Fixes for build

Reviewed-on: #186

api/billing/fees/go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/tech/sendico/pkg v0.1.0
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
@@ -49,6 +49,6 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 	google.golang.org/protobuf v1.36.11
 )

api/billing/fees/go.sum

@@ -212,10 +212,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/fx/ingestor/go.mod

@@ -49,7 +49,7 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
-	google.golang.org/grpc v1.77.0 // indirect
+	google.golang.org/grpc v1.78.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )

api/fx/ingestor/go.sum

@@ -212,10 +212,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/fx/oracle/go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/tech/sendico/pkg v0.1.0
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -50,5 +50,5 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 )

api/fx/oracle/go.sum

@@ -212,10 +212,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

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

@@ -34,16 +34,23 @@ messaging:
     reconnect_wait: 5
 
 chains:
-  - name: arbitrum_one
+  - name: tron_mainnet
-    rpc_url_env: CHAIN_GATEWAY_ARBITRUM_RPC_URL
+    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: USDC
-        contract: "0xaf88d065e77c8cc2239327c5edb3a432268e5831"
       - symbol: USDT
-        contract: "0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9"
+        contract: "0xa614f803b6fd780986a42c78ec9c7f77e6ded13c"
+      - symbol: USDC
+        contract: "0x3487b63d30b5b2c87fb7ffa8bcfade38eaac1abe"
 
 service_wallet:
-  chain: arbitrum_one
+  chain: tron_mainnet
   address_env: CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS
   private_key_env: CHAIN_GATEWAY_SERVICE_WALLET_KEY
 
@@ -58,3 +65,4 @@ key_management:
 
 cache:
   wallet_balance_ttl_seconds: 120
+  rpc_request_timeout_seconds: 15

api/gateway/chain/go.mod

@@ -15,14 +15,14 @@ require (
 	github.com/tech/sendico/pkg v0.1.0
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
 	github.com/Microsoft/go-winio v0.6.2 // indirect
-	github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251213223233-751f36331c62 // indirect
+	github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251225023818-8886bb81c549 // 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
@@ -86,5 +86,5 @@ require (
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // 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 v0.0.0-20251213223233-751f36331c62 h1:Rge3uIIO891+nLqKTfMulCw+tWHtTl16Oudi0yUcAoE=
+github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251225023818-8886bb81c549 h1:NERDcANvDCnspxdMEMLXOMnuITWIWrTQvvhEA8ewBBM=
-github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251213223233-751f36331c62/go.mod h1:ioLG6R+5bUSO1oeGSDxOV3FADARuMoytZCSX6MEMQkI=
+github.com/ProjectZKM/Ziren/crates/go-runtime/zkvm_runtime v0.0.0-20251225023818-8886bb81c549/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=
@@ -362,10 +362,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

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

@@ -2,14 +2,18 @@ package serverimp
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"strings"
 	"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"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	gatewayshared "github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/gateway/chain/storage"
 	gatewaymongo "github.com/tech/sendico/gateway/chain/storage/mongo"
@@ -30,6 +34,8 @@ type Imp struct {
 
 	config *config
 	app    *grpcapp.App[storage.Repository]
+
+	rpcClients *rpcclient.Clients
 }
 
 type config struct {
@@ -41,11 +47,12 @@ type config struct {
 }
 
 type chainConfig struct {
-	Name        string        `yaml:"name"`
+	Name           string                `yaml:"name"`
-	RPCURLEnv   string        `yaml:"rpc_url_env"`
+	RPCURLEnv      string                `yaml:"rpc_url_env"`
-	ChainID     uint64        `yaml:"chain_id"`
+	ChainID        uint64                `yaml:"chain_id"`
-	NativeToken string        `yaml:"native_token"`
+	NativeToken    string                `yaml:"native_token"`
-	Tokens      []tokenConfig `yaml:"tokens"`
+	Tokens         []tokenConfig         `yaml:"tokens"`
+	GasTopUpPolicy *gasTopUpPolicyConfig `yaml:"gas_topup_policy"`
 }
 
 type serviceWalletConfig struct {
@@ -61,6 +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{
@@ -84,6 +104,9 @@ func (i *Imp) Shutdown() {
 	defer cancel()
 
 	i.app.Shutdown(ctx)
+	if i.rpcClients != nil {
+		i.rpcClients.Close()
+	}
 }
 
 func (i *Imp) Start() error {
@@ -98,20 +121,34 @@ func (i *Imp) Start() error {
 	}
 
 	cl := i.logger.Named("config")
-	networkConfigs := resolveNetworkConfigs(cl.Named("network"), cfg.Chains)
+	networkConfigs, err := resolveNetworkConfigs(cl.Named("network"), cfg.Chains)
+	if err != nil {
+		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))
+		return err
+	}
+	i.rpcClients = rpcClients
 	walletConfig := resolveServiceWallet(cl.Named("wallet"), cfg.ServiceWallet)
 	keyManager, err := resolveKeyManager(i.logger.Named("key_manager"), cfg.KeyManagement)
 	if err != nil {
 		return err
 	}
+	driverRegistry, err := drivers.NewRegistry(i.logger.Named("drivers"), networkConfigs)
+	if err != nil {
+		return err
+	}
 
 	serviceFactory := func(logger mlogger.Logger, repo storage.Repository, producer msg.Producer) (grpcapp.Service, error) {
-		executor := gatewayservice.NewOnChainExecutor(logger, keyManager)
 		opts := []gatewayservice.Option{
 			gatewayservice.WithNetworks(networkConfigs),
 			gatewayservice.WithServiceWallet(walletConfig),
 			gatewayservice.WithKeyManager(keyManager),
-			gatewayservice.WithTransferExecutor(executor),
+			gatewayservice.WithRPCClients(rpcClients),
+			gatewayservice.WithDriverRegistry(driverRegistry),
 			gatewayservice.WithSettings(cfg.Settings),
 		}
 		return gatewayservice.NewService(logger, repo, producer, opts...), nil
@@ -157,7 +194,7 @@ func (i *Imp) loadConfig() (*config, error) {
 	return cfg, nil
 }
 
-func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) []gatewayshared.Network {
+func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) ([]gatewayshared.Network, error) {
 	result := make([]gatewayshared.Network, 0, len(chains))
 	for _, chain := range chains {
 		if strings.TrimSpace(chain.Name) == "" {
@@ -166,7 +203,8 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) []gatewa
 		}
 		rpcURL := strings.TrimSpace(os.Getenv(chain.RPCURLEnv))
 		if rpcURL == "" {
-			logger.Warn("chain RPC endpoint not configured", zap.String("chain", chain.Name), zap.String("env", chain.RPCURLEnv))
+			logger.Error("RPC url not configured", zap.String("chain", chain.Name), zap.String("env", chain.RPCURLEnv))
+			return nil, merrors.InvalidArgument(fmt.Sprintf("chain RPC endpoint not configured (chain=%s env=%s)", chain.Name, chain.RPCURLEnv))
 		}
 		contracts := make([]gatewayshared.TokenContract, 0, len(chain.Tokens))
 		for _, token := range chain.Tokens {
@@ -194,15 +232,84 @@ func resolveNetworkConfigs(logger mlogger.Logger, chains []chainConfig) []gatewa
 			})
 		}
 
+		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,
+			Name:           chain.Name,
-			RPCURL:       rpcURL,
+			RPCURL:         rpcURL,
-			ChainID:      chain.ChainID,
+			ChainID:        chain.ChainID,
-			NativeToken:  chain.NativeToken,
+			NativeToken:    chain.NativeToken,
-			TokenConfigs: contracts,
+			TokenConfigs:   contracts,
+			GasTopUpPolicy: gasPolicy,
 		})
 	}
-	return result
+	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 {

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/deps.go

@@ -2,7 +2,10 @@ package transfer
 
 import (
 	"context"
+	"time"
 
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/gateway/chain/storage"
 	clockpkg "github.com/tech/sendico/pkg/clock"
@@ -11,9 +14,11 @@ import (
 
 type Deps struct {
 	Logger           mlogger.Logger
-	Networks         map[string]shared.Network
+	Drivers          *drivers.Registry
+	Networks         *rpcclient.Registry
 	Storage          storage.Repository
 	Clock            clockpkg.Clock
+	RPCTimeout       time.Duration
 	EnsureRepository func(context.Context) error
 	LaunchExecution  func(transferRef, sourceWalletRef string, network shared.Network)
 }

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{
@@ -40,11 +40,25 @@ 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))
+		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))
+		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))
+		return model.TransferDestination{}, err
+	}
 	return model.TransferDestination{
-		ExternalAddress: strings.ToLower(external),
+		ExternalAddress: normalized,
 		Memo:            strings.TrimSpace(dest.GetMemo()),
 	}, nil
 }

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

@@ -4,11 +4,12 @@ import (
 	"context"
 	"strings"
 
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
 	"github.com/tech/sendico/gateway/chain/storage/model"
 	"github.com/tech/sendico/pkg/merrors"
 )
 
-func destinationAddress(ctx context.Context, deps Deps, dest model.TransferDestination) (string, error) {
+func destinationAddress(ctx context.Context, deps Deps, chainDriver driver.Driver, dest model.TransferDestination) (string, error) {
 	if ref := strings.TrimSpace(dest.ManagedWalletRef); ref != "" {
 		wallet, err := deps.Storage.Wallets().Get(ctx, ref)
 		if err != nil {
@@ -17,10 +18,10 @@ func destinationAddress(ctx context.Context, deps Deps, dest model.TransferDesti
 		if strings.TrimSpace(wallet.DepositAddress) == "" {
 			return "", merrors.Internal("destination wallet missing deposit address")
 		}
-		return wallet.DepositAddress, nil
+		return chainDriver.NormalizeAddress(wallet.DepositAddress)
 	}
 	if addr := strings.TrimSpace(dest.ExternalAddress); addr != "" {
-		return strings.ToLower(addr), nil
+		return chainDriver.NormalizeAddress(addr)
 	}
 	return "", merrors.InvalidArgument("transfer destination address not resolved")
 }

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

@@ -3,22 +3,13 @@ package transfer
 import (
 	"context"
 	"errors"
-	"math/big"
 	"strings"
-	"time"
 
-	"github.com/ethereum/go-ethereum"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
-	"github.com/ethereum/go-ethereum/accounts/abi"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/ethclient"
-	"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/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"
 )
@@ -33,11 +24,11 @@ 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"))
 	}
 
@@ -55,194 +46,72 @@ func (c *estimateTransferFeeCommand) Execute(ctx context.Context, req *chainv1.E
 	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[networkKey]
+	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))
+		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))
 		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, dest)
+	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)
 	}
 
-	feeMoney, err := estimateNetworkFee(ctx, c.deps.Logger, networkCfg, sourceWallet, destinationAddress, amount)
+	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, 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)
 }
-
-func estimateNetworkFee(ctx context.Context, logger mlogger.Logger, network shared.Network, wallet *model.ManagedWallet, destination string, amount *moneyv1.Money) (*moneyv1.Money, error) {
-	rpcURL := strings.TrimSpace(network.RPCURL)
-	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 !common.IsHexAddress(wallet.DepositAddress) {
-		return nil, merrors.InvalidArgument("invalid source wallet address")
-	}
-	if !common.IsHexAddress(destination) {
-		return nil, merrors.InvalidArgument("invalid destination address")
-	}
-
-	client, err := ethclient.DialContext(ctx, rpcURL)
-	if err != nil {
-		return nil, merrors.Internal("failed to connect to rpc: " + err.Error())
-	}
-	defer client.Close()
-
-	timeoutCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
-	defer cancel()
-
-	tokenABI, err := abi.JSON(strings.NewReader(erc20TransferABI))
-	if err != nil {
-		return nil, merrors.Internal("failed to parse erc20 abi: " + err.Error())
-	}
-	tokenAddr := common.HexToAddress(wallet.ContractAddress)
-	toAddr := common.HexToAddress(destination)
-	fromAddr := common.HexToAddress(wallet.DepositAddress)
-
-	decimals, err := erc20Decimals(timeoutCtx, client, tokenABI, tokenAddr)
-	if err != nil {
-		logger.Warn("failed to read token decimals", zap.Error(err))
-		return nil, err
-	}
-
-	amountBase, err := toBaseUnits(strings.TrimSpace(amount.GetAmount()), decimals)
-	if err != nil {
-		return nil, err
-	}
-
-	input, err := tokenABI.Pack("transfer", toAddr, amountBase)
-	if err != nil {
-		return nil, merrors.Internal("failed to encode transfer call: " + err.Error())
-	}
-
-	gasPrice, err := client.SuggestGasPrice(timeoutCtx)
-	if err != nil {
-		return nil, merrors.Internal("failed to suggest gas price: " + err.Error())
-	}
-
-	callMsg := ethereum.CallMsg{
-		From:     fromAddr,
-		To:       &tokenAddr,
-		GasPrice: gasPrice,
-		Data:     input,
-	}
-	gasLimit, err := client.EstimateGas(timeoutCtx, callMsg)
-	if err != nil {
-		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,
-		Amount:   feeDec.String(),
-	}, nil
-}
-
-func erc20Decimals(ctx context.Context, client *ethclient.Client, tokenABI abi.ABI, token common.Address) (uint8, error) {
-	callData, err := tokenABI.Pack("decimals")
-	if err != nil {
-		return 0, merrors.Internal("failed to encode decimals call: " + err.Error())
-	}
-	msg := ethereum.CallMsg{
-		To:   &token,
-		Data: callData,
-	}
-	output, err := client.CallContract(ctx, msg, nil)
-	if err != nil {
-		return 0, merrors.Internal("decimals call failed: " + err.Error())
-	}
-	values, err := tokenABI.Unpack("decimals", output)
-	if err != nil {
-		return 0, merrors.Internal("failed to unpack decimals: " + err.Error())
-	}
-	if len(values) == 0 {
-		return 0, merrors.Internal("decimals call returned no data")
-	}
-	decimals, ok := values[0].(uint8)
-	if !ok {
-		return 0, merrors.Internal("decimals call returned unexpected type")
-	}
-	return decimals, nil
-}
-
-func toBaseUnits(amount string, decimals uint8) (*big.Int, error) {
-	value, err := decimal.NewFromString(strings.TrimSpace(amount))
-	if err != nil {
-		return nil, merrors.InvalidArgument("invalid amount " + amount + ": " + err.Error())
-	}
-	if value.IsNegative() {
-		return nil, merrors.InvalidArgument("amount must be positive")
-	}
-	multiplier := decimal.NewFromInt(1).Shift(int32(decimals))
-	scaled := value.Mul(multiplier)
-	if !scaled.Equal(scaled.Truncate(0)) {
-		return nil, merrors.InvalidArgument("amount " + amount + " exceeds token precision")
-	}
-	return scaled.BigInt(), nil
-}
-
-const erc20TransferABI = `
-[
-	{
-		"constant": true,
-		"inputs": [],
-		"name": "decimals",
-		"outputs": [{ "name": "", "type": "uint8" }],
-		"payable": false,
-		"stateMutability": "view",
-        "type": "function"
-	},
-	{
-		"constant": false,
-		"inputs": [
-			{ "name": "_to", "type": "address" },
-			{ "name": "_value", "type": "uint256" }
-		],
-		"name": "transfer",
-		"outputs": [{ "name": "", "type": "bool" }],
-		"payable": false,
-		"stateMutability": "nonpayable",
-		"type": "function"
-	}
-]`

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/submit.go

@@ -25,7 +25,7 @@ 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 {
@@ -35,84 +35,92 @@ func (c *submitTransferCommand) Execute(ctx context.Context, req *chainv1.Submit
 
 	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("mMssing 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[networkKey]
+	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,
+		TokenSymbol:     effectiveTokenSymbol,
-		ContractAddress: sourceWallet.ContractAddress,
+		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

@@ -51,7 +51,7 @@ func (c *getWalletBalanceCommand) Execute(ctx context.Context, req *chainv1.GetW
 		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))
 		stored, err := c.deps.Storage.Wallets().GetBalance(ctx, walletRef)
@@ -74,37 +74,47 @@ 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 {
+func onChainBalanceToProto(balance *moneyv1.Money, native *moneyv1.Money, calculatedAt time.Time) *chainv1.WalletBalance {
-	if balance == nil {
+	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) {
+func (c *getWalletBalanceCommand) persistCachedBalance(ctx context.Context, walletRef string, available *moneyv1.Money, nativeAvailable *moneyv1.Money, calculatedAt time.Time) {
-	if available == nil {
+	if available == nil && nativeAvailable == nil {
 		return
 	}
 	record := &model.WalletBalance{
 		WalletRef:       walletRef,
 		Available:       shared.CloneMoney(available),
-		PendingInbound:  zeroMoney(available.Currency),
+		NativeAvailable: shared.CloneMoney(nativeAvailable),
-		PendingOutbound: zeroMoney(available.Currency),
 		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))
 	}

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

@@ -9,6 +9,7 @@ import (
 	"github.com/tech/sendico/gateway/chain/storage/model"
 	"github.com/tech/sendico/pkg/api/routers/gsresponse"
 	"github.com/tech/sendico/pkg/merrors"
+	pkgmodel "github.com/tech/sendico/pkg/model"
 	"github.com/tech/sendico/pkg/mservice"
 	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
 	"go.uber.org/zap"
@@ -59,11 +60,20 @@ func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.C
 		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[chainKey]
+	networkCfg, ok := c.deps.Networks.Network(chainKey)
 	if !ok {
 		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))
+		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))
+		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported chain"))
+	}
 
 	tokenSymbol := strings.ToUpper(strings.TrimSpace(asset.GetTokenSymbol()))
 	if tokenSymbol == "" {
@@ -72,10 +82,12 @@ func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.C
 	}
 	contractAddress := strings.ToLower(strings.TrimSpace(asset.GetContractAddress()))
 	if contractAddress == "" {
-		contractAddress = shared.ResolveContractAddress(networkCfg.TokenConfigs, tokenSymbol)
+		if !strings.EqualFold(tokenSymbol, networkCfg.NativeToken) {
-		if contractAddress == "" {
+			contractAddress = shared.ResolveContractAddress(networkCfg.TokenConfigs, tokenSymbol)
-			c.deps.Logger.Warn("unsupported token", zap.String("token", tokenSymbol), zap.String("chain", chainKey))
+			if contractAddress == "" {
-			return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, merrors.InvalidArgument("unsupported token for chain"))
+				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"))
+			}
 		}
 	}
 
@@ -94,8 +106,37 @@ func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.C
 		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))
+		return gsresponse.InvalidArgument[chainv1.CreateManagedWalletResponse](c.deps.Logger, mservice.ChainGateway, err)
+	}
+
+	metadata := shared.CloneMetadata(req.GetMetadata())
+	desc := req.GetDescribable()
+	name := strings.TrimSpace(desc.GetName())
+	if name == "" {
+		name = strings.TrimSpace(metadata["name"])
+	}
+	var description *string
+	if desc != nil && desc.Description != nil {
+		if trimmed := strings.TrimSpace(desc.GetDescription()); trimmed != "" {
+			description = &trimmed
+		}
+	}
+	if description == nil {
+		if trimmed := strings.TrimSpace(metadata["description"]); trimmed != "" {
+			description = &trimmed
+		}
+	}
+	if name == "" {
+		name = walletRef
+	}
 
 	wallet := &model.ManagedWallet{
+		Describable: pkgmodel.Describable{
+			Name: name,
+		},
 		IdempotencyKey:  idempotencyKey,
 		WalletRef:       walletRef,
 		OrganizationRef: organizationRef,
@@ -103,10 +144,13 @@ func (c *createManagedWalletCommand) Execute(ctx context.Context, req *chainv1.C
 		Network:         chainKey,
 		TokenSymbol:     tokenSymbol,
 		ContractAddress: contractAddress,
-		DepositAddress:  strings.ToLower(keyInfo.Address),
+		DepositAddress:  depositAddress,
 		KeyReference:    keyInfo.KeyID,
 		Status:          model.ManagedWalletStatusActive,
-		Metadata:        shared.CloneMetadata(req.GetMetadata()),
+		Metadata:        metadata,
+	}
+	if description != nil {
+		wallet.Describable.Description = description
 	}
 
 	created, err := c.deps.Storage.Wallets().Create(ctx, wallet)

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

@@ -5,7 +5,8 @@ import (
 	"time"
 
 	"github.com/tech/sendico/gateway/chain/internal/keymanager"
-	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	"github.com/tech/sendico/gateway/chain/storage"
 	clockpkg "github.com/tech/sendico/pkg/clock"
 	"github.com/tech/sendico/pkg/mlogger"
@@ -13,17 +14,20 @@ import (
 
 type Deps struct {
 	Logger           mlogger.Logger
-	Networks         map[string]shared.Network
+	Drivers          *drivers.Registry
+	Networks         *rpcclient.Registry
 	KeyManager       keymanager.Manager
 	Storage          storage.Repository
 	Clock            clockpkg.Clock
 	BalanceCacheTTL  time.Duration
+	RPCTimeout       time.Duration
 	EnsureRepository func(context.Context) error
 }
 
 func (d Deps) WithLogger(name string) Deps {
-	if d.Logger != nil {
+	if d.Logger == nil {
-		d.Logger = d.Logger.Named(name)
+		panic("wallet deps: logger is required")
 	}
+	d.Logger = d.Logger.Named(name)
 	return d
 }

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

@@ -2,123 +2,61 @@ package wallet
 
 import (
 	"context"
-	"math/big"
+	"fmt"
 	"strings"
-	"time"
 
-	"github.com/ethereum/go-ethereum"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
-	"github.com/ethereum/go-ethereum/accounts/abi"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/ethclient"
-	"github.com/shopspring/decimal"
 	"github.com/tech/sendico/gateway/chain/storage/model"
 	"github.com/tech/sendico/pkg/merrors"
 	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"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) {
-	network := deps.Networks[strings.ToLower(strings.TrimSpace(wallet.Network))]
+	logger := deps.Logger
-	rpcURL := strings.TrimSpace(network.RPCURL)
+	if wallet == nil {
-	if rpcURL == "" {
+		return nil, nil, merrors.InvalidArgument("wallet is required")
-		return nil, merrors.Internal("network rpc url is not configured")
 	}
-	contract := strings.TrimSpace(wallet.ContractAddress)
+	if deps.Networks == nil {
-	if contract == "" || !common.IsHexAddress(contract) {
+		return nil, nil, merrors.Internal("rpc clients not initialised")
-		return nil, merrors.InvalidArgument("invalid contract address")
 	}
-	if wallet.DepositAddress == "" || !common.IsHexAddress(wallet.DepositAddress) {
+	if deps.Drivers == nil {
-		return nil, merrors.InvalidArgument("invalid wallet address")
+		return nil, nil, merrors.Internal("chain drivers not configured")
 	}
 
-	client, err := ethclient.DialContext(ctx, rpcURL)
+	networkKey := strings.ToLower(strings.TrimSpace(wallet.Network))
-	if err != nil {
+	network, ok := deps.Networks.Network(networkKey)
-		return nil, merrors.Internal("failed to connect rpc: " + err.Error())
-	}
-	defer client.Close()
-
-	timeoutCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
-	defer cancel()
-
-	tokenABI, err := abi.JSON(strings.NewReader(erc20ABIJSON))
-	if err != nil {
-		return nil, merrors.Internal("failed to parse erc20 abi: " + err.Error())
-	}
-	tokenAddr := common.HexToAddress(contract)
-	walletAddr := common.HexToAddress(wallet.DepositAddress)
-
-	decimals, err := readDecimals(timeoutCtx, client, tokenABI, tokenAddr)
-	if err != nil {
-		return nil, err
-	}
-
-	bal, err := readBalanceOf(timeoutCtx, client, tokenABI, tokenAddr, walletAddr)
-	if err != nil {
-		return nil, err
-	}
-
-	dec := decimal.NewFromBigInt(bal, 0).Shift(-int32(decimals))
-	return &moneyv1.Money{Currency: wallet.TokenSymbol, Amount: dec.String()}, nil
-}
-
-func readDecimals(ctx context.Context, client *ethclient.Client, tokenABI abi.ABI, token common.Address) (uint8, error) {
-	data, err := tokenABI.Pack("decimals")
-	if err != nil {
-		return 0, merrors.Internal("failed to encode decimals call: " + err.Error())
-	}
-	msg := ethereum.CallMsg{To: &token, Data: data}
-	out, err := client.CallContract(ctx, msg, nil)
-	if err != nil {
-		return 0, merrors.Internal("decimals call failed: " + err.Error())
-	}
-	values, err := tokenABI.Unpack("decimals", out)
-	if err != nil || len(values) == 0 {
-		return 0, merrors.Internal("failed to unpack decimals")
-	}
-	if val, ok := values[0].(uint8); ok {
-		return val, nil
-	}
-	return 0, merrors.Internal("decimals returned unexpected type")
-}
-
-func readBalanceOf(ctx context.Context, client *ethclient.Client, tokenABI abi.ABI, token common.Address, wallet common.Address) (*big.Int, error) {
-	data, err := tokenABI.Pack("balanceOf", wallet)
-	if err != nil {
-		return nil, merrors.Internal("failed to encode balanceOf: " + err.Error())
-	}
-	msg := ethereum.CallMsg{To: &token, Data: data}
-	out, err := client.CallContract(ctx, msg, nil)
-	if err != nil {
-		return nil, merrors.Internal("balanceOf call failed: " + err.Error())
-	}
-	values, err := tokenABI.Unpack("balanceOf", out)
-	if err != nil || len(values) == 0 {
-		return nil, merrors.Internal("failed to unpack balanceOf")
-	}
-	raw, ok := values[0].(*big.Int)
 	if !ok {
-		return nil, merrors.Internal("balanceOf returned unexpected type")
+		logger.Warn("Requested network is not configured",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", networkKey),
+		)
+		return nil, nil, merrors.Internal(fmt.Sprintf("Requested network '%s' is not configured", networkKey))
 	}
-	return decimal.NewFromBigInt(raw, 0).BigInt(), nil
-}
 
-const erc20ABIJSON = `
+	chainDriver, err := deps.Drivers.Driver(networkKey)
-[
+	if err != nil {
-	{
+		logger.Warn("Chain driver not configured",
-		"constant": true,
+			zap.String("wallet_ref", wallet.WalletRef),
-		"inputs": [],
+			zap.String("network", networkKey),
-		"name": "decimals",
+			zap.Error(err),
-		"outputs": [{ "name": "", "type": "uint8" }],
+		)
-		"payable": false,
+		return nil, nil, merrors.InvalidArgument("unsupported chain")
-		"stateMutability": "view",
-        "type": "function"
-	},
-	{
-		"constant": true,
-		"inputs": [{ "name": "_owner", "type": "address" }],
-		"name": "balanceOf",
-		"outputs": [{ "name": "balance", "type": "uint256" }],
-		"payable": false,
-		"stateMutability": "view",
-		"type": "function"
 	}
-]`
+
+	driverDeps := driver.Deps{
+		Logger:     deps.Logger,
+		Registry:   deps.Networks,
+		KeyManager: deps.KeyManager,
+		RPCTimeout: deps.RPCTimeout,
+	}
+	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

@@ -1,8 +1,11 @@
 package wallet
 
 import (
+	"strings"
+
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/gateway/chain/storage/model"
+	describablev1 "github.com/tech/sendico/pkg/proto/common/describable/v1"
 	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
@@ -16,6 +19,25 @@ func toProtoManagedWallet(wallet *model.ManagedWallet) *chainv1.ManagedWallet {
 		TokenSymbol:     wallet.TokenSymbol,
 		ContractAddress: wallet.ContractAddress,
 	}
+	name := strings.TrimSpace(wallet.Name)
+	if name == "" {
+		name = strings.TrimSpace(wallet.Metadata["name"])
+	}
+	if name == "" {
+		name = wallet.WalletRef
+	}
+	description := ""
+	switch {
+	case wallet.Description != nil:
+		description = strings.TrimSpace(*wallet.Description)
+	default:
+		description = strings.TrimSpace(wallet.Metadata["description"])
+	}
+	desc := &describablev1.Describable{Name: name}
+	if description != "" {
+		desc.Description = &description
+	}
+
 	return &chainv1.ManagedWallet{
 		WalletRef:       wallet.WalletRef,
 		OrganizationRef: wallet.OrganizationRef,
@@ -26,6 +48,7 @@ func toProtoManagedWallet(wallet *model.ManagedWallet) *chainv1.ManagedWallet {
 		Metadata:        shared.CloneMetadata(wallet.Metadata),
 		CreatedAt:       timestamppb.New(wallet.CreatedAt.UTC()),
 		UpdatedAt:       timestamppb.New(wallet.UpdatedAt.UTC()),
+		Describable:     desc,
 	}
 }
 
@@ -35,6 +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

@@ -0,0 +1,173 @@
+package arbitrum
+
+import (
+	"context"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/evm"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/mlogger"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"go.uber.org/zap"
+)
+
+// Driver implements Arbitrum-specific behavior using the shared EVM logic.
+type Driver struct {
+	logger mlogger.Logger
+}
+
+func New(logger mlogger.Logger) *Driver {
+	return &Driver{logger: logger.Named("arbitrum")}
+}
+
+func (d *Driver) Name() string {
+	return "arbitrum"
+}
+
+func (d *Driver) FormatAddress(address string) (string, error) {
+	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))
+	}
+	return normalized, err
+}
+
+func (d *Driver) NormalizeAddress(address string) (string, error) {
+	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))
+	}
+	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",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	result, err := evm.Balance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
+	if err != nil {
+		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",
+			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),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+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",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+		zap.String("destination", destination),
+	)
+	driverDeps := deps
+	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",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else if result != nil {
+		d.logger.Debug("Estimate fee 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) 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",
+		zap.String("transfer_ref", transfer.TransferRef),
+		zap.String("network", network.Name),
+		zap.String("destination", destination),
+	)
+	driverDeps := deps
+	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",
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else {
+		d.logger.Debug("submit transfer result",
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+			zap.String("tx_hash", txHash),
+		)
+	}
+	return txHash, err
+}
+
+func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
+	d.logger.Debug("await confirmation",
+		zap.String("tx_hash", txHash),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	receipt, err := evm.AwaitConfirmation(ctx, driverDeps, network, txHash)
+	if err != nil {
+		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",
+			zap.String("tx_hash", txHash),
+			zap.String("network", network.Name),
+			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),
+			zap.Uint64("status", receipt.Status),
+		)
+	}
+	return receipt, err
+}
+
+var _ driver.Driver = (*Driver)(nil)

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

@@ -0,0 +1,34 @@
+package driver
+
+import (
+	"context"
+	"time"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/tech/sendico/gateway/chain/internal/keymanager"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/mlogger"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+)
+
+// Deps bundles dependencies shared across chain drivers.
+type Deps struct {
+	Logger     mlogger.Logger
+	Registry   *rpcclient.Registry
+	KeyManager keymanager.Manager
+	RPCTimeout time.Duration
+}
+
+// Driver defines chain-specific behavior for wallet and transfer operations.
+type Driver interface {
+	Name() string
+	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

@@ -0,0 +1,173 @@
+package ethereum
+
+import (
+	"context"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/evm"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/mlogger"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"go.uber.org/zap"
+)
+
+// Driver implements Ethereum-specific behavior using the shared EVM logic.
+type Driver struct {
+	logger mlogger.Logger
+}
+
+func New(logger mlogger.Logger) *Driver {
+	return &Driver{logger: logger.Named("ethereum")}
+}
+
+func (d *Driver) Name() string {
+	return "ethereum"
+}
+
+func (d *Driver) FormatAddress(address string) (string, error) {
+	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))
+	}
+	return normalized, err
+}
+
+func (d *Driver) NormalizeAddress(address string) (string, error) {
+	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))
+	}
+	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",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	result, err := evm.Balance(ctx, driverDeps, network, wallet, wallet.DepositAddress)
+	if err != nil {
+		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",
+			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),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+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",
+		zap.String("wallet_ref", wallet.WalletRef),
+		zap.String("network", network.Name),
+		zap.String("destination", destination),
+	)
+	driverDeps := deps
+	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",
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else if result != nil {
+		d.logger.Debug("Estimate fee 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) 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",
+		zap.String("transfer_ref", transfer.TransferRef),
+		zap.String("network", network.Name),
+		zap.String("destination", destination),
+	)
+	driverDeps := deps
+	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",
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+			zap.Error(err),
+		)
+	} else {
+		d.logger.Debug("submit transfer result",
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+			zap.String("tx_hash", txHash),
+		)
+	}
+	return txHash, err
+}
+
+func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
+	d.logger.Debug("await confirmation",
+		zap.String("tx_hash", txHash),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	receipt, err := evm.AwaitConfirmation(ctx, driverDeps, network, txHash)
+	if err != nil {
+		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",
+			zap.String("tx_hash", txHash),
+			zap.String("network", network.Name),
+			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),
+			zap.Uint64("status", receipt.Status),
+		)
+	}
+	return receipt, err
+}
+
+var _ driver.Driver = (*Driver)(nil)

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

@@ -0,0 +1,747 @@
+package evm
+
+import (
+	"context"
+	"errors"
+	"math/big"
+	"strings"
+	"time"
+
+	"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"
+	"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"
+	"github.com/tech/sendico/pkg/merrors"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"go.uber.org/zap"
+)
+
+var (
+	erc20ABI abi.ABI
+)
+
+func init() {
+	var err error
+	erc20ABI, err = abi.JSON(strings.NewReader(erc20ABIJSON))
+	if err != nil {
+		panic("evm driver: failed to parse erc20 abi: " + err.Error())
+	}
+}
+
+const erc20ABIJSON = `
+[
+	{
+		"constant": false,
+		"inputs": [
+			{ "name": "_to", "type": "address" },
+			{ "name": "_value", "type": "uint256" }
+		],
+		"name": "transfer",
+		"outputs": [{ "name": "", "type": "bool" }],
+		"payable": false,
+		"stateMutability": "nonpayable",
+		"type": "function"
+	},
+	{
+		"constant": true,
+		"inputs": [],
+		"name": "decimals",
+		"outputs": [{ "name": "", "type": "uint8" }],
+		"payable": false,
+		"stateMutability": "view",
+        "type": "function"
+	}
+]`
+
+// NormalizeAddress validates and normalizes EVM hex addresses.
+func NormalizeAddress(address string) (string, error) {
+	trimmed := strings.TrimSpace(address)
+	if trimmed == "" {
+		return "", merrors.InvalidArgument("address is required")
+	}
+	if !common.IsHexAddress(trimmed) {
+		return "", merrors.InvalidArgument("invalid hex address")
+	}
+	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.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("token_symbol", strings.ToUpper(strings.TrimSpace(wallet.TokenSymbol))),
+		zap.String("contract", strings.ToLower(strings.TrimSpace(wallet.ContractAddress))),
+		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")
+	}
+
+	contract := strings.TrimSpace(wallet.ContractAddress)
+	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")
+	}
+
+	logger.Info("Fetching on-chain wallet balance", logFields...)
+
+	rpcClient, err := registry.RPCClient(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()
+
+	logger.Debug("Calling token decimals", logFields...)
+	decimals, err := readDecimals(timeoutCtx, rpcClient, contract)
+	if err != nil {
+		logger.Warn("Token decimals call failed", append(logFields, zap.Error(err))...)
+		return nil, err
+	}
+
+	logger.Debug("Calling token balanceOf", append(logFields, zap.Uint8("decimals", decimals))...)
+	bal, err := readBalanceOf(timeoutCtx, rpcClient, contract, normalizedAddress)
+	if err != nil {
+		logger.Warn("Token balanceOf call failed", append(logFields, zap.Uint8("decimals", decimals), zap.Error(err))...)
+		return nil, err
+	}
+
+	dec := decimal.NewFromBigInt(bal, 0).Shift(-int32(decimals))
+	logger.Info("On-chain wallet balance fetched",
+		append(logFields,
+			zap.Uint8("decimals", decimals),
+			zap.String("balance_raw", bal.String()),
+			zap.String("balance", dec.String()),
+		)...,
+	)
+	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.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")
+	}
+	if amount == nil {
+		return nil, merrors.InvalidArgument("amount is required")
+	}
+
+	rpcURL := strings.TrimSpace(network.RPCURL)
+	if rpcURL == "" {
+		return nil, merrors.InvalidArgument("network rpc url not configured")
+	}
+	if _, err := NormalizeAddress(fromAddress); err != nil {
+		return nil, merrors.InvalidArgument("invalid source wallet address")
+	}
+	if _, err := NormalizeAddress(destination); err != nil {
+		return nil, merrors.InvalidArgument("invalid destination address")
+	}
+
+	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
+	}
+
+	timeout := deps.RPCTimeout
+	if timeout <= 0 {
+		timeout = 15 * time.Second
+	}
+	timeoutCtx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	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))
+		return nil, err
+	}
+
+	amountBase, err := toBaseUnits(strings.TrimSpace(amount.GetAmount()), decimals)
+	if err != nil {
+		return nil, err
+	}
+
+	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())
+	}
+
+	callMsg := ethereum.CallMsg{
+		From:     fromAddr,
+		To:       &tokenAddr,
+		GasPrice: gasPrice,
+		Data:     input,
+	}
+	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)
+
+	return &moneyv1.Money{
+		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.Named("evm")
+	registry := deps.Registry
+
+	if deps.KeyManager == nil {
+		logger.Warn("Key manager not configured")
+		return "", executorInternal("key manager is not configured", nil)
+	}
+	if registry == nil {
+		return "", executorInternal("rpc clients not initialised", nil)
+	}
+	rpcURL := strings.TrimSpace(network.RPCURL)
+	if rpcURL == "" {
+		logger.Warn("Network rpc url missing", zap.String("network", network.Name))
+		return "", executorInvalid("network rpc url is not configured")
+	}
+	if source == nil || transfer == nil {
+		logger.Warn("Transfer context missing")
+		return "", executorInvalid("transfer context missing")
+	}
+	if strings.TrimSpace(source.KeyReference) == "" {
+		logger.Warn("Source wallet missing key reference", zap.String("wallet_ref", source.WalletRef))
+		return "", executorInvalid("source wallet missing key reference")
+	}
+	if _, err := NormalizeAddress(fromAddress); err != nil {
+		logger.Warn("Invalid source wallet address", zap.String("wallet_ref", source.WalletRef))
+		return "", executorInvalid("invalid source wallet address")
+	}
+	if _, err := NormalizeAddress(destination); err != nil {
+		logger.Warn("Invalid destination address", zap.String("transfer_ref", transfer.TransferRef), zap.String("address", destination))
+		return "", executorInvalid("invalid destination address " + destination)
+	}
+
+	logger.Info("Submitting transfer",
+		zap.String("transfer_ref", transfer.TransferRef),
+		zap.String("source_wallet_ref", source.WalletRef),
+		zap.String("network", network.Name),
+		zap.String("destination", strings.ToLower(destination)),
+	)
+
+	client, err := registry.Client(network.Name)
+	if err != nil {
+		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))
+		return "", err
+	}
+
+	sourceAddress := common.HexToAddress(fromAddress)
+	destinationAddr := common.HexToAddress(destination)
+
+	ctx, cancel := context.WithTimeout(ctx, 60*time.Second)
+	defer cancel()
+
+	nonce, err := client.PendingNonceAt(ctx, sourceAddress)
+	if err != nil {
+		logger.Warn("Failed to fetch nonce", zap.Error(err),
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("wallet_ref", source.WalletRef),
+		)
+		return "", executorInternal("failed to fetch nonce", err)
+	}
+
+	gasPrice, err := client.SuggestGasPrice(ctx)
+	if err != nil {
+		logger.Warn("Failed to suggest gas price", zap.Error(err),
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+		)
+		return "", executorInternal("failed to suggest gas price", err)
+	}
+
+	chainID := new(big.Int).SetUint64(network.ChainID)
+
+	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")
+	}
+
+	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)
+
+		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
+		}
+
+		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 {
+		logger.Warn("Failed to sign transaction", zap.Error(err),
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("wallet_ref", source.WalletRef),
+		)
+		return "", err
+	}
+
+	if err := client.SendTransaction(ctx, signedTx); err != nil {
+		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()
+	logger.Info("Transaction submitted",
+		zap.String("transfer_ref", transfer.TransferRef),
+		zap.String("tx_hash", txHash),
+		zap.String("network", network.Name),
+	)
+
+	return txHash, nil
+}
+
+// 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.Named("evm")
+	registry := deps.Registry
+
+	if strings.TrimSpace(txHash) == "" {
+		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 == "" {
+		logger.Warn("Network rpc url missing while awaiting confirmation", zap.String("tx_hash", txHash))
+		return nil, executorInvalid("network rpc url is not configured")
+	}
+	if registry == nil {
+		return nil, executorInternal("rpc clients not initialised", nil)
+	}
+
+	client, err := registry.Client(network.Name)
+	if err != nil {
+		return nil, err
+	}
+
+	hash := common.HexToHash(txHash)
+	ticker := time.NewTicker(3 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		receipt, err := client.TransactionReceipt(ctx, hash)
+		if err != nil {
+			if errors.Is(err, ethereum.NotFound) {
+				select {
+				case <-ticker.C:
+					logger.Debug("Transaction not yet mined",
+						zap.String("tx_hash", txHash),
+						zap.String("network", network.Name),
+					)
+					continue
+				case <-ctx.Done():
+					logger.Warn("Context cancelled while awaiting confirmation",
+						zap.String("tx_hash", txHash),
+						zap.String("network", network.Name),
+					)
+					return nil, ctx.Err()
+				}
+			}
+			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)
+		}
+		logger.Info("Transaction confirmed",
+			zap.String("tx_hash", txHash),
+			zap.String("network", network.Name),
+			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),
+			zap.Uint64("status", receipt.Status),
+		)
+		return receipt, nil
+	}
+}
+
+func readDecimals(ctx context.Context, client *rpc.Client, token string) (uint8, error) {
+	call := map[string]string{
+		"to":   strings.ToLower(common.HexToAddress(token).Hex()),
+		"data": "0x313ce567",
+	}
+	var hexResp string
+	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
+		return 0, merrors.Internal("decimals call failed: " + err.Error())
+	}
+	val, err := shared.DecodeHexUint8(hexResp)
+	if err != nil {
+		return 0, merrors.Internal("decimals decode failed: " + err.Error())
+	}
+	return val, nil
+}
+
+func readBalanceOf(ctx context.Context, client *rpc.Client, token string, wallet string) (*big.Int, error) {
+	tokenAddr := common.HexToAddress(token)
+	walletAddr := common.HexToAddress(wallet)
+	addr := strings.TrimPrefix(walletAddr.Hex(), "0x")
+	if len(addr) < 64 {
+		addr = strings.Repeat("0", 64-len(addr)) + addr
+	}
+	call := map[string]string{
+		"to":   strings.ToLower(tokenAddr.Hex()),
+		"data": "0x70a08231" + addr,
+	}
+	var hexResp string
+	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
+		return nil, merrors.Internal("balanceOf call failed: " + err.Error())
+	}
+	bigVal, err := shared.DecodeHexBig(hexResp)
+	if err != nil {
+		return nil, merrors.Internal("balanceOf decode failed: " + err.Error())
+	}
+	return bigVal, nil
+}
+
+func erc20Decimals(ctx context.Context, client *rpc.Client, token common.Address) (uint8, error) {
+	call := map[string]string{
+		"to":   strings.ToLower(token.Hex()),
+		"data": "0x313ce567",
+	}
+	var hexResp string
+	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
+		return 0, executorInternal("decimals call failed", err)
+	}
+	val, err := shared.DecodeHexUint8(hexResp)
+	if err != nil {
+		return 0, executorInternal("decimals decode failed", err)
+	}
+	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 {
+		return nil, merrors.InvalidArgument("invalid amount " + amount + ": " + err.Error())
+	}
+	if value.IsNegative() {
+		return nil, merrors.InvalidArgument("amount must be positive")
+	}
+	multiplier := decimal.NewFromInt(1).Shift(int32(decimals))
+	scaled := value.Mul(multiplier)
+	if !scaled.Equal(scaled.Truncate(0)) {
+		return nil, merrors.InvalidArgument("amount " + amount + " exceeds token precision")
+	}
+	return scaled.BigInt(), nil
+}
+
+func executorInvalid(msg string) error {
+	return merrors.InvalidArgument("executor: " + msg)
+}
+
+func executorInternal(msg string, err error) error {
+	if err != nil {
+		msg = msg + ": " + err.Error()
+	}
+	return merrors.Internal("executor: " + msg)
+}

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/address.go

@@ -0,0 +1,193 @@
+package tron
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"math/big"
+	"strings"
+
+	"github.com/tech/sendico/pkg/merrors"
+)
+
+const tronHexPrefix = "0x"
+
+var base58Alphabet = []byte("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz")
+
+func normalizeAddress(address string) (string, error) {
+	trimmed := strings.TrimSpace(address)
+	if trimmed == "" {
+		return "", merrors.InvalidArgument("address is required")
+	}
+	if strings.HasPrefix(trimmed, tronHexPrefix) || isHexString(trimmed) {
+		return hexToBase58(trimmed)
+	}
+	decoded, err := base58Decode(trimmed)
+	if err != nil {
+		return "", err
+	}
+	if err := validateChecksum(decoded); err != nil {
+		return "", err
+	}
+	return base58Encode(decoded), nil
+}
+
+func rpcAddress(address string) (string, error) {
+	trimmed := strings.TrimSpace(address)
+	if trimmed == "" {
+		return "", merrors.InvalidArgument("address is required")
+	}
+	if strings.HasPrefix(trimmed, tronHexPrefix) || isHexString(trimmed) {
+		return normalizeHexRPC(trimmed)
+	}
+	return base58ToHex(trimmed)
+}
+
+func hexToBase58(address string) (string, error) {
+	bytesAddr, err := parseHexAddress(address)
+	if err != nil {
+		return "", err
+	}
+	payload := append(bytesAddr, checksum(bytesAddr)...)
+	return base58Encode(payload), nil
+}
+
+func base58ToHex(address string) (string, error) {
+	decoded, err := base58Decode(address)
+	if err != nil {
+		return "", err
+	}
+	if err := validateChecksum(decoded); err != nil {
+		return "", err
+	}
+	return tronHexPrefix + hex.EncodeToString(decoded[1:21]), nil
+}
+
+func parseHexAddress(address string) ([]byte, error) {
+	trimmed := strings.TrimPrefix(strings.TrimSpace(address), tronHexPrefix)
+	if trimmed == "" {
+		return nil, merrors.InvalidArgument("address is required")
+	}
+	if len(trimmed)%2 == 1 {
+		trimmed = "0" + trimmed
+	}
+	decoded, err := hex.DecodeString(trimmed)
+	if err != nil {
+		return nil, merrors.InvalidArgument("invalid hex address")
+	}
+	switch len(decoded) {
+	case 20:
+		prefixed := make([]byte, 21)
+		prefixed[0] = 0x41
+		copy(prefixed[1:], decoded)
+		return prefixed, nil
+	case 21:
+		if decoded[0] != 0x41 {
+			return nil, merrors.InvalidArgument("invalid tron address prefix")
+		}
+		return decoded, nil
+	default:
+		return nil, merrors.InvalidArgument(fmt.Sprintf("invalid tron address length %d", len(decoded)))
+	}
+}
+
+func normalizeHexRPC(address string) (string, error) {
+	decoded, err := parseHexAddress(address)
+	if err != nil {
+		return "", err
+	}
+	return tronHexPrefix + hex.EncodeToString(decoded[1:21]), nil
+}
+
+func validateChecksum(decoded []byte) error {
+	if len(decoded) != 25 {
+		return merrors.InvalidArgument("invalid tron address length")
+	}
+	payload := decoded[:21]
+	expected := checksum(payload)
+	if !bytes.Equal(expected, decoded[21:]) {
+		return merrors.InvalidArgument("invalid tron address checksum")
+	}
+	if payload[0] != 0x41 {
+		return merrors.InvalidArgument("invalid tron address prefix")
+	}
+	return nil
+}
+
+func checksum(payload []byte) []byte {
+	first := sha256.Sum256(payload)
+	second := sha256.Sum256(first[:])
+	return second[:4]
+}
+
+func base58Encode(input []byte) string {
+	if len(input) == 0 {
+		return ""
+	}
+	x := new(big.Int).SetBytes(input)
+	base := big.NewInt(58)
+	zero := big.NewInt(0)
+	mod := new(big.Int)
+
+	encoded := make([]byte, 0, len(input))
+	for x.Cmp(zero) > 0 {
+		x.DivMod(x, base, mod)
+		encoded = append(encoded, base58Alphabet[mod.Int64()])
+	}
+	for _, b := range input {
+		if b != 0 {
+			break
+		}
+		encoded = append(encoded, base58Alphabet[0])
+	}
+	reverse(encoded)
+	return string(encoded)
+}
+
+func base58Decode(input string) ([]byte, error) {
+	result := big.NewInt(0)
+	base := big.NewInt(58)
+
+	for i := 0; i < len(input); i++ {
+		idx := bytes.IndexByte(base58Alphabet, input[i])
+		if idx < 0 {
+			return nil, merrors.InvalidArgument("invalid base58 address")
+		}
+		result.Mul(result, base)
+		result.Add(result, big.NewInt(int64(idx)))
+	}
+
+	decoded := result.Bytes()
+	zeroCount := 0
+	for zeroCount < len(input) && input[zeroCount] == base58Alphabet[0] {
+		zeroCount++
+	}
+	if zeroCount > 0 {
+		decoded = append(make([]byte, zeroCount), decoded...)
+	}
+	return decoded, nil
+}
+
+func reverse(data []byte) {
+	for i, j := 0, len(data)-1; i < j; i, j = i+1, j-1 {
+		data[i], data[j] = data[j], data[i]
+	}
+}
+
+func isHexString(value string) bool {
+	trimmed := strings.TrimPrefix(strings.TrimSpace(value), tronHexPrefix)
+	if trimmed == "" {
+		return false
+	}
+	for _, r := range trimmed {
+		switch {
+		case r >= '0' && r <= '9':
+		case r >= 'a' && r <= 'f':
+		case r >= 'A' && r <= 'F':
+		default:
+			return false
+		}
+	}
+	return true
+}

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

@@ -0,0 +1,245 @@
+package tron
+
+import (
+	"context"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/evm"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/gateway/chain/storage/model"
+	"github.com/tech/sendico/pkg/merrors"
+	"github.com/tech/sendico/pkg/mlogger"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	"go.uber.org/zap"
+)
+
+// Driver implements Tron-specific behavior, including address conversion.
+type Driver struct {
+	logger mlogger.Logger
+}
+
+func New(logger mlogger.Logger) *Driver {
+	return &Driver{logger: logger.Named("tron")}
+}
+
+func (d *Driver) Name() string {
+	return "tron"
+}
+
+func (d *Driver) FormatAddress(address string) (string, error) {
+	d.logger.Debug("Format address", zap.String("address", address))
+	normalized, err := normalizeAddress(address)
+	if err != nil {
+		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))
+	normalized, err := normalizeAddress(address)
+	if err != nil {
+		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) {
+	if wallet == nil {
+		return nil, merrors.InvalidArgument("wallet is required")
+	}
+	d.logger.Debug("Balance request", zap.String("wallet_ref", wallet.WalletRef), zap.String("network", network.Name))
+	rpcAddr, err := rpcAddress(wallet.DepositAddress)
+	if err != nil {
+		d.logger.Warn("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.Balance(ctx, driverDeps, network, wallet, rpcAddr)
+	if err != nil {
+		d.logger.Warn("Balance failed", zap.Error(err),
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("network", network.Name),
+		)
+	} else if result != nil {
+		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),
+			zap.String("currency", result.Currency),
+		)
+	}
+	return result, err
+}
+
+func (d *Driver) EstimateFee(ctx context.Context, deps driver.Deps, network shared.Network, wallet *model.ManagedWallet, destination string, amount *moneyv1.Money) (*moneyv1.Money, error) {
+	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),
+		zap.String("destination", destination),
+	)
+	rpcFrom, err := rpcAddress(wallet.DepositAddress)
+	if err != nil {
+		d.logger.Warn("Estimate fee address conversion failed", zap.Error(err),
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("address", wallet.DepositAddress),
+		)
+		return nil, err
+	}
+	rpcTo, err := rpcAddress(destination)
+	if err != nil {
+		d.logger.Warn("Estimate fee destination conversion failed", zap.Error(err),
+			zap.String("wallet_ref", wallet.WalletRef),
+			zap.String("destination", destination),
+		)
+		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)
+	if err != nil {
+		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",
+			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) SubmitTransfer(ctx context.Context, deps driver.Deps, network shared.Network, transfer *model.Transfer, source *model.ManagedWallet, destination string) (string, error) {
+	if source == nil {
+		return "", merrors.InvalidArgument("source wallet is required")
+	}
+	d.logger.Debug("Submit transfer request",
+		zap.String("transfer_ref", transfer.TransferRef),
+		zap.String("network", network.Name),
+		zap.String("destination", destination),
+	)
+	rpcFrom, err := rpcAddress(source.DepositAddress)
+	if err != nil {
+		d.logger.Warn("Submit transfer address conversion failed", zap.Error(err),
+			zap.String("wallet_ref", source.WalletRef),
+			zap.String("address", source.DepositAddress),
+		)
+		return "", err
+	}
+	rpcTo, err := rpcAddress(destination)
+	if err != nil {
+		d.logger.Warn("Submit transfer destination conversion failed", zap.Error(err),
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("destination", destination),
+		)
+		return "", err
+	}
+	driverDeps := deps
+	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),
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+		)
+	} else {
+		d.logger.Debug("Submit transfer result",
+			zap.String("transfer_ref", transfer.TransferRef),
+			zap.String("network", network.Name),
+			zap.String("tx_hash", txHash),
+		)
+	}
+	return txHash, err
+}
+
+func (d *Driver) AwaitConfirmation(ctx context.Context, deps driver.Deps, network shared.Network, txHash string) (*types.Receipt, error) {
+	d.logger.Debug("Awaiting confirmation",
+		zap.String("tx_hash", txHash),
+		zap.String("network", network.Name),
+	)
+	driverDeps := deps
+	driverDeps.Logger = d.logger
+	receipt, err := evm.AwaitConfirmation(ctx, driverDeps, network, txHash)
+	if err != nil {
+		d.logger.Warn("Awaiting of confirmation failed", zap.Error(err),
+			zap.String("tx_hash", txHash),
+			zap.String("network", network.Name),
+		)
+	} else if receipt != nil {
+		d.logger.Debug("Await confirmation result",
+			zap.String("tx_hash", txHash),
+			zap.String("network", network.Name),
+			zap.Uint64("block_number", receipt.BlockNumber.Uint64()),
+			zap.Uint64("status", receipt.Status),
+		)
+	}
+	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

@@ -0,0 +1,74 @@
+package drivers
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/arbitrum"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/driver/ethereum"
+	"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/pkg/merrors"
+	"github.com/tech/sendico/pkg/mlogger"
+	"go.uber.org/zap"
+)
+
+// Registry maps configured network keys to chain drivers.
+type Registry struct {
+	byNetwork map[string]driver.Driver
+}
+
+// NewRegistry selects drivers for the configured networks.
+func NewRegistry(logger mlogger.Logger, networks []shared.Network) (*Registry, error) {
+	if logger == nil {
+		return nil, merrors.InvalidArgument("driver registry: logger is required")
+	}
+	result := &Registry{byNetwork: map[string]driver.Driver{}}
+	for _, network := range networks {
+		name := strings.ToLower(strings.TrimSpace(network.Name))
+		if name == "" {
+			continue
+		}
+		chainDriver, err := resolveDriver(logger, name)
+		if err != nil {
+			logger.Error("unsupported chain driver", zap.String("network", name), zap.Error(err))
+			return nil, err
+		}
+		result.byNetwork[name] = chainDriver
+	}
+	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)))
+	return result, nil
+}
+
+// Driver resolves a driver for the provided network key.
+func (r *Registry) Driver(network string) (driver.Driver, error) {
+	if r == nil || len(r.byNetwork) == 0 {
+		return nil, merrors.Internal("driver registry is not configured")
+	}
+	key := strings.ToLower(strings.TrimSpace(network))
+	if key == "" {
+		return nil, merrors.InvalidArgument("network is required")
+	}
+	chainDriver, ok := r.byNetwork[key]
+	if !ok {
+		return nil, merrors.InvalidArgument(fmt.Sprintf("unsupported chain network %s", key))
+	}
+	return chainDriver, nil
+}
+
+func resolveDriver(logger mlogger.Logger, network string) (driver.Driver, error) {
+	switch {
+	case strings.HasPrefix(network, "tron"):
+		return tron.New(logger), nil
+	case strings.HasPrefix(network, "arbitrum"):
+		return arbitrum.New(logger), nil
+	case strings.HasPrefix(network, "ethereum"):
+		return ethereum.New(logger), nil
+	default:
+		return nil, merrors.InvalidArgument("unsupported chain network " + network)
+	}
+}

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

@@ -5,15 +5,15 @@ import (
 	"errors"
 	"math/big"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/shopspring/decimal"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"go.uber.org/zap"
 
@@ -30,11 +30,11 @@ type TransferExecutor interface {
 }
 
 // NewOnChainExecutor constructs a TransferExecutor that talks to an EVM-compatible chain.
-func NewOnChainExecutor(logger mlogger.Logger, keyManager keymanager.Manager) TransferExecutor {
+func NewOnChainExecutor(logger mlogger.Logger, keyManager keymanager.Manager, clients *rpcclient.Clients) TransferExecutor {
 	return &onChainExecutor{
 		logger:     logger.Named("executor"),
 		keyManager: keyManager,
-		clients:    map[string]*ethclient.Client{},
+		clients:    clients,
 	}
 }
 
@@ -42,34 +42,33 @@ type onChainExecutor struct {
 	logger     mlogger.Logger
 	keyManager keymanager.Manager
 
-	mu      sync.Mutex
+	clients *rpcclient.Clients
-	clients map[string]*ethclient.Client
 }
 
 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.Error("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.Error("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.Error("transfer context missing")
+		o.logger.Warn("transfer context missing")
 		return "", executorInvalid("transfer context missing")
 	}
 	if strings.TrimSpace(source.KeyReference) == "" {
-		o.logger.Error("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.Error("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.Error("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)
 	}
 
@@ -80,11 +79,15 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 		zap.String("destination", strings.ToLower(destinationAddress)),
 	)
 
-	client, err := o.getClient(ctx, rpcURL)
+	client, err := o.clients.Client(network.Name)
 	if err != nil {
-		o.logger.Warn("failed to initialise rpc client",
+		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",
 			zap.String("network", network.Name),
-			zap.String("rpc_url", rpcURL),
 			zap.Error(err),
 		)
 		return "", err
@@ -98,17 +101,16 @@ 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",
+		o.logger.Warn("Failed to fetch nonce", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("wallet_ref", source.WalletRef),
-			zap.Error(err),
 		)
 		return "", executorInternal("failed to fetch nonce", err)
 	}
 
 	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),
@@ -122,12 +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),
 		)
@@ -135,27 +137,25 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 	}
 	tokenAddress := common.HexToAddress(transfer.ContractAddress)
 
-	decimals, err := erc20Decimals(ctx, client, tokenAddress)
+	decimals, err := erc20Decimals(ctx, rpcClient, tokenAddress)
 	if err != nil {
-		o.logger.Warn("failed to read token decimals",
+		o.logger.Warn("Failed to read token decimals", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("contract", transfer.ContractAddress),
-			zap.Error(err),
 		)
 		return "", err
 	}
 
 	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",
+		o.logger.Warn("Failed to convert amount to base units", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("amount", amount.Amount),
-			zap.Error(err),
 		)
 		return "", 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),
 		)
@@ -188,24 +188,22 @@ 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",
+		o.logger.Warn("Failed to sign transaction", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
 			zap.String("wallet_ref", source.WalletRef),
-			zap.Error(err),
 		)
 		return "", err
 	}
 
 	if err := client.SendTransaction(ctx, signedTx); err != nil {
-		o.logger.Warn("failed to send transaction",
+		o.logger.Warn("Failed to send transaction", zap.Error(err),
 			zap.String("transfer_ref", transfer.TransferRef),
-			zap.Error(err),
 		)
 		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),
@@ -214,42 +212,18 @@ func (o *onChainExecutor) SubmitTransfer(ctx context.Context, transfer *model.Tr
 	return txHash, nil
 }
 
-func (o *onChainExecutor) getClient(ctx context.Context, rpcURL string) (*ethclient.Client, error) {
-	o.mu.Lock()
-	client, ok := o.clients[rpcURL]
-	o.mu.Unlock()
-	if ok {
-		return client, nil
-	}
-
-	c, err := ethclient.DialContext(ctx, rpcURL)
-	if err != nil {
-		return nil, executorInternal("failed to connect to rpc "+rpcURL, err)
-	}
-
-	o.mu.Lock()
-	defer o.mu.Unlock()
-	if existing, ok := o.clients[rpcURL]; ok {
-		// Another routine initialised it in the meantime; prefer the existing client and close the new one.
-		c.Close()
-		return existing, nil
-	}
-	o.clients[rpcURL] = c
-	return c, nil
-}
-
 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")
 	}
 
-	client, err := o.getClient(ctx, rpcURL)
+	client, err := o.clients.Client(network.Name)
 	if err != nil {
 		return nil, err
 	}
@@ -264,27 +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()),
@@ -331,31 +305,20 @@ const erc20ABIJSON = `
 	}
 ]`
 
-func erc20Decimals(ctx context.Context, client *ethclient.Client, token common.Address) (uint8, error) {
+func erc20Decimals(ctx context.Context, client *rpc.Client, token common.Address) (uint8, error) {
-	callData, err := erc20ABI.Pack("decimals")
+	call := map[string]string{
-	if err != nil {
+		"to":   strings.ToLower(token.Hex()),
-		return 0, executorInternal("failed to encode decimals call", err)
+		"data": "0x313ce567",
 	}
-	msg := ethereum.CallMsg{
+	var hexResp string
-		To:   &token,
+	if err := client.CallContext(ctx, &hexResp, "eth_call", call, "latest"); err != nil {
-		Data: callData,
-	}
-	output, err := client.CallContract(ctx, msg, nil)
-	if err != nil {
 		return 0, executorInternal("decimals call failed", err)
 	}
-	values, err := erc20ABI.Unpack("decimals", output)
+	val, err := shared.DecodeHexUint8(hexResp)
 	if err != nil {
-		return 0, executorInternal("failed to unpack decimals", err)
+		return 0, executorInternal("decimals decode failed", err)
 	}
-	if len(values) == 0 {
+	return val, nil
-		return 0, executorInternal("decimals call returned no data", nil)
-	}
-	decimals, ok := values[0].(uint8)
-	if !ok {
-		return 0, executorInternal("decimals call returned unexpected type", nil)
-	}
-	return decimals, nil
 }
 
 func toBaseUnits(amount string, decimals uint8) (*big.Int, error) {

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

@@ -4,6 +4,8 @@ import (
 	"strings"
 
 	"github.com/tech/sendico/gateway/chain/internal/keymanager"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	clockpkg "github.com/tech/sendico/pkg/clock"
 )
@@ -18,10 +20,10 @@ func WithKeyManager(manager keymanager.Manager) Option {
 	}
 }
 
-// WithTransferExecutor configures the executor responsible for on-chain submissions.
+// WithRPCClients configures pre-initialised RPC clients.
-func WithTransferExecutor(executor TransferExecutor) Option {
+func WithRPCClients(clients *rpcclient.Clients) Option {
 	return func(s *Service) {
-		s.executor = executor
+		s.rpcClients = clients
 	}
 }
 
@@ -59,6 +61,13 @@ func WithServiceWallet(wallet shared.ServiceWallet) Option {
 	}
 }
 
+// WithDriverRegistry configures the chain driver registry.
+func WithDriverRegistry(registry *drivers.Registry) Option {
+	return func(s *Service) {
+		s.drivers = registry
+	}
+}
+
 // WithClock overrides the service clock.
 func WithClock(clk clockpkg.Clock) Option {
 	return func(s *Service) {

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

@@ -0,0 +1,204 @@
+package rpcclient
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/pkg/merrors"
+	"github.com/tech/sendico/pkg/mlogger"
+	"go.uber.org/zap"
+)
+
+// Clients holds pre-initialised RPC clients keyed by network name.
+type Clients struct {
+	logger  mlogger.Logger
+	clients map[string]clientEntry
+}
+
+type clientEntry struct {
+	eth *ethclient.Client
+	rpc *rpc.Client
+}
+
+// Prepare dials all configured networks up front and returns a ready-to-use client set.
+func Prepare(ctx context.Context, logger mlogger.Logger, networks []shared.Network) (*Clients, error) {
+	if logger == nil {
+		return nil, merrors.Internal("rpc clients: logger is required")
+	}
+	clientLogger := logger.Named("rpc_client")
+	result := &Clients{
+		logger:  clientLogger,
+		clients: make(map[string]clientEntry),
+	}
+
+	for _, network := range networks {
+		name := strings.ToLower(strings.TrimSpace(network.Name))
+		rpcURL := strings.TrimSpace(network.RPCURL)
+		if name == "" {
+			clientLogger.Warn("Skipping network with empty name during rpc client preparation")
+			continue
+		}
+		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))
+			return nil, err
+		}
+
+		fields := []zap.Field{
+			zap.String("network", name),
+		}
+		clientLogger.Info("initialising rpc client", fields...)
+
+		dialCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
+		httpClient := &http.Client{
+			Transport: &loggingRoundTripper{
+				logger:   clientLogger,
+				network:  name,
+				endpoint: rpcURL,
+				base:     http.DefaultTransport,
+			},
+		}
+		rpcCli, err := rpc.DialOptions(dialCtx, rpcURL, rpc.WithHTTPClient(httpClient))
+		cancel()
+		if err != nil {
+			result.Close()
+			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)
+		result.clients[name] = clientEntry{
+			eth: client,
+			rpc: rpcCli,
+		}
+		clientLogger.Info("RPC client ready", fields...)
+	}
+
+	if len(result.clients) == 0 {
+		clientLogger.Warn("No rpc clients were initialised")
+		return nil, merrors.InvalidArgument("no rpc clients initialised")
+	} else {
+		clientLogger.Info("RPC clients initialised", zap.Int("count", len(result.clients)))
+	}
+
+	return result, nil
+}
+
+// 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")
+	}
+	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 entry.eth, nil
+}
+
+// RPCClient returns the raw RPC client for low-level calls.
+func (c *Clients) RPCClient(network string) (*rpc.Client, error) {
+	if c == nil {
+		return nil, merrors.Internal("rpc clients not initialised")
+	}
+	name := strings.ToLower(strings.TrimSpace(network))
+	entry, ok := c.clients[name]
+	if !ok || entry.rpc == nil {
+		return nil, merrors.InvalidArgument(fmt.Sprintf("rpc client not configured for network %s", name))
+	}
+	return entry.rpc, nil
+}
+
+// Close tears down all RPC clients, logging each close.
+func (c *Clients) Close() {
+	if c == nil {
+		return
+	}
+	for name, entry := range c.clients {
+		if entry.rpc != nil {
+			entry.rpc.Close()
+		} else if entry.eth != nil {
+			entry.eth.Close()
+		}
+		if c.logger != nil {
+			c.logger.Info("RPC client closed", zap.String("network", name))
+		}
+	}
+}
+
+type loggingRoundTripper struct {
+	logger   mlogger.Logger
+	network  string
+	endpoint string
+	base     http.RoundTripper
+}
+
+func (l *loggingRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	if l.base == nil {
+		l.base = http.DefaultTransport
+	}
+
+	var reqBody []byte
+	if req.Body != nil {
+		raw, _ := io.ReadAll(req.Body)
+		reqBody = raw
+		req.Body = io.NopCloser(strings.NewReader(string(raw)))
+	}
+
+	fields := []zap.Field{
+		zap.String("network", l.network),
+	}
+	if len(reqBody) > 0 {
+		fields = append(fields, zap.String("rpc_request", truncate(string(reqBody), 2048)))
+	}
+	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))...)
+		return nil, err
+	}
+
+	bodyBytes, _ := io.ReadAll(resp.Body)
+	resp.Body.Close()
+	resp.Body = io.NopCloser(strings.NewReader(string(bodyBytes)))
+
+	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
+}
+
+func truncate(s string, max int) string {
+	if len(s) <= max {
+		return s
+	}
+	if max <= 3 {
+		return s[:max]
+	}
+	return s[:max-3] + "..."
+}

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

@@ -0,0 +1,54 @@
+package rpcclient
+
+import (
+	"strings"
+
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
+	"github.com/tech/sendico/pkg/merrors"
+)
+
+// Registry binds static network metadata with prepared RPC clients.
+type Registry struct {
+	networks map[string]shared.Network
+	clients  *Clients
+}
+
+// NewRegistry constructs a registry keyed by lower-cased network name.
+func NewRegistry(networks map[string]shared.Network, clients *Clients) *Registry {
+	return &Registry{
+		networks: networks,
+		clients:  clients,
+	}
+}
+
+// Network fetches network metadata by key (case-insensitive).
+func (r *Registry) Network(key string) (shared.Network, bool) {
+	if r == nil || len(r.networks) == 0 {
+		return shared.Network{}, false
+	}
+	n, ok := r.networks[strings.ToLower(strings.TrimSpace(key))]
+	return n, ok
+}
+
+// Client returns the prepared RPC client for the given network name.
+func (r *Registry) Client(key string) (*ethclient.Client, error) {
+	if r == nil || r.clients == nil {
+		return nil, merrors.Internal("rpc clients not initialised")
+	}
+	return r.clients.Client(strings.ToLower(strings.TrimSpace(key)))
+}
+
+// RPCClient returns the raw RPC client for low-level calls.
+func (r *Registry) RPCClient(key string) (*rpc.Client, error) {
+	if r == nil || r.clients == nil {
+		return nil, merrors.Internal("rpc clients not initialised")
+	}
+	return r.clients.RPCClient(strings.ToLower(strings.TrimSpace(key)))
+}
+
+// Networks exposes the registry map for iteration when needed.
+func (r *Registry) Networks() map[string]shared.Network {
+	return r.networks
+}

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

@@ -7,6 +7,8 @@ import (
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/commands"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/commands/transfer"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/commands/wallet"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/rpcclient"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/gateway/chain/storage"
 	"github.com/tech/sendico/pkg/api/routers"
@@ -38,11 +40,13 @@ type Service struct {
 
 	settings CacheSettings
 
-	networks      map[string]shared.Network
+	networks        map[string]shared.Network
-	serviceWallet shared.ServiceWallet
+	serviceWallet   shared.ServiceWallet
-	keyManager    keymanager.Manager
+	keyManager      keymanager.Manager
-	executor      TransferExecutor
+	rpcClients      *rpcclient.Clients
-	commands      commands.Registry
+	networkRegistry *rpcclient.Registry
+	drivers         *drivers.Registry
+	commands        commands.Registry
 
 	chainv1.UnimplementedChainGatewayServiceServer
 }
@@ -73,6 +77,7 @@ func NewService(logger mlogger.Logger, repo storage.Repository, producer msg.Pro
 		svc.networks = map[string]shared.Network{}
 	}
 	svc.settings = svc.settings.withDefaults()
+	svc.networkRegistry = rpcclient.NewRegistry(svc.networks, svc.rpcClients)
 
 	svc.commands = commands.NewRegistry(commands.RegistryDeps{
 		Wallet:   commandsWalletDeps(svc),
@@ -121,6 +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
@@ -131,11 +144,13 @@ func (s *Service) ensureRepository(ctx context.Context) error {
 func commandsWalletDeps(s *Service) wallet.Deps {
 	return wallet.Deps{
 		Logger:           s.logger.Named("command"),
-		Networks:         s.networks,
+		Drivers:          s.drivers,
+		Networks:         s.networkRegistry,
 		KeyManager:       s.keyManager,
 		Storage:          s.storage,
 		Clock:            s.clock,
 		BalanceCacheTTL:  s.settings.walletBalanceCacheTTL(),
+		RPCTimeout:       s.settings.rpcTimeout(),
 		EnsureRepository: s.ensureRepository,
 	}
 }
@@ -143,9 +158,11 @@ func commandsWalletDeps(s *Service) wallet.Deps {
 func commandsTransferDeps(s *Service) transfer.Deps {
 	return transfer.Deps{
 		Logger:           s.logger.Named("transfer_cmd"),
-		Networks:         s.networks,
+		Drivers:          s.drivers,
+		Networks:         s.networkRegistry,
 		Storage:          s.storage,
 		Clock:            s.clock,
+		RPCTimeout:       s.settings.rpcTimeout(),
 		EnsureRepository: s.ensureRepository,
 		LaunchExecution:  s.launchTransferExecution,
 	}

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

@@ -18,6 +18,7 @@ import (
 	"google.golang.org/grpc/status"
 
 	"github.com/tech/sendico/gateway/chain/internal/keymanager"
+	"github.com/tech/sendico/gateway/chain/internal/service/gateway/drivers"
 	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 	"github.com/tech/sendico/gateway/chain/storage"
 	"github.com/tech/sendico/gateway/chain/storage/model"
@@ -65,6 +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()
@@ -143,6 +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 {
@@ -526,18 +577,23 @@ func sanitizeLimit(requested int32, def, max int64) int64 {
 	return int64(requested)
 }
 
-func newTestService(_ *testing.T) (*Service, *inMemoryRepository) {
+func newTestService(t *testing.T) (*Service, *inMemoryRepository) {
 	repo := newInMemoryRepository()
 	logger := zap.NewNop()
+	networks := []shared.Network{{
+		Name:        "ethereum_mainnet",
+		NativeToken: "ETH",
+		TokenConfigs: []shared.TokenContract{
+			{Symbol: "USDC", ContractAddress: "0xusdc"},
+		},
+	}}
+	driverRegistry, err := drivers.NewRegistry(logger.Named("drivers"), networks)
+	require.NoError(t, err)
 	svc := NewService(logger, repo, nil,
 		WithKeyManager(&fakeKeyManager{}),
-		WithNetworks([]shared.Network{{
+		WithNetworks(networks),
-			Name: "ethereum_mainnet",
-			TokenConfigs: []shared.TokenContract{
-				{Symbol: "USDC", ContractAddress: "0xusdc"},
-			},
-		}}),
 		WithServiceWallet(shared.ServiceWallet{Network: "ethereum_mainnet", Address: "0xservice"}),
+		WithDriverRegistry(driverRegistry),
 	)
 	return svc, repo
 }

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

@@ -3,15 +3,18 @@ package gateway
 import "time"
 
 const defaultWalletBalanceCacheTTL = 120 * time.Second
+const defaultRPCRequestTimeout = 15 * time.Second
 
 // CacheSettings holds tunable gateway behaviour.
 type CacheSettings struct {
 	WalletBalanceCacheTTLSeconds int `yaml:"wallet_balance_ttl_seconds"`
+	RPCRequestTimeoutSeconds     int `yaml:"rpc_request_timeout_seconds"`
 }
 
 func defaultSettings() CacheSettings {
 	return CacheSettings{
 		WalletBalanceCacheTTLSeconds: int(defaultWalletBalanceCacheTTL.Seconds()),
+		RPCRequestTimeoutSeconds:     int(defaultRPCRequestTimeout.Seconds()),
 	}
 }
 
@@ -19,6 +22,9 @@ func (s CacheSettings) withDefaults() CacheSettings {
 	if s.WalletBalanceCacheTTLSeconds <= 0 {
 		s.WalletBalanceCacheTTLSeconds = int(defaultWalletBalanceCacheTTL.Seconds())
 	}
+	if s.RPCRequestTimeoutSeconds <= 0 {
+		s.RPCRequestTimeoutSeconds = int(defaultRPCRequestTimeout.Seconds())
+	}
 	return s
 }
 
@@ -28,3 +34,10 @@ func (s CacheSettings) walletBalanceCacheTTL() time.Duration {
 	}
 	return time.Duration(s.WalletBalanceCacheTTLSeconds) * time.Second
 }
+
+func (s CacheSettings) rpcTimeout() time.Duration {
+	if s.RPCRequestTimeoutSeconds <= 0 {
+		return defaultRPCRequestTimeout
+	}
+	return time.Duration(s.RPCRequestTimeoutSeconds) * time.Second
+}

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
+	Name           string
-	RPCURL       string
+	RPCURL         string
-	ChainID      uint64
+	ChainID        uint64
-	NativeToken  string
+	NativeToken    string
-	TokenConfigs []TokenContract
+	TokenConfigs   []TokenContract
+	GasTopUpPolicy *GasTopUpPolicy
 }
 
 // TokenContract captures the metadata needed to work with a specific on-chain token.

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

@@ -0,0 +1,49 @@
+package shared
+
+import (
+	"errors"
+	"math/big"
+	"strings"
+)
+
+var (
+	errHexEmpty      = errors.New("hex value is empty")
+	errHexInvalid    = errors.New("invalid hex number")
+	errHexOutOfRange = errors.New("hex number out of range")
+)
+
+// DecodeHexBig parses a hex string that may include leading zero digits.
+func DecodeHexBig(input string) (*big.Int, error) {
+	trimmed := strings.TrimSpace(input)
+	if trimmed == "" {
+		return nil, errHexEmpty
+	}
+	noPrefix := strings.TrimPrefix(trimmed, "0x")
+	if noPrefix == "" {
+		return nil, errHexEmpty
+	}
+	value := strings.TrimLeft(noPrefix, "0")
+	if value == "" {
+		return big.NewInt(0), nil
+	}
+	val := new(big.Int)
+	if _, ok := val.SetString(value, 16); !ok {
+		return nil, errHexInvalid
+	}
+	return val, nil
+}
+
+// DecodeHexUint8 parses a hex string into uint8, allowing leading zeros.
+func DecodeHexUint8(input string) (uint8, error) {
+	val, err := DecodeHexBig(input)
+	if err != nil {
+		return 0, err
+	}
+	if val == nil {
+		return 0, errHexInvalid
+	}
+	if val.BitLen() > 8 {
+		return 0, errHexOutOfRange
+	}
+	return uint8(val.Uint64()), nil
+}

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

@@ -0,0 +1,16 @@
+package shared
+
+import "testing"
+
+func TestDecodeHexUint8_LeadingZeros(t *testing.T) {
+	t.Parallel()
+
+	const resp = "0x0000000000000000000000000000000000000000000000000000000000000006"
+	val, err := DecodeHexUint8(resp)
+	if err != nil {
+		t.Fatalf("DecodeHexUint8 error: %v", err)
+	}
+	if val != 6 {
+		t.Fatalf("DecodeHexUint8 value = %d, want 6", val)
+	}
+}

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

@@ -7,15 +7,15 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/core/types"
+	"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"
 	"github.com/tech/sendico/pkg/merrors"
 	"go.uber.org/zap"
-
-	"github.com/tech/sendico/gateway/chain/internal/service/gateway/shared"
 )
 
 func (s *Service) launchTransferExecution(transferRef, sourceWalletRef string, network shared.Network) {
-	if s.executor == nil {
+	if s.drivers == nil {
 		return
 	}
 
@@ -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.Error("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)
 }
@@ -44,13 +44,37 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 		s.logger.Warn("failed to update transfer status to signing", zap.String("transfer_ref", transferRef), zap.Error(err))
 	}
 
-	destinationAddress, err := s.destinationAddress(ctx, transfer.Destination)
+	driverDeps := s.driverDeps()
+	chainDriver, err := s.driverForNetwork(network.Name)
 	if err != nil {
 		_, _ = s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusFailed, err.Error(), "")
 		return err
 	}
 
-	txHash, err := s.executor.SubmitTransfer(ctx, transfer, sourceWallet, destinationAddress, network)
+	destinationAddress, err := s.destinationAddress(ctx, chainDriver, transfer.Destination)
+	if err != nil {
+		_, _ = s.storage.Transfers().UpdateStatus(ctx, transferRef, model.TransferStatusFailed, err.Error(), "")
+		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(), "")
 		return err
@@ -62,7 +86,7 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 
 	receiptCtx, cancel := context.WithTimeout(ctx, 10*time.Minute)
 	defer cancel()
-	receipt, err := s.executor.AwaitConfirmation(receiptCtx, network, txHash)
+	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))
@@ -83,7 +107,7 @@ func (s *Service) executeTransfer(ctx context.Context, transferRef, sourceWallet
 	return nil
 }
 
-func (s *Service) destinationAddress(ctx context.Context, dest model.TransferDestination) (string, error) {
+func (s *Service) destinationAddress(ctx context.Context, chainDriver driver.Driver, dest model.TransferDestination) (string, error) {
 	if ref := strings.TrimSpace(dest.ManagedWalletRef); ref != "" {
 		wallet, err := s.storage.Wallets().Get(ctx, ref)
 		if err != nil {
@@ -92,10 +116,26 @@ func (s *Service) destinationAddress(ctx context.Context, dest model.TransferDes
 		if strings.TrimSpace(wallet.DepositAddress) == "" {
 			return "", merrors.Internal("destination wallet missing deposit address")
 		}
-		return wallet.DepositAddress, nil
+		return chainDriver.NormalizeAddress(wallet.DepositAddress)
 	}
 	if addr := strings.TrimSpace(dest.ExternalAddress); addr != "" {
-		return strings.ToLower(addr), nil
+		return chainDriver.NormalizeAddress(addr)
 	}
 	return "", merrors.InvalidArgument("transfer destination address not resolved")
 }
+
+func (s *Service) driverDeps() driver.Deps {
+	return driver.Deps{
+		Logger:     s.logger.Named("driver"),
+		Registry:   s.networkRegistry,
+		KeyManager: s.keyManager,
+		RPCTimeout: s.settings.rpcTimeout(),
+	}
+}
+
+func (s *Service) driverForNetwork(network string) (driver.Driver, error) {
+	if s.drivers == nil {
+		return nil, merrors.Internal("chain drivers not configured")
+	}
+	return s.drivers.Driver(network)
+}

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

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/tech/sendico/pkg/db/storable"
+	pkgmodel "github.com/tech/sendico/pkg/model"
 	"github.com/tech/sendico/pkg/mservice"
 	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
 )
@@ -19,7 +20,8 @@ const (
 
 // ManagedWallet represents a user-controlled on-chain wallet managed by the service.
 type ManagedWallet struct {
-	storable.Base `bson:",inline" json:",inline"`
+	storable.Base        `bson:",inline" json:",inline"`
+	pkgmodel.Describable `bson:",inline" json:",inline"`
 
 	IdempotencyKey  string              `bson:"idempotencyKey" json:"idempotencyKey"`
 	WalletRef       string              `bson:"walletRef" json:"walletRef"`
@@ -45,6 +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"`
@@ -77,10 +80,19 @@ func (m *ManagedWallet) Normalize() {
 	m.WalletRef = strings.TrimSpace(m.WalletRef)
 	m.OrganizationRef = strings.TrimSpace(m.OrganizationRef)
 	m.OwnerRef = strings.TrimSpace(m.OwnerRef)
+	m.Name = strings.TrimSpace(m.Name)
+	if m.Description != nil {
+		desc := strings.TrimSpace(*m.Description)
+		if desc == "" {
+			m.Description = nil
+		} else {
+			m.Description = &desc
+		}
+	}
 	m.Network = strings.TrimSpace(strings.ToLower(m.Network))
 	m.TokenSymbol = strings.TrimSpace(strings.ToUpper(m.TokenSymbol))
 	m.ContractAddress = strings.TrimSpace(strings.ToLower(m.ContractAddress))
-	m.DepositAddress = strings.TrimSpace(strings.ToLower(m.DepositAddress))
+	m.DepositAddress = normalizeWalletAddress(m.DepositAddress)
 	m.KeyReference = strings.TrimSpace(m.KeyReference)
 }
 
@@ -88,3 +100,31 @@ func (m *ManagedWallet) Normalize() {
 func (b *WalletBalance) Normalize() {
 	b.WalletRef = strings.TrimSpace(b.WalletRef)
 }
+
+func normalizeWalletAddress(address string) string {
+	trimmed := strings.TrimSpace(address)
+	if trimmed == "" {
+		return ""
+	}
+	if isHexAddress(trimmed) {
+		return strings.ToLower(trimmed)
+	}
+	return trimmed
+}
+
+func isHexAddress(value string) bool {
+	trimmed := strings.TrimPrefix(strings.TrimSpace(value), "0x")
+	if len(trimmed) != 40 && len(trimmed) != 42 {
+		return false
+	}
+	for _, r := range trimmed {
+		switch {
+		case r >= '0' && r <= '9':
+		case r >= 'a' && r <= 'f':
+		case r >= 'A' && r <= 'F':
+		default:
+			return false
+		}
+	}
+	return true
+}

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

@@ -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) {
+func (w *Wallets) Get(ctx context.Context, walletID string) (*model.ManagedWallet, error) {
-	walletRef = strings.TrimSpace(walletRef)
+	walletID = strings.TrimSpace(walletID)
-	if walletRef == "" {
+	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.balanceRepo.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))
 		}
 	}
 
 	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) {
+	listErr := w.walletRepo.FindManyByFilter(ctx, query, decoder)
-		return nil, err
+	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) {
+func (w *Wallets) GetBalance(ctx context.Context, walletID string) (*model.WalletBalance, error) {
-	walletRef = strings.TrimSpace(walletRef)
+	walletID = strings.TrimSpace(walletID)
-	if walletRef == "" {
+	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/go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/shopspring/decimal v1.4.0
 	github.com/tech/sendico/pkg v0.1.0
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -50,5 +50,5 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 )

api/gateway/mntx/go.sum

@@ -214,10 +214,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/ledger/go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/tech/sendico/pkg v0.1.0
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -51,5 +51,5 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 )

api/ledger/go.sum

@@ -214,10 +214,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/notification/go.mod

@@ -52,7 +52,7 @@ require (
 	golang.org/x/net v0.48.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
-	google.golang.org/grpc v1.77.0 // indirect
+	google.golang.org/grpc v1.78.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )

api/notification/go.sum

@@ -227,10 +227,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

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"
+    funding_address: "TGBDXEg9rxSqGFJDcb889zqTjDwx1bmLRF"
-    fee_address: "wallet_fee_monetix"
+    fee_wallet_ref: "694c124ed76f9f811ac57133"
 
 fee_ledger_accounts:
   monetix: "ledger:fees:monetix"

api/payments/orchestrator/go.mod

@@ -24,7 +24,7 @@ require (
 	github.com/tech/sendico/pkg v0.1.0
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -62,5 +62,5 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 )

api/payments/orchestrator/go.sum

@@ -215,10 +215,10 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

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)
+	amount, err := cardPayoutAmount(payment)
-	if amount == nil || strings.TrimSpace(amount.GetAmount()) == "" || strings.TrimSpace(amount.GetCurrency()) == "" {
+	if err != nil {
-		return merrors.InvalidArgument("card payout: amount is required")
+		return err
 	}
 	amtDec, err := decimalFromMoney(amount)
 	if err != nil {
@@ -193,13 +359,92 @@ 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 {
+	exec := payment.Execution
-		payment.Execution = &model.ExecutionRefs{}
+	if exec == nil {
+		exec = &model.ExecutionRefs{}
 	}
-	if payment.Execution.CardPayoutRef == "" {
+	if exec.CardPayoutRef == "" {
-		payment.Execution.CardPayoutRef = strings.TrimSpace(state.GetPayoutId())
+		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 +495,147 @@ 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 +1,407 @@
+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"},
+		},
+		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

@@ -5,9 +5,7 @@ import (
 	"time"
 
 	"github.com/tech/sendico/payments/orchestrator/storage/model"
-	"github.com/tech/sendico/pkg/merrors"
 	fxv1 "github.com/tech/sendico/pkg/proto/common/fx/v1"
-	paginationv1 "github.com/tech/sendico/pkg/proto/common/pagination/v1"
 	chainv1 "github.com/tech/sendico/pkg/proto/gateway/chain/v1"
 	oraclev1 "github.com/tech/sendico/pkg/proto/oracle/v1"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
@@ -127,6 +125,7 @@ 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 {
@@ -253,6 +252,41 @@ 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
@@ -413,74 +447,3 @@ func cloneNetworkEstimate(resp *chainv1.EstimateTransferFeeResponse) *chainv1.Es
 	}
 	return nil
 }
-
-func protoFailureToModel(code orchestratorv1.PaymentFailureCode) model.PaymentFailureCode {
-	switch code {
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_BALANCE:
-		return model.PaymentFailureCodeBalance
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_LEDGER:
-		return model.PaymentFailureCodeLedger
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_FX:
-		return model.PaymentFailureCodeFX
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_CHAIN:
-		return model.PaymentFailureCodeChain
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_FEES:
-		return model.PaymentFailureCodeFees
-	case orchestratorv1.PaymentFailureCode_PAYMENT_FAILURE_CODE_POLICY:
-		return model.PaymentFailureCodePolicy
-	default:
-		return model.PaymentFailureCodeUnspecified
-	}
-}
-
-func applyProtoPaymentToModel(src *orchestratorv1.Payment, dst *model.Payment) error {
-	if src == nil || dst == nil {
-		return merrors.InvalidArgument("payment payload is required")
-	}
-	dst.PaymentRef = strings.TrimSpace(src.GetPaymentRef())
-	dst.IdempotencyKey = strings.TrimSpace(src.GetIdempotencyKey())
-	dst.Intent = intentFromProto(src.GetIntent())
-	dst.State = modelStateFromProto(src.GetState())
-	dst.FailureCode = protoFailureToModel(src.GetFailureCode())
-	dst.FailureReason = strings.TrimSpace(src.GetFailureReason())
-	dst.Metadata = cloneMetadata(src.GetMetadata())
-	dst.LastQuote = quoteSnapshotToModel(src.GetLastQuote())
-	dst.Execution = executionFromProto(src.GetExecution())
-	if src.GetCardPayout() != nil {
-		dst.CardPayout = &model.CardPayout{
-			PayoutRef:         strings.TrimSpace(src.GetCardPayout().GetPayoutRef()),
-			ProviderPaymentID: strings.TrimSpace(src.GetCardPayout().GetProviderPaymentId()),
-			Status:            strings.TrimSpace(src.GetCardPayout().GetStatus()),
-			FailureReason:     strings.TrimSpace(src.GetCardPayout().GetFailureReason()),
-			CardCountry:       strings.TrimSpace(src.GetCardPayout().GetCardCountry()),
-			MaskedPan:         strings.TrimSpace(src.GetCardPayout().GetMaskedPan()),
-			ProviderCode:      strings.TrimSpace(src.GetCardPayout().GetProviderCode()),
-			GatewayReference:  strings.TrimSpace(src.GetCardPayout().GetGatewayReference()),
-		}
-	}
-	return nil
-}
-
-func executionFromProto(src *orchestratorv1.ExecutionRefs) *model.ExecutionRefs {
-	if src == nil {
-		return nil
-	}
-	return &model.ExecutionRefs{
-		DebitEntryRef:    strings.TrimSpace(src.GetDebitEntryRef()),
-		CreditEntryRef:   strings.TrimSpace(src.GetCreditEntryRef()),
-		FXEntryRef:       strings.TrimSpace(src.GetFxEntryRef()),
-		ChainTransferRef: strings.TrimSpace(src.GetChainTransferRef()),
-		CardPayoutRef:    strings.TrimSpace(src.GetCardPayoutRef()),
-		FeeTransferRef:   strings.TrimSpace(src.GetFeeTransferRef()),
-	}
-}
-
-func ensurePageRequest(req *orchestratorv1.ListPaymentsRequest) *paginationv1.CursorPageRequest {
-	if req == nil {
-		return &paginationv1.CursorPageRequest{}
-	}
-	if req.GetPage() == nil {
-		return &paginationv1.CursorPageRequest{}
-	}
-	return req.GetPage()
-}

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 {
+	quoteRef := strings.TrimSpace(req.GetQuoteRef())
-		return gsresponse.InvalidArgument[orchestratorv1.InitiatePaymentResponse](h.logger, mservice.PaymentOrchestrator, err)
+	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/helpers.go

@@ -214,20 +214,6 @@ func decimalFromMoney(m *moneyv1.Money) (decimal.Decimal, error) {
 	return decimal.NewFromString(m.GetAmount())
 }
 
-func decimalFromMoneyMatching(reference, candidate *moneyv1.Money) (*decimal.Decimal, error) {
-	if reference == nil || candidate == nil {
-		return nil, nil
-	}
-	if !strings.EqualFold(reference.GetCurrency(), candidate.GetCurrency()) {
-		return nil, nil
-	}
-	value, err := decimal.NewFromString(candidate.GetAmount())
-	if err != nil {
-		return nil, err
-	}
-	return &value, nil
-}
-
 func makeMoney(currency string, value decimal.Decimal) *moneyv1.Money {
 	return &moneyv1.Money{
 		Currency: currency,

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/quote_batch_test.go

@@ -57,7 +57,7 @@ func TestMinQuoteExpiry(t *testing.T) {
 	later := now.Add(10 * time.Minute)
 	earliest := now.Add(5 * time.Minute)
 
-	min, ok := minQuoteExpiry([]time.Time{later, time.Time{}, earliest})
+	min, ok := minQuoteExpiry([]time.Time{later, {}, earliest})
 	if !ok {
 		t.Fatal("expected min expiry to be set")
 	}
@@ -65,7 +65,7 @@ func TestMinQuoteExpiry(t *testing.T) {
 		t.Fatalf("expected min expiry %v, got %v", earliest, min)
 	}
 
-	if _, ok := minQuoteExpiry([]time.Time{time.Time{}}); ok {
+	if _, ok := minQuoteExpiry([]time.Time{{}}); ok {
 		t.Fatal("expected min expiry to be unset")
 	}
 }

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) {
+		intent, err := recordIntentFromQuote(record)
-			return nil, quoteResolutionError{code: "quote_intent_mismatch", err: merrors.InvalidArgument("quote_ref does not match intent")}
+		if err != nil {
+			return nil, nil, err
 		}
-		quote := modelQuoteToProto(record.Quote)
+		if in.Intent != nil && !proto.Equal(intent, in.Intent) {
-		if quote == nil {
+			return nil, nil, quoteResolutionError{code: "quote_intent_mismatch", err: merrors.InvalidArgument("quote_ref does not match intent")}
-			return nil, merrors.InvalidArgument("stored quote is empty")
+		}
+		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

@@ -158,6 +158,24 @@ 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 +189,7 @@ 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"`
 }
@@ -218,6 +237,23 @@ func (p *Payment) Normalize() {
 		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) {

api/pkg/api/routers/gsresponse/response.go

@@ -47,12 +47,7 @@ func Error[T any](logger mlogger.Logger, service mservice.Type, code codes.Code,
 		if err != nil {
 			fields = append(fields, zap.Error(err))
 		}
-		logFn := logger.Warn
+		logger.Warn("gRPC request failed", fields...)
-		switch code {
-		case codes.Internal, codes.DataLoss, codes.Unavailable:
-			logFn = logger.Error
-		}
-		logFn("gRPC request failed", fields...)
 
 		msg := message(err)
 		switch {

api/pkg/api/routers/gsresponse/response_test.go

@@ -6,9 +6,9 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/stretchr/testify/require"
 	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mservice"
-	"github.com/stretchr/testify/require"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.uber.org/zap"
 	"google.golang.org/grpc/codes"
@@ -32,7 +32,7 @@ func TestUnarySuccess(t *testing.T) {
 		return Success(resp)
 	}
 
-	unary := Unary[testRequest, testResponse](logger, mservice.Type("test"), handler)
+	unary := Unary(logger, mservice.Type("test"), handler)
 	resp, err := unary(context.Background(), &testRequest{Value: "hello"})
 	require.NoError(t, err)
 	require.NotNil(t, resp)

api/pkg/db/internal/mongo/refreshtokensdb/db.go

@@ -37,7 +37,9 @@ func Create(logger mlogger.Logger, db *mongo.Database) (*RefreshTokenDB, error)
 			{Field: "clientId", Sort: ri.Asc},
 			{Field: "deviceId", Sort: ri.Asc},
 		},
-		Unique: true,
+		Unique:        true,
+		Name:          "unique_active_session",
+		PartialFilter: repository.Filter(IsRevokedField, false),
 	}); err != nil {
 		p.Logger.Error("Failed to create unique account/client/device index", zap.Error(err))
 		return nil, err

api/pkg/db/internal/mongo/refreshtokensdb/refreshtokensdb_test.go

@@ -10,23 +10,29 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/tech/sendico/pkg/db/internal/mongo/refreshtokensdb"
 	"github.com/tech/sendico/pkg/db/repository"
 	"github.com/tech/sendico/pkg/db/repository/builder"
 	"github.com/tech/sendico/pkg/merrors"
 	factory "github.com/tech/sendico/pkg/mlogger/factory"
 	"github.com/tech/sendico/pkg/model"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 	"github.com/testcontainers/testcontainers-go"
 	"github.com/testcontainers/testcontainers-go/modules/mongodb"
 	"github.com/testcontainers/testcontainers-go/wait"
+	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 )
 
 func setupTestDB(t *testing.T) (*refreshtokensdb.RefreshTokenDB, func()) {
+	db, _, cleanup := setupTestDBWithMongo(t)
+	return db, cleanup
+}
+
+func setupTestDBWithMongo(t *testing.T) (*refreshtokensdb.RefreshTokenDB, *mongo.Database, func()) {
 	// mark as helper for better test failure reporting
 	t.Helper()
 
@@ -62,7 +68,7 @@ func setupTestDB(t *testing.T) (*refreshtokensdb.RefreshTokenDB, func()) {
 		_ = mongoContainer.Terminate(termCtx)
 	}
 
-	return db, cleanup
+	return db, database, cleanup
 }
 
 func createTestRefreshToken(accountRef primitive.ObjectID, clientID, deviceID, token string) *model.RefreshToken {
@@ -332,6 +338,63 @@ func TestRefreshTokenDB_SessionReplacement(t *testing.T) {
 		_, err = db.GetByCRT(ctx, secondCRT)
 		require.NoError(t, err)
 	})
+
+	t.Run("Create_After_GlobalRevocation_AllowsNewActive", func(t *testing.T) {
+		userID := primitive.NewObjectID()
+		clientID := "web-app"
+		deviceID := "user-laptop"
+
+		firstToken := createTestRefreshToken(userID, clientID, deviceID, "revoked_token_123")
+		err := db.Create(ctx, firstToken)
+		require.NoError(t, err)
+		require.NotNil(t, firstToken.GetID())
+
+		// Global revoke (deviceID empty) — all tokens should be revoked
+		err = db.RevokeAll(ctx, userID, "")
+		require.NoError(t, err)
+
+		var revoked model.RefreshToken
+		err = db.Get(ctx, *firstToken.GetID(), &revoked)
+		require.NoError(t, err)
+		assert.True(t, revoked.IsRevoked)
+
+		// Creating a new token for the same account/client/device must succeed and produce an active token
+		reissueToken := createTestRefreshToken(userID, clientID, deviceID, "new_token_after_revocation")
+		err = db.Create(ctx, reissueToken)
+		require.NoError(t, err)
+
+		newCRT := &model.ClientRefreshToken{
+			SessionIdentifier: model.SessionIdentifier{
+				ClientID: clientID,
+				DeviceID: deviceID,
+			},
+			RefreshToken: "new_token_after_revocation",
+		}
+		_, err = db.GetByCRT(ctx, newCRT)
+		require.NoError(t, err)
+
+		// Old token must remain unusable
+		oldCRT := &model.ClientRefreshToken{
+			SessionIdentifier: model.SessionIdentifier{
+				ClientID: clientID,
+				DeviceID: deviceID,
+			},
+			RefreshToken: "revoked_token_123",
+		}
+		_, err = db.GetByCRT(ctx, oldCRT)
+		assert.Error(t, err)
+
+		// Both records exist: revoked + new active
+		query := repository.Query().
+			Filter(repository.AccountField(), userID).
+			And(
+				repository.Query().Comparison(repository.Field("clientId"), builder.Eq, clientID),
+				repository.Query().Comparison(repository.Field("deviceId"), builder.Eq, deviceID),
+			)
+		ids, err := db.Repository.ListIDs(ctx, query)
+		require.NoError(t, err)
+		assert.Len(t, ids, 2)
+	})
 }
 
 func TestRefreshTokenDB_ClientManagement(t *testing.T) {
@@ -637,3 +700,29 @@ func TestRefreshTokenDB_DatabaseIndexes(t *testing.T) {
 		assert.Len(t, ids, 5) // Should find 5 non-revoked tokens
 	})
 }
+
+func TestRefreshTokenDB_IndexPartialUniqueActiveSession(t *testing.T) {
+	db, database, cleanup := setupTestDBWithMongo(t)
+	defer cleanup()
+
+	ctx := context.Background()
+
+	cursor, err := database.Collection(db.Repository.Collection()).Indexes().List(ctx)
+	require.NoError(t, err)
+	defer cursor.Close(ctx)
+
+	found := false
+	for cursor.Next(ctx) {
+		var idx bson.M
+		require.NoError(t, cursor.Decode(&idx))
+		if idx["name"] == "unique_active_session" {
+			found = true
+			assert.Equal(t, true, idx["unique"])
+
+			partial, ok := idx["partialFilterExpression"].(bson.M)
+			require.True(t, ok)
+			assert.Equal(t, bson.M{"isRevoked": false}, partial)
+		}
+	}
+	assert.True(t, found, "unique_active_session index not found")
+}

api/pkg/db/internal/mongo/repositoryimp/index.go

@@ -41,6 +41,9 @@ func (r *MongoRepository) CreateIndex(def *ri.Definition) error {
 	if def.Name != "" {
 		opts.SetName(def.Name)
 	}
+	if def.PartialFilter != nil {
+		opts.SetPartialFilterExpression(def.PartialFilter.BuildQuery())
+	}
 
 	_, err := r.collection.Indexes().CreateOne(
 		context.Background(),

api/pkg/db/internal/mongo/repositoryimp/index_integration_test.go

@@ -0,0 +1,83 @@
+//go:build integration
+// +build integration
+
+package repositoryimp_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/tech/sendico/pkg/db/repository"
+	ri "github.com/tech/sendico/pkg/db/repository/index"
+	"github.com/testcontainers/testcontainers-go"
+	"github.com/testcontainers/testcontainers-go/modules/mongodb"
+	"github.com/testcontainers/testcontainers-go/wait"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+func TestCreateIndex_WithPartialFilter(t *testing.T) {
+	startCtx, startCancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer startCancel()
+
+	mongoContainer, err := mongodb.Run(startCtx,
+		"mongo:latest",
+		mongodb.WithUsername("root"),
+		mongodb.WithPassword("password"),
+		testcontainers.WithWaitStrategy(wait.ForListeningPort("27017/tcp").WithStartupTimeout(2*time.Minute)),
+	)
+	require.NoError(t, err)
+
+	mongoURI, err := mongoContainer.ConnectionString(startCtx)
+	require.NoError(t, err)
+
+	client, err := mongo.Connect(startCtx, options.Client().ApplyURI(mongoURI))
+	require.NoError(t, err)
+	defer client.Disconnect(context.Background())
+
+	database := client.Database("test_partial_index_" + t.Name())
+	defer database.Drop(context.Background())
+
+	repo := repository.CreateMongoRepository(database, "partial_index_items")
+
+	def := &ri.Definition{
+		Keys: []ri.Key{
+			{Field: "field", Sort: ri.Asc},
+		},
+		Unique:        true,
+		Name:          "partial_unique_field_true",
+		PartialFilter: repository.Filter("flag", treu),
+	}
+
+	require.NoError(t, repo.CreateIndex(def))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cursor, err := database.Collection(repo.Collection()).Indexes().List(ctx)
+	require.NoError(t, err)
+	defer cursor.Close(ctx)
+
+	found := false
+	for cursor.Next(ctx) {
+		var idx bson.M
+		require.NoError(t, cursor.Decode(&idx))
+		if idx["name"] == def.Name {
+			found = true
+			assert.Equal(t, true, idx["unique"])
+			assert.Equal(t, bson.M{"field": int32(1)}, idx["key"])
+			partial, ok := idx["partialFilterExpression"].(bson.M)
+			require.True(t, ok)
+			assert.Equal(t, bson.M{"flag": true}, partial)
+		}
+	}
+	assert.True(t, found, "partial unique index was not created")
+
+	termCtx, termCancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer termCancel()
+	_ = mongoContainer.Terminate(termCtx)
+}

api/pkg/db/repository/index/index.go

@@ -1,5 +1,7 @@
 package repository
 
+import "github.com/tech/sendico/pkg/db/repository/builder"
+
 type Sort int8
 
 const (
@@ -14,8 +16,9 @@ type Key struct {
 }
 
 type Definition struct {
-	Keys   []Key  // mandatory, at least one element
+	Keys          []Key         // mandatory, at least one element
-	Unique bool   // unique constraint?
+	Unique        bool          // unique constraint?
-	TTL    *int32 // seconds; nil means “no TTL”
+	TTL           *int32        // seconds; nil means “no TTL”
-	Name   string // optional explicit name
+	Name          string        // optional explicit name
+	PartialFilter builder.Query // optional: partialFilterExpression for conditional indexes
 }

api/pkg/go.mod

@@ -17,7 +17,7 @@ require (
 	go.mongodb.org/mongo-driver v1.17.6
 	go.uber.org/zap v1.27.1
 	golang.org/x/crypto v0.46.0
-	google.golang.org/grpc v1.77.0
+	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 )
 
@@ -93,6 +93,6 @@ require (
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

api/pkg/go.sum

@@ -267,12 +267,12 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/api v0.0.0-20251022142026-3a174f9686a8 h1:mepRgnBZa07I4TRuomDE4sTIYieg/osKmzIf4USdWS4=
+google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda h1:+2XxjfsAu6vqFxwGBRcHiMaDCuZiqXGDUDVWVtrFAnE=
-google.golang.org/genproto/googleapis/api v0.0.0-20251022142026-3a174f9686a8/go.mod h1:fDMmzKV90WSg1NbozdqrE64fkuTv6mlq2zxo9ad+3yo=
+google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda/go.mod h1:fDMmzKV90WSg1NbozdqrE64fkuTv6mlq2zxo9ad+3yo=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/proto/common/describable/v1/describable.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package common.describable.v1;
+
+option go_package = "github.com/tech/sendico/pkg/proto/common/describable/v1;describablev1";
+
+// Describable captures a name/description pair reusable across resources.
+message Describable {
+  string name = 1;
+  optional string description = 2;
+}

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

@@ -7,13 +7,15 @@ option go_package = "github.com/tech/sendico/pkg/proto/gateway/chain/v1;chainv1"
 import "google/protobuf/timestamp.proto";
 import "common/money/v1/money.proto";
 import "common/pagination/v1/cursor.proto";
+import "common/describable/v1/describable.proto";
 
 // Supported blockchain networks for the managed wallets.
 enum ChainNetwork {
   CHAIN_NETWORK_UNSPECIFIED = 0;
   CHAIN_NETWORK_ETHEREUM_MAINNET = 1;
   CHAIN_NETWORK_ARBITRUM_ONE = 2;
-  CHAIN_NETWORK_OTHER_EVM = 3;
+  CHAIN_NETWORK_TRON_MAINNET = 4;
+  CHAIN_NETWORK_TRON_NILE = 5;
 }
 
 enum ManagedWalletStatus {
@@ -57,6 +59,7 @@ message ManagedWallet {
   map<string, string> metadata = 7;
   google.protobuf.Timestamp created_at = 8;
   google.protobuf.Timestamp updated_at = 9;
+  common.describable.v1.Describable describable = 10;
 }
 
 message CreateManagedWalletRequest {
@@ -65,6 +68,7 @@ message CreateManagedWalletRequest {
   string owner_ref = 3;
   Asset asset = 4;
   map<string, string> metadata = 5;
+  common.describable.v1.Describable describable = 6;
 }
 
 message CreateManagedWalletResponse {
@@ -96,6 +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 {
@@ -184,6 +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;
@@ -213,4 +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

@@ -141,6 +141,22 @@ 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 +182,7 @@ 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/config.yml

@@ -80,7 +80,7 @@ api:
     call_timeout_seconds: 5
     insecure: true
     default_asset:
-      chain: ARBITRUM_ONE
+      chain: TRON_MAINNET
       token_symbol: USDT
       contract_address: ""
   ledger:

api/server/go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/aws/aws-sdk-go-v2 v1.41.0
 	github.com/aws/aws-sdk-go-v2/config v1.32.6
 	github.com/aws/aws-sdk-go-v2/credentials v1.19.6
-	github.com/aws/aws-sdk-go-v2/service/s3 v1.94.0
+	github.com/aws/aws-sdk-go-v2/service/s3 v1.95.0
 	github.com/go-chi/chi/v5 v5.2.3
 	github.com/go-chi/cors v1.2.2
 	github.com/go-chi/jwtauth/v5 v5.3.3
@@ -139,6 +139,6 @@ require (
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect
 	golang.org/x/text v0.32.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b // indirect
-	google.golang.org/grpc v1.77.0 // indirect
+	google.golang.org/grpc v1.78.0 // indirect
 )

api/server/go.sum

@@ -32,8 +32,8 @@ github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.16 h1:oHjJHeUy
 github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.16/go.mod h1:iRSNGgOYmiYwSCXxXaKb9HfOEj40+oTKn8pTxMlYkRM=
 github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.19.16 h1:NSbvS17MlI2lurYgXnCOLvCFX38sBW4eiVER7+kkgsU=
 github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.19.16/go.mod h1:SwT8Tmqd4sA6G1qaGdzWCJN99bUmPGHfRwwq3G5Qb+A=
-github.com/aws/aws-sdk-go-v2/service/s3 v1.94.0 h1:SWTxh/EcUCDVqi/0s26V6pVUq0BBG7kx0tDTmF/hCgA=
+github.com/aws/aws-sdk-go-v2/service/s3 v1.95.0 h1:MIWra+MSq53CFaXXAywB2qg9YvVZifkk6vEGl/1Qor0=
-github.com/aws/aws-sdk-go-v2/service/s3 v1.94.0/go.mod h1:79S2BdqCJpScXZA2y+cpZuocWsjGjJINyXnOsf5DTz8=
+github.com/aws/aws-sdk-go-v2/service/s3 v1.95.0/go.mod h1:79S2BdqCJpScXZA2y+cpZuocWsjGjJINyXnOsf5DTz8=
 github.com/aws/aws-sdk-go-v2/service/signin v1.0.4 h1:HpI7aMmJ+mm1wkSHIA2t5EaFFv5EFYXePW30p1EIrbQ=
 github.com/aws/aws-sdk-go-v2/service/signin v1.0.4/go.mod h1:C5RdGMYGlfM0gYq/tifqgn4EbyX99V15P2V3R+VHbQU=
 github.com/aws/aws-sdk-go-v2/service/sso v1.30.8 h1:aM/Q24rIlS3bRAhTyFurowU8A0SMyGDtEOY/l/s/1Uw=
@@ -359,12 +359,12 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/api v0.0.0-20251022142026-3a174f9686a8 h1:mepRgnBZa07I4TRuomDE4sTIYieg/osKmzIf4USdWS4=
+google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda h1:+2XxjfsAu6vqFxwGBRcHiMaDCuZiqXGDUDVWVtrFAnE=
-google.golang.org/genproto/googleapis/api v0.0.0-20251022142026-3a174f9686a8/go.mod h1:fDMmzKV90WSg1NbozdqrE64fkuTv6mlq2zxo9ad+3yo=
+google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda/go.mod h1:fDMmzKV90WSg1NbozdqrE64fkuTv6mlq2zxo9ad+3yo=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b h1:Mv8VFug0MP9e5vUxfBcE3vUkV6CImK3cMNMIDFjmzxU=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251222181119-0a764e51fe1b/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.77.0 h1:wVVY6/8cGA6vvffn+wWK5ToddbgdU3d8MNENr4evgXM=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.77.0/go.mod h1:z0BY1iVj0q8E1uSQCjL9cppRj+gnZjzDnzV0dHhrNig=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/server/interface/api/srequest/payment_enums.go

@@ -36,7 +36,8 @@ const (
 	ChainNetworkUnspecified     ChainNetwork = "unspecified"
 	ChainNetworkEthereumMainnet ChainNetwork = "ethereum_mainnet"
 	ChainNetworkArbitrumOne     ChainNetwork = "arbitrum_one"
-	ChainNetworkOtherEVM        ChainNetwork = "other_evm"
+	ChainNetworkTronMainnet     ChainNetwork = "tron_mainnet"
+	ChainNetworkTronNile        ChainNetwork = "tron_nile"
 )
 
 // InsufficientNetPolicy mirrors the fee engine policy override.

api/server/interface/api/srequest/payment_types_test.go

@@ -65,7 +65,7 @@ func TestEndpointDTOBuildersAndDecoders(t *testing.T) {
 	t.Run("external chain", func(t *testing.T) {
 		payload := ExternalChainEndpoint{
 			Asset: &Asset{
-				Chain:       ChainNetworkOtherEVM,
+				Chain:       ChainNetworkEthereumMainnet,
 				TokenSymbol: "ETH",
 			},
 			Address: "0x123",
@@ -364,7 +364,7 @@ func TestPaymentIntentMinimalRoundTrip(t *testing.T) {
 func TestLegacyEndpointRoundTrip(t *testing.T) {
 	legacy := &LegacyPaymentEndpoint{
 		ExternalChain: &ExternalChainEndpoint{
-			Asset:   &Asset{Chain: ChainNetworkOtherEVM, TokenSymbol: "DAI", ContractAddress: "0xdef"},
+			Asset:   &Asset{Chain: ChainNetworkEthereumMainnet, TokenSymbol: "DAI", ContractAddress: "0xdef"},
 			Address: "0x123",
 			Memo:    "memo",
 		},

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

@@ -7,7 +7,6 @@ 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"
 	oraclev1 "github.com/tech/sendico/pkg/proto/oracle/v1"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 )
@@ -20,11 +19,6 @@ 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 +39,6 @@ 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 +46,6 @@ 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 {
@@ -146,16 +138,6 @@ 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 +174,6 @@ 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 +186,6 @@ func toPaymentQuoteAggregate(q *orchestratorv1.PaymentQuoteAggregate) *PaymentQu
 		DebitAmounts:              toMoneyList(q.GetDebitAmounts()),
 		ExpectedSettlementAmounts: toMoneyList(q.GetExpectedSettlementAmounts()),
 		ExpectedFeeTotals:         toMoneyList(q.GetExpectedFeeTotals()),
-		NetworkFeeTotals:          toMoneyList(q.GetNetworkFeeTotals()),
 	}
 }
 

api/server/interface/api/sresponse/wallet.go

@@ -2,6 +2,7 @@ package sresponse
 
 import (
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/tech/sendico/pkg/api/http/response"
@@ -26,6 +27,8 @@ type wallet struct {
 	DepositAddress  string            `json:"depositAddress"`
 	Status          string            `json:"status"`
 	Metadata        map[string]string `json:"metadata,omitempty"`
+	Name            string            `json:"name"`
+	Description     *string           `json:"description,omitempty"`
 	CreatedAt       string            `json:"createdAt,omitempty"`
 	UpdatedAt       string            `json:"updatedAt,omitempty"`
 }
@@ -76,10 +79,31 @@ func toWallet(w *chainv1.ManagedWallet) wallet {
 	token := ""
 	contract := ""
 	if asset != nil {
-		chain = asset.GetChain().String()
+		chain = chainNetworkValue(asset.GetChain())
 		token = asset.GetTokenSymbol()
 		contract = asset.GetContractAddress()
 	}
+	name := ""
+	if d := w.GetDescribable(); d != nil {
+		name = strings.TrimSpace(d.GetName())
+	}
+	if name == "" {
+		name = strings.TrimSpace(w.GetMetadata()["name"])
+	}
+	if name == "" {
+		name = w.GetWalletRef()
+	}
+	var description *string
+	if d := w.GetDescribable(); d != nil && d.Description != nil {
+		if trimmed := strings.TrimSpace(d.GetDescription()); trimmed != "" {
+			description = &trimmed
+		}
+	}
+	if description == nil {
+		if trimmed := strings.TrimSpace(w.GetMetadata()["description"]); trimmed != "" {
+			description = &trimmed
+		}
+	}
 	return wallet{
 		WalletRef:       w.GetWalletRef(),
 		OrganizationRef: w.GetOrganizationRef(),
@@ -92,6 +116,8 @@ func toWallet(w *chainv1.ManagedWallet) wallet {
 		DepositAddress: w.GetDepositAddress(),
 		Status:         w.GetStatus().String(),
 		Metadata:       w.GetMetadata(),
+		Name:           name,
+		Description:    description,
 		CreatedAt:      tsToString(w.GetCreatedAt()),
 		UpdatedAt:      tsToString(w.GetUpdatedAt()),
 	}
@@ -115,3 +141,15 @@ func tsToString(ts *timestamppb.Timestamp) string {
 	}
 	return ts.AsTime().UTC().Format(time.RFC3339)
 }
+
+func chainNetworkValue(chain chainv1.ChainNetwork) string {
+	name := chain.String()
+	if !strings.HasPrefix(name, "CHAIN_NETWORK_") {
+		return "unspecified"
+	}
+	trimmed := strings.TrimPrefix(name, "CHAIN_NETWORK_")
+	if trimmed == "" {
+		return "unspecified"
+	}
+	return strings.ToLower(trimmed)
+}

api/server/internal/api/routers/public/login.go

@@ -53,9 +53,7 @@ func (pr *PublicRouter) logUserIn(ctx context.Context, _ *http.Request, req *sre
 		pr.logger.Warn("Failed to create login confirmation code", zap.Error(err))
 		return response.Internal(pr.logger, pr.service, err)
 	}
-	pr.logger.Info("Login confirmation code issued",
+	pr.logger.Info("Login confirmation code issued", zap.String("destination", pr.maskEmail(account.Login)))
-		zap.String("destination", pr.maskEmail(account.Login)),
-		zap.String("account", account.Login))
 
 	return sresponse.LoginPending(pr.logger, account, &pendingToken, pr.maskEmail(account.Login), int(time.Until(rec.ExpiresAt).Seconds()))
 }

api/server/internal/server/accountapiimp/service.go

@@ -214,8 +214,10 @@ func parseChainNetwork(value string) (chainv1.ChainNetwork, error) {
 		return chainv1.ChainNetwork_CHAIN_NETWORK_ETHEREUM_MAINNET, nil
 	case "ARBITRUM_ONE", "CHAIN_NETWORK_ARBITRUM_ONE":
 		return chainv1.ChainNetwork_CHAIN_NETWORK_ARBITRUM_ONE, nil
-	case "OTHER_EVM", "CHAIN_NETWORK_OTHER_EVM":
+	case "TRON_MAINNET", "CHAIN_NETWORK_TRON_MAINNET":
-		return chainv1.ChainNetwork_CHAIN_NETWORK_OTHER_EVM, nil
+		return chainv1.ChainNetwork_CHAIN_NETWORK_TRON_MAINNET, nil
+	case "TRON_NILE", "CHAIN_NETWORK_TRON_NILE":
+		return chainv1.ChainNetwork_CHAIN_NETWORK_TRON_NILE, nil
 	case "", "CHAIN_NETWORK_UNSPECIFIED":
 		return chainv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, merrors.InvalidArgument("chain network must be specified")
 	default:

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

@@ -286,8 +286,10 @@ func mapChainNetwork(chain srequest.ChainNetwork) (chainv1.ChainNetwork, error)
 		return chainv1.ChainNetwork_CHAIN_NETWORK_ETHEREUM_MAINNET, nil
 	case string(srequest.ChainNetworkArbitrumOne):
 		return chainv1.ChainNetwork_CHAIN_NETWORK_ARBITRUM_ONE, nil
-	case string(srequest.ChainNetworkOtherEVM):
+	case string(srequest.ChainNetworkTronMainnet):
-		return chainv1.ChainNetwork_CHAIN_NETWORK_OTHER_EVM, nil
+		return chainv1.ChainNetwork_CHAIN_NETWORK_TRON_MAINNET, nil
+	case string(srequest.ChainNetworkTronNile):
+		return chainv1.ChainNetwork_CHAIN_NETWORK_TRON_NILE, nil
 	default:
 		return chainv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, merrors.InvalidArgument("unsupported chain network: " + string(chain))
 	}

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)
 	}
 
@@ -76,7 +77,7 @@ 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)
 	}
 

ci/prod/compose/chain_gateway.yml

@@ -44,7 +44,7 @@ services:
       NATS_PORT: ${NATS_PORT}
       NATS_USER: ${NATS_USER}
       NATS_PASSWORD: ${NATS_PASSWORD}
-      CHAIN_GATEWAY_ARBITRUM_RPC_URL: ${CHAIN_GATEWAY_ARBITRUM_RPC_URL}
+      CHAIN_GATEWAY_RPC_URL: ${CHAIN_GATEWAY_RPC_URL}
       CHAIN_GATEWAY_SERVICE_WALLET_KEY: ${CHAIN_GATEWAY_SERVICE_WALLET_KEY}
       CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS: ${CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS}
       VAULT_TOKEN_FILE: /run/vault/token

ci/prod/scripts/deploy/chain_gateway.sh

@@ -18,7 +18,7 @@ SERVICE_NAMES="${CHAIN_GATEWAY_SERVICE_NAME}"
 REQUIRED_SECRETS=(
   CHAIN_GATEWAY_MONGO_USER
   CHAIN_GATEWAY_MONGO_PASSWORD
-  CHAIN_GATEWAY_ARBITRUM_RPC_URL
+  CHAIN_GATEWAY_RPC_URL
   CHAIN_GATEWAY_SERVICE_WALLET_KEY
   CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS
   CHAIN_GATEWAY_VAULT_ROLE_ID
@@ -46,7 +46,7 @@ b64enc() {
 
 CHAIN_GATEWAY_MONGO_USER_B64="$(b64enc "${CHAIN_GATEWAY_MONGO_USER}")"
 CHAIN_GATEWAY_MONGO_PASSWORD_B64="$(b64enc "${CHAIN_GATEWAY_MONGO_PASSWORD}")"
-CHAIN_GATEWAY_ARBITRUM_RPC_URL_B64="$(b64enc "${CHAIN_GATEWAY_ARBITRUM_RPC_URL}")"
+CHAIN_GATEWAY_RPC_URL_B64="$(b64enc "${CHAIN_GATEWAY_RPC_URL}")"
 CHAIN_GATEWAY_SERVICE_WALLET_KEY_B64="$(b64enc "${CHAIN_GATEWAY_SERVICE_WALLET_KEY}")"
 CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS_B64="$(b64enc "${CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS}")"
 CHAIN_GATEWAY_VAULT_ROLE_ID_B64="$(b64enc "${CHAIN_GATEWAY_VAULT_ROLE_ID}")"
@@ -84,7 +84,7 @@ ssh "${SSH_OPTS[@]}" "$REMOTE_TARGET" \
   SERVICES_LINE="$SERVICES_LINE" \
   CHAIN_GATEWAY_MONGO_USER_B64="$CHAIN_GATEWAY_MONGO_USER_B64" \
   CHAIN_GATEWAY_MONGO_PASSWORD_B64="$CHAIN_GATEWAY_MONGO_PASSWORD_B64" \
-  CHAIN_GATEWAY_ARBITRUM_RPC_URL_B64="$CHAIN_GATEWAY_ARBITRUM_RPC_URL_B64" \
+  CHAIN_GATEWAY_RPC_URL_B64="$CHAIN_GATEWAY_RPC_URL_B64" \
   CHAIN_GATEWAY_SERVICE_WALLET_KEY_B64="$CHAIN_GATEWAY_SERVICE_WALLET_KEY_B64" \
   CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS_B64="$CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS_B64" \
   CHAIN_GATEWAY_VAULT_ROLE_ID_B64="$CHAIN_GATEWAY_VAULT_ROLE_ID_B64" \
@@ -135,7 +135,7 @@ decode_b64() {
 
 CHAIN_GATEWAY_MONGO_USER="$(decode_b64 "$CHAIN_GATEWAY_MONGO_USER_B64")"
 CHAIN_GATEWAY_MONGO_PASSWORD="$(decode_b64 "$CHAIN_GATEWAY_MONGO_PASSWORD_B64")"
-CHAIN_GATEWAY_ARBITRUM_RPC_URL="$(decode_b64 "$CHAIN_GATEWAY_ARBITRUM_RPC_URL_B64")"
+CHAIN_GATEWAY_RPC_URL="$(decode_b64 "$CHAIN_GATEWAY_RPC_URL_B64")"
 CHAIN_GATEWAY_SERVICE_WALLET_KEY="$(decode_b64 "$CHAIN_GATEWAY_SERVICE_WALLET_KEY_B64")"
 CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS="$(decode_b64 "$CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS_B64")"
 CHAIN_GATEWAY_VAULT_ROLE_ID="$(decode_b64 "$CHAIN_GATEWAY_VAULT_ROLE_ID_B64")"
@@ -145,7 +145,7 @@ NATS_PASSWORD="$(decode_b64 "$NATS_PASSWORD_B64")"
 NATS_URL="$(decode_b64 "$NATS_URL_B64")"
 
 export CHAIN_GATEWAY_MONGO_USER CHAIN_GATEWAY_MONGO_PASSWORD
-export CHAIN_GATEWAY_ARBITRUM_RPC_URL
+export CHAIN_GATEWAY_RPC_URL
 export CHAIN_GATEWAY_SERVICE_WALLET_KEY CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS
 export CHAIN_GATEWAY_VAULT_ROLE_ID CHAIN_GATEWAY_VAULT_SECRET_ID
 export NATS_USER NATS_PASSWORD NATS_URL

ci/scripts/chain_gateway/deploy.sh

@@ -56,7 +56,7 @@ CHAIN_GATEWAY_VAULT_SECRET_PATH="${CHAIN_GATEWAY_VAULT_SECRET_PATH:?missing CHAI
 export CHAIN_GATEWAY_MONGO_USER="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_MONGO_SECRET_PATH}" user)"
 export CHAIN_GATEWAY_MONGO_PASSWORD="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_MONGO_SECRET_PATH}" password)"
 
-export CHAIN_GATEWAY_ARBITRUM_RPC_URL="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_RPC_SECRET_PATH}" arbitrum_rpc_url)"
+export CHAIN_GATEWAY_RPC_URL="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_RPC_SECRET_PATH}" tron_rpc_url)"
 
 export CHAIN_GATEWAY_SERVICE_WALLET_KEY="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_WALLET_SECRET_PATH}" private_key)"
 export CHAIN_GATEWAY_SERVICE_WALLET_ADDRESS="$(./ci/vlt kv_get kv "${CHAIN_GATEWAY_WALLET_SECRET_PATH}" address || true)"

frontend/pshared/lib/api/requests/password/change.dart

@@ -11,7 +11,9 @@ class ChangePassword {
   @JsonKey(name: 'new')
   final String newPassword;
 
-  const ChangePassword({required this.oldPassword, required this.newPassword});
+  final String deviceId;
+
+  const ChangePassword({required this.oldPassword, required this.newPassword, required this.deviceId});
 
   factory ChangePassword.fromJson(Map<String, dynamic> json) => _$ChangePasswordFromJson(json);
   Map<String, dynamic> toJson() => _$ChangePasswordToJson(this);