fix(openai): gate Codex image bridge injection

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/internal/config/config.go

@@ -611,6 +611,9 @@ type GatewayConfig struct {
 	// ForceCodexCLI: 强制将 OpenAI `/v1/responses` 请求按 Codex CLI 处理。
 	// 用于网关未透传/改写 User-Agent 时的兼容兜底（默认关闭，避免影响其他客户端）。
 	ForceCodexCLI bool `mapstructure:"force_codex_cli"`
+	// CodexImageGenerationBridgeEnabled: 是否为 Codex `/v1/responses` 自动注入 image_generation 工具和桥接指令。
+	// 默认关闭，避免纯文本 Codex 请求被意外改写；显式携带 image_generation 工具的请求仍按分组能力转发。
+	CodexImageGenerationBridgeEnabled bool `mapstructure:"codex_image_generation_bridge_enabled"`
 	// ForcedCodexInstructionsTemplateFile: 服务端强制附加到 Codex 顶层 instructions 的模板文件路径。
 	// 模板渲染后会直接覆盖最终 instructions；若需要保留客户端 system 转换结果，请在模板中显式引用 {{ .ExistingInstructions }}。
 	ForcedCodexInstructionsTemplateFile string `mapstructure:"forced_codex_instructions_template_file"`
@@ -1649,6 +1652,7 @@ func setDefaults() {
 	viper.SetDefault("gateway.max_account_switches", 10)
 	viper.SetDefault("gateway.max_account_switches_gemini", 3)
 	viper.SetDefault("gateway.force_codex_cli", false)
+	viper.SetDefault("gateway.codex_image_generation_bridge_enabled", false)
 	viper.SetDefault("gateway.openai_passthrough_allow_timeout_headers", false)
 	// OpenAI Responses WebSocket（默认开启；可通过 force_http 紧急回滚）
 	viper.SetDefault("gateway.openai_ws.enabled", true)

backend/internal/service/codex_image_generation_bridge.go

@@ -0,0 +1,64 @@
+package service
+
+import "strings"
+
+const featureKeyCodexImageGenerationBridge = "codex_image_generation_bridge"
+
+func boolOverridePtr(v bool) *bool {
+	return &v
+}
+
+func boolOverrideFromMap(values map[string]any, keys ...string) *bool {
+	if values == nil {
+		return nil
+	}
+	for _, key := range keys {
+		if v, ok := values[key].(bool); ok {
+			return boolOverridePtr(v)
+		}
+	}
+	return nil
+}
+
+func platformBoolOverride(values map[string]any, key string, platform string) *bool {
+	if values == nil {
+		return nil
+	}
+	if v, ok := values[key].(bool); ok {
+		return boolOverridePtr(v)
+	}
+	raw, ok := values[key].(map[string]any)
+	if !ok {
+		return nil
+	}
+	platform = strings.TrimSpace(platform)
+	if platform == "" {
+		return nil
+	}
+	if v, ok := raw[platform].(bool); ok {
+		return boolOverridePtr(v)
+	}
+	return nil
+}
+
+// CodexImageGenerationBridgeOverride returns the channel-level override for Codex
+// image_generation bridge injection. Nil means follow the global/account policy.
+func (c *Channel) CodexImageGenerationBridgeOverride(platform string) *bool {
+	if c == nil {
+		return nil
+	}
+	return platformBoolOverride(c.FeaturesConfig, featureKeyCodexImageGenerationBridge, platform)
+}
+
+// CodexImageGenerationBridgeOverride returns the account-level override for Codex
+// image_generation bridge injection. Nil means follow the channel/global policy.
+func (a *Account) CodexImageGenerationBridgeOverride() *bool {
+	if a == nil || a.Platform != PlatformOpenAI || a.Extra == nil {
+		return nil
+	}
+	if override := boolOverrideFromMap(a.Extra, featureKeyCodexImageGenerationBridge, "codex_image_generation_bridge_enabled"); override != nil {
+		return override
+	}
+	openaiConfig, _ := a.Extra[PlatformOpenAI].(map[string]any)
+	return boolOverrideFromMap(openaiConfig, featureKeyCodexImageGenerationBridge, "codex_image_generation_bridge_enabled")
+}

backend/internal/service/openai_gateway_service.go

@@ -440,6 +440,21 @@ func (s *OpenAIGatewayService) ResolveChannelMappingAndRestrict(ctx context.Cont
 	return s.channelService.ResolveChannelMappingAndRestrict(ctx, groupID, model)
 }
 
+func (s *OpenAIGatewayService) isCodexImageGenerationBridgeEnabled(ctx context.Context, account *Account, apiKey *APIKey) bool {
+	if override := account.CodexImageGenerationBridgeOverride(); override != nil {
+		return *override
+	}
+	if s != nil && s.channelService != nil && apiKey != nil && apiKey.GroupID != nil {
+		ch, err := s.channelService.GetChannelForGroup(ctx, *apiKey.GroupID)
+		if err != nil {
+			slog.Warn("failed to resolve codex image generation bridge channel override", "group_id", *apiKey.GroupID, "error", err)
+		} else if override := ch.CodexImageGenerationBridgeOverride(PlatformOpenAI); override != nil {
+			return *override
+		}
+	}
+	return s != nil && s.cfg != nil && s.cfg.Gateway.CodexImageGenerationBridgeEnabled
+}
+
 func (s *OpenAIGatewayService) checkChannelPricingRestriction(ctx context.Context, groupID *int64, requestedModel string) bool {
 	if groupID == nil || s.channelService == nil || requestedModel == "" {
 		return false
@@ -2059,6 +2074,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 	if apiKey != nil {
 		imageGenerationAllowed = GroupAllowsImageGeneration(apiKey.Group)
 	}
+	codexImageGenerationBridgeEnabled := isCodexCLI && imageGenerationAllowed && s.isCodexImageGenerationBridgeEnabled(ctx, account, apiKey)
 	if IsImageGenerationIntentMap(openAIResponsesEndpoint, reqModel, reqBody) && !imageGenerationAllowed {
 		setOpsUpstreamError(c, http.StatusForbidden, ImageGenerationPermissionMessage(), "")
 		c.JSON(http.StatusForbidden, gin.H{
@@ -2128,7 +2144,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		markPatchSet("instructions", "You are a helpful coding assistant.")
 	}
 
-	if isCodexCLI && imageGenerationAllowed && ensureOpenAIResponsesImageGenerationTool(reqBody) {
+	if codexImageGenerationBridgeEnabled && ensureOpenAIResponsesImageGenerationTool(reqBody) {
 		bodyModified = true
 		disablePatch()
 		logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Injected /responses image_generation tool for Codex client")
@@ -2139,7 +2155,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		disablePatch()
 		logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Normalized /responses image_generation tool payload")
 	}
-	if isCodexCLI && imageGenerationAllowed && applyCodexImageGenerationBridgeInstructions(reqBody) {
+	if codexImageGenerationBridgeEnabled && applyCodexImageGenerationBridgeInstructions(reqBody) {
 		bodyModified = true
 		disablePatch()
 		logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Added Codex image_generation bridge instructions")

backend/internal/service/openai_image_generation_controls_test.go

@@ -83,12 +83,14 @@ func TestOpenAIGatewayServiceForward_CodexImageInjectionRespectsGroupCapability(
 	gin.SetMode(gin.TestMode)
 
 	tests := []struct {
-		name         string
-		allowImages  bool
-		wantInjected bool
+		name          string
+		allowImages   bool
+		bridgeEnabled bool
+		wantInjected  bool
 	}{
-		{name: "disabled group skips injection", allowImages: false, wantInjected: false},
-		{name: "enabled group injects image tool", allowImages: true, wantInjected: true},
+		{name: "disabled group skips injection", allowImages: false, bridgeEnabled: true, wantInjected: false},
+		{name: "enabled group skips injection by default", allowImages: true, bridgeEnabled: false, wantInjected: false},
+		{name: "enabled group injects image tool when bridge enabled", allowImages: true, bridgeEnabled: true, wantInjected: true},
 	}
 
 	for _, tt := range tests {
@@ -101,6 +103,7 @@ func TestOpenAIGatewayServiceForward_CodexImageInjectionRespectsGroupCapability(
 				},
 			}
 			svc := newOpenAIImageGenerationControlTestService(upstream)
+			svc.cfg.Gateway.CodexImageGenerationBridgeEnabled = tt.bridgeEnabled
 			c, _ := newOpenAIImageGenerationControlTestContext(tt.allowImages, "codex_cli_rs/0.98.0")
 			account := newOpenAIImageGenerationControlTestAccount()
 
@@ -117,6 +120,154 @@ func TestOpenAIGatewayServiceForward_CodexImageInjectionRespectsGroupCapability(
 	}
 }
 
+func TestOpenAIGatewayServiceForward_ExplicitImageToolWorksWithBridgeDisabled(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	upstream := &httpUpstreamRecorder{
+		resp: &http.Response{
+			StatusCode: http.StatusOK,
+			Header:     http.Header{"Content-Type": []string{"application/json"}},
+			Body:       io.NopCloser(strings.NewReader(`{"id":"resp_explicit_image","model":"gpt-5.4","usage":{"input_tokens":2,"output_tokens":1}}`)),
+		},
+	}
+	svc := newOpenAIImageGenerationControlTestService(upstream)
+	c, _ := newOpenAIImageGenerationControlTestContext(true, "codex_cli_rs/0.98.0")
+	account := newOpenAIImageGenerationControlTestAccount()
+	body := []byte(`{"model":"gpt-5.4","input":"draw","stream":false,"tools":[{"type":"image_generation","format":"jpeg"}]}`)
+
+	result, err := svc.Forward(context.Background(), c, account, body)
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, upstream.lastReq)
+	require.True(t, gjson.GetBytes(upstream.lastBody, `tools.#(type=="image_generation")`).Exists())
+	require.Equal(t, "jpeg", gjson.GetBytes(upstream.lastBody, `tools.#(type=="image_generation").output_format`).String())
+	require.False(t, gjson.GetBytes(upstream.lastBody, `tools.#(type=="image_generation").format`).Exists())
+	instructions := gjson.GetBytes(upstream.lastBody, "instructions").String()
+	require.NotContains(t, instructions, "image_generation")
+}
+
+func TestOpenAIGatewayServiceForward_ChannelBridgeOverrideEnablesCodexInjection(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	upstream := &httpUpstreamRecorder{
+		resp: &http.Response{
+			StatusCode: http.StatusOK,
+			Header:     http.Header{"Content-Type": []string{"application/json"}},
+			Body:       io.NopCloser(strings.NewReader(`{"id":"resp_channel_bridge","model":"gpt-5.4","usage":{"input_tokens":1,"output_tokens":1}}`)),
+		},
+	}
+	svc := newOpenAIImageGenerationControlTestService(upstream)
+	groupID := int64(4242)
+	svc.channelService = newOpenAIImageGenerationControlChannelService(groupID, &Channel{
+		ID:     9001,
+		Status: StatusActive,
+		FeaturesConfig: map[string]any{
+			featureKeyCodexImageGenerationBridge: map[string]any{PlatformOpenAI: true},
+		},
+	})
+	c, _ := newOpenAIImageGenerationControlTestContext(true, "codex_cli_rs/0.98.0")
+	account := newOpenAIImageGenerationControlTestAccount()
+
+	result, err := svc.Forward(context.Background(), c, account, []byte(`{"model":"gpt-5.4","input":"write code","stream":false}`))
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, upstream.lastReq)
+	require.True(t, gjson.GetBytes(upstream.lastBody, `tools.#(type=="image_generation")`).Exists())
+	instructions := gjson.GetBytes(upstream.lastBody, "instructions").String()
+	require.Contains(t, instructions, "image_generation")
+}
+
+func TestOpenAIGatewayService_CodexImageGenerationBridgeOverridePrecedence(t *testing.T) {
+	groupID := int64(4242)
+
+	tests := []struct {
+		name    string
+		global  bool
+		channel *Channel
+		account *Account
+		want    bool
+	}{
+		{
+			name:   "global default enables bridge",
+			global: true,
+			account: &Account{
+				Platform: PlatformOpenAI,
+			},
+			want: true,
+		},
+		{
+			name:   "channel true overrides disabled global",
+			global: false,
+			channel: &Channel{ID: 1, Status: StatusActive, FeaturesConfig: map[string]any{
+				featureKeyCodexImageGenerationBridge: map[string]any{PlatformOpenAI: true},
+			}},
+			account: &Account{Platform: PlatformOpenAI},
+			want:    true,
+		},
+		{
+			name:   "channel false overrides enabled global",
+			global: true,
+			channel: &Channel{ID: 1, Status: StatusActive, FeaturesConfig: map[string]any{
+				featureKeyCodexImageGenerationBridge: map[string]any{PlatformOpenAI: false},
+			}},
+			account: &Account{Platform: PlatformOpenAI},
+			want:    false,
+		},
+		{
+			name:   "account false overrides channel and global true",
+			global: true,
+			channel: &Channel{ID: 1, Status: StatusActive, FeaturesConfig: map[string]any{
+				featureKeyCodexImageGenerationBridge: map[string]any{PlatformOpenAI: true},
+			}},
+			account: &Account{
+				Platform: PlatformOpenAI,
+				Extra:    map[string]any{featureKeyCodexImageGenerationBridge: false},
+			},
+			want: false,
+		},
+		{
+			name:   "nested account true overrides channel false",
+			global: false,
+			channel: &Channel{ID: 1, Status: StatusActive, FeaturesConfig: map[string]any{
+				featureKeyCodexImageGenerationBridge: map[string]any{PlatformOpenAI: false},
+			}},
+			account: &Account{
+				Platform: PlatformOpenAI,
+				Extra: map[string]any{
+					PlatformOpenAI: map[string]any{"codex_image_generation_bridge_enabled": true},
+				},
+			},
+			want: true,
+		},
+		{
+			name:   "non openai account extra is ignored",
+			global: false,
+			account: &Account{
+				Platform: PlatformAnthropic,
+				Extra:    map[string]any{featureKeyCodexImageGenerationBridge: true},
+			},
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			svc := newOpenAIImageGenerationControlTestService(&httpUpstreamRecorder{})
+			svc.cfg.Gateway.CodexImageGenerationBridgeEnabled = tt.global
+			if tt.channel != nil {
+				svc.channelService = newOpenAIImageGenerationControlChannelService(groupID, tt.channel)
+			}
+			apiKey := &APIKey{GroupID: &groupID}
+
+			got := svc.isCodexImageGenerationBridgeEnabled(context.Background(), tt.account, apiKey)
+
+			require.Equal(t, tt.want, got)
+		})
+	}
+}
+
 func TestOpenAIGatewayServiceHandleResponsesImageOutputs_NonStreaming(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 
@@ -180,6 +331,18 @@ func newOpenAIImageGenerationControlTestService(upstream *httpUpstreamRecorder)
 	}
 }
 
+func newOpenAIImageGenerationControlChannelService(groupID int64, ch *Channel) *ChannelService {
+	svc := &ChannelService{}
+	cache := newEmptyChannelCache()
+	if ch != nil {
+		cache.channelByGroupID[groupID] = ch
+		cache.byID[ch.ID] = ch
+	}
+	cache.loadedAt = time.Now()
+	svc.cache.Store(cache)
+	return svc
+}
+
 func newOpenAIImageGenerationControlTestContext(allowImages bool, userAgent string) (*gin.Context, *httptest.ResponseRecorder) {
 	recorder := httptest.NewRecorder()
 	c, _ := gin.CreateTestContext(recorder)