fix: support realtime translation routing

backend/internal/handler/endpoint.go

@@ -154,6 +154,8 @@ func isRealtimeRESTEndpoint(path string) bool {
 		return true
 	case strings.Contains(trimmed, "/realtime/translations/client_secrets"):
 		return true
+	case strings.Contains(trimmed, "/realtime/translations/calls"):
+		return true
 	case strings.Contains(trimmed, "/realtime/sessions"):
 		return true
 	case strings.Contains(trimmed, "/realtime/transcription_sessions"):

backend/internal/handler/endpoint_test.go

@@ -30,6 +30,7 @@ func TestNormalizeInboundEndpoint(t *testing.T) {
 		{"/v1/realtime/client_secrets", EndpointRealtimeREST},
 		{"/v1/realtime/translations/client_secrets", EndpointRealtimeREST},
 		{"/v1/realtime/calls", EndpointRealtimeREST},
+		{"/v1/realtime/translations/calls", EndpointRealtimeREST},
 		{"/v1/realtime/calls/call_123/hangup", EndpointRealtimeREST},
 		{"/v1/realtime/calls/call_123/refer", EndpointRealtimeREST},
 		{"/v1/realtime/calls/call_123/reject", EndpointRealtimeREST},
@@ -99,12 +100,14 @@ func TestDeriveUpstreamEndpoint(t *testing.T) {
 		{"openai realtime client secrets", EndpointRealtimeREST, "/v1/realtime/client_secrets", service.PlatformOpenAI, "/v1/realtime/client_secrets"},
 		{"openai realtime translation client secrets", EndpointRealtimeREST, "/v1/realtime/translations/client_secrets", service.PlatformOpenAI, "/v1/realtime/translations/client_secrets"},
 		{"openai realtime calls create", EndpointRealtimeREST, "/v1/realtime/calls", service.PlatformOpenAI, "/v1/realtime/calls"},
+		{"openai realtime translation calls create", EndpointRealtimeREST, "/v1/realtime/translations/calls", service.PlatformOpenAI, "/v1/realtime/translations/calls"},
 		{"openai realtime calls hangup", EndpointRealtimeREST, "/v1/realtime/calls/call_123/hangup", service.PlatformOpenAI, "/v1/realtime/calls/call_123/hangup"},
 		{"openai realtime calls refer", EndpointRealtimeREST, "/v1/realtime/calls/call_123/refer", service.PlatformOpenAI, "/v1/realtime/calls/call_123/refer"},
 		{"openai realtime calls reject", EndpointRealtimeREST, "/v1/realtime/calls/call_123/reject", service.PlatformOpenAI, "/v1/realtime/calls/call_123/reject"},
 		{"openai realtime sessions", EndpointRealtimeREST, "/v1/realtime/sessions", service.PlatformOpenAI, "/v1/realtime/sessions"},
 		{"openai realtime transcription sessions", EndpointRealtimeREST, "/v1/realtime/transcription_sessions", service.PlatformOpenAI, "/v1/realtime/transcription_sessions"},
 		{"openai prefixed realtime reject", EndpointRealtimeREST, "/openai/v1/realtime/calls/call_789/reject", service.PlatformOpenAI, "/v1/realtime/calls/call_789/reject"},
+		{"openai prefixed realtime translation calls", EndpointRealtimeREST, "/openai/v1/realtime/translations/calls", service.PlatformOpenAI, "/v1/realtime/translations/calls"},
 		{"openai audio transcriptions", EndpointAudioTranscriptions, "/v1/audio/transcriptions", service.PlatformOpenAI, EndpointAudioTranscriptions},
 		{"openai transcribe alias", EndpointTranscribe, "/transcribe", service.PlatformOpenAI, EndpointAudioTranscriptions},
 		{"openai image generations", EndpointImagesGenerations, "/v1/images/generations", service.PlatformOpenAI, EndpointImagesGenerations},

backend/internal/handler/openai_gateway_handler.go

@@ -1094,7 +1094,8 @@ func (h *OpenAIGatewayHandler) acquireResponsesAccountSlot(
 }
 
 type openAIWebSocketEndpointOptions struct {
-	Realtime bool
+	Realtime    bool
+	Translation bool
 }
 
 // ResponsesWebSocket handles OpenAI Responses API WebSocket ingress endpoint
@@ -1109,6 +1110,12 @@ func (h *OpenAIGatewayHandler) RealtimeWebSocket(c *gin.Context) {
 	h.openAIWebSocket(c, openAIWebSocketEndpointOptions{Realtime: true})
 }
 
+// RealtimeTranslationWebSocket handles OpenAI Realtime translation WebSocket ingress endpoint.
+// GET /v1/realtime/translations?model=... (Upgrade: websocket)
+func (h *OpenAIGatewayHandler) RealtimeTranslationWebSocket(c *gin.Context) {
+	h.openAIWebSocket(c, openAIWebSocketEndpointOptions{Realtime: true, Translation: true})
+}
+
 func (h *OpenAIGatewayHandler) openAIWebSocket(c *gin.Context, opts openAIWebSocketEndpointOptions) {
 	if !isOpenAIWSUpgradeRequest(c.Request) {
 		h.errorResponse(c, http.StatusUpgradeRequired, "invalid_request_error", "WebSocket upgrade required (Upgrade: websocket)")
@@ -1450,7 +1457,7 @@ func (h *OpenAIGatewayHandler) openAIWebSocket(c *gin.Context, opts openAIWebSoc
 		if channelMappingWS.Mapped && strings.TrimSpace(channelMappingWS.MappedModel) != "" {
 			realtimeModel = channelMappingWS.MappedModel
 		}
-		proxyErr = h.gatewayService.ProxyRealtimeWebSocketFromClient(ctx, c, wsConn, account, token, wsFirstMessage, realtimeModel, hooks)
+		proxyErr = h.gatewayService.ProxyRealtimeWebSocketFromClient(ctx, c, wsConn, account, token, wsFirstMessage, realtimeModel, opts.RealtimeUpstreamEndpoint(), hooks)
 	} else {
 		proxyErr = h.gatewayService.ProxyResponsesWebSocketFromClient(ctx, c, wsConn, account, token, wsFirstMessage, hooks)
 	}
@@ -1476,11 +1483,21 @@ func (h *OpenAIGatewayHandler) openAIWebSocket(c *gin.Context, opts openAIWebSoc
 
 func openAIWebSocketLoggerName(opts openAIWebSocketEndpointOptions) string {
 	if opts.Realtime {
+		if opts.Translation {
+			return "handler.openai_gateway.realtime_translation_ws"
+		}
 		return "handler.openai_gateway.realtime_ws"
 	}
 	return "handler.openai_gateway.responses_ws"
 }
 
+func (opts openAIWebSocketEndpointOptions) RealtimeUpstreamEndpoint() string {
+	if opts.Realtime && opts.Translation {
+		return "/v1/realtime/translations"
+	}
+	return "/v1/realtime"
+}
+
 func openAIWebSocketMissingFirstMessageReason(opts openAIWebSocketEndpointOptions) string {
 	if opts.Realtime {
 		return "missing first realtime message"

backend/internal/handler/openai_gateway_handler_test.go

@@ -122,6 +122,11 @@ func TestOpenAIWebSocketRequiredAccountTypeAllowsRealtimeOAuth(t *testing.T) {
 	require.Empty(t, openAIWebSocketRequiredAccountType(openAIWebSocketEndpointOptions{}))
 }
 
+func TestOpenAIWebSocketEndpointOptionsRealtimeTranslationEndpoint(t *testing.T) {
+	require.Equal(t, "/v1/realtime", openAIWebSocketEndpointOptions{Realtime: true}.RealtimeUpstreamEndpoint())
+	require.Equal(t, "/v1/realtime/translations", openAIWebSocketEndpointOptions{Realtime: true, Translation: true}.RealtimeUpstreamEndpoint())
+}
+
 func TestResolveOpenAIMessagesMetadataSession_DoesNotDerivePromptCacheKey(t *testing.T) {
 	body := []byte(`{"model":"claude-sonnet-4-5","metadata":{"user_id":"claude-code-session"},"messages":[{"role":"user","content":"hello"}]}`)
 

backend/internal/handler/openai_realtime_calls.go

@@ -122,7 +122,7 @@ func (h *OpenAIGatewayHandler) RealtimeREST(c *gin.Context) {
 			apiKey.GroupID,
 			"",
 			sessionHash,
-			parsed.Model,
+			"",
 			failedAccountIDs,
 			service.OpenAIUpstreamTransportHTTPSSE,
 			"",

backend/internal/handler/openai_realtime_calls_test.go

@@ -149,6 +149,31 @@ func TestOpenAIGatewayHandlerRealtimeREST_ClientSecretAccountMappingForwardsMapp
 	require.Equal(t, "gpt-4o-transcribe", gjson.GetBytes(upstream.bodies[0], "session.audio.input.transcription.model").String())
 }
 
+func TestOpenAIGatewayHandlerRealtimeREST_TranslationClientSecretDoesNotFilterBySessionModel(t *testing.T) {
+	upstream := &realtimeCallsHandlerUpstream{statuses: []int{http.StatusOK}}
+	account := newRealtimeCallsHandlerAccount(1)
+	account.Type = service.AccountTypeOAuth
+	account.Credentials = map[string]any{
+		"access_token":       "oauth-token",
+		"chatgpt_account_id": "chatgpt-acc",
+		"model_mapping": map[string]any{
+			"client-transcribe": "gpt-4o-transcribe",
+		},
+	}
+	handler := newRealtimeCallsHandlerForTest(t, upstream, []service.Account{account})
+	body := []byte(`{"session":{"model":"gpt-realtime-translate","audio":{"input":{"transcription":{"model":"client-transcribe"}}}}}`)
+	c, rec := newRealtimeCallsHandlerContext(t, "/v1/realtime/translations/client_secrets", body)
+
+	handler.RealtimeREST(c)
+
+	require.Equal(t, http.StatusOK, rec.Code)
+	require.Equal(t, []int64{1}, upstream.accountIDs)
+	require.Len(t, upstream.bodies, 1)
+	require.Equal(t, "https://api.openai.com/v1/realtime/translations/client_secrets", upstream.urls[0])
+	require.Equal(t, "gpt-realtime-translate", gjson.GetBytes(upstream.bodies[0], "session.model").String())
+	require.Equal(t, "gpt-4o-transcribe", gjson.GetBytes(upstream.bodies[0], "session.audio.input.transcription.model").String())
+}
+
 func TestOpenAIGatewayHandlerRealtimeREST_CallControlNoModelDispatchesAccount(t *testing.T) {
 	upstream := &realtimeCallsHandlerUpstream{statuses: []int{http.StatusOK}}
 	handler := newRealtimeCallsHandlerForTest(t, upstream, []service.Account{

backend/internal/server/routes/gateway.go

@@ -92,6 +92,18 @@ func RegisterGatewayRoutes(
 			}
 			h.OpenAIGateway.RealtimeWebSocket(c)
 		})
+		gateway.GET("/realtime/translations", func(c *gin.Context) {
+			if getGroupPlatform(c) != service.PlatformOpenAI {
+				c.JSON(http.StatusNotFound, gin.H{
+					"error": gin.H{
+						"type":    "not_found_error",
+						"message": "Realtime API is not supported for this platform",
+					},
+				})
+				return
+			}
+			h.OpenAIGateway.RealtimeTranslationWebSocket(c)
+		})
 		realtimeRESTHandler := func(c *gin.Context) {
 			if getGroupPlatform(c) != service.PlatformOpenAI {
 				c.JSON(http.StatusNotFound, gin.H{
@@ -107,6 +119,7 @@ func RegisterGatewayRoutes(
 		gateway.POST("/realtime/client_secrets", realtimeRESTHandler)
 		gateway.POST("/realtime/translations/client_secrets", realtimeRESTHandler)
 		gateway.POST("/realtime/calls", realtimeRESTHandler)
+		gateway.POST("/realtime/translations/calls", realtimeRESTHandler)
 		gateway.POST("/realtime/calls/:call_id/accept", realtimeRESTHandler)
 		gateway.POST("/realtime/calls/:call_id/hangup", realtimeRESTHandler)
 		gateway.POST("/realtime/calls/:call_id/refer", realtimeRESTHandler)

backend/internal/server/routes/gateway_test.go

@@ -117,6 +117,17 @@ func TestGatewayRoutesOpenAIRealtimePathIsRegistered(t *testing.T) {
 	require.Equal(t, http.StatusUpgradeRequired, w.Code)
 }
 
+func TestGatewayRoutesOpenAIRealtimeTranslationPathIsRegistered(t *testing.T) {
+	router := newGatewayRoutesTestRouter()
+
+	req := httptest.NewRequest(http.MethodGet, "/v1/realtime/translations?model=gpt-realtime-translate", nil)
+	w := httptest.NewRecorder()
+
+	router.ServeHTTP(w, req)
+	require.NotEqual(t, http.StatusNotFound, w.Code)
+	require.Equal(t, http.StatusUpgradeRequired, w.Code)
+}
+
 func TestGatewayRoutesOpenAIRealtimeRejectsNonOpenAIPlatform(t *testing.T) {
 	router := newGatewayRoutesTestRouterForPlatform(service.PlatformAnthropic)
 
@@ -128,6 +139,17 @@ func TestGatewayRoutesOpenAIRealtimeRejectsNonOpenAIPlatform(t *testing.T) {
 	require.Contains(t, w.Body.String(), "Realtime API is not supported for this platform")
 }
 
+func TestGatewayRoutesOpenAIRealtimeTranslationRejectsNonOpenAIPlatform(t *testing.T) {
+	router := newGatewayRoutesTestRouterForPlatform(service.PlatformAnthropic)
+
+	req := httptest.NewRequest(http.MethodGet, "/v1/realtime/translations?model=gpt-realtime-translate", nil)
+	w := httptest.NewRecorder()
+
+	router.ServeHTTP(w, req)
+	require.Equal(t, http.StatusNotFound, w.Code)
+	require.Contains(t, w.Body.String(), "Realtime API is not supported for this platform")
+}
+
 func TestGatewayRoutesOpenAIRealtimeCallsAcceptPathIsRegistered(t *testing.T) {
 	router := newGatewayRoutesTestRouter()
 
@@ -149,6 +171,7 @@ func TestGatewayRoutesOpenAIRealtimeRESTPathsAreRegistered(t *testing.T) {
 		{"/v1/realtime/client_secrets", `{"session":{"type":"realtime","model":"gpt-realtime"}}`},
 		{"/v1/realtime/translations/client_secrets", `{"session":{"model":"gpt-realtime-translate"}}`},
 		{"/v1/realtime/calls", `{"model":"gpt-realtime"}`},
+		{"/v1/realtime/translations/calls", `{"model":"gpt-realtime-translate"}`},
 		{"/v1/realtime/calls/call_123/hangup", `{}`},
 		{"/v1/realtime/calls/call_123/refer", `{"target_uri":"tel:+15551234567"}`},
 		{"/v1/realtime/calls/call_123/reject", `{"status_code":603}`},

backend/internal/service/openai_gateway_service.go

@@ -5237,8 +5237,8 @@ func buildOpenAIResponsesURL(base string) string {
 	return buildOpenAIEndpointURL(base, "/v1/responses")
 }
 
-func buildOpenAIRealtimeURL(base string) string {
-	return buildOpenAIEndpointURL(base, "/v1/realtime")
+func buildOpenAIRealtimeEndpointURL(base string, endpoint string) string {
+	return buildOpenAIEndpointURL(base, endpoint)
 }
 
 func trimOpenAIEncryptedReasoningItems(reqBody map[string]any) bool {

backend/internal/service/openai_realtime_calls.go

@@ -115,6 +115,7 @@ func normalizeOpenAIRealtimeRESTEndpoint(path string) (endpoint string, callID s
 	case "/v1/realtime/client_secrets",
 		"/v1/realtime/translations/client_secrets",
 		"/v1/realtime/calls",
+		"/v1/realtime/translations/calls",
 		"/v1/realtime/sessions",
 		"/v1/realtime/transcription_sessions":
 		return trimmed, "", "", nil
@@ -149,7 +150,7 @@ func extractOpenAIRealtimeRESTModelRefs(endpoint string, body []byte) []OpenAIRe
 		paths = []string{"session.model", "session.audio.input.transcription.model"}
 	case "/v1/realtime/translations/client_secrets":
 		paths = []string{"session.model", "session.audio.input.transcription.model"}
-	case "/v1/realtime/calls":
+	case "/v1/realtime/calls", "/v1/realtime/translations/calls":
 		paths = []string{"model", "session.model"}
 	case "/v1/realtime/sessions":
 		paths = []string{"model"}
@@ -387,7 +388,9 @@ func (s *OpenAIGatewayService) buildOpenAIRealtimeRESTRequest(
 	req.Header.Del("X-Api-Key")
 	req.Header.Del("X-Goog-Api-Key")
 	req.Header.Set("Authorization", "Bearer "+token)
-	req.Header.Set("Content-Type", "application/json")
+	if strings.TrimSpace(req.Header.Get("Content-Type")) == "" {
+		req.Header.Set("Content-Type", "application/json")
+	}
 	if account.Type == AccountTypeOAuth {
 		if chatgptAccountID := account.GetChatGPTAccountID(); chatgptAccountID != "" {
 			req.Header.Set("chatgpt-account-id", chatgptAccountID)

backend/internal/service/openai_realtime_calls_test.go

@@ -257,6 +257,64 @@ func TestOpenAIGatewayService_ForwardRealtimeREST_TranslationMapsSessionAndTrans
 	require.Equal(t, "gpt-realtime-translate", result.UpstreamModel)
 }
 
+func TestOpenAIGatewayService_ForwardRealtimeREST_TranslationCallsMapsModel(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	body := []byte(`{"model":"client-translate-call","sdp":"v=0"}`)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1/realtime/translations/calls", bytes.NewReader(body))
+	c.Request.Header.Set("Content-Type", "application/sdp")
+
+	upstream := &httpUpstreamRecorder{resp: &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     http.Header{"Content-Type": []string{"application/json"}, "x-request-id": []string{"rid_translation_call"}},
+		Body:       io.NopCloser(bytes.NewReader([]byte(`{"id":"call_123"}`))),
+	}}
+	svc := &OpenAIGatewayService{
+		cfg:          &config.Config{},
+		httpUpstream: upstream,
+	}
+	account := &Account{
+		ID:          123,
+		Name:        "acc",
+		Platform:    PlatformOpenAI,
+		Type:        AccountTypeOAuth,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"access_token":       "oauth-token",
+			"chatgpt_account_id": "chatgpt-acc",
+			"model_mapping": map[string]any{
+				"mapped-translate-call": "gpt-realtime-translate",
+			},
+		},
+		Status:      StatusActive,
+		Schedulable: true,
+	}
+	parsed, err := ParseOpenAIRealtimeRESTRequest(c, body)
+	require.NoError(t, err)
+	require.Equal(t, "/v1/realtime/translations/calls", parsed.Endpoint)
+	require.Equal(t, "client-translate-call", parsed.Model)
+	require.Equal(t, "model", parsed.ScheduleModelPath)
+
+	result, err := svc.ForwardRealtimeREST(
+		context.Background(),
+		c,
+		account,
+		parsed,
+		map[string]string{"model": "mapped-translate-call"},
+	)
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, "https://api.openai.com/v1/realtime/translations/calls", upstream.lastReq.URL.String())
+	require.Equal(t, "application/sdp", upstream.lastReq.Header.Get("Content-Type"))
+	require.Equal(t, "Bearer oauth-token", upstream.lastReq.Header.Get("Authorization"))
+	require.Equal(t, "chatgpt-acc", upstream.lastReq.Header.Get("chatgpt-account-id"))
+	require.Equal(t, "gpt-realtime-translate", gjson.GetBytes(upstream.lastBody, "model").String())
+	require.Equal(t, "client-translate-call", result.Model)
+	require.Equal(t, "gpt-realtime-translate", result.UpstreamModel)
+}
+
 func TestOpenAIGatewayService_ForwardRealtimeREST_TranslationOAuthHeaders(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	rec := httptest.NewRecorder()