diff --git a/grpc/client.go b/grpc/client.go
index 210c835d1..43824b3f1 100644
--- a/grpc/client.go
+++ b/grpc/client.go
@@ -10,6 +10,7 @@ import (
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/metadata"
 
+	"github.com/pace/bricks/http/middleware"
 	"github.com/pace/bricks/http/security"
 	"github.com/pace/bricks/locale"
 	"github.com/pace/bricks/maintenance/log"
@@ -72,14 +73,19 @@ func dialCtx(ctx context.Context, addr string) (*grpc.ClientConn, error) {
 
 func prepareClientContext(ctx context.Context) context.Context {
 	if loc, ok := locale.FromCtx(ctx); ok {
-		ctx = metadata.AppendToOutgoingContext(ctx, "locale", loc.Serialize())
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyLocale, loc.Serialize())
 	}
 	if token, ok := security.GetTokenFromContext(ctx); ok {
-		ctx = metadata.AppendToOutgoingContext(ctx, "bearer_token", token.GetValue())
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyBearerToken, token.GetValue())
 	}
 	if reqID := log.RequestIDFromContext(ctx); reqID != "" {
-		ctx = metadata.AppendToOutgoingContext(ctx, "req_id", reqID)
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyRequestID, reqID)
 	}
 	ctx = EncodeContextWithUTMData(ctx)
+
+	if dep := middleware.ExternalDependencyContextFromContext(ctx); dep != nil {
+		ctx = metadata.AppendToOutgoingContext(ctx, MetadataKeyExternalDependencies, dep.String())
+	}
+
 	return ctx
 }
diff --git a/grpc/consts.go b/grpc/consts.go
new file mode 100644
index 000000000..9646c21e9
--- /dev/null
+++ b/grpc/consts.go
@@ -0,0 +1,9 @@
+package grpc
+
+const (
+	MetadataKeyBearerToken          = "bearer_token"
+	MetadataKeyContentType          = "content-type"
+	MetadataKeyExternalDependencies = "external_dependencies"
+	MetadataKeyLocale               = "locale"
+	MetadataKeyRequestID            = "req_id"
+)
diff --git a/grpc/server.go b/grpc/server.go
index 223a2fbd9..99d9296d6 100644
--- a/grpc/server.go
+++ b/grpc/server.go
@@ -14,6 +14,7 @@ import (
 	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
 	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	grpc_opentracing "github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing"
+	"github.com/pace/bricks/http/middleware"
 	"github.com/pace/bricks/http/security"
 	"github.com/pace/bricks/locale"
 	"github.com/pace/bricks/maintenance/errors"
@@ -151,7 +152,7 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 
 	// add request context if req_id is given
 	var reqID xid.ID
-	if ri := md.Get("req_id"); len(ri) > 0 {
+	if ri := md.Get(MetadataKeyRequestID); len(ri) > 0 {
 		var err error
 		reqID, err = xid.FromString(ri[0])
 		if err != nil {
@@ -174,7 +175,7 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 	})
 
 	// handle locale
-	if l := md.Get("locale"); len(l) > 0 {
+	if l := md.Get(MetadataKeyLocale); len(l) > 0 {
 		loc, err := locale.ParseLocale(l[0])
 		if err != nil {
 			log.Ctx(ctx).Debug().Err(err).Msgf("unable to parse locale: %v", err)
@@ -186,13 +187,24 @@ func prepareContext(ctx context.Context) (context.Context, metadata.MD) {
 	ctx = ContextWithUTMFromMetadata(ctx, md)
 
 	// add security context if bearer token is given
-	if bt := md.Get("bearer_token"); len(bt) > 0 {
+	if bt := md.Get(MetadataKeyBearerToken); len(bt) > 0 {
 		ctx = security.ContextWithToken(ctx, security.TokenString(bt[0]))
 	}
-	delete(md, "content-type")
-	delete(md, "locale")
-	delete(md, "bearer_token")
-	delete(md, "req_id")
+
+	// add external dependencies to context
+	externalDependencyContext := middleware.ExternalDependencyContext{}
+
+	if externalDependencies := md.Get(MetadataKeyExternalDependencies); len(externalDependencies) > 0 {
+		externalDependencyContext.Parse(externalDependencies[0])
+	}
+
+	ctx = middleware.ContextWithExternalDependency(ctx, &externalDependencyContext)
+
+	delete(md, MetadataKeyContentType)
+	delete(md, MetadataKeyLocale)
+	delete(md, MetadataKeyBearerToken)
+	delete(md, MetadataKeyRequestID)
+	delete(md, MetadataKeyExternalDependencies)
 
 	return ctx, md
 }
diff --git a/grpc/server_test.go b/grpc/server_test.go
index e2d653205..a2bda5f50 100644
--- a/grpc/server_test.go
+++ b/grpc/server_test.go
@@ -7,9 +7,11 @@ import (
 	"context"
 	"testing"
 
+	"github.com/pace/bricks/http/middleware"
 	"github.com/pace/bricks/locale"
 	"github.com/pace/bricks/maintenance/log"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/grpc/metadata"
 )
 
@@ -29,14 +31,14 @@ func TestPrepareContext(t *testing.T) {
 
 	// remote site is providing data using a bearer token
 	ctx = metadata.NewIncomingContext(ctx, metadata.MD{
-		"req_id":       []string{"c690uu0ta2rv348epm8g"},
-		"locale":       []string{"fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5|Europe/Paris"},
-		"bearer_token": []string{"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"},
+		MetadataKeyRequestID:   []string{"c690uu0ta2rv348epm8g"},
+		MetadataKeyLocale:      []string{"fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5|Europe/Paris"},
+		MetadataKeyBearerToken: []string{"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"},
 	})
 
 	ctx1, md := prepareContext(ctx)
-	assert.Len(t, md.Get("req_id"), 0)
-	assert.Len(t, md.Get("bearer_token"), 0)
+	assert.Len(t, md.Get(MetadataKeyRequestID), 0)
+	assert.Len(t, md.Get(MetadataKeyBearerToken), 0)
 	assert.Equal(t, "c690uu0ta2rv348epm8g", log.RequestIDFromContext(ctx1))
 	loc, ok := locale.FromCtx(ctx1)
 	assert.True(t, ok)
@@ -51,13 +53,13 @@ func TestPrepareContext(t *testing.T) {
 
 	// remote site is providing data using a bearer token
 	ctx = metadata.NewIncomingContext(ctx, metadata.MD{
-		"req_id":       []string{"c690uu0ta2rv348epm8g"},
-		"bearer_token": []string{"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9"},
+		MetadataKeyRequestID:   []string{"c690uu0ta2rv348epm8g"},
+		MetadataKeyBearerToken: []string{"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9"},
 	})
 
 	ctx2, md := prepareContext(ctx)
-	assert.Len(t, md.Get("req_id"), 0)
-	assert.Len(t, md.Get("bearer_token"), 0)
+	assert.Len(t, md.Get(MetadataKeyRequestID), 0)
+	assert.Len(t, md.Get(MetadataKeyBearerToken), 0)
 	assert.Equal(t, "c690uu0ta2rv348epm8g", log.RequestIDFromContext(ctx1))
 
 	var buf2 bytes.Buffer
@@ -67,4 +69,24 @@ func TestPrepareContext(t *testing.T) {
 	assert.Contains(t, buf2.String(), ",\"message\":\"test\"}\n")
 	_, ok = locale.FromCtx(ctx2)
 	assert.False(t, ok)
+
+	ctx = metadata.NewIncomingContext(ctx, metadata.MD{
+		MetadataKeyExternalDependencies: []string{"foo:60000,bar:1000"},
+	})
+
+	ctx3, md := prepareContext(ctx)
+	assert.Len(t, md.Get(MetadataKeyExternalDependencies), 0)
+
+	externalDependencyContext := middleware.ExternalDependencyContextFromContext(ctx3)
+	require.NotNil(t, externalDependencyContext)
+	assert.Equal(t, "foo:60000,bar:1000", externalDependencyContext.String())
+
+	ctx = metadata.NewIncomingContext(context.Background(), metadata.MD{})
+
+	ctx4, md := prepareContext(ctx)
+	assert.Len(t, md.Get(MetadataKeyExternalDependencies), 0)
+
+	externalDependencyContext = middleware.ExternalDependencyContextFromContext(ctx4)
+	require.NotNil(t, externalDependencyContext)
+	assert.Empty(t, externalDependencyContext.String())
 }
diff --git a/pkg/context/transfer.go b/pkg/context/transfer.go
index 0d86c61a3..a4e122672 100755
--- a/pkg/context/transfer.go
+++ b/pkg/context/transfer.go
@@ -28,7 +28,10 @@ func Transfer(in context.Context) context.Context {
 	out = utm.ContextTransfer(in, out)
 	out = hlog.ContextTransfer(in, out)
 	out = TransferTracingContext(in, out)
-	return locale.ContextTransfer(in, out)
+	out = locale.ContextTransfer(in, out)
+	out = TransferExternalDependencyContext(in, out)
+
+	return out
 }
 
 func TransferTracingContext(in, out context.Context) context.Context {