diff --git a/api/.DS_Store b/api/.DS_Store
deleted file mode 100644
index eace314..0000000
Binary files a/api/.DS_Store and /dev/null differ
diff --git a/api/fx/oracle/client/client.go b/api/fx/oracle/client/client.go
index 82ab2d2..ca8b6fd 100644
--- a/api/fx/oracle/client/client.go
+++ b/api/fx/oracle/client/client.go
@@ -3,11 +3,11 @@ package client
 import (
 	"context"
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"strings"
 	"time"
 
+	"github.com/tech/sendico/pkg/merrors"
 	fxv1 "github.com/tech/sendico/pkg/proto/common/fx/v1"
 	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
 	tracev1 "github.com/tech/sendico/pkg/proto/common/trace/v1"
@@ -88,7 +88,7 @@ type oracleClient struct {
 func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
 	cfg.setDefaults()
 	if strings.TrimSpace(cfg.Address) == "" {
-		return nil, errors.New("oracle: address is required")
+		return nil, merrors.InvalidArgument("oracle: address is required")
 	}
 
 	dialCtx, cancel := context.WithTimeout(ctx, cfg.DialTimeout)
@@ -105,7 +105,7 @@ func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, erro
 
 	conn, err := grpc.DialContext(dialCtx, cfg.Address, dialOpts...)
 	if err != nil {
-		return nil, fmt.Errorf("oracle: dial %s: %w", cfg.Address, err)
+		return nil, merrors.InternalWrap(err, fmt.Sprintf("oracle: dial %s", cfg.Address))
 	}
 
 	return &oracleClient{
@@ -133,7 +133,7 @@ func (c *oracleClient) Close() error {
 
 func (c *oracleClient) LatestRate(ctx context.Context, req LatestRateParams) (*RateSnapshot, error) {
 	if req.Pair == nil {
-		return nil, errors.New("oracle: pair is required")
+		return nil, merrors.InvalidArgument("oracle: pair is required")
 	}
 
 	callCtx, cancel := c.callContext(ctx)
@@ -145,26 +145,26 @@ func (c *oracleClient) LatestRate(ctx context.Context, req LatestRateParams) (*R
 		Provider: req.Provider,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("oracle: latest rate: %w", err)
+		return nil, merrors.InternalWrap(err, "oracle: latest rate")
 	}
 	if resp.GetRate() == nil {
-		return nil, errors.New("oracle: latest rate: empty payload")
+		return nil, merrors.Internal("oracle: latest rate: empty payload")
 	}
 	return fromProtoRate(resp.GetRate()), nil
 }
 
 func (c *oracleClient) GetQuote(ctx context.Context, req GetQuoteParams) (*Quote, error) {
 	if req.Pair == nil {
-		return nil, errors.New("oracle: pair is required")
+		return nil, merrors.InvalidArgument("oracle: pair is required")
 	}
 	if req.Side == fxv1.Side_SIDE_UNSPECIFIED {
-		return nil, errors.New("oracle: side is required")
+		return nil, merrors.InvalidArgument("oracle: side is required")
 	}
 
 	baseSupplied := req.BaseAmount != nil
 	quoteSupplied := req.QuoteAmount != nil
 	if baseSupplied == quoteSupplied {
-		return nil, errors.New("oracle: exactly one of base_amount or quote_amount must be set")
+		return nil, merrors.InvalidArgument("oracle: exactly one of base_amount or quote_amount must be set")
 	}
 
 	callCtx, cancel := c.callContext(ctx)
@@ -191,10 +191,10 @@ func (c *oracleClient) GetQuote(ctx context.Context, req GetQuoteParams) (*Quote
 
 	resp, err := c.client.GetQuote(callCtx, protoReq)
 	if err != nil {
-		return nil, fmt.Errorf("oracle: get quote: %w", err)
+		return nil, merrors.InternalWrap(err, "oracle: get quote")
 	}
 	if resp.GetQuote() == nil {
-		return nil, errors.New("oracle: get quote: empty payload")
+		return nil, merrors.Internal("oracle: get quote: empty payload")
 	}
 	return fromProtoQuote(resp.GetQuote()), nil
 }
diff --git a/api/ledger/client/client.go b/api/ledger/client/client.go
index f71927c..3b0671a 100644
--- a/api/ledger/client/client.go
+++ b/api/ledger/client/client.go
@@ -3,11 +3,11 @@ package client
 import (
 	"context"
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"strings"
 	"time"
 
+	"github.com/tech/sendico/pkg/merrors"
 	ledgerv1 "github.com/tech/sendico/pkg/proto/ledger/v1"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -48,7 +48,7 @@ type ledgerClient struct {
 func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
 	cfg.setDefaults()
 	if strings.TrimSpace(cfg.Address) == "" {
-		return nil, errors.New("ledger: address is required")
+		return nil, merrors.InvalidArgument("ledger: address is required")
 	}
 
 	dialCtx, cancel := context.WithTimeout(ctx, cfg.DialTimeout)
@@ -65,7 +65,7 @@ func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, erro
 
 	conn, err := grpc.DialContext(dialCtx, cfg.Address, dialOpts...)
 	if err != nil {
-		return nil, fmt.Errorf("ledger: dial %s: %w", cfg.Address, err)
+		return nil, merrors.InternalWrap(err, fmt.Sprintf("ledger: dial %s", cfg.Address))
 	}
 
 	return &ledgerClient{
diff --git a/api/ledger/internal/service/ledger/helpers.go b/api/ledger/internal/service/ledger/helpers.go
index 63baf19..de0b9b8 100644
--- a/api/ledger/internal/service/ledger/helpers.go
+++ b/api/ledger/internal/service/ledger/helpers.go
@@ -146,7 +146,7 @@ func calculateBalance(lines []*model.PostingLine) (decimal.Decimal, error) {
 	for _, line := range lines {
 		amount, err := parseDecimal(line.Amount)
 		if err != nil {
-			return decimal.Zero, fmt.Errorf("invalid line amount: %w", err)
+			return decimal.Zero, merrors.InvalidArgumentWrap(err, "invalid line amount")
 		}
 		balance = balance.Add(amount)
 	}
diff --git a/api/ledger/internal/service/ledger/outbox_publisher.go b/api/ledger/internal/service/ledger/outbox_publisher.go
index 30a3a3d..bad4baf 100644
--- a/api/ledger/internal/service/ledger/outbox_publisher.go
+++ b/api/ledger/internal/service/ledger/outbox_publisher.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/tech/sendico/ledger/storage"
 	ledgerModel "github.com/tech/sendico/ledger/storage/model"
+	"github.com/tech/sendico/pkg/merrors"
 	pmessaging "github.com/tech/sendico/pkg/messaging"
 	me "github.com/tech/sendico/pkg/messaging/envelope"
 	"github.com/tech/sendico/pkg/mlogger"
@@ -126,7 +127,7 @@ func (p *outboxPublisher) dispatchPending(ctx context.Context) (int, error) {
 func (p *outboxPublisher) publishEvent(_ context.Context, event *ledgerModel.OutboxEvent) error {
 	docID := event.GetID()
 	if docID == nil || docID.IsZero() {
-		return errors.New("outbox event missing identifier")
+		return merrors.InvalidArgument("outbox event missing identifier")
 	}
 
 	payload, err := p.wrapPayload(event)
@@ -157,7 +158,7 @@ func (p *outboxPublisher) wrapPayload(event *ledgerModel.OutboxEvent) ([]byte, e
 func (p *outboxPublisher) markSent(ctx context.Context, event *ledgerModel.OutboxEvent) error {
 	eventRef := event.GetID()
 	if eventRef == nil || eventRef.IsZero() {
-		return errors.New("outbox event missing identifier")
+		return merrors.InvalidArgument("outbox event missing identifier")
 	}
 
 	return p.store.MarkSent(ctx, *eventRef, time.Now().UTC())
diff --git a/api/ledger/internal/service/ledger/queries.go b/api/ledger/internal/service/ledger/queries.go
index e59e8dd..a61ea9f 100644
--- a/api/ledger/internal/service/ledger/queries.go
+++ b/api/ledger/internal/service/ledger/queries.go
@@ -249,15 +249,15 @@ func (s *Service) getStatementResponder(_ context.Context, req *ledgerv1.GetStat
 func parseCursor(cursor string) (int, error) {
 	decoded, err := base64.StdEncoding.DecodeString(cursor)
 	if err != nil {
-		return 0, fmt.Errorf("invalid base64: %w", err)
+		return 0, merrors.InvalidArgumentWrap(err, "invalid cursor base64 encoding")
 	}
 	parts := strings.Split(string(decoded), ":")
 	if len(parts) != 2 || parts[0] != "offset" {
-		return 0, fmt.Errorf("invalid cursor format")
+		return 0, merrors.InvalidArgument("invalid cursor format")
 	}
 	offset, err := strconv.Atoi(parts[1])
 	if err != nil {
-		return 0, fmt.Errorf("invalid offset: %w", err)
+		return 0, merrors.InvalidArgumentWrap(err, "invalid cursor offset")
 	}
 	return offset, nil
 }
diff --git a/api/ledger/internal/service/ledger/service.go b/api/ledger/internal/service/ledger/service.go
index ce9c4cb..3763481 100644
--- a/api/ledger/internal/service/ledger/service.go
+++ b/api/ledger/internal/service/ledger/service.go
@@ -18,6 +18,7 @@ import (
 
 	"github.com/tech/sendico/ledger/storage"
 	"github.com/tech/sendico/pkg/api/routers"
+	"github.com/tech/sendico/pkg/merrors"
 	pmessaging "github.com/tech/sendico/pkg/messaging"
 	"github.com/tech/sendico/pkg/mlogger"
 	ledgerv1 "github.com/tech/sendico/pkg/proto/ledger/v1"
@@ -241,10 +242,10 @@ func (s *Service) quoteFees(ctx context.Context, trigger feesv1.Trigger, organiz
 		return nil, nil
 	}
 	if strings.TrimSpace(organizationRef) == "" {
-		return nil, fmt.Errorf("organization reference is required to quote fees")
+		return nil, merrors.InvalidArgument("organization reference is required to quote fees")
 	}
 	if baseAmount == nil {
-		return nil, fmt.Errorf("base amount is required to quote fees")
+		return nil, merrors.InvalidArgument("base amount is required to quote fees")
 	}
 
 	amountCopy := &moneyv1.Money{Amount: baseAmount.GetAmount(), Currency: baseAmount.GetCurrency()}
@@ -309,11 +310,11 @@ func convertFeeDerivedLines(lines []*feesv1.DerivedPostingLine) ([]*ledgerv1.Pos
 			continue
 		}
 		if line.GetMoney() == nil {
-			return nil, fmt.Errorf("fee line %d missing money", idx)
+			return nil, merrors.Internal(fmt.Sprintf("fee line %d missing money", idx))
 		}
 		dec, err := decimal.NewFromString(line.GetMoney().GetAmount())
 		if err != nil {
-			return nil, fmt.Errorf("fee line %d invalid amount: %w", idx, err)
+			return nil, merrors.InternalWrap(err, fmt.Sprintf("fee line %d invalid amount", idx))
 		}
 		dec = ensureAmountForSide(dec, line.GetSide())
 		posting := &ledgerv1.PostingLine{
diff --git a/api/notification/internal/server/notificationimp/notification.go b/api/notification/internal/server/notificationimp/notification.go
index 35913b4..c5d32c3 100644
--- a/api/notification/internal/server/notificationimp/notification.go
+++ b/api/notification/internal/server/notificationimp/notification.go
@@ -2,12 +2,12 @@ package notificationimp
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/tech/sendico/notification/interface/api"
 	mmail "github.com/tech/sendico/notification/internal/server/notificationimp/mail"
 	"github.com/tech/sendico/notification/internal/server/notificationimp/telegram"
 	"github.com/tech/sendico/pkg/domainprovider"
+	"github.com/tech/sendico/pkg/merrors"
 	na "github.com/tech/sendico/pkg/messaging/notifications/account"
 	ni "github.com/tech/sendico/pkg/messaging/notifications/invitation"
 	snotifications "github.com/tech/sendico/pkg/messaging/notifications/site"
@@ -39,10 +39,10 @@ func CreateAPI(a api.API) (*NotificationAPI, error) {
 	p.logger = a.Logger().Named(p.Name())
 
 	if a.Config().Notification == nil {
-		return nil, fmt.Errorf("notification configuration is missing")
+		return nil, merrors.InvalidArgument("notification configuration is missing")
 	}
 	if a.Config().Notification.Telegram == nil {
-		return nil, fmt.Errorf("telegram configuration is missing")
+		return nil, merrors.InvalidArgument("telegram configuration is missing")
 	}
 
 	var err error
@@ -90,7 +90,7 @@ func CreateAPI(a api.API) (*NotificationAPI, error) {
 
 func (a *NotificationAPI) onDemoRequest(ctx context.Context, request *model.DemoRequest) error {
 	if a.tg == nil {
-		return fmt.Errorf("telegram client is not configured")
+		return merrors.Internal("telegram client is not configured")
 	}
 	if err := a.tg.SendDemoRequest(ctx, request); err != nil {
 		a.logger.Warn("Failed to send demo request via telegram", zap.Error(err))
diff --git a/api/notification/internal/server/notificationimp/telegram/client.go b/api/notification/internal/server/notificationimp/telegram/client.go
index d91c7b9..030264c 100644
--- a/api/notification/internal/server/notificationimp/telegram/client.go
+++ b/api/notification/internal/server/notificationimp/telegram/client.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	notconfig "github.com/tech/sendico/notification/interface/services/notification/config"
+	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/mlogger"
 	"github.com/tech/sendico/pkg/model"
 )
@@ -45,15 +46,15 @@ type sendMessagePayload struct {
 
 func NewClient(logger mlogger.Logger, cfg *notconfig.TelegramConfig) (Client, error) {
 	if cfg == nil {
-		return nil, fmt.Errorf("telegram configuration is not provided")
+		return nil, merrors.InvalidArgument("telegram configuration is not provided")
 	}
 	token := strings.TrimSpace(os.Getenv(cfg.BotTokenEnv))
 	if token == "" {
-		return nil, fmt.Errorf("telegram bot token env %s is empty", cfg.BotTokenEnv)
+		return nil, merrors.InvalidArgument(fmt.Sprintf("telegram bot token env %s is empty", cfg.BotTokenEnv))
 	}
 	chatID := strings.TrimSpace(os.Getenv(cfg.ChatIDEnv))
 	if chatID == "" {
-		return nil, fmt.Errorf("telegram chat id env %s is empty", cfg.ChatIDEnv)
+		return nil, merrors.InvalidArgument(fmt.Sprintf("telegram chat id env %s is empty", cfg.ChatIDEnv))
 	}
 
 	var threadID *int64
@@ -62,7 +63,7 @@ func NewClient(logger mlogger.Logger, cfg *notconfig.TelegramConfig) (Client, er
 		if raw != "" {
 			val, err := strconv.ParseInt(raw, 10, 64)
 			if err != nil {
-				return nil, fmt.Errorf("telegram thread id env %s is invalid: %w", env, err)
+				return nil, merrors.InvalidArgumentWrap(err, fmt.Sprintf("telegram thread id env %s is invalid", env))
 			}
 			threadID = &val
 		}
@@ -93,7 +94,7 @@ func NewClient(logger mlogger.Logger, cfg *notconfig.TelegramConfig) (Client, er
 
 func (c *client) SendDemoRequest(ctx context.Context, request *model.DemoRequest) error {
 	if request == nil {
-		return fmt.Errorf("demo request payload is nil")
+		return merrors.InvalidArgument("demo request payload is nil")
 	}
 	message := buildMessage(request)
 	payload := sendMessagePayload{
@@ -127,7 +128,7 @@ func (c *client) sendMessage(ctx context.Context, payload sendMessagePayload) er
 		return nil
 	}
 	respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 4<<10))
-	return fmt.Errorf("telegram sendMessage failed with status %d: %s", resp.StatusCode, string(respBody))
+	return merrors.Internal(fmt.Sprintf("telegram sendMessage failed with status %d: %s", resp.StatusCode, string(respBody)))
 }
 
 func (c *client) endpoint() string {
diff --git a/api/payments/orchestrator/client/client.go b/api/payments/orchestrator/client/client.go
index e98b3ee..c571933 100644
--- a/api/payments/orchestrator/client/client.go
+++ b/api/payments/orchestrator/client/client.go
@@ -3,11 +3,11 @@ package client
 import (
 	"context"
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"strings"
 	"time"
 
+	"github.com/tech/sendico/pkg/merrors"
 	orchestratorv1 "github.com/tech/sendico/pkg/proto/payments/orchestrator/v1"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -48,7 +48,7 @@ type orchestratorClient struct {
 func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
 	cfg.setDefaults()
 	if strings.TrimSpace(cfg.Address) == "" {
-		return nil, errors.New("payment-orchestrator: address is required")
+		return nil, merrors.InvalidArgument("payment-orchestrator: address is required")
 	}
 
 	dialCtx, cancel := context.WithTimeout(ctx, cfg.DialTimeout)
@@ -65,7 +65,7 @@ func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, erro
 
 	conn, err := grpc.DialContext(dialCtx, cfg.Address, dialOpts...)
 	if err != nil {
-		return nil, fmt.Errorf("payment-orchestrator: dial %s: %w", cfg.Address, err)
+		return nil, merrors.InternalWrap(err, fmt.Sprintf("payment-orchestrator: dial %s", cfg.Address))
 	}
 
 	return &orchestratorClient{
diff --git a/api/pkg/merrors/errors.go b/api/pkg/merrors/errors.go
index cb558c0..3667374 100644
--- a/api/pkg/merrors/errors.go
+++ b/api/pkg/merrors/errors.go
@@ -49,13 +49,13 @@ func AccessDenied(object, action string, objectRef primitive.ObjectID) error {
 var ErrInvalidDataType = errors.New("invalidDataType")
 
 func InvalidDataType(msg string) error {
-	return fmt.Errorf("%w: %s", ErrDataConflict, msg)
+	return fmt.Errorf("%w: %s", ErrInvalidDataType, msg)
 }
 
 var ErrUnauthorized = errors.New("unathorized")
 
 func Unauthorized(msg string) error {
-	return fmt.Errorf("%w: %s", ErrDataConflict, msg)
+	return fmt.Errorf("%w: %s", ErrUnauthorized, msg)
 }
 
 var ErrNoMessagingTopic = errors.New("messagingTopicError")
@@ -63,3 +63,19 @@ var ErrNoMessagingTopic = errors.New("messagingTopicError")
 func NoMessagingTopic(topic string) error {
 	return fmt.Errorf("%w: messaging topic '%s' not found", ErrNoMessagingTopic, topic)
 }
+
+func InvalidArgumentWrap(err error, msg string) error {
+	return wrapError(ErrInvalidArg, msg, err)
+}
+
+func InternalWrap(err error, msg string) error {
+	return wrapError(ErrInternal, msg, err)
+}
+
+func wrapError(base error, msg string, err error) error {
+	baseErr := fmt.Errorf("%w: %s", base, msg)
+	if err == nil {
+		return baseErr
+	}
+	return errors.Join(baseErr, err)
+}
diff --git a/api/pkg/messaging/internal/notifications/site/notification.go b/api/pkg/messaging/internal/notifications/site/notification.go
index 0225c23..d40f824 100644
--- a/api/pkg/messaging/internal/notifications/site/notification.go
+++ b/api/pkg/messaging/internal/notifications/site/notification.go
@@ -1,9 +1,8 @@
 package notifications
 
 import (
-	"fmt"
-
 	gmessaging "github.com/tech/sendico/pkg/generated/gmessaging"
+	"github.com/tech/sendico/pkg/merrors"
 	messaging "github.com/tech/sendico/pkg/messaging/envelope"
 	"github.com/tech/sendico/pkg/model"
 	nm "github.com/tech/sendico/pkg/model/notification"
@@ -18,7 +17,7 @@ type DemoRequestNotification struct {
 
 func (drn *DemoRequestNotification) Serialize() ([]byte, error) {
 	if drn.request == nil {
-		return nil, fmt.Errorf("demo request payload is empty")
+		return nil, merrors.InvalidArgument("demo request payload is empty")
 	}
 	msg := gmessaging.DemoRequestEvent{
 		Name:             drn.request.Name,
diff --git a/api/server/interface/api/config.go b/api/server/interface/api/config.go
index c1f8850..f21e3af 100644
--- a/api/server/interface/api/config.go
+++ b/api/server/interface/api/config.go
@@ -6,12 +6,13 @@ import (
 )
 
 type Config struct {
-	Mw           *mwa.Config        `yaml:"middleware"`
-	Storage      *fsc.Config        `yaml:"storage"`
+	Mw           *mwa.Config         `yaml:"middleware"`
+	Storage      *fsc.Config         `yaml:"storage"`
 	ChainGateway *ChainGatewayConfig `yaml:"chain_gateway"`
 }
 
 type ChainGatewayConfig struct {
+	Address            string                  `yaml:"address"`
 	AddressEnv         string                  `yaml:"address_env"`
 	DialTimeoutSeconds int                     `yaml:"dial_timeout_seconds"`
 	CallTimeoutSeconds int                     `yaml:"call_timeout_seconds"`
diff --git a/api/server/internal/server/accountapiimp/service.go b/api/server/internal/server/accountapiimp/service.go
index 169d464..df3a0e8 100644
--- a/api/server/internal/server/accountapiimp/service.go
+++ b/api/server/internal/server/accountapiimp/service.go
@@ -16,6 +16,7 @@ import (
 	"github.com/tech/sendico/pkg/db/refreshtokens"
 	"github.com/tech/sendico/pkg/db/transaction"
 	"github.com/tech/sendico/pkg/domainprovider"
+	"github.com/tech/sendico/pkg/merrors"
 	"github.com/tech/sendico/pkg/messaging"
 	"github.com/tech/sendico/pkg/mlogger"
 	"github.com/tech/sendico/pkg/mservice"
@@ -142,7 +143,12 @@ func CreateAPI(a eapi.API) (*AccountAPI, error) {
 	}
 	p.accountsPermissionRef = accountsPolicy.ID
 
-	if err := p.initChainGateway(a.Config()); err != nil {
+	cfg := a.Config()
+	if cfg == nil {
+		p.logger.Error("Failed to fetch service configuration")
+		return nil, merrors.InvalidArgument("No configuration provided")
+	}
+	if err := p.initChainGateway(cfg.ChainGateway); err != nil {
 		p.logger.Error("Failed to initialize chain gateway client", zap.Error(err))
 		return nil, err
 	}
@@ -150,21 +156,21 @@ func CreateAPI(a eapi.API) (*AccountAPI, error) {
 	return p, nil
 }
 
-func (a *AccountAPI) initChainGateway(cfg *eapi.Config) error {
-	if cfg == nil || cfg.ChainGateway == nil {
-		return fmt.Errorf("chain gateway configuration is not provided")
+func (a *AccountAPI) initChainGateway(cfg *eapi.ChainGatewayConfig) error {
+	if cfg == nil {
+		return merrors.InvalidArgument("chain gateway configuration is not provided")
 	}
 
-	address := strings.TrimSpace(os.Getenv(cfg.ChainGateway.AddressEnv))
+	address := strings.TrimSpace(os.Getenv(cfg.AddressEnv))
 	if address == "" {
-		return fmt.Errorf("chain gateway address env %s is empty", cfg.ChainGateway.AddressEnv)
+		return merrors.InvalidArgument(fmt.Sprintf("chain gateway address env %s is empty", cfg.AddressEnv))
 	}
 
 	clientCfg := chaingatewayclient.Config{
 		Address:     address,
-		DialTimeout: time.Duration(cfg.ChainGateway.DialTimeoutSeconds) * time.Second,
-		CallTimeout: time.Duration(cfg.ChainGateway.CallTimeoutSeconds) * time.Second,
-		Insecure:    cfg.ChainGateway.Insecure,
+		DialTimeout: time.Duration(cfg.DialTimeoutSeconds) * time.Second,
+		CallTimeout: time.Duration(cfg.CallTimeoutSeconds) * time.Second,
+		Insecure:    cfg.Insecure,
 	}
 
 	client, err := chaingatewayclient.New(context.Background(), clientCfg)
@@ -172,7 +178,7 @@ func (a *AccountAPI) initChainGateway(cfg *eapi.Config) error {
 		return err
 	}
 
-	asset, err := buildGatewayAsset(cfg.ChainGateway.DefaultAsset)
+	asset, err := buildGatewayAsset(cfg.DefaultAsset)
 	if err != nil {
 		_ = client.Close()
 		return err
@@ -190,7 +196,7 @@ func buildGatewayAsset(cfg eapi.ChainGatewayAssetConfig) (*gatewayv1.Asset, erro
 	}
 	tokenSymbol := strings.TrimSpace(cfg.TokenSymbol)
 	if tokenSymbol == "" {
-		return nil, fmt.Errorf("chain gateway token symbol is required")
+		return nil, merrors.InvalidArgument("chain gateway token symbol is required")
 	}
 	return &gatewayv1.Asset{
 		Chain:           chain,
@@ -208,8 +214,8 @@ func parseChainNetwork(value string) (gatewayv1.ChainNetwork, error) {
 	case "OTHER_EVM", "CHAIN_NETWORK_OTHER_EVM":
 		return gatewayv1.ChainNetwork_CHAIN_NETWORK_OTHER_EVM, nil
 	case "", "CHAIN_NETWORK_UNSPECIFIED":
-		return gatewayv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, fmt.Errorf("chain network must be specified")
+		return gatewayv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, merrors.InvalidArgument("chain network must be specified")
 	default:
-		return gatewayv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, fmt.Errorf("unsupported chain network %s", value)
+		return gatewayv1.ChainNetwork_CHAIN_NETWORK_UNSPECIFIED, merrors.InvalidArgument("unsupported chain network %s", value)
 	}
 }