fix(gateway): resolve composite routes for websocket aliases

backend/cmd/server/wire_gen.go

@@ -294,7 +294,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	legacyEngine := securityaudit.NewLegacyModerationAdapter(contentModerationService)
 	coordinator := securityaudit.NewCoordinator(legacyEngine, promptService)
 	gatewayHandler := handler.ProvideGatewayHandler(gatewayService, openAIGatewayService, geminiMessagesCompatService, antigravityGatewayService, userService, concurrencyService, billingCacheService, usageService, apiKeyService, usageRecordWorkerPool, errorPassthroughService, contentModerationService, userMessageQueueService, configConfig, settingService, coordinator)
-	openAIGatewayHandler := handler.ProvideOpenAIGatewayHandler(openAIGatewayService, pluginManager, concurrencyService, billingCacheService, apiKeyService, usageRecordWorkerPool, errorPassthroughService, contentModerationService, opsService, grokQuotaService, configConfig, coordinator)
+	openAIGatewayHandler := handler.ProvideOpenAIGatewayHandler(openAIGatewayService, pluginManager, concurrencyService, billingCacheService, apiKeyService, usageRecordWorkerPool, errorPassthroughService, contentModerationService, opsService, grokQuotaService, configConfig, coordinator, compositeRouteResolver)
 	handlerSettingHandler := handler.ProvideSettingHandler(settingService, buildInfo, notificationEmailService)
 	totpHandler := handler.NewTotpHandler(totpService)
 	passkeyRepository := repository.NewPasskeyRepository(db)

backend/internal/handler/openai_gateway_handler.go

@@ -34,6 +34,7 @@ import (
 
 // OpenAIGatewayHandler handles OpenAI API gateway requests
 type OpenAIGatewayHandler struct {
+	compositeResolver          *service.CompositeRouteResolver
 	gatewayService             *service.OpenAIGatewayService
 	billingCacheService        *service.BillingCacheService
 	apiKeyService              *service.APIKeyService
@@ -2391,7 +2392,7 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 		return
 	}
 	// 分组级模型白名单：首帧校验客户端模型，不通过则关闭连接并标记运维原因。
-	// 必须在 ensureCompositeTargetPlatform（合成路由改写）之前执行。
+	// 必须在合成路由解析和上游模型映射之前执行。
 	// 与 HTTP 准入一致：帧内重复 model 键/大小写变体可能被上游按末值绑定，
 	// 全部候选值逐一校验，任一未命中即拒绝。
 	if blocked := blockedModelAllowlistCandidate(apiKey.Group, requestmodel.FromBodyCandidates("", "application/json", firstMessage)); blocked != "" {
@@ -2400,7 +2401,21 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 		closeOpenAIClientWS(wsConn, coderws.StatusPolicyViolation, fmt.Sprintf("Model %q is not available for this group", blocked))
 		return
 	}
-	ensureCompositeTargetPlatform(c, apiKey, reqModel)
+	// Keep the client model in the frame for admission, response identity and usage.
+	// Apply the resolved upstream model through MapRequestModel on every turn.
+	wsRouteModel := reqModel
+	if apiKey.Group != nil && apiKey.Group.Platform == service.PlatformComposite {
+		decision, resolveErr := h.compositeResolver.Resolve(c.Request.Context(), apiKey.Group.ID, reqModel, service.CompositeRouteEndpointResponses)
+		if resolveErr != nil {
+			reqLog.Error("openai.websocket_composite_route_failed", zap.Error(resolveErr))
+			closeOpenAIClientWS(wsConn, coderws.StatusInternalError, "Failed to resolve composite model route")
+			return
+		}
+		if decision.Matched {
+			c.Request = c.Request.WithContext(service.WithCompositeRouteDecision(c.Request.Context(), decision))
+			wsRouteModel = decision.UpstreamModel
+		}
+	}
 	ctx = c.Request.Context()
 	if apiKey.Group != nil && apiKey.Group.Platform == service.PlatformComposite {
 		platform, ok := service.ResolvedTargetPlatformFromContext(ctx)
@@ -2464,8 +2479,8 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 	}
 
 	// 解析渠道级模型映射
-	channelMappingWS, _ := h.gatewayService.ResolveChannelMappingAndRestrict(ctx, apiKey.GroupID, reqModel)
-	wsForwardModel := openAIChannelForwardModel(channelMappingWS, reqModel)
+	channelMappingWS, _ := h.gatewayService.ResolveChannelMappingAndRestrict(ctx, apiKey.GroupID, wsRouteModel)
+	wsForwardModel := openAIChannelForwardModel(channelMappingWS, wsRouteModel)
 
 	var currentUserRelease func()
 	var currentAccountRelease func()
@@ -2856,7 +2871,16 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 					model = reqModel
 				}
 				setOpsRequestContext(c, model, true)
-				mapping, _ := h.gatewayService.ResolveChannelMappingAndRestrict(ctx, apiKey.GroupID, model)
+				routeModel := model
+				if apiKey.Group != nil && apiKey.Group.Platform == service.PlatformComposite {
+					// The account, target platform and route context are connection-scoped.
+					// A different public model needs a new connection and fresh resolution.
+					if model != reqModel {
+						return "", newOpenAIWSUnsupportedModelSwitchError(model)
+					}
+					routeModel = wsRouteModel
+				}
+				mapping, _ := h.gatewayService.ResolveChannelMappingAndRestrict(ctx, apiKey.GroupID, routeModel)
 				mappedModelUnchanged := false
 				if previous := turnChannelMapping.Load(); previous != nil && previous.turn < turn {
 					mappedModelUnchanged = strings.TrimSpace(previous.mapping.MappedModel) == strings.TrimSpace(mapping.MappedModel)

backend/internal/handler/openai_gateway_handler_test.go

@@ -1931,7 +1931,10 @@ func newOpenAIWSHandlerTestServer(t *testing.T, h *OpenAIGatewayHandler, subject
 
 type openAIResponsesWSUsageLogCase struct {
 	simpleModeRejectAtRead int64
+	compositeResolver      *service.CompositeRouteResolver
+	accountPlatform        string
 	closeReason            string
+	closeStatus            coderws.StatusCode
 	firstPayload           string
 	// midPayload 在首个 turn 完成后发送（如 session.update），上游桩会为它
 	// 回一个 response.completed，客户端按普通事件读取。
@@ -2878,6 +2881,17 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 	upstreamErrCh := make(chan error, 1)
 	var channelSvc *service.ChannelService
 	upstreamServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if tc.accountPlatform == service.PlatformGrok {
+			payload, err := io.ReadAll(r.Body)
+			if err != nil {
+				upstreamErrCh <- err
+				return
+			}
+			upstreamPayloadCh <- payload
+			w.Header().Set("Content-Type", "text/event-stream")
+			_, _ = fmt.Fprintf(w, "data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_grok_test\",\"model\":%q,\"usage\":{\"input_tokens\":2,\"output_tokens\":1}}}\n\n", gjson.GetBytes(payload, "model").String())
+			return
+		}
 		conn, err := coderws.Accept(w, r, &coderws.AcceptOptions{
 			CompressionMode: coderws.CompressionContextTakeover,
 		})
@@ -2945,6 +2959,9 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 			"openai_apikey_responses_websockets_v2_mode":    service.OpenAIWSIngressModePassthrough,
 		},
 	}
+	if tc.accountPlatform != "" {
+		account.Platform = tc.accountPlatform
+	}
 	if strings.TrimSpace(tc.ingressMode) != "" {
 		account.Extra["openai_apikey_responses_websockets_v2_mode"] = tc.ingressMode
 	}
@@ -3000,7 +3017,7 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 		service.NewBillingService(cfg, nil),
 		nil,
 		billingCacheSvc,
-		nil,
+		&compositeWSHTTPUpstream{},
 		&service.DeferredService{},
 		nil,
 		nil,
@@ -3021,6 +3038,7 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 	}
 	h := &OpenAIGatewayHandler{
 		cfg:                 cfg,
+		compositeResolver:   tc.compositeResolver,
 		gatewayService:      gatewaySvc,
 		billingCacheService: billingCacheSvc,
 		apiKeyService:       &service.APIKeyService{},
@@ -3069,6 +3087,12 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 	cancelWrite()
 	require.NoError(t, err)
 
+	if tc.closeReason == "" {
+		tc.closeReason = "not available for this group"
+	}
+	if tc.closeStatus == 0 {
+		tc.closeStatus = coderws.StatusPolicyViolation
+	}
 	if tc.firstFrameCloseExpected {
 		readCtx, cancelRead := context.WithTimeout(context.Background(), 3*time.Second)
 		_, _, readErr := clientConn.Read(readCtx)
@@ -3076,12 +3100,17 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 		require.Error(t, readErr, "first frame should have been rejected with a close")
 		var closeErr coderws.CloseError
 		require.ErrorAs(t, readErr, &closeErr)
-		require.Equal(t, coderws.StatusPolicyViolation, closeErr.Code)
+		status := tc.closeStatus
+		if status == 0 {
+			status = coderws.StatusPolicyViolation
+		}
+		require.Equal(t, status, closeErr.Code)
 		reason := tc.closeReason
 		if reason == "" {
 			reason = "not available for this group"
 		}
 		require.Contains(t, closeErr.Reason, reason)
+		require.Empty(t, upstreamPayloadCh, "rejected first frame must not reach upstream")
 		_ = clientConn.CloseNow()
 		return openAIResponsesWSUsageLogResult{}
 	}
@@ -3115,12 +3144,17 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 			require.Error(t, readErr, "second turn should have been rejected with a close")
 			var closeErr coderws.CloseError
 			require.ErrorAs(t, readErr, &closeErr)
-			require.Equal(t, coderws.StatusPolicyViolation, closeErr.Code)
+			status := tc.closeStatus
+			if status == 0 {
+				status = coderws.StatusPolicyViolation
+			}
+			require.Equal(t, status, closeErr.Code)
 			reason := tc.closeReason
 			if reason == "" {
 				reason = "not available for this group"
 			}
 			require.Contains(t, closeErr.Reason, reason)
+			require.Len(t, upstreamPayloadCh, turnCount-1, "rejected turn must not reach upstream")
 			_ = clientConn.CloseNow()
 			return openAIResponsesWSUsageLogResult{}
 		}
@@ -3149,6 +3183,9 @@ func runOpenAIResponsesWebSocketUsageLogCase(t *testing.T, tc openAIResponsesWSU
 		}
 	}
 
+	if tc.accountPlatform == service.PlatformGrok {
+		upstreamErrCh <- nil
+	}
 	select {
 	case upstreamErr := <-upstreamErrCh:
 		require.NoError(t, upstreamErr)

backend/internal/handler/openai_gateway_ws_composite_test.go

@@ -0,0 +1,159 @@
+package handler
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	coderws "github.com/coder/websocket"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+type compositeWSRouteRepo struct {
+	service.CompositeModelRouteRepository
+	routes []service.CompositeModelRoute
+	err    error
+}
+
+func (r *compositeWSRouteRepo) ListByGroup(context.Context, int64, bool) ([]service.CompositeModelRoute, error) {
+	return r.routes, r.err
+}
+
+type compositeWSHTTPUpstream struct{ service.HTTPUpstream }
+
+func (*compositeWSHTTPUpstream) Do(req *http.Request, _ string, _ int64, _ int) (*http.Response, error) {
+	return http.DefaultClient.Do(req)
+}
+
+func compositeWSResolver(platform, endpoint, upstream string) *service.CompositeRouteResolver {
+	return service.NewCompositeRouteResolver(&compositeWSRouteRepo{routes: []service.CompositeModelRoute{{
+		GroupID: 4201, PublicModel: "public-alias", MatchType: service.CompositeRouteMatchExact,
+		TargetPlatform: platform, Endpoint: endpoint, UpstreamModel: upstream, Enabled: true,
+	}}})
+}
+func compositeWSGroup(models ...string) *service.Group {
+	g := wsAllowlistGroup(len(models) > 0, models...)
+	g.Platform = service.PlatformComposite
+	return g
+}
+
+func TestOpenAIResponsesWebSocket_CompositeAlias(t *testing.T) {
+	for _, platform := range []string{service.PlatformOpenAI, service.PlatformGrok} {
+		for _, endpoint := range []string{service.CompositeRouteEndpointResponses, service.CompositeRouteEndpointAny} {
+			for _, mode := range []string{service.OpenAIWSIngressModePassthrough, service.OpenAIWSIngressModeDedicated} {
+				t.Run(platform+"/"+endpoint+"/"+mode, func(t *testing.T) {
+					upstream := "gpt-5.4"
+					if platform == service.PlatformGrok {
+						upstream = "grok-4.3"
+					}
+					got := runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+						firstPayload:  `{"type":"response.create","model":"public-alias","input":"hi"}`,
+						secondPayload: `{"type":"response.create","input":"again"}`,
+						group:         compositeWSGroup("public-alias"), accountPlatform: platform, ingressMode: mode,
+						compositeResolver: compositeWSResolver(platform, endpoint, upstream),
+					})
+					require.Len(t, got.upstreamPayloads, 2)
+					for i, payload := range got.upstreamPayloads {
+						require.Equal(t, upstream, gjson.GetBytes(payload, "model").String())
+						require.Equal(t, "public-alias", gjson.GetBytes(got.clientEvents[i], "response.model").String())
+						require.Equal(t, "public-alias", got.logs[i].RequestedModel)
+						require.NotNil(t, got.logs[i].UpstreamModel)
+						require.Equal(t, upstream, *got.logs[i].UpstreamModel)
+					}
+				})
+			}
+		}
+	}
+}
+
+func TestOpenAIResponsesWebSocket_CompositeRouteRejections(t *testing.T) {
+	for _, tc := range []struct {
+		name, platform, endpoint, model, reason string
+		repoErr                                 error
+		status                                  coderws.StatusCode
+	}{
+		{name: "disallowed platform", platform: service.PlatformAnthropic, endpoint: "responses", model: "public-alias", reason: "only supports OpenAI-compatible"},
+		{name: "wrong endpoint", platform: service.PlatformOpenAI, endpoint: "messages", model: "public-alias", reason: "only supports OpenAI-compatible"},
+		{name: "unknown alias", platform: service.PlatformOpenAI, endpoint: "responses", model: "unknown-alias", reason: "only supports OpenAI-compatible"},
+		{name: "resolver error", model: "gpt-5.4", repoErr: errors.New("database unavailable"), reason: "Failed to resolve composite model route", status: coderws.StatusInternalError},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			resolver := compositeWSResolver(tc.platform, tc.endpoint, "gpt-5.4")
+			if tc.repoErr != nil {
+				resolver = service.NewCompositeRouteResolver(&compositeWSRouteRepo{err: tc.repoErr})
+			}
+			runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+				firstPayload: `{"type":"response.create","model":"` + tc.model + `"}`, group: compositeWSGroup(), compositeResolver: resolver,
+				firstFrameCloseExpected: true, closeReason: tc.reason, closeStatus: tc.status,
+			})
+		})
+	}
+}
+
+func TestOpenAIResponsesWebSocket_CompositeAdmissionUsesPublicModel(t *testing.T) {
+	runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+		firstPayload: `{"type":"response.create","model":"public-alias"}`, group: compositeWSGroup("gpt-5.4"),
+		compositeResolver: compositeWSResolver(service.PlatformOpenAI, "responses", "gpt-5.4"), firstFrameCloseExpected: true,
+	})
+}
+
+func TestOpenAIResponsesWebSocket_CompositeModelSwitchRequiresReconnect(t *testing.T) {
+	for _, mode := range []string{service.OpenAIWSIngressModePassthrough, service.OpenAIWSIngressModeDedicated} {
+		for _, model := range []string{"gpt-5.4", "grok-4.3", "unknown-alias"} {
+			t.Run(mode+"/"+model, func(t *testing.T) {
+				runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+					firstPayload:  `{"type":"response.create","model":"public-alias"}`,
+					secondPayload: `{"type":"response.create","model":"` + model + `"}`, group: compositeWSGroup(), ingressMode: mode,
+					compositeResolver:       compositeWSResolver(service.PlatformOpenAI, "responses", "gpt-5.4"),
+					secondTurnCloseExpected: true, closeReason: "model switch requires reconnect",
+				})
+			})
+		}
+	}
+}
+
+func TestOpenAIResponsesWebSocket_CompositeChannelBilling(t *testing.T) {
+	for _, source := range []string{service.BillingModelSourceRequested, service.BillingModelSourceChannelMapped, service.BillingModelSourceUpstream} {
+		t.Run(source, func(t *testing.T) {
+			got := runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+				firstPayload:      `{"type":"response.create","model":"gpt-5.6-sol"}`,
+				secondPayload:     `{"type":"response.create","model":"gpt-5.6-sol"}`,
+				group:             compositeWSGroup("gpt-5.6-sol"),
+				compositeResolver: service.NewCompositeRouteResolver(&compositeWSRouteRepo{routes: []service.CompositeModelRoute{{PublicModel: "gpt-5.6-sol", MatchType: service.CompositeRouteMatchExact, TargetPlatform: service.PlatformOpenAI, Endpoint: service.CompositeRouteEndpointResponses, UpstreamModel: "route-target"}}}),
+				channelMapping:    map[string]string{"route-target": "gpt-5.4"}, billingModelSource: source,
+				accountModelMapping: map[string]any{"gpt-5.4": "gpt-5.4"},
+			})
+			for i, log := range got.logs {
+				require.Equal(t, "gpt-5.4", gjson.GetBytes(got.upstreamPayloads[i], "model").String())
+				require.Equal(t, "gpt-5.6-sol", log.RequestedModel)
+				require.Equal(t, "gpt-5.6-sol", log.Model)
+				if source == service.BillingModelSourceRequested {
+					require.InDelta(t, 40e-6, log.TotalCost, 1e-12)
+				} else {
+					require.InDelta(t, 20e-6, log.TotalCost, 1e-12)
+				}
+			}
+		})
+	}
+}
+
+func TestOpenAIResponsesWebSocket_CompositeDetectorFallback(t *testing.T) {
+	got := runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+		firstPayload: `{"type":"response.create","model":"gpt-5.4"}`, group: compositeWSGroup(),
+		compositeResolver: service.NewCompositeRouteResolver(&compositeWSRouteRepo{}),
+	})
+	require.Equal(t, "gpt-5.4", gjson.GetBytes(got.upstreamFirstPayload, "model").String())
+}
+
+func TestOpenAIResponsesWebSocket_CompositeSessionModelSwitchRequiresReconnect(t *testing.T) {
+	runOpenAIResponsesWebSocketUsageLogCase(t, openAIResponsesWSUsageLogCase{
+		firstPayload:  `{"type":"response.create","model":"public-alias"}`,
+		midPayload:    `{"type":"session.update","session":{"model":"grok-4.3"}}`,
+		secondPayload: `{"type":"response.create"}`, group: compositeWSGroup(),
+		compositeResolver:       compositeWSResolver(service.PlatformOpenAI, "responses", "gpt-5.4"),
+		secondTurnCloseExpected: true, closeReason: "model switch requires reconnect",
+	})
+}

backend/internal/handler/wire.go

@@ -130,10 +130,12 @@ func ProvideOpenAIGatewayHandler(
 	grokQuotaService *service.GrokQuotaService,
 	cfg *config.Config,
 	coordinator *securityaudit.Coordinator,
+	compositeResolver *service.CompositeRouteResolver,
 ) *OpenAIGatewayHandler {
 	gatewayService.SetPluginManager(pluginManager)
 	h := NewOpenAIGatewayHandler(gatewayService, concurrencyService, billingCacheService, apiKeyService,
 		usageRecordWorkerPool, errorPassthroughService, contentModerationService, opsService, cfg)
+	h.compositeResolver = compositeResolver
 	h.securityAuditCoordinator = coordinator
 	h.grokMediaEligibilityProber = grokQuotaService
 	return h

backend/internal/service/openai_ws_forwarder_ingress.go

@@ -585,7 +585,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 		bridgeAccountFailoverInputExists := false
 		for turn := 1; ; turn++ {
 			if turn > 1 && hooks != nil && hooks.BeforeRequest != nil {
-				if err := hooks.BeforeRequest(turn, currentBridgePayload.payloadRaw, currentBridgePayload.originalModel); err != nil {
+				if err := hooks.BeforeRequest(turn, currentBridgePayload.rawForHash, currentBridgePayload.originalModel); err != nil {
 					return err
 				}
 			}
@@ -1272,6 +1272,8 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 	}
 
 	currentPayload := firstPayload.payloadRaw
+	// Admission hooks must see client model candidates before upstream mapping.
+	currentClientPayload := firstPayload.rawForHash
 	currentOriginalModel := firstPayload.originalModel
 	currentImageBillingModel := firstPayload.imageBillingModel
 	currentImageSizeTier := firstPayload.imageSizeTier
@@ -1460,7 +1462,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 	}
 	for {
 		if turn > 1 && !skipBeforeTurn && hooks != nil && hooks.BeforeRequest != nil {
-			if err := hooks.BeforeRequest(turn, currentPayload, currentOriginalModel); err != nil {
+			if err := hooks.BeforeRequest(turn, currentClientPayload, currentOriginalModel); err != nil {
 				return err
 			}
 		}
@@ -1941,6 +1943,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 			}
 		}
 		currentPayload = nextPayload.payloadRaw
+		currentClientPayload = nextPayload.rawForHash
 		currentOriginalModel = nextPayload.originalModel
 		currentImageBillingModel = nextPayload.imageBillingModel
 		currentImageSizeTier = nextPayload.imageSizeTier

docs/COMPOSITE_GROUPS.md

@@ -63,6 +63,13 @@ payloads, and apply the configured `upstream_model` before dispatch.
 Codex model manifest requests reuse the existing OpenAI account selection and
 failover path within the Composite group.
 
+Responses WebSocket resolves the first `response.create` model in the
+`responses` route domain (including `any` routes). Only OpenAI and Grok targets
+are supported. The public model remains the admission and response identity;
+the route's upstream model is applied before channel/account mapping. Subsequent
+turns can repeat or omit the public model. Changing it requires reconnecting so
+the gateway can resolve the route and select an account again.
+
 ## Built-In Detection
 
 Composite routing detects common public model IDs and provider-prefixed IDs: