fix(auth): strip "generate" from payload during WebSocket HTTP fallback

- Added `sanitizeDownstreamWebsocketFallbackRequest` to clean `generate` from payload for HTTP fallback requests.
- Implemented tests to validate payload handling logic in WebSocket-to-HTTP transitions.

Closes: #3556

sdk/api/handlers/openai/openai_responses_websocket_test.go

@@ -77,6 +77,12 @@ type websocketPinnedFailoverExecutor struct {
 	payloads map[string][][]byte
 }
 
+type websocketBootstrapFallbackExecutor struct {
+	mu       sync.Mutex
+	authIDs  []string
+	payloads map[string][][]byte
+}
+
 type websocketPinnedFailoverStatusError struct {
 	status int
 	msg    string
@@ -86,6 +92,70 @@ func (e websocketPinnedFailoverStatusError) Error() string { return e.msg }
 
 func (e websocketPinnedFailoverStatusError) StatusCode() int { return e.status }
 
+func (e *websocketBootstrapFallbackExecutor) Identifier() string { return "test-provider" }
+
+func (e *websocketBootstrapFallbackExecutor) Execute(context.Context, *coreauth.Auth, coreexecutor.Request, coreexecutor.Options) (coreexecutor.Response, error) {
+	return coreexecutor.Response{}, errors.New("not implemented")
+}
+
+func (e *websocketBootstrapFallbackExecutor) ExecuteStream(_ context.Context, auth *coreauth.Auth, req coreexecutor.Request, _ coreexecutor.Options) (*coreexecutor.StreamResult, error) {
+	authID := ""
+	if auth != nil {
+		authID = auth.ID
+	}
+
+	e.mu.Lock()
+	if e.payloads == nil {
+		e.payloads = make(map[string][][]byte)
+	}
+	e.authIDs = append(e.authIDs, authID)
+	e.payloads[authID] = append(e.payloads[authID], bytes.Clone(req.Payload))
+	e.mu.Unlock()
+
+	chunks := make(chan coreexecutor.StreamChunk, 1)
+	if authID == "auth-ws" {
+		chunks <- coreexecutor.StreamChunk{Err: websocketPinnedFailoverStatusError{
+			status: http.StatusServiceUnavailable,
+			msg:    `{"error":{"message":"websocket bootstrap failed","type":"server_error","code":"ws_failed"}}`,
+		}}
+		close(chunks)
+		return &coreexecutor.StreamResult{Chunks: chunks}, nil
+	}
+
+	chunks <- coreexecutor.StreamChunk{Payload: []byte(`{"type":"response.completed","response":{"id":"resp-http","output":[{"type":"message","id":"out-http"}]}}`)}
+	close(chunks)
+	return &coreexecutor.StreamResult{Chunks: chunks}, nil
+}
+
+func (e *websocketBootstrapFallbackExecutor) Refresh(_ context.Context, auth *coreauth.Auth) (*coreauth.Auth, error) {
+	return auth, nil
+}
+
+func (e *websocketBootstrapFallbackExecutor) CountTokens(context.Context, *coreauth.Auth, coreexecutor.Request, coreexecutor.Options) (coreexecutor.Response, error) {
+	return coreexecutor.Response{}, errors.New("not implemented")
+}
+
+func (e *websocketBootstrapFallbackExecutor) HttpRequest(context.Context, *coreauth.Auth, *http.Request) (*http.Response, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (e *websocketBootstrapFallbackExecutor) AuthIDs() []string {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return append([]string(nil), e.authIDs...)
+}
+
+func (e *websocketBootstrapFallbackExecutor) Payloads(authID string) [][]byte {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	src := e.payloads[authID]
+	out := make([][]byte, len(src))
+	for i := range src {
+		out[i] = bytes.Clone(src[i])
+	}
+	return out
+}
+
 type websocketUpstreamDisconnectExecutor struct {
 	mu         sync.Mutex
 	subscribed chan string
@@ -1340,6 +1410,87 @@ func TestResponsesWebsocketPrewarmHandledLocallyForSSEUpstream(t *testing.T) {
 	}
 }
 
+func TestResponsesWebsocketStripsGenerateWhenWebsocketAttemptFallsBackToHTTP(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	selector := &orderedWebsocketSelector{order: []string{"auth-ws", "auth-http"}}
+	executor := &websocketBootstrapFallbackExecutor{}
+	manager := coreauth.NewManager(nil, selector, nil)
+	manager.RegisterExecutor(executor)
+
+	authWS := &coreauth.Auth{
+		ID:         "auth-ws",
+		Provider:   executor.Identifier(),
+		Status:     coreauth.StatusActive,
+		Attributes: map[string]string{"websockets": "true"},
+	}
+	if _, err := manager.Register(context.Background(), authWS); err != nil {
+		t.Fatalf("Register websocket auth: %v", err)
+	}
+	authHTTP := &coreauth.Auth{ID: "auth-http", Provider: executor.Identifier(), Status: coreauth.StatusActive}
+	if _, err := manager.Register(context.Background(), authHTTP); err != nil {
+		t.Fatalf("Register HTTP auth: %v", err)
+	}
+
+	registry.GetGlobalRegistry().RegisterClient(authWS.ID, authWS.Provider, []*registry.ModelInfo{{ID: "test-model"}})
+	registry.GetGlobalRegistry().RegisterClient(authHTTP.ID, authHTTP.Provider, []*registry.ModelInfo{{ID: "test-model"}})
+	t.Cleanup(func() {
+		registry.GetGlobalRegistry().UnregisterClient(authWS.ID)
+		registry.GetGlobalRegistry().UnregisterClient(authHTTP.ID)
+	})
+
+	base := handlers.NewBaseAPIHandlers(&sdkconfig.SDKConfig{}, manager)
+	h := NewOpenAIResponsesAPIHandler(base)
+	router := gin.New()
+	router.GET("/v1/responses/ws", h.ResponsesWebsocket)
+
+	server := httptest.NewServer(router)
+	defer server.Close()
+
+	wsURL := "ws" + strings.TrimPrefix(server.URL, "http") + "/v1/responses/ws"
+	conn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
+	if err != nil {
+		t.Fatalf("dial websocket: %v", err)
+	}
+	defer func() {
+		if errClose := conn.Close(); errClose != nil {
+			t.Fatalf("close websocket: %v", errClose)
+		}
+	}()
+
+	request := `{"type":"response.create","model":"test-model","generate":false,"input":[{"type":"message","id":"msg-1"}]}`
+	if errWrite := conn.WriteMessage(websocket.TextMessage, []byte(request)); errWrite != nil {
+		t.Fatalf("write websocket message: %v", errWrite)
+	}
+	_, payload, errReadMessage := conn.ReadMessage()
+	if errReadMessage != nil {
+		t.Fatalf("read websocket message: %v", errReadMessage)
+	}
+	if got := gjson.GetBytes(payload, "type").String(); got != wsEventTypeCompleted {
+		t.Fatalf("payload type = %s, want %s: %s", got, wsEventTypeCompleted, payload)
+	}
+
+	if got := executor.AuthIDs(); len(got) != 2 || got[0] != "auth-ws" || got[1] != "auth-http" {
+		t.Fatalf("selected auth IDs = %v, want [auth-ws auth-http]", got)
+	}
+
+	wsPayloads := executor.Payloads("auth-ws")
+	if len(wsPayloads) != 1 {
+		t.Fatalf("auth-ws payload count = %d, want 1", len(wsPayloads))
+	}
+	if !gjson.GetBytes(wsPayloads[0], "generate").Exists() {
+		t.Fatalf("websocket attempt payload unexpectedly stripped generate: %s", wsPayloads[0])
+	}
+
+	httpPayloads := executor.Payloads("auth-http")
+	if len(httpPayloads) != 1 {
+		t.Fatalf("auth-http payload count = %d, want 1", len(httpPayloads))
+	}
+	if gjson.GetBytes(httpPayloads[0], "generate").Exists() {
+		t.Fatalf("generate leaked after HTTP fallback: %s", httpPayloads[0])
+	}
+}
+
 func TestWebsocketClientAddressUsesGinClientIP(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 

sdk/cliproxy/auth/conductor.go

@@ -25,6 +25,7 @@ import (
 	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/executor"
 	coreusage "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/usage"
 	log "github.com/sirupsen/logrus"
+	"github.com/tidwall/sjson"
 )
 
 // ProviderExecutor defines the contract required by Manager to execute provider calls.
@@ -1581,7 +1582,8 @@ func (m *Manager) executeStreamMixedOnce(ctx context.Context, providers []string
 			lastErr = errPrepare
 			continue
 		}
-		streamResult, errStream := m.executeStreamWithModelPool(execCtx, executor, auth, provider, req, opts, routeModel, models, pooled)
+		execReq := sanitizeDownstreamWebsocketFallbackRequest(execCtx, auth, req)
+		streamResult, errStream := m.executeStreamWithModelPool(execCtx, executor, auth, provider, execReq, opts, routeModel, models, pooled)
 		if errStream != nil {
 			if errCtx := execCtx.Err(); errCtx != nil {
 				return nil, errCtx
@@ -1599,6 +1601,18 @@ func (m *Manager) executeStreamMixedOnce(ctx context.Context, providers []string
 	}
 }
 
+func sanitizeDownstreamWebsocketFallbackRequest(ctx context.Context, auth *Auth, req cliproxyexecutor.Request) cliproxyexecutor.Request {
+	if !cliproxyexecutor.DownstreamWebsocket(ctx) || authWebsocketsEnabled(auth) || len(req.Payload) == 0 {
+		return req
+	}
+	updated, errDelete := sjson.DeleteBytes(req.Payload, "generate")
+	if errDelete != nil {
+		return req
+	}
+	req.Payload = updated
+	return req
+}
+
 func ensureRequestedModelMetadata(opts cliproxyexecutor.Options, requestedModel string) cliproxyexecutor.Options {
 	requestedModel = strings.TrimSpace(requestedModel)
 	if requestedModel == "" {