context, sourceWalletRef string, destination *chainv1.TransferDestination, amount *moneyv1.Money) (*moneyv1.Money, error) {
+	if !s.deps.gateway.available() {
+		return nil, merrors.InvalidArgument("chain gateway unavailable")
+	}
+	sourceWalletRef = strings.TrimSpace(sourceWalletRef)
+	if sourceWalletRef == "" {
+		return nil, merrors.InvalidArgument("source wallet ref is required")
+	}
+	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
+		return nil, merrors.InvalidArgument("amount is required")
+	}
+
+	resp, err := s.deps.gateway.client.EstimateTransferFee(ctx, &chainv1.EstimateTransferFeeRequest{
+		SourceWalletRef: sourceWalletRef,
+		Destination:     destination,
+		Amount:          cloneMoney(amount),
+	})
+	if err != nil {
+		s.logger.Warn("chain gateway fee estimation failed", zap.Error(err), zap.String("source_wallet_ref", sourceWalletRef))
+		return nil, merrors.Internal("chain_gateway_fee_estimation_failed")
+	}
+	if resp == nil {
+		s.logger.Warn("chain gateway fee estimation returned empty response", zap.String("source_wallet_ref", sourceWalletRef))
+		return nil, merrors.Internal("chain_gateway_fee_estimation_failed")
+	}
+	fee := resp.GetNetworkFee()
+	if fee == nil || strings.TrimSpace(fee.GetAmount()) == "" || strings.TrimSpace(fee.GetCurrency()) == "" {
+		s.logger.Warn("chain gateway fee estimation missing network fee", zap.String("source_wallet_ref", sourceWalletRef))
+		return nil, merrors.Internal("chain_gateway_fee_estimation_failed")
+	}
+	return cloneMoney(fee), nil
+}
+
+func sumNetworkFees(fees ...*moneyv1.Money) (decimal.Decimal, string, error) {
+	total := decimal.Zero
+	currency := ""
+	for _, fee := range fees {
+		if fee == nil {
+			continue
+		}
+		amount := strings.TrimSpace(fee.GetAmount())
+		feeCurrency := strings.TrimSpace(fee.GetCurrency())
+		if amount == "" || feeCurrency == "" {
+			return decimal.Zero, "", merrors.InvalidArgument("network fee is required")
+		}
+		value, err := decimalFromMoney(fee)
+		if err != nil {
+			return decimal.Zero, "", err
+		}
+		if currency == "" {
+			currency = feeCurrency
+		} else if !strings.EqualFold(currency, feeCurrency) {
+			return decimal.Zero, "", merrors.InvalidArgument("network fee currency mismatch")
+		}
+		total = total.Add(value)
+	}
+	return total, currency, nil
+}
+
+func ensureExecutionPlan(payment *model.Payment) *model.ExecutionPlan {
+	if payment == nil {
+		return nil
+	}
+	if payment.ExecutionPlan == nil {
+		payment.ExecutionPlan = &model.ExecutionPlan{}
+	}
+	return payment.ExecutionPlan
+}
+
+func ensureExecutionStep(plan *model.ExecutionPlan, code string) *model.ExecutionStep {
+	if plan == nil {
+		return nil
+	}
+	code = strings.TrimSpace(code)
+	if code == "" {
+		return nil
+	}
+	for _, step := range plan.Steps {
+		if step == nil {
+			continue
+		}
+		if strings.EqualFold(step.Code, code) {
+			if step.Code == "" {
+				step.Code = code
+			}
+			return step
+		}
+	}
+	step := &model.ExecutionStep{Code: code}
+	plan.Steps = append(plan.Steps, step)
+	return step
+}
+
+func updateExecutionPlanTotalNetworkFee(plan *model.ExecutionPlan) {
+	if plan == nil {
+		return
+	}
+	total := decimal.Zero
+	currency := ""
+	hasFee := false
+	for _, step := range plan.Steps {
+		if step == nil || step.NetworkFee == nil {
+			continue
+		}
+		fee := step.NetworkFee
+		if strings.TrimSpace(fee.GetAmount()) == "" || strings.TrimSpace(fee.GetCurrency()) == "" {
+			continue
+		}
+		if currency == "" {
+			currency = strings.TrimSpace(fee.GetCurrency())
+		} else if !strings.EqualFold(currency, fee.GetCurrency()) {
+			continue
+		}
+		value, err := decimalFromMoney(fee)
+		if err != nil {
+			continue
+		}
+		total = total.Add(value)
+		hasFee = true
+	}
+	if !hasFee || currency == "" {
+		plan.TotalNetworkFee = nil
+		return
+	}
+	plan.TotalNetworkFee = makeMoney(currency, total)
+}

api/payments/orchestrator/internal/service/orchestrator/card_payout_test.go

@@ -0,0 +1,413 @@
+package orchestrator
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	chainclient "github.com/tech/sendico/gateway/chain/client"
+	mntxclient "github.com/tech/sendico/gateway/mntx/client"
+	"github.com/tech/sendico/payments/orchestrator/storage/model"
+	mo "github.com/tech/sendico/pkg/model"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
+	mntxv1 "github.com/tech/sendico/pkg/proto/gateway/mntx/v1"
+	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.uber.org/zap"
+)
+
+func TestSubmitCardFundingTransfers_PlansTopUpAndFunding(t *testing.T) {
+	ctx := context.Background()
+
+	const (
+		sourceWalletRef = "wallet-src"
+		feeWalletRef    = "wallet-fee"
+		fundingAddress  = "0xfunding"
+	)
+
+	var estimateCalls []*chainv1.EstimateTransferFeeRequest
+	var computeCalls []*chainv1.ComputeGasTopUpRequest
+	var ensureCalls []*chainv1.EnsureGasTopUpRequest
+	var submitCalls []*chainv1.SubmitTransferRequest
+
+	gateway := &chainclient.Fake{
+		EstimateTransferFeeFn: func(ctx context.Context, req *chainv1.EstimateTransferFeeRequest) (*chainv1.EstimateTransferFeeResponse, error) {
+			estimateCalls = append(estimateCalls, req)
+			dest := req.GetDestination()
+			if req.GetSourceWalletRef() == feeWalletRef {
+				return &chainv1.EstimateTransferFeeResponse{
+					NetworkFee: &moneyv1.Money{Currency: "ETH", Amount: "0.005"},
+				}, nil
+			}
+			if dest != nil && strings.TrimSpace(dest.GetExternalAddress()) != "" {
+				return &chainv1.EstimateTransferFeeResponse{
+					NetworkFee: &moneyv1.Money{Currency: "ETH", Amount: "0.01"},
+				}, nil
+			}
+			return &chainv1.EstimateTransferFeeResponse{
+				NetworkFee: &moneyv1.Money{Currency: "ETH", Amount: "0.02"},
+			}, nil
+		},
+		ComputeGasTopUpFn: func(ctx context.Context, req *chainv1.ComputeGasTopUpRequest) (*chainv1.ComputeGasTopUpResponse, error) {
+			computeCalls = append(computeCalls, req)
+			return &chainv1.ComputeGasTopUpResponse{
+				TopupAmount: &moneyv1.Money{Currency: "ETH", Amount: "0.025"},
+			}, nil
+		},
+		EnsureGasTopUpFn: func(ctx context.Context, req *chainv1.EnsureGasTopUpRequest) (*chainv1.EnsureGasTopUpResponse, error) {
+			ensureCalls = append(ensureCalls, req)
+			return &chainv1.EnsureGasTopUpResponse{
+				TopupAmount: &moneyv1.Money{Currency: "ETH", Amount: "0.025"},
+				Transfer:    &chainv1.Transfer{TransferRef: req.GetIdempotencyKey()},
+			}, nil
+		},
+		SubmitTransferFn: func(ctx context.Context, req *chainv1.SubmitTransferRequest) (*chainv1.SubmitTransferResponse, error) {
+			submitCalls = append(submitCalls, req)
+			return &chainv1.SubmitTransferResponse{
+				Transfer: &chainv1.Transfer{TransferRef: req.GetIdempotencyKey()},
+			}, nil
+		},
+	}
+
+	svc := &Service{
+		logger: zap.NewNop(),
+		deps: serviceDependencies{
+			gateway: gatewayDependency{client: gateway},
+			cardRoutes: map[string]CardGatewayRoute{
+				defaultCardGateway: {
+					FundingAddress: fundingAddress,
+					FeeWalletRef:   feeWalletRef,
+				},
+			},
+		},
+	}
+
+	payment := &model.Payment{
+		PaymentRef:            "pay-1",
+		IdempotencyKey:        "pay-1",
+		OrganizationBoundBase: mo.OrganizationBoundBase{OrganizationRef: primitive.NewObjectID()},
+		Intent: model.PaymentIntent{
+			Kind: model.PaymentKindPayout,
+			Source: model.PaymentEndpoint{
+				Type: model.EndpointTypeManagedWallet,
+				ManagedWallet: &model.ManagedWalletEndpoint{
+					ManagedWalletRef: sourceWalletRef,
+				},
+			},
+			Destination: model.PaymentEndpoint{
+				Type: model.EndpointTypeCard,
+				Card: &model.CardEndpoint{
+					MaskedPan: "4111",
+				},
+			},
+			Amount: &moneyv1.Money{Currency: "USDT", Amount: "5"},
+		},
+	}
+
+	quote := &orchestratorv1.PaymentQuote{
+		ExpectedFeeTotal: &moneyv1.Money{Currency: "USDT", Amount: "0.35"},
+	}
+
+	if err := svc.submitCardFundingTransfers(ctx, payment, quote); err != nil {
+		t.Fatalf("submitCardFundingTransfers error: %v", err)
+	}
+
+	if len(estimateCalls) != 4 {
+		t.Fatalf("expected 4 fee estimates, got %d", len(estimateCalls))
+	}
+	if len(computeCalls) != 1 {
+		t.Fatalf("expected 1 gas top-up compute call, got %d", len(computeCalls))
+	}
+	if len(ensureCalls) != 1 {
+		t.Fatalf("expected 1 gas top-up ensure call, got %d", len(ensureCalls))
+	}
+	if len(submitCalls) != 1 {
+		t.Fatalf("expected 1 transfer submission, got %d", len(submitCalls))
+	}
+
+	computeCall := computeCalls[0]
+	if computeCall.GetWalletRef() != sourceWalletRef {
+		t.Fatalf("gas top-up compute wallet mismatch: %s", computeCall.GetWalletRef())
+	}
+	if computeCall.GetEstimatedTotalFee().GetCurrency() != "ETH" || computeCall.GetEstimatedTotalFee().GetAmount() != "0.03" {
+		t.Fatalf("gas top-up compute fee mismatch: %s %s", computeCall.GetEstimatedTotalFee().GetCurrency(), computeCall.GetEstimatedTotalFee().GetAmount())
+	}
+
+	ensureCall := ensureCalls[0]
+	if ensureCall.GetSourceWalletRef() != feeWalletRef {
+		t.Fatalf("gas top-up source wallet mismatch: %s", ensureCall.GetSourceWalletRef())
+	}
+	if ensureCall.GetTargetWalletRef() != sourceWalletRef {
+		t.Fatalf("gas top-up destination mismatch: %s", ensureCall.GetTargetWalletRef())
+	}
+	if ensureCall.GetEstimatedTotalFee().GetCurrency() != "ETH" || ensureCall.GetEstimatedTotalFee().GetAmount() != "0.03" {
+		t.Fatalf("gas top-up ensure fee mismatch: %s %s", ensureCall.GetEstimatedTotalFee().GetCurrency(), ensureCall.GetEstimatedTotalFee().GetAmount())
+	}
+
+	fundCall := findSubmitCall(t, submitCalls, "pay-1:card:fund")
+	if fundCall.GetDestination().GetExternalAddress() != fundingAddress {
+		t.Fatalf("funding destination mismatch: %s", fundCall.GetDestination().GetExternalAddress())
+	}
+	if fundCall.GetAmount().GetCurrency() != "USDT" || fundCall.GetAmount().GetAmount() != "5" {
+		t.Fatalf("funding amount mismatch: %s %s", fundCall.GetAmount().GetCurrency(), fundCall.GetAmount().GetAmount())
+	}
+
+	if payment.Execution == nil || payment.Execution.ChainTransferRef != "pay-1:card:fund" {
+		t.Fatalf("expected funding transfer ref recorded, got %v", payment.Execution)
+	}
+
+	plan := payment.ExecutionPlan
+	if plan == nil {
+		t.Fatal("expected execution plan to be populated")
+	}
+	gasStep := findExecutionStep(t, plan, stepCodeGasTopUp)
+	if gasStep.Amount.GetAmount() != "0.025" || gasStep.Amount.GetCurrency() != "ETH" {
+		t.Fatalf("gas step amount mismatch: %s %s", gasStep.Amount.GetCurrency(), gasStep.Amount.GetAmount())
+	}
+	if gasStep.NetworkFee.GetAmount() != "0.005" || gasStep.NetworkFee.GetCurrency() != "ETH" {
+		t.Fatalf("gas step fee mismatch: %s %s", gasStep.NetworkFee.GetCurrency(), gasStep.NetworkFee.GetAmount())
+	}
+	if gasStep.TransferRef != "pay-1:card:gas" {
+		t.Fatalf("expected gas step transfer ref to be set, got %s", gasStep.TransferRef)
+	}
+
+	fundStep := findExecutionStep(t, plan, stepCodeFundingTransfer)
+	if fundStep.NetworkFee.GetAmount() != "0.01" || fundStep.NetworkFee.GetCurrency() != "ETH" {
+		t.Fatalf("funding step fee mismatch: %s %s", fundStep.NetworkFee.GetCurrency(), fundStep.NetworkFee.GetAmount())
+	}
+	if fundStep.TransferRef != "pay-1:card:fund" {
+		t.Fatalf("funding step transfer ref mismatch: %s", fundStep.TransferRef)
+	}
+
+	cardStep := findExecutionStep(t, plan, stepCodeCardPayout)
+	if cardStep.Amount.GetAmount() != "5" || cardStep.Amount.GetCurrency() != "USDT" {
+		t.Fatalf("card step amount mismatch: %s %s", cardStep.Amount.GetCurrency(), cardStep.Amount.GetAmount())
+	}
+
+	feeStep := findExecutionStep(t, plan, stepCodeFeeTransfer)
+	if feeStep.Amount.GetAmount() != "0.35" || feeStep.Amount.GetCurrency() != "USDT" {
+		t.Fatalf("fee step amount mismatch: %s %s", feeStep.Amount.GetCurrency(), feeStep.Amount.GetAmount())
+	}
+	if feeStep.NetworkFee.GetAmount() != "0.02" || feeStep.NetworkFee.GetCurrency() != "ETH" {
+		t.Fatalf("fee step network fee mismatch: %s %s", feeStep.NetworkFee.GetCurrency(), feeStep.NetworkFee.GetAmount())
+	}
+	if feeStep.TransferRef != "" {
+		t.Fatalf("expected fee step transfer ref to be empty before payout, got %s", feeStep.TransferRef)
+	}
+
+	if plan.TotalNetworkFee == nil || plan.TotalNetworkFee.GetAmount() != "0.035" || plan.TotalNetworkFee.GetCurrency() != "ETH" {
+		t.Fatalf("total network fee mismatch: %v", plan.TotalNetworkFee)
+	}
+}
+
+func TestSubmitCardPayout_UsesSettlementAmountAndTransfersFee(t *testing.T) {
+	ctx := context.Background()
+
+	const (
+		sourceWalletRef = "wallet-src"
+		feeWalletRef    = "wallet-fee"
+	)
+
+	var payoutReq *mntxv1.CardPayoutRequest
+	var submitCalls []*chainv1.SubmitTransferRequest
+
+	gateway := &chainclient.Fake{
+		SubmitTransferFn: func(ctx context.Context, req *chainv1.SubmitTransferRequest) (*chainv1.SubmitTransferResponse, error) {
+			submitCalls = append(submitCalls, req)
+			return &chainv1.SubmitTransferResponse{
+				Transfer: &chainv1.Transfer{TransferRef: "fee-transfer"},
+			}, nil
+		},
+	}
+	mntx := &mntxclient.Fake{
+		CreateCardPayoutFn: func(ctx context.Context, req *mntxv1.CardPayoutRequest) (*mntxv1.CardPayoutResponse, error) {
+			payoutReq = req
+			return &mntxv1.CardPayoutResponse{
+				Payout: &mntxv1.CardPayoutState{
+					PayoutId: "payout-1",
+					Status:   mntxv1.PayoutStatus_PAYOUT_STATUS_PENDING,
+				},
+			}, nil
+		},
+	}
+
+	svc := &Service{
+		logger: zap.NewNop(),
+		deps: serviceDependencies{
+			gateway: gatewayDependency{client: gateway},
+			mntx:    mntxDependency{client: mntx},
+			cardRoutes: map[string]CardGatewayRoute{
+				defaultCardGateway: {
+					FundingAddress: "0xfunding",
+					FeeWalletRef:   feeWalletRef,
+				},
+			},
+		},
+	}
+
+	payment := &model.Payment{
+		PaymentRef:            "pay-2",
+		IdempotencyKey:        "pay-2",
+		OrganizationBoundBase: mo.OrganizationBoundBase{OrganizationRef: primitive.NewObjectID()},
+		Intent: model.PaymentIntent{
+			Kind: model.PaymentKindPayout,
+			Source: model.PaymentEndpoint{
+				Type: model.EndpointTypeManagedWallet,
+				ManagedWallet: &model.ManagedWalletEndpoint{
+					ManagedWalletRef: sourceWalletRef,
+				},
+			},
+			Destination: model.PaymentEndpoint{
+				Type: model.EndpointTypeCard,
+				Card: &model.CardEndpoint{
+					Pan:        "5536913762657597",
+					Cardholder: "Stephan",
+				},
+			},
+			Amount: &moneyv1.Money{Currency: "USDT", Amount: "5"},
+			Customer: &model.Customer{
+				ID:        "recipient-1",
+				FirstName: "Stephan",
+				LastName:  "Tester",
+				IP:        "198.51.100.10",
+			},
+		},
+		LastQuote: &model.PaymentQuoteSnapshot{
+			ExpectedSettlementAmount: &moneyv1.Money{Currency: "RUB", Amount: "392.30"},
+			ExpectedFeeTotal:         &moneyv1.Money{Currency: "USDT", Amount: "0.35"},
+		},
+	}
+
+	if err := svc.submitCardPayout(ctx, payment); err != nil {
+		t.Fatalf("submitCardPayout error: %v", err)
+	}
+
+	if payoutReq == nil {
+		t.Fatal("expected card payout request to be sent")
+	}
+	if payoutReq.GetCurrency() != "RUB" || payoutReq.GetAmountMinor() != 39230 {
+		t.Fatalf("payout request amount mismatch: %s %d", payoutReq.GetCurrency(), payoutReq.GetAmountMinor())
+	}
+
+	if payment.Execution == nil || payment.Execution.CardPayoutRef != "payout-1" {
+		t.Fatalf("expected card payout ref recorded, got %v", payment.Execution)
+	}
+	if payment.Execution.FeeTransferRef != "fee-transfer" {
+		t.Fatalf("expected fee transfer ref recorded, got %v", payment.Execution)
+	}
+
+	if len(submitCalls) != 1 {
+		t.Fatalf("expected 1 fee transfer submission, got %d", len(submitCalls))
+	}
+	feeCall := submitCalls[0]
+	if feeCall.GetSourceWalletRef() != sourceWalletRef {
+		t.Fatalf("fee transfer source mismatch: %s", feeCall.GetSourceWalletRef())
+	}
+	if feeCall.GetDestination().GetManagedWalletRef() != feeWalletRef {
+		t.Fatalf("fee transfer destination mismatch: %s", feeCall.GetDestination().GetManagedWalletRef())
+	}
+
+	plan := payment.ExecutionPlan
+	if plan == nil {
+		t.Fatal("expected execution plan to be populated")
+	}
+	cardStep := findExecutionStep(t, plan, stepCodeCardPayout)
+	if cardStep.TransferRef != "payout-1" {
+		t.Fatalf("card step transfer ref mismatch: %s", cardStep.TransferRef)
+	}
+	if cardStep.Amount.GetAmount() != "392.30" || cardStep.Amount.GetCurrency() != "RUB" {
+		t.Fatalf("card step amount mismatch: %s %s", cardStep.Amount.GetCurrency(), cardStep.Amount.GetAmount())
+	}
+
+	feeStep := findExecutionStep(t, plan, stepCodeFeeTransfer)
+	if feeStep.TransferRef != "fee-transfer" {
+		t.Fatalf("fee step transfer ref mismatch: %s", feeStep.TransferRef)
+	}
+	if feeStep.Amount.GetAmount() != "0.35" || feeStep.Amount.GetCurrency() != "USDT" {
+		t.Fatalf("fee step amount mismatch: %s %s", feeStep.Amount.GetCurrency(), feeStep.Amount.GetAmount())
+	}
+}
+
+func TestSubmitCardFundingTransfers_RequiresFeeWalletRef(t *testing.T) {
+	ctx := context.Background()
+
+	gateway := &chainclient.Fake{
+		EstimateTransferFeeFn: func(ctx context.Context, req *chainv1.EstimateTransferFeeRequest) (*chainv1.EstimateTransferFeeResponse, error) {
+			return &chainv1.EstimateTransferFeeResponse{
+				NetworkFee: &moneyv1.Money{Currency: "ETH", Amount: "0.01"},
+			}, nil
+		},
+	}
+
+	svc := &Service{
+		logger: zap.NewNop(),
+		deps: serviceDependencies{
+			gateway: gatewayDependency{client: gateway},
+			cardRoutes: map[string]CardGatewayRoute{
+				defaultCardGateway: {
+					FundingAddress: "0xfunding",
+				},
+			},
+		},
+	}
+
+	payment := &model.Payment{
+		PaymentRef:            "pay-3",
+		IdempotencyKey:        "pay-3",
+		OrganizationBoundBase: mo.OrganizationBoundBase{OrganizationRef: primitive.NewObjectID()},
+		Intent: model.PaymentIntent{
+			Kind: model.PaymentKindPayout,
+			Source: model.PaymentEndpoint{
+				Type: model.EndpointTypeManagedWallet,
+				ManagedWallet: &model.ManagedWalletEndpoint{
+					ManagedWalletRef: "wallet-src",
+				},
+			},
+			Destination: model.PaymentEndpoint{
+				Type: model.EndpointTypeCard,
+				Card: &model.CardEndpoint{
+					MaskedPan: "4111",
+				},
+			},
+			Amount: &moneyv1.Money{Currency: "USDT", Amount: "5"},
+		},
+	}
+
+	quote := &orchestratorv1.PaymentQuote{
+		ExpectedFeeTotal: &moneyv1.Money{Currency: "USDT", Amount: "0.35"},
+	}
+
+	err := svc.submitCardFundingTransfers(ctx, payment, quote)
+	if err == nil {
+		t.Fatal("expected error for missing fee wallet ref")
+	}
+	if !strings.Contains(err.Error(), "fee wallet ref") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func findSubmitCall(t *testing.T, calls []*chainv1.SubmitTransferRequest, idempotencyKey string) *chainv1.SubmitTransferRequest {
+	t.Helper()
+	for _, call := range calls {
+		if call.GetIdempotencyKey() == idempotencyKey {
+			return call
+		}
+	}
+	t.Fatalf("missing submit transfer call for %s", idempotencyKey)
+	return nil
+}
+
+func findExecutionStep(t *testing.T, plan *model.ExecutionPlan, code string) *model.ExecutionStep {
+	t.Helper()
+	if plan == nil {
+		t.Fatal("execution plan is nil")
+	}
+	for _, step := range plan.Steps {
+		if step != nil && strings.EqualFold(step.Code, code) {
+			return step
+		}
+	}
+	t.Fatalf("missing execution step %s", code)
+	return nil
+}

api/payments/orchestrator/internal/service/orchestrator/command_factory.go

@@ -13,7 +13,7 @@ import (
 type paymentEngine interface {
 	EnsureRepository(ctx context.Context) error
 	BuildPaymentQuote(ctx context.Context, orgRef string, req *orchestratorv1.QuotePaymentRequest) (*orchestratorv1.PaymentQuote, time.Time, error)
-	ResolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, error)
+	ResolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, *orchestratorv1.PaymentIntent, error)
 	ExecutePayment(ctx context.Context, store storage.PaymentsStore, payment *model.Payment, quote *orchestratorv1.PaymentQuote) error
 	Repository() storage.Repository
 }
@@ -30,7 +30,7 @@ func (e defaultPaymentEngine) BuildPaymentQuote(ctx context.Context, orgRef stri
 	return e.svc.buildPaymentQuote(ctx, orgRef, req)
 }
 
-func (e defaultPaymentEngine) ResolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, error) {
+func (e defaultPaymentEngine) ResolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, *orchestratorv1.PaymentIntent, error) {
 	return e.svc.resolvePaymentQuote(ctx, in)
 }
 

api/payments/orchestrator/internal/service/orchestrator/convert.go

@@ -26,6 +26,7 @@ func intentFromProto(src *orchestratorv1.PaymentIntent) model.PaymentIntent {
 		FeePolicy:      src.GetFeePolicy(),
 		SettlementMode: src.GetSettlementMode(),
 		Attributes:     cloneMetadata(src.GetAttributes()),
+		Customer:       customerFromProto(src.GetCustomer()),
 	}
 	if src.GetFx() != nil {
 		intent.FX = fxIntentFromProto(src.GetFx())
@@ -69,13 +70,14 @@ func endpointFromProto(src *orchestratorv1.PaymentEndpoint) model.PaymentEndpoin
 	if card := src.GetCard(); card != nil {
 		result.Type = model.EndpointTypeCard
 		result.Card = &model.CardEndpoint{
-			Pan:        strings.TrimSpace(card.GetPan()),
-			Token:      strings.TrimSpace(card.GetToken()),
-			Cardholder: strings.TrimSpace(card.GetCardholderName()),
-			ExpMonth:   card.GetExpMonth(),
-			ExpYear:    card.GetExpYear(),
-			Country:    strings.TrimSpace(card.GetCountry()),
-			MaskedPan:  strings.TrimSpace(card.GetMaskedPan()),
+			Pan:               strings.TrimSpace(card.GetPan()),
+			Token:             strings.TrimSpace(card.GetToken()),
+			Cardholder:        strings.TrimSpace(card.GetCardholderName()),
+			CardholderSurname: strings.TrimSpace(card.GetCardholderSurname()),
+			ExpMonth:          card.GetExpMonth(),
+			ExpYear:           card.GetExpYear(),
+			Country:           strings.TrimSpace(card.GetCountry()),
+			MaskedPan:         strings.TrimSpace(card.GetMaskedPan()),
 		}
 		return result
 	}
@@ -125,6 +127,7 @@ func toProtoPayment(src *model.Payment) *orchestratorv1.Payment {
 		FailureReason:  src.FailureReason,
 		LastQuote:      modelQuoteToProto(src.LastQuote),
 		Execution:      protoExecutionFromModel(src.Execution),
+		ExecutionPlan:  protoExecutionPlanFromModel(src.ExecutionPlan),
 		Metadata:       cloneMetadata(src.Metadata),
 	}
 	if src.CardPayout != nil {
@@ -160,6 +163,7 @@ func protoIntentFromModel(src model.PaymentIntent) *orchestratorv1.PaymentIntent
 		FeePolicy:      src.FeePolicy,
 		SettlementMode: src.SettlementMode,
 		Attributes:     cloneMetadata(src.Attributes),
+		Customer:       protoCustomerFromModel(src.Customer),
 	}
 	if src.FX != nil {
 		intent.Fx = protoFXIntentFromModel(src.FX)
@@ -167,6 +171,42 @@ func protoIntentFromModel(src model.PaymentIntent) *orchestratorv1.PaymentIntent
 	return intent
 }
 
+func customerFromProto(src *orchestratorv1.Customer) *model.Customer {
+	if src == nil {
+		return nil
+	}
+	return &model.Customer{
+		ID:         strings.TrimSpace(src.GetId()),
+		FirstName:  strings.TrimSpace(src.GetFirstName()),
+		MiddleName: strings.TrimSpace(src.GetMiddleName()),
+		LastName:   strings.TrimSpace(src.GetLastName()),
+		IP:         strings.TrimSpace(src.GetIp()),
+		Zip:        strings.TrimSpace(src.GetZip()),
+		Country:    strings.TrimSpace(src.GetCountry()),
+		State:      strings.TrimSpace(src.GetState()),
+		City:       strings.TrimSpace(src.GetCity()),
+		Address:    strings.TrimSpace(src.GetAddress()),
+	}
+}
+
+func protoCustomerFromModel(src *model.Customer) *orchestratorv1.Customer {
+	if src == nil {
+		return nil
+	}
+	return &orchestratorv1.Customer{
+		Id:         strings.TrimSpace(src.ID),
+		FirstName:  strings.TrimSpace(src.FirstName),
+		MiddleName: strings.TrimSpace(src.MiddleName),
+		LastName:   strings.TrimSpace(src.LastName),
+		Ip:         strings.TrimSpace(src.IP),
+		Zip:        strings.TrimSpace(src.Zip),
+		Country:    strings.TrimSpace(src.Country),
+		State:      strings.TrimSpace(src.State),
+		City:       strings.TrimSpace(src.City),
+		Address:    strings.TrimSpace(src.Address),
+	}
+}
+
 func protoEndpointFromModel(src model.PaymentEndpoint) *orchestratorv1.PaymentEndpoint {
 	endpoint := &orchestratorv1.PaymentEndpoint{
 		Metadata: cloneMetadata(src.Metadata),
@@ -203,11 +243,12 @@ func protoEndpointFromModel(src model.PaymentEndpoint) *orchestratorv1.PaymentEn
 	case model.EndpointTypeCard:
 		if src.Card != nil {
 			card := &orchestratorv1.CardEndpoint{
-				CardholderName: src.Card.Cardholder,
-				ExpMonth:       src.Card.ExpMonth,
-				ExpYear:        src.Card.ExpYear,
-				Country:        src.Card.Country,
-				MaskedPan:      src.Card.MaskedPan,
+				CardholderName:    src.Card.Cardholder,
+				CardholderSurname: src.Card.CardholderSurname,
+				ExpMonth:          src.Card.ExpMonth,
+				ExpYear:           src.Card.ExpYear,
+				Country:           src.Card.Country,
+				MaskedPan:         src.Card.MaskedPan,
 			}
 			if pan := strings.TrimSpace(src.Card.Pan); pan != "" {
 				card.Card = &orchestratorv1.CardEndpoint_Pan{Pan: pan}
@@ -251,6 +292,41 @@ func protoExecutionFromModel(src *model.ExecutionRefs) *orchestratorv1.Execution
 	}
 }
 
+func protoExecutionStepFromModel(src *model.ExecutionStep) *orchestratorv1.ExecutionStep {
+	if src == nil {
+		return nil
+	}
+	return &orchestratorv1.ExecutionStep{
+		Code:            src.Code,
+		Description:     src.Description,
+		Amount:          cloneMoney(src.Amount),
+		NetworkFee:      cloneMoney(src.NetworkFee),
+		SourceWalletRef: src.SourceWalletRef,
+		DestinationRef:  src.DestinationRef,
+		TransferRef:     src.TransferRef,
+		Metadata:        cloneMetadata(src.Metadata),
+	}
+}
+
+func protoExecutionPlanFromModel(src *model.ExecutionPlan) *orchestratorv1.ExecutionPlan {
+	if src == nil {
+		return nil
+	}
+	steps := make([]*orchestratorv1.ExecutionStep, 0, len(src.Steps))
+	for _, step := range src.Steps {
+		if protoStep := protoExecutionStepFromModel(step); protoStep != nil {
+			steps = append(steps, protoStep)
+		}
+	}
+	if len(steps) == 0 {
+		steps = nil
+	}
+	return &orchestratorv1.ExecutionPlan{
+		Steps:           steps,
+		TotalNetworkFee: cloneMoney(src.TotalNetworkFee),
+	}
+}
+
 func modelQuoteToProto(src *model.PaymentQuoteSnapshot) *orchestratorv1.PaymentQuote {
 	if src == nil {
 		return nil

api/payments/orchestrator/internal/service/orchestrator/convert_card_test.go

@@ -11,12 +11,13 @@ func TestEndpointFromProtoCard(t *testing.T) {
 	protoEndpoint := &orchestratorv1.PaymentEndpoint{
 		Endpoint: &orchestratorv1.PaymentEndpoint_Card{
 			Card: &orchestratorv1.CardEndpoint{
-				Card:           &orchestratorv1.CardEndpoint_Pan{Pan: " 411111 "},
-				CardholderName: " Jane Doe ",
-				ExpMonth:       12,
-				ExpYear:        2030,
-				Country:        " US ",
-				MaskedPan:      " ****1111 ",
+				Card:              &orchestratorv1.CardEndpoint_Pan{Pan: " 411111 "},
+				CardholderName:    " Jane ",
+				CardholderSurname: " Doe ",
+				ExpMonth:          12,
+				ExpYear:           2030,
+				Country:           " US ",
+				MaskedPan:         " ****1111 ",
 			},
 		},
 		Metadata: map[string]string{"k": "v"},
@@ -29,7 +30,7 @@ func TestEndpointFromProtoCard(t *testing.T) {
 	if modelEndpoint.Card == nil {
 		t.Fatalf("card payload missing")
 	}
-	if modelEndpoint.Card.Pan != "411111" || modelEndpoint.Card.Cardholder != "Jane Doe" || modelEndpoint.Card.Country != "US" || modelEndpoint.Card.MaskedPan != "****1111" {
+	if modelEndpoint.Card.Pan != "411111" || modelEndpoint.Card.Cardholder != "Jane" || modelEndpoint.Card.CardholderSurname != "Doe" || modelEndpoint.Card.Country != "US" || modelEndpoint.Card.MaskedPan != "****1111" {
 		t.Fatalf("card payload not trimmed as expected: %#v", modelEndpoint.Card)
 	}
 	if modelEndpoint.Metadata["k"] != "v" {
@@ -41,12 +42,13 @@ func TestProtoEndpointFromModelCard(t *testing.T) {
 	modelEndpoint := model.PaymentEndpoint{
 		Type: model.EndpointTypeCard,
 		Card: &model.CardEndpoint{
-			Token:      "tok_123",
-			Cardholder: "Jane",
-			ExpMonth:   1,
-			ExpYear:    2028,
-			Country:    "GB",
-			MaskedPan:  "****1234",
+			Token:             "tok_123",
+			Cardholder:        "Jane",
+			CardholderSurname: "Doe",
+			ExpMonth:          1,
+			ExpYear:           2028,
+			Country:           "GB",
+			MaskedPan:         "****1234",
 		},
 		Metadata: map[string]string{"k": "v"},
 	}
@@ -60,7 +62,7 @@ func TestProtoEndpointFromModelCard(t *testing.T) {
 	if !ok || token.Token != "tok_123" {
 		t.Fatalf("expected token payload, got %T %#v", card.Card, card.Card)
 	}
-	if card.GetCardholderName() != "Jane" || card.GetCountry() != "GB" || card.GetMaskedPan() != "****1234" {
+	if card.GetCardholderName() != "Jane" || card.GetCardholderSurname() != "Doe" || card.GetCountry() != "GB" || card.GetMaskedPan() != "****1234" {
 		t.Fatalf("card details mismatch: %#v", card)
 	}
 	if protoEndpoint.GetMetadata()["k"] != "v" {

api/payments/orchestrator/internal/service/orchestrator/handlers_commands.go

@@ -12,6 +12,7 @@ import (
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mlogger"
 	"github.com/tech/sendico/pkg/mservice"
+	"github.com/tech/sendico/pkg/mutil/mzap"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.uber.org/zap"
@@ -61,7 +62,13 @@ func (h *quotePaymentCommand) Execute(ctx context.Context, req *orchestratorv1.Q
 		if err := quotesStore.Create(ctx, record); err != nil {
 			return gsresponse.Auto[orchestratorv1.QuotePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 		}
-		h.logger.Info("stored payment quote", zap.String("quote_ref", quoteRef), zap.String("org_ref", orgID.Hex()))
+		h.logger.Info(
+			"Stored payment quote",
+			zap.String("quote_ref", quoteRef),
+			mzap.ObjRef("org_ref", orgID),
+			zap.String("idempotency_key", strings.TrimSpace(req.GetIdempotencyKey())),
+			zap.String("kind", intent.GetKind().String()),
+		)
 	}
 
 	return gsresponse.Success(&orchestratorv1.QuotePaymentResponse{Quote: quote})
@@ -79,7 +86,7 @@ func (h *quotePaymentsCommand) Execute(ctx context.Context, req *orchestratorv1.
 	if req == nil {
 		return gsresponse.InvalidArgument[orchestratorv1.QuotePaymentsResponse](h.logger, mservice.PaymentOrchestrator, merrors.InvalidArgument("nil request"))
 	}
-	orgRef, orgID, err := validateMetaAndOrgRef(req.GetMeta())
+	orgID, orgRef, err := validateMetaAndOrgRef(req.GetMeta())
 	if err != nil {
 		return gsresponse.InvalidArgument[orchestratorv1.QuotePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
@@ -101,7 +108,7 @@ func (h *quotePaymentsCommand) Execute(ctx context.Context, req *orchestratorv1.
 			Intent:         intent,
 			PreviewOnly:    req.GetPreviewOnly(),
 		}
-		quote, expiresAt, err := h.engine.BuildPaymentQuote(ctx, orgRef, quoteReq)
+		quote, expiresAt, err := h.engine.BuildPaymentQuote(ctx, orgID, quoteReq)
 		if err != nil {
 			return gsresponse.Auto[orchestratorv1.QuotePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 		}
@@ -132,11 +139,14 @@ func (h *quotePaymentsCommand) Execute(ctx context.Context, req *orchestratorv1.
 			ExpiresAt: expiresAt,
 		}
 		record.SetID(primitive.NewObjectID())
-		record.SetOrganizationRef(orgID)
+		record.SetOrganizationRef(orgRef)
 		if err := quotesStore.Create(ctx, record); err != nil {
 			return gsresponse.Auto[orchestratorv1.QuotePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 		}
-		h.logger.Info("stored payment quotes", zap.String("quote_ref", quoteRef), zap.String("org_ref", orgID.Hex()))
+		h.logger.Info("Stored payment quotes",
+			zap.String("quote_ref", quoteRef), mzap.ObjRef("org_ref", orgRef),
+			zap.String("idempotency_key", baseKey), zap.Int("quote_count", len(quotes)),
+		)
 	}
 
 	return gsresponse.Success(&orchestratorv1.QuotePaymentsResponse{
@@ -158,7 +168,7 @@ func (h *initiatePaymentsCommand) Execute(ctx context.Context, req *orchestrator
 	if req == nil {
 		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, merrors.InvalidArgument("nil request"))
 	}
-	_, orgID, err := validateMetaAndOrgRef(req.GetMeta())
+	_, orgRef, err := validateMetaAndOrgRef(req.GetMeta())
 	if err != nil {
 		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
@@ -175,7 +185,7 @@ func (h *initiatePaymentsCommand) Execute(ctx context.Context, req *orchestrator
 	if err != nil {
 		return gsresponse.Unavailable[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
-	record, err := quotesStore.GetByRef(ctx, orgID, quoteRef)
+	record, err := quotesStore.GetByRef(ctx, orgRef, quoteRef)
 	if err != nil {
 		if errors.Is(err, storage.ErrQuoteNotFound) {
 			return gsresponse.FailedPrecondition[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, "quote_not_found", merrors.InvalidArgument("quote_ref not found or expired"))
@@ -213,14 +223,14 @@ func (h *initiatePaymentsCommand) Execute(ctx context.Context, req *orchestrator
 		quoteProto.QuoteRef = quoteRef
 
 		perKey := perIntentIdempotencyKey(idempotencyKey, i, len(intents))
-		if existing, err := getPaymentByIdempotencyKey(ctx, store, orgID, perKey); err == nil && existing != nil {
+		if existing, err := getPaymentByIdempotencyKey(ctx, store, orgRef, perKey); err == nil && existing != nil {
 			payments = append(payments, toProtoPayment(existing))
 			continue
 		} else if err != nil && !errors.Is(err, storage.ErrPaymentNotFound) {
 			return gsresponse.Auto[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, err)
 		}
 
-		entity := newPayment(orgID, intentProto, perKey, req.GetMetadata(), quoteProto)
+		entity := newPayment(orgRef, intentProto, perKey, req.GetMetadata(), quoteProto)
 		if err = store.Create(ctx, entity); err != nil {
 			if errors.Is(err, storage.ErrDuplicatePayment) {
 				return gsresponse.Auto[orchestratorv1.InitiatePaymentsResponse](h.logger, mservice.PaymentOrchestrator, merrors.DataConflict("payment already exists"))
@@ -235,6 +245,13 @@ func (h *initiatePaymentsCommand) Execute(ctx context.Context, req *orchestrator
 		payments = append(payments, toProtoPayment(entity))
 	}
 
+	h.logger.Info(
+		"Payments initiated",
+		mzap.ObjRef("org_ref", orgRef),
+		zap.String("quote_ref", quoteRef),
+		zap.String("idempotency_key", idempotencyKey),
+		zap.Int("payment_count", len(payments)),
+	)
 	return gsresponse.Success(&orchestratorv1.InitiatePaymentsResponse{Payments: payments})
 }
 
@@ -255,13 +272,31 @@ func (h *initiatePaymentCommand) Execute(ctx context.Context, req *orchestratorv
 		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
 	intent := req.GetIntent()
-	if err := requireNonNilIntent(intent); err != nil {
-		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
+	quoteRef := strings.TrimSpace(req.GetQuoteRef())
+	hasIntent := intent != nil
+	hasQuote := quoteRef != ""
+	switch {
+	case !hasIntent && !hasQuote:
+		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, merrors.InvalidArgument("intent or quote_ref is required"))
+	case hasIntent && hasQuote:
+		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, merrors.InvalidArgument("intent and quote_ref are mutually exclusive"))
+	}
+	if hasIntent {
+		if err := requireNonNilIntent(intent); err != nil {
+			return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
+		}
 	}
 	idempotencyKey, err := requireIdempotencyKey(req.GetIdempotencyKey())
 	if err != nil {
 		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
+	h.logger.Debug(
+		"Initiate payment request accepted",
+		zap.String("org_ref", orgID.Hex()),
+		zap.String("idempotency_key", idempotencyKey),
+		zap.String("quote_ref", quoteRef),
+		zap.Bool("has_intent", hasIntent),
+	)
 
 	store, err := ensurePaymentsStore(h.engine.Repository())
 	if err != nil {
@@ -269,18 +304,24 @@ func (h *initiatePaymentCommand) Execute(ctx context.Context, req *orchestratorv
 	}
 
 	if existing, err := getPaymentByIdempotencyKey(ctx, store, orgID, idempotencyKey); err == nil && existing != nil {
-		h.logger.Debug("idempotent payment request reused", zap.String("payment_ref", existing.PaymentRef), zap.String("org_ref", orgID.Hex()))
+		h.logger.Debug(
+			"idempotent payment request reused",
+			zap.String("payment_ref", existing.PaymentRef),
+			zap.String("org_ref", orgID.Hex()),
+			zap.String("idempotency_key", idempotencyKey),
+			zap.String("quote_ref", quoteRef),
+		)
 		return gsresponse.Success(&orchestratorv1.InitiatePaymentResponse{Payment: toProtoPayment(existing)})
 	} else if err != nil && !errors.Is(err, storage.ErrPaymentNotFound) {
 		return gsresponse.Auto[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
 
-	quoteSnapshot, err := h.engine.ResolvePaymentQuote(ctx, quoteResolutionInput{
+	quoteSnapshot, resolvedIntent, err := h.engine.ResolvePaymentQuote(ctx, quoteResolutionInput{
 		OrgRef:         orgRef,
 		OrgID:          orgID,
 		Meta:           req.GetMeta(),
 		Intent:         intent,
-		QuoteRef:       req.GetQuoteRef(),
+		QuoteRef:       quoteRef,
 		IdempotencyKey: req.GetIdempotencyKey(),
 	})
 	if err != nil {
@@ -301,8 +342,17 @@ func (h *initiatePaymentCommand) Execute(ctx context.Context, req *orchestratorv
 	if quoteSnapshot == nil {
 		quoteSnapshot = &orchestratorv1.PaymentQuote{}
 	}
+	if err := requireNonNilIntent(resolvedIntent); err != nil {
+		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
+	}
+	h.logger.Debug(
+		"Payment quote resolved",
+		zap.String("org_ref", orgID.Hex()),
+		zap.String("quote_ref", quoteRef),
+		zap.Bool("quote_ref_used", quoteRef != ""),
+	)
 
-	entity := newPayment(orgID, intent, idempotencyKey, req.GetMetadata(), quoteSnapshot)
+	entity := newPayment(orgID, resolvedIntent, idempotencyKey, req.GetMetadata(), quoteSnapshot)
 
 	if err = store.Create(ctx, entity); err != nil {
 		if errors.Is(err, storage.ErrDuplicatePayment) {
@@ -315,7 +365,14 @@ func (h *initiatePaymentCommand) Execute(ctx context.Context, req *orchestratorv
 		return gsresponse.Auto[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
 
-	h.logger.Info("payment initiated", zap.String("payment_ref", entity.PaymentRef), zap.String("org_ref", orgID.Hex()), zap.String("kind", intent.GetKind().String()))
+	h.logger.Info(
+		"Payment initiated",
+		zap.String("payment_ref", entity.PaymentRef),
+		zap.String("org_ref", orgID.Hex()),
+		zap.String("kind", resolvedIntent.GetKind().String()),
+		zap.String("quote_ref", quoteSnapshot.GetQuoteRef()),
+		zap.String("idempotency_key", idempotencyKey),
+	)
 	return gsresponse.Success(&orchestratorv1.InitiatePaymentResponse{
 		Payment: toProtoPayment(entity),
 	})
@@ -355,7 +412,7 @@ func (h *cancelPaymentCommand) Execute(ctx context.Context, req *orchestratorv1.
 	if err := store.Update(ctx, payment); err != nil {
 		return gsresponse.Auto[orchestratorv1.CancelPaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
-	h.logger.Info("payment cancelled", zap.String("payment_ref", payment.PaymentRef), zap.String("org_ref", payment.OrganizationRef.Hex()))
+	h.logger.Info("Payment cancelled", zap.String("payment_ref", payment.PaymentRef), zap.String("org_ref", payment.OrganizationRef.Hex()))
 	return gsresponse.Success(&orchestratorv1.CancelPaymentResponse{Payment: toProtoPayment(payment)})
 }
 
@@ -396,7 +453,7 @@ func (h *initiateConversionCommand) Execute(ctx context.Context, req *orchestrat
 	}
 
 	if existing, err := getPaymentByIdempotencyKey(ctx, store, orgID, idempotencyKey); err == nil && existing != nil {
-		h.logger.Debug("idempotent conversion request reused", zap.String("payment_ref", existing.PaymentRef), zap.String("org_ref", orgID.Hex()))
+		h.logger.Debug("Idempotent conversion request reused", zap.String("payment_ref", existing.PaymentRef), zap.String("org_ref", orgID.Hex()))
 		return gsresponse.Success(&orchestratorv1.InitiateConversionResponse{Conversion: toProtoPayment(existing)})
 	} else if err != nil && !errors.Is(err, storage.ErrPaymentNotFound) {
 		return gsresponse.Auto[orchestratorv1.InitiateConversionResponse](h.logger, mservice.PaymentOrchestrator, err)
@@ -439,7 +496,7 @@ func (h *initiateConversionCommand) Execute(ctx context.Context, req *orchestrat
 		return gsresponse.Auto[orchestratorv1.InitiateConversionResponse](h.logger, mservice.PaymentOrchestrator, err)
 	}
 
-	h.logger.Info("conversion initiated", zap.String("payment_ref", entity.PaymentRef), zap.String("org_ref", orgID.Hex()))
+	h.logger.Info("Conversion initiated", zap.String("payment_ref", entity.PaymentRef), zap.String("org_ref", orgID.Hex()))
 	return gsresponse.Success(&orchestratorv1.InitiateConversionResponse{
 		Conversion: toProtoPayment(entity),
 	})

api/payments/orchestrator/internal/service/orchestrator/options.go

@@ -56,10 +56,11 @@ func (m mntxDependency) available() bool {
 	return m.client != nil
 }
 
-// CardGatewayRoute maps a gateway to its funding and fee destinations (addresses).
+// CardGatewayRoute maps a gateway to its funding and fee destinations.
 type CardGatewayRoute struct {
 	FundingAddress string
 	FeeAddress     string
+	FeeWalletRef   string
 }
 
 // WithFeeEngine wires the fee engine client.

api/payments/orchestrator/internal/service/orchestrator/service_helpers.go

@@ -103,33 +103,40 @@ type quoteResolutionError struct {
 
 func (e quoteResolutionError) Error() string { return e.err.Error() }
 
-func (s *Service) resolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, error) {
+func (s *Service) resolvePaymentQuote(ctx context.Context, in quoteResolutionInput) (*orchestratorv1.PaymentQuote, *orchestratorv1.PaymentIntent, error) {
 	if ref := strings.TrimSpace(in.QuoteRef); ref != "" {
 		quotesStore, err := ensureQuotesStore(s.storage)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 		record, err := quotesStore.GetByRef(ctx, in.OrgID, ref)
 		if err != nil {
 			if errors.Is(err, storage.ErrQuoteNotFound) {
-				return nil, quoteResolutionError{code: "quote_not_found", err: merrors.InvalidArgument("quote_ref not found or expired")}
+				return nil, nil, quoteResolutionError{code: "quote_not_found", err: merrors.InvalidArgument("quote_ref not found or expired")}
 			}
-			return nil, err
+			return nil, nil, err
 		}
 		if !record.ExpiresAt.IsZero() && s.clock.Now().After(record.ExpiresAt) {
-			return nil, quoteResolutionError{code: "quote_expired", err: merrors.InvalidArgument("quote_ref expired")}
+			return nil, nil, quoteResolutionError{code: "quote_expired", err: merrors.InvalidArgument("quote_ref expired")}
 		}
-		if !proto.Equal(protoIntentFromModel(record.Intent), in.Intent) {
-			return nil, quoteResolutionError{code: "quote_intent_mismatch", err: merrors.InvalidArgument("quote_ref does not match intent")}
+		intent, err := recordIntentFromQuote(record)
+		if err != nil {
+			return nil, nil, err
 		}
-		quote := modelQuoteToProto(record.Quote)
-		if quote == nil {
-			return nil, merrors.InvalidArgument("stored quote is empty")
+		if in.Intent != nil && !proto.Equal(intent, in.Intent) {
+			return nil, nil, quoteResolutionError{code: "quote_intent_mismatch", err: merrors.InvalidArgument("quote_ref does not match intent")}
+		}
+		quote, err := recordQuoteFromQuote(record)
+		if err != nil {
+			return nil, nil, err
 		}
 		quote.QuoteRef = ref
-		return quote, nil
+		return quote, intent, nil
 	}
 
+	if in.Intent == nil {
+		return nil, nil, merrors.InvalidArgument("intent is required")
+	}
 	req := &orchestratorv1.QuotePaymentRequest{
 		Meta:           in.Meta,
 		IdempotencyKey: in.IdempotencyKey,
@@ -138,9 +145,41 @@ func (s *Service) resolvePaymentQuote(ctx context.Context, in quoteResolutionInp
 	}
 	quote, _, err := s.buildPaymentQuote(ctx, in.OrgRef, req)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return quote, nil
+	return quote, in.Intent, nil
+}
+
+func recordIntentFromQuote(record *model.PaymentQuoteRecord) (*orchestratorv1.PaymentIntent, error) {
+	if record == nil {
+		return nil, merrors.InvalidArgument("stored quote payload is incomplete")
+	}
+	if len(record.Intents) > 0 {
+		if len(record.Intents) != 1 {
+			return nil, merrors.InvalidArgument("stored quote payload is incomplete")
+		}
+		return protoIntentFromModel(record.Intents[0]), nil
+	}
+	if record.Intent.Amount == nil && (record.Intent.Kind == "" || record.Intent.Kind == model.PaymentKindUnspecified) {
+		return nil, merrors.InvalidArgument("stored quote payload is incomplete")
+	}
+	return protoIntentFromModel(record.Intent), nil
+}
+
+func recordQuoteFromQuote(record *model.PaymentQuoteRecord) (*orchestratorv1.PaymentQuote, error) {
+	if record == nil {
+		return nil, merrors.InvalidArgument("stored quote is empty")
+	}
+	if record.Quote != nil {
+		return modelQuoteToProto(record.Quote), nil
+	}
+	if len(record.Quotes) > 0 {
+		if len(record.Quotes) != 1 {
+			return nil, merrors.InvalidArgument("stored quote payload is incomplete")
+		}
+		return modelQuoteToProto(record.Quotes[0]), nil
+	}
+	return nil, merrors.InvalidArgument("stored quote is empty")
 }
 
 func newPayment(orgID primitive.ObjectID, intent *orchestratorv1.PaymentIntent, idempotencyKey string, metadata map[string]string, quote *orchestratorv1.PaymentQuote) *model.Payment {

api/payments/orchestrator/internal/service/orchestrator/service_helpers_test.go

@@ -73,7 +73,7 @@ func TestResolvePaymentQuote_NotFound(t *testing.T) {
 		storage: stubRepo{quotes: &helperQuotesStore{}},
 		clock:   clockpkg.NewSystem(),
 	}
-	_, err := svc.resolvePaymentQuote(context.Background(), quoteResolutionInput{
+	_, _, err := svc.resolvePaymentQuote(context.Background(), quoteResolutionInput{
 		OrgRef:   org.Hex(),
 		OrgID:    org,
 		Meta:     &orchestratorv1.RequestMeta{OrganizationRef: org.Hex()},
@@ -98,7 +98,7 @@ func TestResolvePaymentQuote_Expired(t *testing.T) {
 		storage: stubRepo{quotes: &helperQuotesStore{records: map[string]*model.PaymentQuoteRecord{"q1": record}}},
 		clock:   clockpkg.NewSystem(),
 	}
-	_, err := svc.resolvePaymentQuote(context.Background(), quoteResolutionInput{
+	_, _, err := svc.resolvePaymentQuote(context.Background(), quoteResolutionInput{
 		OrgRef:   org.Hex(),
 		OrgID:    org,
 		Meta:     &orchestratorv1.RequestMeta{OrganizationRef: org.Hex()},
@@ -110,6 +110,35 @@ func TestResolvePaymentQuote_Expired(t *testing.T) {
 	}
 }
 
+func TestResolvePaymentQuote_QuoteRefUsesStoredIntent(t *testing.T) {
+	org := primitive.NewObjectID()
+	intent := &orchestratorv1.PaymentIntent{Amount: &moneyv1.Money{Currency: "USD", Amount: "1"}}
+	record := &model.PaymentQuoteRecord{
+		QuoteRef: "q1",
+		Intent:   intentFromProto(intent),
+		Quote:    &model.PaymentQuoteSnapshot{},
+	}
+	svc := &Service{
+		storage: stubRepo{quotes: &helperQuotesStore{records: map[string]*model.PaymentQuoteRecord{"q1": record}}},
+		clock:   clockpkg.NewSystem(),
+	}
+	quote, resolvedIntent, err := svc.resolvePaymentQuote(context.Background(), quoteResolutionInput{
+		OrgRef:   org.Hex(),
+		OrgID:    org,
+		Meta:     &orchestratorv1.RequestMeta{OrganizationRef: org.Hex()},
+		QuoteRef: "q1",
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if quote == nil || quote.GetQuoteRef() != "q1" {
+		t.Fatalf("expected quote_ref q1, got %#v", quote)
+	}
+	if resolvedIntent == nil || resolvedIntent.GetAmount().GetAmount() != "1" {
+		t.Fatalf("expected resolved intent with amount, got %#v", resolvedIntent)
+	}
+}
+
 func TestInitiatePaymentIdempotency(t *testing.T) {
 	logger := mloggerfactory.NewLogger(false)
 	org := primitive.NewObjectID()
@@ -140,6 +169,42 @@ func TestInitiatePaymentIdempotency(t *testing.T) {
 	}
 }
 
+func TestInitiatePaymentByQuoteRef(t *testing.T) {
+	logger := mloggerfactory.NewLogger(false)
+	org := primitive.NewObjectID()
+	store := newHelperPaymentStore()
+	intent := &orchestratorv1.PaymentIntent{Amount: &moneyv1.Money{Currency: "USD", Amount: "1"}}
+	record := &model.PaymentQuoteRecord{
+		QuoteRef: "q1",
+		Intent:   intentFromProto(intent),
+		Quote:    &model.PaymentQuoteSnapshot{},
+	}
+	svc := NewService(logger, stubRepo{
+		payments: store,
+		quotes:   &helperQuotesStore{records: map[string]*model.PaymentQuoteRecord{"q1": record}},
+	}, WithClock(clockpkg.NewSystem()))
+	svc.ensureHandlers()
+
+	req := &orchestratorv1.InitiatePaymentRequest{
+		Meta:           &orchestratorv1.RequestMeta{OrganizationRef: org.Hex()},
+		QuoteRef:       "q1",
+		IdempotencyKey: "k1",
+	}
+	resp, err := svc.h.commands.InitiatePayment().Execute(context.Background(), req)(context.Background())
+	if err != nil {
+		t.Fatalf("initiate by quote_ref failed: %v", err)
+	}
+	if resp == nil || resp.GetPayment() == nil {
+		t.Fatalf("expected payment response")
+	}
+	if resp.GetPayment().GetIntent().GetAmount().GetAmount() != "1" {
+		t.Fatalf("expected intent amount to be resolved from quote")
+	}
+	if resp.GetPayment().GetLastQuote().GetQuoteRef() != "q1" {
+		t.Fatalf("expected last quote_ref to be set from stored quote")
+	}
+}
+
 // --- test doubles ---
 
 type stubRepo struct {

api/payments/orchestrator/storage/model/payment.go

@@ -82,13 +82,14 @@ type ExternalChainEndpoint struct {
 
 // CardEndpoint describes a card payout destination.
 type CardEndpoint struct {
-	Pan        string `bson:"pan,omitempty" json:"pan,omitempty"`
-	Token      string `bson:"token,omitempty" json:"token,omitempty"`
-	Cardholder string `bson:"cardholder,omitempty" json:"cardholder,omitempty"`
-	ExpMonth   uint32 `bson:"expMonth,omitempty" json:"expMonth,omitempty"`
-	ExpYear    uint32 `bson:"expYear,omitempty" json:"expYear,omitempty"`
-	Country    string `bson:"country,omitempty" json:"country,omitempty"`
-	MaskedPan  string `bson:"maskedPan,omitempty" json:"maskedPan,omitempty"`
+	Pan               string `bson:"pan,omitempty" json:"pan,omitempty"`
+	Token             string `bson:"token,omitempty" json:"token,omitempty"`
+	Cardholder        string `bson:"cardholder,omitempty" json:"cardholder,omitempty"`
+	CardholderSurname string `bson:"cardholderSurname,omitempty" json:"cardholderSurname,omitempty"`
+	ExpMonth          uint32 `bson:"expMonth,omitempty" json:"expMonth,omitempty"`
+	ExpYear           uint32 `bson:"expYear,omitempty" json:"expYear,omitempty"`
+	Country           string `bson:"country,omitempty" json:"country,omitempty"`
+	MaskedPan         string `bson:"maskedPan,omitempty" json:"maskedPan,omitempty"`
 }
 
 // CardPayout stores gateway payout tracking info.
@@ -134,6 +135,21 @@ type PaymentIntent struct {
 	FeePolicy      *feesv1.PolicyOverrides       `bson:"feePolicy,omitempty" json:"feePolicy,omitempty"`
 	SettlementMode orchestratorv1.SettlementMode `bson:"settlementMode,omitempty" json:"settlementMode,omitempty"`
 	Attributes     map[string]string             `bson:"attributes,omitempty" json:"attributes,omitempty"`
+	Customer       *Customer                     `bson:"customer,omitempty" json:"customer,omitempty"`
+}
+
+// Customer captures payer/recipient identity details for downstream processing.
+type Customer struct {
+	ID         string `bson:"id,omitempty" json:"id,omitempty"`
+	FirstName  string `bson:"firstName,omitempty" json:"firstName,omitempty"`
+	MiddleName string `bson:"middleName,omitempty" json:"middleName,omitempty"`
+	LastName   string `bson:"lastName,omitempty" json:"lastName,omitempty"`
+	IP         string `bson:"ip,omitempty" json:"ip,omitempty"`
+	Zip        string `bson:"zip,omitempty" json:"zip,omitempty"`
+	Country    string `bson:"country,omitempty" json:"country,omitempty"`
+	State      string `bson:"state,omitempty" json:"state,omitempty"`
+	City       string `bson:"city,omitempty" json:"city,omitempty"`
+	Address    string `bson:"address,omitempty" json:"address,omitempty"`
 }
 
 // PaymentQuoteSnapshot stores the latest quote info.
@@ -158,6 +174,24 @@ type ExecutionRefs struct {
 	FeeTransferRef   string `bson:"feeTransferRef,omitempty" json:"feeTransferRef,omitempty"`
 }
 
+// ExecutionStep describes a planned or executed payment step for reporting.
+type ExecutionStep struct {
+	Code            string            `bson:"code,omitempty" json:"code,omitempty"`
+	Description     string            `bson:"description,omitempty" json:"description,omitempty"`
+	Amount          *moneyv1.Money    `bson:"amount,omitempty" json:"amount,omitempty"`
+	NetworkFee      *moneyv1.Money    `bson:"networkFee,omitempty" json:"networkFee,omitempty"`
+	SourceWalletRef string            `bson:"sourceWalletRef,omitempty" json:"sourceWalletRef,omitempty"`
+	DestinationRef  string            `bson:"destinationRef,omitempty" json:"destinationRef,omitempty"`
+	TransferRef     string            `bson:"transferRef,omitempty" json:"transferRef,omitempty"`
+	Metadata        map[string]string `bson:"metadata,omitempty" json:"metadata,omitempty"`
+}
+
+// ExecutionPlan captures the ordered list of steps to execute a payment.
+type ExecutionPlan struct {
+	Steps           []*ExecutionStep `bson:"steps,omitempty" json:"steps,omitempty"`
+	TotalNetworkFee *moneyv1.Money   `bson:"totalNetworkFee,omitempty" json:"totalNetworkFee,omitempty"`
+}
+
 // Payment persists orchestrated payment lifecycle.
 type Payment struct {
 	storable.Base               `bson:",inline" json:",inline"`
@@ -171,6 +205,7 @@ type Payment struct {
 	FailureReason  string                `bson:"failureReason,omitempty" json:"failureReason,omitempty"`
 	LastQuote      *PaymentQuoteSnapshot `bson:"lastQuote,omitempty" json:"lastQuote,omitempty"`
 	Execution      *ExecutionRefs        `bson:"execution,omitempty" json:"execution,omitempty"`
+	ExecutionPlan  *ExecutionPlan        `bson:"executionPlan,omitempty" json:"executionPlan,omitempty"`
 	Metadata       map[string]string     `bson:"metadata,omitempty" json:"metadata,omitempty"`
 	CardPayout     *CardPayout           `bson:"cardPayout,omitempty" json:"cardPayout,omitempty"`
 }
@@ -212,12 +247,41 @@ func (p *Payment) Normalize() {
 			p.Intent.Attributes[k] = strings.TrimSpace(v)
 		}
 	}
+	if p.Intent.Customer != nil {
+		p.Intent.Customer.ID = strings.TrimSpace(p.Intent.Customer.ID)
+		p.Intent.Customer.FirstName = strings.TrimSpace(p.Intent.Customer.FirstName)
+		p.Intent.Customer.MiddleName = strings.TrimSpace(p.Intent.Customer.MiddleName)
+		p.Intent.Customer.LastName = strings.TrimSpace(p.Intent.Customer.LastName)
+		p.Intent.Customer.IP = strings.TrimSpace(p.Intent.Customer.IP)
+		p.Intent.Customer.Zip = strings.TrimSpace(p.Intent.Customer.Zip)
+		p.Intent.Customer.Country = strings.TrimSpace(p.Intent.Customer.Country)
+		p.Intent.Customer.State = strings.TrimSpace(p.Intent.Customer.State)
+		p.Intent.Customer.City = strings.TrimSpace(p.Intent.Customer.City)
+		p.Intent.Customer.Address = strings.TrimSpace(p.Intent.Customer.Address)
+	}
 	if p.Execution != nil {
 		p.Execution.DebitEntryRef = strings.TrimSpace(p.Execution.DebitEntryRef)
 		p.Execution.CreditEntryRef = strings.TrimSpace(p.Execution.CreditEntryRef)
 		p.Execution.FXEntryRef = strings.TrimSpace(p.Execution.FXEntryRef)
 		p.Execution.ChainTransferRef = strings.TrimSpace(p.Execution.ChainTransferRef)
 	}
+	if p.ExecutionPlan != nil {
+		for _, step := range p.ExecutionPlan.Steps {
+			if step == nil {
+				continue
+			}
+			step.Code = strings.TrimSpace(step.Code)
+			step.Description = strings.TrimSpace(step.Description)
+			step.SourceWalletRef = strings.TrimSpace(step.SourceWalletRef)
+			step.DestinationRef = strings.TrimSpace(step.DestinationRef)
+			step.TransferRef = strings.TrimSpace(step.TransferRef)
+			if step.Metadata != nil {
+				for k, v := range step.Metadata {
+					step.Metadata[k] = strings.TrimSpace(v)
+				}
+			}
+		}
+	}
 }
 
 func normalizeEndpoint(ep *PaymentEndpoint) {
@@ -257,6 +321,7 @@ func normalizeEndpoint(ep *PaymentEndpoint) {
 			ep.Card.Pan = strings.TrimSpace(ep.Card.Pan)
 			ep.Card.Token = strings.TrimSpace(ep.Card.Token)
 			ep.Card.Cardholder = strings.TrimSpace(ep.Card.Cardholder)
+			ep.Card.CardholderSurname = strings.TrimSpace(ep.Card.CardholderSurname)
 			ep.Card.Country = strings.TrimSpace(ep.Card.Country)
 			ep.Card.MaskedPan = strings.TrimSpace(ep.Card.MaskedPan)
 		}

api/proto/gateway/chain/v1/chain.proto

@@ -100,6 +100,7 @@ message WalletBalance {
   common.money.v1.Money pending_inbound = 2;
   common.money.v1.Money pending_outbound = 3;
   google.protobuf.Timestamp calculated_at = 4;
+  common.money.v1.Money native_available = 5;
 }
 
 message GetWalletBalanceRequest {
@@ -188,6 +189,32 @@ message EstimateTransferFeeResponse {
   string estimation_context = 2;
 }
 
+message ComputeGasTopUpRequest {
+  string wallet_ref = 1;
+  common.money.v1.Money estimated_total_fee = 2;
+}
+
+message ComputeGasTopUpResponse {
+  common.money.v1.Money topup_amount = 1;
+  bool cap_hit = 2;
+}
+
+message EnsureGasTopUpRequest {
+  string idempotency_key = 1;
+  string organization_ref = 2;
+  string source_wallet_ref = 3;
+  string target_wallet_ref = 4;
+  common.money.v1.Money estimated_total_fee = 5;
+  map<string, string> metadata = 6;
+  string client_reference = 7;
+}
+
+message EnsureGasTopUpResponse {
+  common.money.v1.Money topup_amount = 1;
+  bool cap_hit = 2;
+  Transfer transfer = 3;
+}
+
 message WalletDepositObservedEvent {
   string deposit_ref = 1;
   string wallet_ref = 2;
@@ -217,4 +244,6 @@ service ChainGatewayService {
   rpc ListTransfers(ListTransfersRequest) returns (ListTransfersResponse);
 
   rpc EstimateTransferFee(EstimateTransferFeeRequest) returns (EstimateTransferFeeResponse);
+  rpc ComputeGasTopUp(ComputeGasTopUpRequest) returns (ComputeGasTopUpResponse);
+  rpc EnsureGasTopUp(EnsureGasTopUpRequest) returns (EnsureGasTopUpResponse);
 }

api/proto/payments/orchestrator/v1/orchestrator.proto

@@ -112,6 +112,20 @@ message PaymentIntent {
   fees.v1.PolicyOverrides fee_policy = 7;
   map<string, string> attributes = 8;
   SettlementMode settlement_mode = 9;
+  Customer customer = 10;
+}
+
+message Customer {
+  string id = 1;
+  string first_name = 2;
+  string middle_name = 3;
+  string last_name = 4;
+  string ip = 5;
+  string zip = 6;
+  string country = 7;
+  string state = 8;
+  string city = 9;
+  string address = 10;
 }
 
 message PaymentQuote {
@@ -141,6 +155,22 @@ message ExecutionRefs {
   string fee_transfer_ref = 6;
 }
 
+message ExecutionStep {
+  string code = 1;
+  string description = 2;
+  common.money.v1.Money amount = 3;
+  common.money.v1.Money network_fee = 4;
+  string source_wallet_ref = 5;
+  string destination_ref = 6;
+  string transfer_ref = 7;
+  map<string, string> metadata = 8;
+}
+
+message ExecutionPlan {
+  repeated ExecutionStep steps = 1;
+  common.money.v1.Money total_network_fee = 2;
+}
+
 // Card payout gateway tracking info.
 message CardPayout {
   string payout_ref = 1;
@@ -166,6 +196,7 @@ message Payment {
   google.protobuf.Timestamp created_at = 10;
   google.protobuf.Timestamp updated_at = 11;
   CardPayout card_payout = 12;
+  ExecutionPlan execution_plan = 13;
 }
 
 message QuotePaymentRequest {

api/server/interface/api/srequest/customer.go

@@ -0,0 +1,15 @@
+package srequest
+
+// Customer captures payer/recipient identity details for downstream processing.
+type Customer struct {
+	ID         string `json:"id,omitempty"`
+	FirstName  string `json:"first_name,omitempty"`
+	MiddleName string `json:"middle_name,omitempty"`
+	LastName   string `json:"last_name,omitempty"`
+	IP         string `json:"ip,omitempty"`
+	Zip        string `json:"zip,omitempty"`
+	Country    string `json:"country,omitempty"`
+	State      string `json:"state,omitempty"`
+	City       string `json:"city,omitempty"`
+	Address    string `json:"address,omitempty"`
+}

api/server/interface/api/srequest/payment_intent.go

@@ -13,6 +13,7 @@ type PaymentIntent struct {
 	FX             *FXIntent         `json:"fx,omitempty"`
 	SettlementMode SettlementMode    `json:"settlement_mode,omitempty"`
 	Attributes     map[string]string `json:"attributes,omitempty"`
+	Customer       *Customer         `json:"customer,omitempty"`
 }
 
 type AssetResolverStub struct{}

api/server/interface/api/sresponse/payment.go

@@ -7,7 +7,7 @@ import (
 	"github.com/tech/sendico/pkg/mlogger"
 	"github.com/tech/sendico/pkg/model"
 	feesv1 "github.com/tech/sendico/pkg/proto/billing/fees/v1"
-	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
+	paginationv1 "github.com/tech/sendico/pkg/proto/common/pagination/v1"
 	oraclev1 "github.com/tech/sendico/pkg/proto/oracle/v1"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 )
@@ -20,11 +20,6 @@ type FeeLine struct {
 	Meta             map[string]string `json:"meta,omitempty"`
 }
 
-type NetworkFee struct {
-	NetworkFee        *model.Money `json:"networkFee,omitempty"`
-	EstimationContext string       `json:"estimationContext,omitempty"`
-}
-
 type FxQuote struct {
 	QuoteRef        string       `json:"quoteRef,omitempty"`
 	BaseCurrency    string       `json:"baseCurrency,omitempty"`
@@ -45,7 +40,6 @@ type PaymentQuote struct {
 	ExpectedSettlementAmount *model.Money `json:"expectedSettlementAmount,omitempty"`
 	ExpectedFeeTotal         *model.Money `json:"expectedFeeTotal,omitempty"`
 	FeeLines                 []FeeLine    `json:"feeLines,omitempty"`
-	NetworkFee               *NetworkFee  `json:"networkFee,omitempty"`
 	FxQuote                  *FxQuote     `json:"fxQuote,omitempty"`
 }
 
@@ -53,7 +47,6 @@ type PaymentQuoteAggregate struct {
 	DebitAmounts              []*model.Money `json:"debitAmounts,omitempty"`
 	ExpectedSettlementAmounts []*model.Money `json:"expectedSettlementAmounts,omitempty"`
 	ExpectedFeeTotals         []*model.Money `json:"expectedFeeTotals,omitempty"`
-	NetworkFeeTotals          []*model.Money `json:"networkFeeTotals,omitempty"`
 }
 
 type PaymentQuotes struct {
@@ -83,7 +76,8 @@ type paymentQuotesResponse struct {
 
 type paymentsResponse struct {
 	authResponse `json:",inline"`
-	Payments     []Payment `json:"payments"`
+	Payments     []Payment                        `json:"payments"`
+	Page         *paginationv1.CursorPageResponse `json:"page,omitempty"`
 }
 
 type paymentResponse struct {
@@ -115,6 +109,15 @@ func PaymentsResponse(logger mlogger.Logger, payments []*orchestratorv1.Payment,
 	})
 }
 
+// PaymentsList wraps a list of payments with refreshed access token and pagination data.
+func PaymentsListResponse(logger mlogger.Logger, resp *orchestratorv1.ListPaymentsResponse, token *TokenData) http.HandlerFunc {
+	return response.Ok(logger, paymentsResponse{
+		Payments:     toPayments(resp.GetPayments()),
+		Page:         resp.GetPage(),
+		authResponse: authResponse{AccessToken: *token},
+	})
+}
+
 // Payment wraps a payment with refreshed access token.
 func PaymentResponse(logger mlogger.Logger, payment *orchestratorv1.Payment, token *TokenData) http.HandlerFunc {
 	return response.Ok(logger, paymentResponse{
@@ -146,16 +149,6 @@ func toFeeLines(lines []*feesv1.DerivedPostingLine) []FeeLine {
 	return result
 }
 
-func toNetworkFee(n *chainv1.EstimateTransferFeeResponse) *NetworkFee {
-	if n == nil {
-		return nil
-	}
-	return &NetworkFee{
-		NetworkFee:        toMoney(n.GetNetworkFee()),
-		EstimationContext: n.GetEstimationContext(),
-	}
-}
-
 func toFxQuote(q *oraclev1.Quote) *FxQuote {
 	if q == nil {
 		return nil
@@ -192,7 +185,6 @@ func toPaymentQuote(q *orchestratorv1.PaymentQuote) *PaymentQuote {
 		ExpectedSettlementAmount: toMoney(q.GetExpectedSettlementAmount()),
 		ExpectedFeeTotal:         toMoney(q.GetExpectedFeeTotal()),
 		FeeLines:                 toFeeLines(q.GetFeeLines()),
-		NetworkFee:               toNetworkFee(q.GetNetworkFee()),
 		FxQuote:                  toFxQuote(q.GetFxQuote()),
 	}
 }
@@ -205,7 +197,6 @@ func toPaymentQuoteAggregate(q *orchestratorv1.PaymentQuoteAggregate) *PaymentQu
 		DebitAmounts:              toMoneyList(q.GetDebitAmounts()),
 		ExpectedSettlementAmounts: toMoneyList(q.GetExpectedSettlementAmounts()),
 		ExpectedFeeTotals:         toMoneyList(q.GetExpectedFeeTotals()),
-		NetworkFeeTotals:          toMoneyList(q.GetNetworkFeeTotals()),
 	}
 }
 

api/server/internal/server/paymentapiimp/customer.go

@@ -0,0 +1,25 @@
+package paymentapiimp
+
+import (
+	"net"
+	"strings"
+
+	"github.com/tech/sendico/server/interface/api/srequest"
+)
+
+func applyCustomerIP(intent *srequest.PaymentIntent, remoteAddr string) {
+	if intent == nil {
+		return
+	}
+	ip := strings.TrimSpace(remoteAddr)
+	if ip == "" {
+		return
+	}
+	if host, _, err := net.SplitHostPort(ip); err == nil && host != "" {
+		ip = host
+	}
+	if intent.Customer == nil {
+		intent.Customer = &srequest.Customer{}
+	}
+	intent.Customer.IP = strings.TrimSpace(ip)
+}

api/server/internal/server/paymentapiimp/list.go

@@ -0,0 +1,153 @@
+package paymentapiimp
+
+import (
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/tech/sendico/pkg/api/http/response"
+	"github.com/tech/sendico/pkg/merrors"
+	"github.com/tech/sendico/pkg/model"
+	"github.com/tech/sendico/pkg/mutil/mzap"
+	paginationv1 "github.com/tech/sendico/pkg/proto/common/pagination/v1"
+	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
+	"github.com/tech/sendico/server/interface/api/sresponse"
+	mutil "github.com/tech/sendico/server/internal/mutil/param"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.uber.org/zap"
+)
+
+const maxInt32 = int64(1<<31 - 1)
+
+func (a *PaymentAPI) listPayments(r *http.Request, account *model.Account, token *sresponse.TokenData) http.HandlerFunc {
+	orgRef, err := a.oph.GetRef(r)
+	if err != nil {
+		a.logger.Warn("Failed to parse organization reference for payments list", zap.Error(err), mutil.PLog(a.oph, r))
+		return response.BadReference(a.logger, a.Name(), a.oph.Name(), a.oph.GetID(r), err)
+	}
+
+	ctx := r.Context()
+	allowed, err := a.enf.Enforce(ctx, a.permissionRef, account.ID, orgRef, primitive.NilObjectID, model.ActionRead)
+	if err != nil {
+		a.logger.Warn("Failed to check payments access permissions", zap.Error(err), mutil.PLog(a.oph, r))
+		return response.Auto(a.logger, a.Name(), err)
+	}
+	if !allowed {
+		a.logger.Debug("Access denied when listing payments", mutil.PLog(a.oph, r))
+		return response.AccessDenied(a.logger, a.Name(), "payments read permission denied")
+	}
+
+	req := &orchestratorv1.ListPaymentsRequest{
+		Meta: &orchestratorv1.RequestMeta{
+			OrganizationRef: orgRef.Hex(),
+		},
+	}
+
+	if page, err := listPaymentsPage(r); err != nil {
+		return response.Auto(a.logger, a.Name(), err)
+	} else if page != nil {
+		req.Page = page
+	}
+
+	query := r.URL.Query()
+	if sourceRef := strings.TrimSpace(query.Get("source_ref")); sourceRef != "" {
+		req.SourceRef = sourceRef
+	}
+	if destinationRef := strings.TrimSpace(query.Get("destination_ref")); destinationRef != "" {
+		req.DestinationRef = destinationRef
+	}
+
+	if states, err := parsePaymentStateFilters(r); err != nil {
+		return response.Auto(a.logger, a.Name(), err)
+	} else if len(states) > 0 {
+		req.FilterStates = states
+	}
+
+	resp, err := a.client.ListPayments(ctx, req)
+	if err != nil {
+		a.logger.Warn("Failed to list payments", zap.Error(err), mzap.ObjRef("organization_ref", orgRef))
+		return response.Auto(a.logger, a.Name(), err)
+	}
+
+	return sresponse.PaymentsListResponse(a.logger, resp, token)
+}
+
+func listPaymentsPage(r *http.Request) (*paginationv1.CursorPageRequest, error) {
+	query := r.URL.Query()
+	cursor := strings.TrimSpace(query.Get("cursor"))
+	limitRaw := strings.TrimSpace(query.Get("limit"))
+
+	var limit int64
+	hasLimit := false
+	if limitRaw != "" {
+		parsed, err := strconv.ParseInt(limitRaw, 10, 32)
+		if err != nil {
+			return nil, merrors.InvalidArgument("invalid limit", "limit")
+		}
+		limit = parsed
+		hasLimit = true
+	}
+
+	if cursor == "" && !hasLimit {
+		return nil, nil
+	}
+
+	page := &paginationv1.CursorPageRequest{
+		Cursor: cursor,
+	}
+	if hasLimit {
+		if limit < 0 {
+			limit = 0
+		} else if limit > maxInt32 {
+			limit = maxInt32
+		}
+		page.Limit = int32(limit)
+	}
+
+	return page, nil
+}
+
+func parsePaymentStateFilters(r *http.Request) ([]orchestratorv1.PaymentState, error) {
+	query := r.URL.Query()
+	values := append([]string{}, query["state"]...)
+	values = append(values, query["states"]...)
+	values = append(values, query["filter_states"]...)
+	if len(values) == 0 {
+		return nil, nil
+	}
+
+	states := make([]orchestratorv1.PaymentState, 0, len(values))
+	for _, raw := range values {
+		for _, part := range strings.Split(raw, ",") {
+			trimmed := strings.TrimSpace(part)
+			if trimmed == "" {
+				continue
+			}
+			state, ok := paymentStateFromString(trimmed)
+			if !ok {
+				return nil, merrors.InvalidArgument("unsupported payment state: "+trimmed, "state")
+			}
+			states = append(states, state)
+		}
+	}
+
+	if len(states) == 0 {
+		return nil, nil
+	}
+	return states, nil
+}
+
+func paymentStateFromString(value string) (orchestratorv1.PaymentState, bool) {
+	upper := strings.ToUpper(strings.TrimSpace(value))
+	if upper == "" {
+		return 0, false
+	}
+	if !strings.HasPrefix(upper, "PAYMENT_STATE_") {
+		upper = "PAYMENT_STATE_" + upper
+	}
+	enumValue, ok := orchestratorv1.PaymentState_value[upper]
+	if !ok {
+		return 0, false
+	}
+	return orchestratorv1.PaymentState(enumValue), true
+}

api/server/internal/server/paymentapiimp/mapper.go

@@ -50,6 +50,7 @@ func mapPaymentIntent(intent *srequest.PaymentIntent) (*orchestratorv1.PaymentIn
 		Fx:             fx,
 		SettlementMode: settlementMode,
 		Attributes:     copyStringMap(intent.Attributes),
+		Customer:       mapCustomer(intent.Customer),
 	}, nil
 }
 
@@ -200,6 +201,24 @@ func mapFXIntent(fx *srequest.FXIntent) (*orchestratorv1.FXIntent, error) {
 	}, nil
 }
 
+func mapCustomer(customer *srequest.Customer) *orchestratorv1.Customer {
+	if customer == nil {
+		return nil
+	}
+	return &orchestratorv1.Customer{
+		Id:         strings.TrimSpace(customer.ID),
+		FirstName:  strings.TrimSpace(customer.FirstName),
+		MiddleName: strings.TrimSpace(customer.MiddleName),
+		LastName:   strings.TrimSpace(customer.LastName),
+		Ip:         strings.TrimSpace(customer.IP),
+		Zip:        strings.TrimSpace(customer.Zip),
+		Country:    strings.TrimSpace(customer.Country),
+		State:      strings.TrimSpace(customer.State),
+		City:       strings.TrimSpace(customer.City),
+		Address:    strings.TrimSpace(customer.Address),
+	}
+}
+
 func mapCurrencyPair(pair *srequest.CurrencyPair) *fxv1.CurrencyPair {
 	if pair == nil {
 		return nil

api/server/internal/server/paymentapiimp/pay.go

@@ -8,6 +8,7 @@ import (
 	"github.com/tech/sendico/pkg/api/http/response"
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/model"
+	"github.com/tech/sendico/pkg/mutil/mzap"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 	"github.com/tech/sendico/server/interface/api/srequest"
 	"github.com/tech/sendico/server/interface/api/sresponse"
@@ -20,7 +21,7 @@ import (
 func (a *PaymentAPI) initiatePayment(r *http.Request, account *model.Account, token *sresponse.TokenData, expectQuote bool) http.HandlerFunc {
 	orgRef, err := a.oph.GetRef(r)
 	if err != nil {
-		a.logger.Warn("Failed to parse organization reference for payment initiation", zap.Error(err), zap.String(a.oph.Name(), a.oph.GetID(r)))
+		a.logger.Warn("Failed to parse organization reference for payment initiation", zap.Error(err), mutil.PLog(a.oph, r))
 		return response.BadReference(a.logger, a.Name(), a.oph.Name(), a.oph.GetID(r), err)
 	}
 
@@ -58,6 +59,7 @@ func (a *PaymentAPI) initiatePayment(r *http.Request, account *model.Account, to
 
 	var intent *orchestratorv1.PaymentIntent
 	if payload.Intent != nil {
+		applyCustomerIP(payload.Intent, r.RemoteAddr)
 		intent, err = mapPaymentIntent(payload.Intent)
 		if err != nil {
 			return response.BadPayload(a.logger, a.Name(), err)
@@ -76,7 +78,7 @@ func (a *PaymentAPI) initiatePayment(r *http.Request, account *model.Account, to
 
 	resp, err := a.client.InitiatePayment(ctx, req)
 	if err != nil {
-		a.logger.Warn("Failed to initiate payment", zap.Error(err), zap.String("organization_ref", orgRef.Hex()))
+		a.logger.Warn("Failed to initiate payment", zap.Error(err), mzap.ObjRef("organization_ref", orgRef))
 		return response.Auto(a.logger, a.Name(), err)
 	}
 

api/server/internal/server/paymentapiimp/quote.go

@@ -44,6 +44,7 @@ func (a *PaymentAPI) quotePayment(r *http.Request, account *model.Account, token
 		return response.Auto(a.logger, a.Name(), err)
 	}
 
+	applyCustomerIP(&payload.Intent, r.RemoteAddr)
 	intent, err := mapPaymentIntent(&payload.Intent)
 	if err != nil {
 		a.logger.Debug("Failed to map payment intent", zap.Error(err), mutil.PLog(a.oph, r))
@@ -97,6 +98,7 @@ func (a *PaymentAPI) quotePayments(r *http.Request, account *model.Account, toke
 
 	intents := make([]*orchestratorv1.PaymentIntent, 0, len(payload.Intents))
 	for i := range payload.Intents {
+		applyCustomerIP(&payload.Intents[i], r.RemoteAddr)
 		intent, err := mapPaymentIntent(&payload.Intents[i])
 		if err != nil {
 			a.logger.Debug("Failed to map payment intent", zap.Error(err), mutil.PLog(a.oph, r))

api/server/internal/server/paymentapiimp/service.go

@@ -25,6 +25,7 @@ type paymentClient interface {
 	QuotePayments(ctx context.Context, req *orchestratorv1.QuotePaymentsRequest) (*orchestratorv1.QuotePaymentsResponse, error)
 	InitiatePayments(ctx context.Context, req *orchestratorv1.InitiatePaymentsRequest) (*orchestratorv1.InitiatePaymentsResponse, error)
 	InitiatePayment(ctx context.Context, req *orchestratorv1.InitiatePaymentRequest) (*orchestratorv1.InitiatePaymentResponse, error)
+	ListPayments(ctx context.Context, req *orchestratorv1.ListPaymentsRequest) (*orchestratorv1.ListPaymentsResponse, error)
 	Close() error
 }
 
@@ -72,6 +73,7 @@ func CreateAPI(apiCtx eapi.API) (*PaymentAPI, error) {
 	apiCtx.Register().AccountHandler(p.Name(), p.oph.AddRef("/immediate"), api.Post, p.initiateImmediate)
 	apiCtx.Register().AccountHandler(p.Name(), p.oph.AddRef("/by-quote"), api.Post, p.initiateByQuote)
 	apiCtx.Register().AccountHandler(p.Name(), p.oph.AddRef("/by-multiquote"), api.Post, p.initiatePaymentsByQuote)
+	apiCtx.Register().AccountHandler(p.Name(), p.oph.AddRef("/"), api.Get, p.listPayments)
 
 	return p, nil
 }

frontend/pshared/lib/api/responses/payment/payment.dart

@@ -0,0 +1,20 @@
+import 'package:json_annotation/json_annotation.dart';
+
+import 'package:pshared/api/responses/base.dart';
+import 'package:pshared/api/responses/token.dart';
+import 'package:pshared/data/dto/payment/payment.dart';
+
+part 'payment.g.dart';
+
+
+@JsonSerializable(explicitToJson: true)
+class PaymentResponse extends BaseAuthorizedResponse {
+
+  final PaymentDTO payment;
+
+  const PaymentResponse({required super.accessToken, required this.payment});
+
+  factory PaymentResponse.fromJson(Map<String, dynamic> json) => _$PaymentResponseFromJson(json);
+  @override
+  Map<String, dynamic> toJson() => _$PaymentResponseToJson(this);
+}

frontend/pshared/lib/api/responses/payment/payments.dart

@@ -0,0 +1,20 @@
+import 'package:json_annotation/json_annotation.dart';
+
+import 'package:pshared/api/responses/base.dart';
+import 'package:pshared/api/responses/token.dart';
+import 'package:pshared/data/dto/payment/payment.dart';
+
+part 'payments.g.dart';
+
+
+@JsonSerializable(explicitToJson: true)
+class PaymentsResponse extends BaseAuthorizedResponse {
+
+  final List<PaymentDTO> payments;
+
+  const PaymentsResponse({required super.accessToken, required this.payments});
+
+  factory PaymentsResponse.fromJson(Map<String, dynamic> json) => _$PaymentsResponseFromJson(json);
+  @override
+  Map<String, dynamic> toJson() => _$PaymentsResponseToJson(this);
+}

frontend/pshared/lib/data/dto/payment/intent/customer.dart

@@ -0,0 +1,41 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'customer.g.dart';
+
+
+@JsonSerializable()
+class CustomerDTO {
+  final String id;
+
+  @JsonKey(name: 'first_name')
+  final String? firstName;
+
+  @JsonKey(name: 'middle_name')
+  final String? middleName;
+
+  @JsonKey(name: 'last_name')
+  final String? lastName;
+
+  final String? ip;
+  final String? zip;
+  final String? country;
+  final String? state;
+  final String? city;
+  final String? address;
+
+  const CustomerDTO({
+    required this.id,
+    this.firstName,
+    this.middleName,
+    this.lastName,
+    this.ip,
+    this.zip,
+    this.country,
+    this.state,
+    this.city,
+    this.address,
+  });
+
+  factory CustomerDTO.fromJson(Map<String, dynamic> json) => _$CustomerDTOFromJson(json);
+  Map<String, dynamic> toJson() => _$CustomerDTOToJson(this);
+}