Merge branch 'Wei-Shaw:main' into rebuild/auth-identity-foundation

backend/internal/handler/endpoint.go

@@ -18,6 +18,8 @@ const (
 	EndpointMessages          = "/v1/messages"
 	EndpointChatCompletions   = "/v1/chat/completions"
 	EndpointResponses         = "/v1/responses"
+	EndpointImagesGenerations = "/v1/images/generations"
+	EndpointImagesEdits       = "/v1/images/edits"
 	EndpointGeminiModels      = "/v1beta/models"
 )
 
@@ -44,6 +46,10 @@ func NormalizeInboundEndpoint(path string) string {
 		return EndpointChatCompletions
 	case strings.Contains(path, EndpointMessages):
 		return EndpointMessages
+	case strings.Contains(path, EndpointImagesGenerations) || strings.Contains(path, "/images/generations"):
+		return EndpointImagesGenerations
+	case strings.Contains(path, EndpointImagesEdits) || strings.Contains(path, "/images/edits"):
+		return EndpointImagesEdits
 	case strings.Contains(path, EndpointResponses):
 		return EndpointResponses
 	case strings.Contains(path, EndpointGeminiModels):
@@ -69,6 +75,9 @@ func DeriveUpstreamEndpoint(inbound, rawRequestPath, platform string) string {
 
 	switch platform {
 	case service.PlatformOpenAI:
+		if inbound == EndpointImagesGenerations || inbound == EndpointImagesEdits {
+			return inbound
+		}
 		// OpenAI forwards everything to the Responses API.
 		// Preserve subresource suffix (e.g. /v1/responses/compact).
 		if suffix := responsesSubpathSuffix(rawRequestPath); suffix != "" {

backend/internal/handler/endpoint_test.go

@@ -25,12 +25,16 @@ func TestNormalizeInboundEndpoint(t *testing.T) {
 		{"/v1/messages", EndpointMessages},
 		{"/v1/chat/completions", EndpointChatCompletions},
 		{"/v1/responses", EndpointResponses},
+		{"/v1/images/generations", EndpointImagesGenerations},
+		{"/v1/images/edits", EndpointImagesEdits},
 		{"/v1beta/models", EndpointGeminiModels},
 
 		// Prefixed paths (antigravity, openai).
 		{"/antigravity/v1/messages", EndpointMessages},
 		{"/openai/v1/responses", EndpointResponses},
 		{"/openai/v1/responses/compact", EndpointResponses},
+		{"/openai/v1/images/generations", EndpointImagesGenerations},
+		{"/openai/v1/images/edits", EndpointImagesEdits},
 		{"/antigravity/v1beta/models/gemini:generateContent", EndpointGeminiModels},
 
 		// Gin route patterns with wildcards.
@@ -73,6 +77,8 @@ func TestDeriveUpstreamEndpoint(t *testing.T) {
 		{"openai responses nested", EndpointResponses, "/openai/v1/responses/compact/detail", service.PlatformOpenAI, "/v1/responses/compact/detail"},
 		{"openai from messages", EndpointMessages, "/v1/messages", service.PlatformOpenAI, EndpointResponses},
 		{"openai from completions", EndpointChatCompletions, "/v1/chat/completions", service.PlatformOpenAI, EndpointResponses},
+		{"openai image generations", EndpointImagesGenerations, "/v1/images/generations", service.PlatformOpenAI, EndpointImagesGenerations},
+		{"openai image edits", EndpointImagesEdits, "/openai/v1/images/edits", service.PlatformOpenAI, EndpointImagesEdits},
 
 		// Antigravity — uses inbound to pick Claude vs Gemini upstream.
 		{"antigravity claude", EndpointMessages, "/antigravity/v1/messages", service.PlatformAntigravity, EndpointMessages},

backend/internal/handler/openai_images.go

+package handler
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strings"
+	"time"
+
+	pkghttputil "github.com/Wei-Shaw/sub2api/internal/pkg/httputil"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/ip"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
+	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+	"go.uber.org/zap"
+)
+
+// Images handles OpenAI Images API requests.
+// POST /v1/images/generations
+// POST /v1/images/edits
+func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
+	streamStarted := false
+	defer h.recoverResponsesPanic(c, &streamStarted)
+
+	requestStart := time.Now()
+
+	apiKey, ok := middleware2.GetAPIKeyFromContext(c)
+	if !ok {
+		h.errorResponse(c, http.StatusUnauthorized, "authentication_error", "Invalid API key")
+		return
+	}
+
+	subject, ok := middleware2.GetAuthSubjectFromContext(c)
+	if !ok {
+		h.errorResponse(c, http.StatusInternalServerError, "api_error", "User context not found")
+		return
+	}
+	reqLog := requestLogger(
+		c,
+		"handler.openai_gateway.images",
+		zap.Int64("user_id", subject.UserID),
+		zap.Int64("api_key_id", apiKey.ID),
+		zap.Any("group_id", apiKey.GroupID),
+	)
+	if !h.ensureResponsesDependencies(c, reqLog) {
+		return
+	}
+
+	body, err := pkghttputil.ReadRequestBodyWithPrealloc(c.Request)
+	if err != nil {
+		if maxErr, ok := extractMaxBytesError(err); ok {
+			h.errorResponse(c, http.StatusRequestEntityTooLarge, "invalid_request_error", buildBodyTooLargeMessage(maxErr.Limit))
+			return
+		}
+		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", "Failed to read request body")
+		return
+	}
+	if len(body) == 0 {
+		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", "Request body is empty")
+		return
+	}
+
+	if isMultipartImagesContentType(c.GetHeader("Content-Type")) {
+		setOpsRequestContext(c, "", false, nil)
+	} else {
+		setOpsRequestContext(c, "", false, body)
+	}
+
+	parsed, err := h.gatewayService.ParseOpenAIImagesRequest(c, body)
+	if err != nil {
+		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", err.Error())
+		return
+	}
+
+	reqLog = reqLog.With(
+		zap.String("model", parsed.Model),
+		zap.Bool("stream", parsed.Stream),
+		zap.Bool("multipart", parsed.Multipart),
+		zap.String("capability", string(parsed.RequiredCapability)),
+	)
+
+	if parsed.Multipart {
+		setOpsRequestContext(c, parsed.Model, parsed.Stream, nil)
+	} else {
+		setOpsRequestContext(c, parsed.Model, parsed.Stream, body)
+	}
+	setOpsEndpointContext(c, "", int16(service.RequestTypeFromLegacy(parsed.Stream, false)))
+
+	channelMapping, _ := h.gatewayService.ResolveChannelMappingAndRestrict(c.Request.Context(), apiKey.GroupID, parsed.Model)
+
+	if h.errorPassthroughService != nil {
+		service.BindErrorPassthroughService(c, h.errorPassthroughService)
+	}
+
+	subscription, _ := middleware2.GetSubscriptionFromContext(c)
+
+	service.SetOpsLatencyMs(c, service.OpsAuthLatencyMsKey, time.Since(requestStart).Milliseconds())
+	routingStart := time.Now()
+
+	userReleaseFunc, acquired := h.acquireResponsesUserSlot(c, subject.UserID, subject.Concurrency, parsed.Stream, &streamStarted, reqLog)
+	if !acquired {
+		return
+	}
+	if userReleaseFunc != nil {
+		defer userReleaseFunc()
+	}
+
+	if err := h.billingCacheService.CheckBillingEligibility(c.Request.Context(), apiKey.User, apiKey, apiKey.Group, subscription); err != nil {
+		reqLog.Info("openai.images.billing_eligibility_check_failed", zap.Error(err))
+		status, code, message := billingErrorDetails(err)
+		h.handleStreamingAwareError(c, status, code, message, streamStarted)
+		return
+	}
+
+	sessionHash := ""
+	if parsed.Multipart {
+		sessionHash = h.gatewayService.GenerateSessionHashWithFallback(c, nil, parsed.StickySessionSeed())
+	} else {
+		sessionHash = h.gatewayService.GenerateSessionHash(c, body)
+	}
+
+	maxAccountSwitches := h.maxAccountSwitches
+	switchCount := 0
+	failedAccountIDs := make(map[int64]struct{})
+	sameAccountRetryCount := make(map[int64]int)
+	var lastFailoverErr *service.UpstreamFailoverError
+
+	for {
+		reqLog.Debug("openai.images.account_selecting", zap.Int("excluded_account_count", len(failedAccountIDs)))
+		selection, scheduleDecision, err := h.gatewayService.SelectAccountWithSchedulerForImages(
+			c.Request.Context(),
+			apiKey.GroupID,
+			sessionHash,
+			parsed.Model,
+			failedAccountIDs,
+			parsed.RequiredCapability,
+		)
+		if err != nil {
+			reqLog.Warn("openai.images.account_select_failed",
+				zap.Error(err),
+				zap.Int("excluded_account_count", len(failedAccountIDs)),
+			)
+			if len(failedAccountIDs) == 0 {
+				h.handleStreamingAwareError(c, http.StatusServiceUnavailable, "api_error", "No available compatible accounts", streamStarted)
+				return
+			}
+			if lastFailoverErr != nil {
+				h.handleFailoverExhausted(c, lastFailoverErr, streamStarted)
+			} else {
+				h.handleFailoverExhaustedSimple(c, 502, streamStarted)
+			}
+			return
+		}
+		if selection == nil || selection.Account == nil {
+			h.handleStreamingAwareError(c, http.StatusServiceUnavailable, "api_error", "No available compatible accounts", streamStarted)
+			return
+		}
+
+		reqLog.Debug("openai.images.account_schedule_decision",
+			zap.String("layer", scheduleDecision.Layer),
+			zap.Bool("sticky_session_hit", scheduleDecision.StickySessionHit),
+			zap.Int("candidate_count", scheduleDecision.CandidateCount),
+			zap.Int("top_k", scheduleDecision.TopK),
+			zap.Int64("latency_ms", scheduleDecision.LatencyMs),
+			zap.Float64("load_skew", scheduleDecision.LoadSkew),
+		)
+
+		account := selection.Account
+		sessionHash = ensureOpenAIPoolModeSessionHash(sessionHash, account)
+		reqLog.Debug("openai.images.account_selected", zap.Int64("account_id", account.ID), zap.String("account_name", account.Name))
+		setOpsSelectedAccount(c, account.ID, account.Platform)
+
+		accountReleaseFunc, acquired := h.acquireResponsesAccountSlot(c, apiKey.GroupID, sessionHash, selection, parsed.Stream, &streamStarted, reqLog)
+		if !acquired {
+			return
+		}
+
+		service.SetOpsLatencyMs(c, service.OpsRoutingLatencyMsKey, time.Since(routingStart).Milliseconds())
+		forwardStart := time.Now()
+		result, err := h.gatewayService.ForwardImages(c.Request.Context(), c, account, body, parsed, channelMapping.MappedModel)
+		forwardDurationMs := time.Since(forwardStart).Milliseconds()
+		if accountReleaseFunc != nil {
+			accountReleaseFunc()
+		}
+		upstreamLatencyMs, _ := getContextInt64(c, service.OpsUpstreamLatencyMsKey)
+		responseLatencyMs := forwardDurationMs
+		if upstreamLatencyMs > 0 && forwardDurationMs > upstreamLatencyMs {
+			responseLatencyMs = forwardDurationMs - upstreamLatencyMs
+		}
+		service.SetOpsLatencyMs(c, service.OpsResponseLatencyMsKey, responseLatencyMs)
+		if err == nil && result != nil && result.FirstTokenMs != nil {
+			service.SetOpsLatencyMs(c, service.OpsTimeToFirstTokenMsKey, int64(*result.FirstTokenMs))
+		}
+		if err != nil {
+			var failoverErr *service.UpstreamFailoverError
+			if errors.As(err, &failoverErr) {
+				h.gatewayService.ReportOpenAIAccountScheduleResult(account.ID, false, nil)
+				if failoverErr.RetryableOnSameAccount {
+					retryLimit := account.GetPoolModeRetryCount()
+					if sameAccountRetryCount[account.ID] < retryLimit {
+						sameAccountRetryCount[account.ID]++
+						reqLog.Warn("openai.images.pool_mode_same_account_retry",
+							zap.Int64("account_id", account.ID),
+							zap.Int("upstream_status", failoverErr.StatusCode),
+							zap.Int("retry_limit", retryLimit),
+							zap.Int("retry_count", sameAccountRetryCount[account.ID]),
+						)
+						select {
+						case <-c.Request.Context().Done():
+							return
+						case <-time.After(sameAccountRetryDelay):
+						}
+						continue
+					}
+				}
+				h.gatewayService.RecordOpenAIAccountSwitch()
+				failedAccountIDs[account.ID] = struct{}{}
+				lastFailoverErr = failoverErr
+				if switchCount >= maxAccountSwitches {
+					h.handleFailoverExhausted(c, failoverErr, streamStarted)
+					return
+				}
+				switchCount++
+				reqLog.Warn("openai.images.upstream_failover_switching",
+					zap.Int64("account_id", account.ID),
+					zap.Int("upstream_status", failoverErr.StatusCode),
+					zap.Int("switch_count", switchCount),
+					zap.Int("max_switches", maxAccountSwitches),
+				)
+				continue
+			}
+			h.gatewayService.ReportOpenAIAccountScheduleResult(account.ID, false, nil)
+			wroteFallback := h.ensureForwardErrorResponse(c, streamStarted)
+			fields := []zap.Field{
+				zap.Int64("account_id", account.ID),
+				zap.Bool("fallback_error_response_written", wroteFallback),
+				zap.Error(err),
+			}
+			if shouldLogOpenAIForwardFailureAsWarn(c, wroteFallback) {
+				reqLog.Warn("openai.images.forward_failed", fields...)
+				return
+			}
+			reqLog.Error("openai.images.forward_failed", fields...)
+			return
+		}
+
+		if result != nil {
+			if account.Type == service.AccountTypeOAuth {
+				h.gatewayService.UpdateCodexUsageSnapshotFromHeaders(c.Request.Context(), account.ID, result.ResponseHeaders)
+			}
+			h.gatewayService.ReportOpenAIAccountScheduleResult(account.ID, true, result.FirstTokenMs)
+		} else {
+			h.gatewayService.ReportOpenAIAccountScheduleResult(account.ID, true, nil)
+		}
+
+		userAgent := c.GetHeader("User-Agent")
+		clientIP := ip.GetClientIP(c)
+		requestPayloadHash := service.HashUsageRequestPayload(body)
+		if parsed.Multipart {
+			requestPayloadHash = service.HashUsageRequestPayload([]byte(parsed.StickySessionSeed()))
+		}
+
+		h.submitUsageRecordTask(func(ctx context.Context) {
+			if err := h.gatewayService.RecordUsage(ctx, &service.OpenAIRecordUsageInput{
+				Result:             result,
+				APIKey:             apiKey,
+				User:               apiKey.User,
+				Account:            account,
+				Subscription:       subscription,
+				InboundEndpoint:    GetInboundEndpoint(c),
+				UpstreamEndpoint:   GetUpstreamEndpoint(c, account.Platform),
+				UserAgent:          userAgent,
+				IPAddress:          clientIP,
+				RequestPayloadHash: requestPayloadHash,
+				APIKeyService:      h.apiKeyService,
+				ChannelUsageFields: channelMapping.ToUsageFields(parsed.Model, result.UpstreamModel),
+			}); err != nil {
+				logger.L().With(
+					zap.String("component", "handler.openai_gateway.images"),
+					zap.Int64("user_id", subject.UserID),
+					zap.Int64("api_key_id", apiKey.ID),
+					zap.Any("group_id", apiKey.GroupID),
+					zap.String("model", parsed.Model),
+					zap.Int64("account_id", account.ID),
+				).Error("openai.images.record_usage_failed", zap.Error(err))
+			}
+		})
+
+		reqLog.Debug("openai.images.request_completed",
+			zap.Int64("account_id", account.ID),
+			zap.Int("switch_count", switchCount),
+		)
+		return
+	}
+}
+
+func isMultipartImagesContentType(contentType string) bool {
+	return strings.HasPrefix(strings.ToLower(strings.TrimSpace(contentType)), "multipart/form-data")
+}

backend/internal/handler/ops_error_logger.go

@@ -1068,7 +1068,7 @@ func guessPlatformFromPath(path string) string {
 		return service.PlatformAntigravity
 	case strings.HasPrefix(p, "/v1beta/"):
 		return service.PlatformGemini
-	case strings.Contains(p, "/responses"):
+	case strings.Contains(p, "/responses"), strings.Contains(p, "/images/"):
 		return service.PlatformOpenAI
 	default:
 		return ""

backend/internal/pkg/openai/constants.go

@@ -20,6 +20,7 @@ var DefaultModels = []Model{
 	{ID: "gpt-5.3-codex", Object: "model", Created: 1735689600, OwnedBy: "openai", Type: "model", DisplayName: "GPT-5.3 Codex"},
 	{ID: "gpt-5.3-codex-spark", Object: "model", Created: 1735689600, OwnedBy: "openai", Type: "model", DisplayName: "GPT-5.3 Codex Spark"},
 	{ID: "gpt-5.2", Object: "model", Created: 1733875200, OwnedBy: "openai", Type: "model", DisplayName: "GPT-5.2"},
+	{ID: "gpt-image-2", Object: "model", Created: 1738368000, OwnedBy: "openai", Type: "model", DisplayName: "GPT Image 2"},
 }
 
 // DefaultModelIDs returns the default model ID list

backend/internal/server/middleware/security_headers.go

@@ -96,7 +96,8 @@ func isAPIRoutePath(c *gin.Context) bool {
 	return strings.HasPrefix(path, "/v1/") ||
 		strings.HasPrefix(path, "/v1beta/") ||
 		strings.HasPrefix(path, "/antigravity/") ||
-		strings.HasPrefix(path, "/responses")
+		strings.HasPrefix(path, "/responses") ||
+		strings.HasPrefix(path, "/images")
 }
 
 // enhanceCSPPolicy ensures the CSP policy includes nonce support, Cloudflare Insights,

backend/internal/server/routes/gateway.go

@@ -88,6 +88,30 @@ func RegisterGatewayRoutes(
 			}
 			h.Gateway.ChatCompletions(c)
 		})
+		gateway.POST("/images/generations", func(c *gin.Context) {
+			if getGroupPlatform(c) != service.PlatformOpenAI {
+				c.JSON(http.StatusNotFound, gin.H{
+					"error": gin.H{
+						"type":    "not_found_error",
+						"message": "Images API is not supported for this platform",
+					},
+				})
+				return
+			}
+			h.OpenAIGateway.Images(c)
+		})
+		gateway.POST("/images/edits", func(c *gin.Context) {
+			if getGroupPlatform(c) != service.PlatformOpenAI {
+				c.JSON(http.StatusNotFound, gin.H{
+					"error": gin.H{
+						"type":    "not_found_error",
+						"message": "Images API is not supported for this platform",
+					},
+				})
+				return
+			}
+			h.OpenAIGateway.Images(c)
+		})
 	}
 
 	// Gemini 原生 API 兼容层（Gemini SDK/CLI 直连）
@@ -124,6 +148,30 @@ func RegisterGatewayRoutes(
 		}
 		h.Gateway.ChatCompletions(c)
 	})
+	r.POST("/images/generations", bodyLimit, clientRequestID, opsErrorLogger, endpointNorm, gin.HandlerFunc(apiKeyAuth), requireGroupAnthropic, func(c *gin.Context) {
+		if getGroupPlatform(c) != service.PlatformOpenAI {
+			c.JSON(http.StatusNotFound, gin.H{
+				"error": gin.H{
+					"type":    "not_found_error",
+					"message": "Images API is not supported for this platform",
+				},
+			})
+			return
+		}
+		h.OpenAIGateway.Images(c)
+	})
+	r.POST("/images/edits", bodyLimit, clientRequestID, opsErrorLogger, endpointNorm, gin.HandlerFunc(apiKeyAuth), requireGroupAnthropic, func(c *gin.Context) {
+		if getGroupPlatform(c) != service.PlatformOpenAI {
+			c.JSON(http.StatusNotFound, gin.H{
+				"error": gin.H{
+					"type":    "not_found_error",
+					"message": "Images API is not supported for this platform",
+				},
+			})
+			return
+		}
+		h.OpenAIGateway.Images(c)
+	})
 
 	// Antigravity 模型列表
 	r.GET("/antigravity/models", gin.HandlerFunc(apiKeyAuth), requireGroupAnthropic, h.Gateway.AntigravityModels)

backend/internal/server/routes/gateway_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/handler"
 	servermiddleware "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
 	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/require"
 )
@@ -24,6 +25,11 @@ func newGatewayRoutesTestRouter() *gin.Engine {
 			OpenAIGateway: &handler.OpenAIGatewayHandler{},
 		},
 		servermiddleware.APIKeyAuthMiddleware(func(c *gin.Context) {
+			groupID := int64(1)
+			c.Set(string(servermiddleware.ContextKeyAPIKey), &service.APIKey{
+				GroupID: &groupID,
+				Group:   &service.Group{Platform: service.PlatformOpenAI},
+			})
 			c.Next()
 		}),
 		nil,
@@ -48,3 +54,21 @@ func TestGatewayRoutesOpenAIResponsesCompactPathIsRegistered(t *testing.T) {
 		require.NotEqual(t, http.StatusNotFound, w.Code, "path=%s should hit OpenAI responses handler", path)
 	}
 }
+
+func TestGatewayRoutesOpenAIImagesPathsAreRegistered(t *testing.T) {
+	router := newGatewayRoutesTestRouter()
+
+	for _, path := range []string{
+		"/v1/images/generations",
+		"/v1/images/edits",
+		"/images/generations",
+		"/images/edits",
+	} {
+		req := httptest.NewRequest(http.MethodPost, path, strings.NewReader(`{"model":"gpt-image-2","prompt":"draw a cat"}`))
+		req.Header.Set("Content-Type", "application/json")
+		w := httptest.NewRecorder()
+
+		router.ServeHTTP(w, req)
+		require.NotEqual(t, http.StatusNotFound, w.Code, "path=%s should hit OpenAI images handler", path)
+	}
+}

backend/internal/service/account.go

@@ -911,6 +911,34 @@ func (a *Account) GetChatGPTAccountID() string {
 	return a.GetCredential("chatgpt_account_id")
 }
 
+func (a *Account) GetOpenAIDeviceID() string {
+	if !a.IsOpenAIOAuth() {
+		return ""
+	}
+	return strings.TrimSpace(a.GetExtraString("openai_device_id"))
+}
+
+func (a *Account) GetOpenAISessionID() string {
+	if !a.IsOpenAIOAuth() {
+		return ""
+	}
+	return strings.TrimSpace(a.GetExtraString("openai_session_id"))
+}
+
+func (a *Account) SupportsOpenAIImageCapability(capability OpenAIImagesCapability) bool {
+	if !a.IsOpenAI() {
+		return false
+	}
+	switch capability {
+	case OpenAIImagesCapabilityBasic:
+		return a.Type == AccountTypeOAuth || a.Type == AccountTypeAPIKey
+	case OpenAIImagesCapabilityNative:
+		return a.Type == AccountTypeAPIKey
+	default:
+		return true
+	}
+}
+
 func (a *Account) GetChatGPTUserID() string {
 	if !a.IsOpenAIOAuth() {
 		return ""

backend/internal/service/model_pricing_resolver.go

@@ -61,6 +61,25 @@ type PricingInput struct {
 // 1. 获取基础定价（LiteLLM → Fallback）
 // 2. 如果指定了 GroupID，查找渠道定价并覆盖
 func (r *ModelPricingResolver) Resolve(ctx context.Context, input PricingInput) *ResolvedPricing {
+	var chPricing *ChannelModelPricing
+	if input.GroupID != nil && r.channelService != nil {
+		chPricing = r.channelService.GetChannelModelPricing(ctx, *input.GroupID, input.Model)
+		if chPricing != nil {
+			mode := chPricing.BillingMode
+			if mode == "" {
+				mode = BillingModeToken
+			}
+			if mode == BillingModePerRequest || mode == BillingModeImage {
+				resolved := &ResolvedPricing{
+					Mode:   mode,
+					Source: PricingSourceChannel,
+				}
+				r.applyRequestTierOverrides(chPricing, resolved)
+				return resolved
+			}
+		}
+	}
+
 	// 1. 获取基础定价
 	basePricing, source := r.resolveBasePricing(input.Model)
 
@@ -72,7 +91,10 @@ func (r *ModelPricingResolver) Resolve(ctx context.Context, input PricingInput)
 	}
 
 	// 2. 如果有 GroupID，尝试渠道覆盖
-	if input.GroupID != nil {
+	if chPricing != nil {
+		resolved.Source = PricingSourceChannel
+		r.applyTokenOverrides(chPricing, resolved)
+	} else if input.GroupID != nil {
 		r.applyChannelOverrides(ctx, *input.GroupID, input.Model, resolved)
 	}
 

backend/internal/service/openai_account_scheduler.go

@@ -44,6 +44,7 @@ type OpenAIAccountScheduleRequest struct {
 	PreviousResponseID      string
 	RequestedModel          string
 	RequiredTransport       OpenAIUpstreamTransport
+	RequiredImageCapability OpenAIImagesCapability
 	ExcludedIDs             map[int64]struct{}
 }
 
@@ -340,7 +341,7 @@ func (s *defaultOpenAIAccountScheduler) selectBySessionHash(
 		_ = s.service.deleteStickySessionAccountID(ctx, req.GroupID, sessionHash)
 		return nil, nil
 	}
-	if req.RequestedModel != "" && !account.IsModelSupported(req.RequestedModel) {
+	if !s.isAccountRequestCompatible(account, req) {
 		return nil, nil
 	}
 	if !s.isAccountTransportCompatible(account, req.RequiredTransport) {
@@ -616,7 +617,7 @@ func (s *defaultOpenAIAccountScheduler) selectByLoadBalance(
 				fmt.Sprintf("Privacy not set, required by group [%s]", schedGroup.Name))
 			continue
 		}
-		if req.RequestedModel != "" && !account.IsModelSupported(req.RequestedModel) {
+		if !s.isAccountRequestCompatible(account, req) {
 			continue
 		}
 		if !s.isAccountTransportCompatible(account, req.RequiredTransport) {
@@ -722,11 +723,11 @@ func (s *defaultOpenAIAccountScheduler) selectByLoadBalance(
 	for i := 0; i < len(selectionOrder); i++ {
 		candidate := selectionOrder[i]
 		fresh := s.service.resolveFreshSchedulableOpenAIAccount(ctx, candidate.account, req.RequestedModel)
-		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) {
+		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) || !s.isAccountRequestCompatible(fresh, req) {
 			continue
 		}
 		fresh = s.service.recheckSelectedOpenAIAccountFromDB(ctx, fresh, req.RequestedModel)
-		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) {
+		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) || !s.isAccountRequestCompatible(fresh, req) {
 			continue
 		}
 		result, acquireErr := s.service.tryAcquireAccountSlot(ctx, fresh.ID, fresh.Concurrency)
@@ -749,7 +750,7 @@ func (s *defaultOpenAIAccountScheduler) selectByLoadBalance(
 	// WaitPlan.MaxConcurrency 使用 Concurrency（非 EffectiveLoadFactor），因为 WaitPlan 控制的是 Redis 实际并发槽位等待。
 	for _, candidate := range selectionOrder {
 		fresh := s.service.resolveFreshSchedulableOpenAIAccount(ctx, candidate.account, req.RequestedModel)
-		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) {
+		if fresh == nil || !s.isAccountTransportCompatible(fresh, req.RequiredTransport) || !s.isAccountRequestCompatible(fresh, req) {
 			continue
 		}
 		return &AccountSelectionResult{
@@ -776,6 +777,16 @@ func (s *defaultOpenAIAccountScheduler) isAccountTransportCompatible(account *Ac
 	return s.service.isOpenAIAccountTransportCompatible(account, requiredTransport)
 }
 
+func (s *defaultOpenAIAccountScheduler) isAccountRequestCompatible(account *Account, req OpenAIAccountScheduleRequest) bool {
+	if account == nil {
+		return false
+	}
+	if req.RequestedModel != "" && !account.IsModelSupported(req.RequestedModel) {
+		return false
+	}
+	return account.SupportsOpenAIImageCapability(req.RequiredImageCapability)
+}
+
 func (s *defaultOpenAIAccountScheduler) ReportResult(accountID int64, success bool, firstTokenMs *int) {
 	if s == nil || s.stats == nil {
 		return
@@ -894,14 +905,59 @@ func (s *OpenAIGatewayService) SelectAccountWithScheduler(
 	requestedModel string,
 	excludedIDs map[int64]struct{},
 	requiredTransport OpenAIUpstreamTransport,
+) (*AccountSelectionResult, OpenAIAccountScheduleDecision, error) {
+	return s.selectAccountWithScheduler(ctx, groupID, previousResponseID, sessionHash, requestedModel, excludedIDs, requiredTransport, "")
+}
+
+func (s *OpenAIGatewayService) SelectAccountWithSchedulerForImages(
+	ctx context.Context,
+	groupID *int64,
+	sessionHash string,
+	requestedModel string,
+	excludedIDs map[int64]struct{},
+	requiredCapability OpenAIImagesCapability,
+) (*AccountSelectionResult, OpenAIAccountScheduleDecision, error) {
+	return s.selectAccountWithScheduler(ctx, groupID, "", sessionHash, requestedModel, excludedIDs, OpenAIUpstreamTransportHTTPSSE, requiredCapability)
+}
+
+func (s *OpenAIGatewayService) selectAccountWithScheduler(
+	ctx context.Context,
+	groupID *int64,
+	previousResponseID string,
+	sessionHash string,
+	requestedModel string,
+	excludedIDs map[int64]struct{},
+	requiredTransport OpenAIUpstreamTransport,
+	requiredImageCapability OpenAIImagesCapability,
 ) (*AccountSelectionResult, OpenAIAccountScheduleDecision, error) {
 	decision := OpenAIAccountScheduleDecision{}
 	scheduler := s.getOpenAIAccountScheduler(ctx)
 	if scheduler == nil {
 		decision.Layer = openAIAccountScheduleLayerLoadBalance
 		if requiredTransport == OpenAIUpstreamTransportAny || requiredTransport == OpenAIUpstreamTransportHTTPSSE {
-			selection, err := s.SelectAccountWithLoadAwareness(ctx, groupID, sessionHash, requestedModel, excludedIDs)
-			return selection, decision, err
+			effectiveExcludedIDs := cloneExcludedAccountIDs(excludedIDs)
+			for {
+				selection, err := s.SelectAccountWithLoadAwareness(ctx, groupID, sessionHash, requestedModel, effectiveExcludedIDs)
+				if err != nil {
+					return nil, decision, err
+				}
+				if selection == nil || selection.Account == nil {
+					return selection, decision, nil
+				}
+				if selection.Account.SupportsOpenAIImageCapability(requiredImageCapability) {
+					return selection, decision, nil
+				}
+				if selection.ReleaseFunc != nil {
+					selection.ReleaseFunc()
+				}
+				if effectiveExcludedIDs == nil {
+					effectiveExcludedIDs = make(map[int64]struct{})
+				}
+				if _, exists := effectiveExcludedIDs[selection.Account.ID]; exists {
+					return nil, decision, ErrNoAvailableAccounts
+				}
+				effectiveExcludedIDs[selection.Account.ID] = struct{}{}
+			}
 		}
 
 		effectiveExcludedIDs := cloneExcludedAccountIDs(excludedIDs)
@@ -943,6 +999,7 @@ func (s *OpenAIGatewayService) SelectAccountWithScheduler(
 		PreviousResponseID:      previousResponseID,
 		RequestedModel:          requestedModel,
 		RequiredTransport:       requiredTransport,
+		RequiredImageCapability: requiredImageCapability,
 		ExcludedIDs:             excludedIDs,
 	})
 }

backend/internal/service/openai_gateway_record_usage_test.go

@@ -1070,3 +1070,31 @@ func TestOpenAIGatewayServiceRecordUsage_SimpleModeSkipsBillingAfterPersist(t *t
 	require.Equal(t, 0, userRepo.deductCalls)
 	require.Equal(t, 0, subRepo.incrementCalls)
 }
+
+func TestOpenAIGatewayServiceRecordUsage_ImageOnlyUsageStillPersists(t *testing.T) {
+	usageRepo := &openAIRecordUsageLogRepoStub{inserted: true}
+	userRepo := &openAIRecordUsageUserRepoStub{}
+	subRepo := &openAIRecordUsageSubRepoStub{}
+	svc := newOpenAIRecordUsageServiceForTest(usageRepo, userRepo, subRepo, nil)
+
+	err := svc.RecordUsage(context.Background(), &OpenAIRecordUsageInput{
+		Result: &OpenAIForwardResult{
+			RequestID:  "resp_image_only_usage",
+			Model:      "gpt-image-2",
+			ImageCount: 2,
+			ImageSize:  "1K",
+			Duration:   time.Second,
+		},
+		APIKey:  &APIKey{ID: 1007},
+		User:    &User{ID: 2007},
+		Account: &Account{ID: 3007},
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, usageRepo.lastLog)
+	require.Equal(t, 2, usageRepo.lastLog.ImageCount)
+	require.NotNil(t, usageRepo.lastLog.ImageSize)
+	require.Equal(t, "1K", *usageRepo.lastLog.ImageSize)
+	require.NotNil(t, usageRepo.lastLog.BillingMode)
+	require.Equal(t, string(BillingModeImage), *usageRepo.lastLog.BillingMode)
+}

backend/internal/service/openai_gateway_service.go

@@ -233,6 +233,8 @@ type OpenAIForwardResult struct {
 	ResponseHeaders http.Header
 	Duration        time.Duration
 	FirstTokenMs    *int
+	ImageCount      int
+	ImageSize       string
 }
 
 type OpenAIWSRetryMetricsSnapshot struct {
@@ -3889,6 +3891,7 @@ func (s *OpenAIGatewayService) parseSSEUsageBytes(data []byte, usage *OpenAIUsag
 	usage.InputTokens = int(gjson.GetBytes(data, "response.usage.input_tokens").Int())
 	usage.OutputTokens = int(gjson.GetBytes(data, "response.usage.output_tokens").Int())
 	usage.CacheReadInputTokens = int(gjson.GetBytes(data, "response.usage.input_tokens_details.cached_tokens").Int())
+	usage.ImageOutputTokens = int(gjson.GetBytes(data, "response.usage.output_tokens_details.image_tokens").Int())
 }
 
 func extractOpenAIUsageFromJSONBytes(body []byte) (OpenAIUsage, bool) {
@@ -3900,11 +3903,13 @@ func extractOpenAIUsageFromJSONBytes(body []byte) (OpenAIUsage, bool) {
 		"usage.input_tokens",
 		"usage.output_tokens",
 		"usage.input_tokens_details.cached_tokens",
+		"usage.output_tokens_details.image_tokens",
 	)
 	return OpenAIUsage{
 		InputTokens:          int(values[0].Int()),
 		OutputTokens:         int(values[1].Int()),
 		CacheReadInputTokens: int(values[2].Int()),
+		ImageOutputTokens:    int(values[3].Int()),
 	}, true
 }
 
@@ -4397,7 +4402,8 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 
 	// 跳过所有 token 均为零的用量记录——上游未返回 usage 时不应写入数据库
 	if result.Usage.InputTokens == 0 && result.Usage.OutputTokens == 0 &&
-		result.Usage.CacheCreationInputTokens == 0 && result.Usage.CacheReadInputTokens == 0 {
+		result.Usage.CacheCreationInputTokens == 0 && result.Usage.CacheReadInputTokens == 0 &&
+		result.Usage.ImageOutputTokens == 0 && result.ImageCount == 0 {
 		return nil
 	}
 
@@ -4451,21 +4457,7 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 	if result.ServiceTier != nil {
 		serviceTier = strings.TrimSpace(*result.ServiceTier)
 	}
-	if s.resolver != nil && apiKey.Group != nil {
-		gid := apiKey.Group.ID
-		cost, err = s.billingService.CalculateCostUnified(CostInput{
-			Ctx:            ctx,
-			Model:          billingModel,
-			GroupID:        &gid,
-			Tokens:         tokens,
-			RequestCount:   1,
-			RateMultiplier: multiplier,
-			ServiceTier:    serviceTier,
-			Resolver:       s.resolver,
-		})
-	} else {
-		cost, err = s.billingService.CalculateCostWithServiceTier(billingModel, tokens, multiplier, serviceTier)
-	}
+	cost, err = s.calculateOpenAIRecordUsageCost(ctx, result, apiKey, billingModel, multiplier, tokens, serviceTier)
 	if err != nil {
 		cost = &CostBreakdown{ActualCost: 0}
 	}
@@ -4505,6 +4497,8 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 		CacheCreationTokens: result.Usage.CacheCreationInputTokens,
 		CacheReadTokens:     result.Usage.CacheReadInputTokens,
 		ImageOutputTokens:   result.Usage.ImageOutputTokens,
+		ImageCount:          result.ImageCount,
+		ImageSize:           optionalTrimmedStringPtr(result.ImageSize),
 	}
 	if cost != nil {
 		usageLog.InputCost = cost.InputCost
@@ -4530,6 +4524,9 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 	if cost != nil && cost.BillingMode != "" {
 		billingMode := cost.BillingMode
 		usageLog.BillingMode = &billingMode
+	} else if result.ImageCount > 0 {
+		billingMode := string(BillingModeImage)
+		usageLog.BillingMode = &billingMode
 	} else {
 		billingMode := string(BillingModeToken)
 		usageLog.BillingMode = &billingMode
@@ -4589,6 +4586,125 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 	return nil
 }
 
+func (s *OpenAIGatewayService) calculateOpenAIRecordUsageCost(
+	ctx context.Context,
+	result *OpenAIForwardResult,
+	apiKey *APIKey,
+	billingModel string,
+	multiplier float64,
+	tokens UsageTokens,
+	serviceTier string,
+) (*CostBreakdown, error) {
+	if result != nil && result.ImageCount > 0 {
+		if hasOpenAIImageUsageTokens(result) {
+			cost, err := s.calculateOpenAIImageTokenCost(ctx, apiKey, billingModel, multiplier, tokens, serviceTier, result.ImageSize)
+			if err == nil {
+				return cost, nil
+			}
+		}
+		return s.calculateOpenAIImageCost(ctx, billingModel, apiKey, result, multiplier), nil
+	}
+	if s.resolver != nil && apiKey.Group != nil {
+		gid := apiKey.Group.ID
+		return s.billingService.CalculateCostUnified(CostInput{
+			Ctx:            ctx,
+			Model:          billingModel,
+			GroupID:        &gid,
+			Tokens:         tokens,
+			RequestCount:   1,
+			RateMultiplier: multiplier,
+			ServiceTier:    serviceTier,
+			Resolver:       s.resolver,
+		})
+	}
+	return s.billingService.CalculateCostWithServiceTier(billingModel, tokens, multiplier, serviceTier)
+}
+
+func (s *OpenAIGatewayService) calculateOpenAIImageTokenCost(
+	ctx context.Context,
+	apiKey *APIKey,
+	billingModel string,
+	multiplier float64,
+	tokens UsageTokens,
+	serviceTier string,
+	sizeTier string,
+) (*CostBreakdown, error) {
+	if s.resolver != nil && apiKey.Group != nil {
+		gid := apiKey.Group.ID
+		return s.billingService.CalculateCostUnified(CostInput{
+			Ctx:            ctx,
+			Model:          billingModel,
+			GroupID:        &gid,
+			Tokens:         tokens,
+			RequestCount:   1,
+			SizeTier:       sizeTier,
+			RateMultiplier: multiplier,
+			ServiceTier:    serviceTier,
+			Resolver:       s.resolver,
+		})
+	}
+	return s.billingService.CalculateCostWithServiceTier(billingModel, tokens, multiplier, serviceTier)
+}
+
+func (s *OpenAIGatewayService) calculateOpenAIImageCost(
+	ctx context.Context,
+	billingModel string,
+	apiKey *APIKey,
+	result *OpenAIForwardResult,
+	multiplier float64,
+) *CostBreakdown {
+	if resolved := s.resolveOpenAIChannelPricing(ctx, billingModel, apiKey); resolved != nil {
+		gid := apiKey.Group.ID
+		cost, err := s.billingService.CalculateCostUnified(CostInput{
+			Ctx:            ctx,
+			Model:          billingModel,
+			GroupID:        &gid,
+			RequestCount:   1,
+			SizeTier:       result.ImageSize,
+			RateMultiplier: multiplier,
+			Resolver:       s.resolver,
+			Resolved:       resolved,
+		})
+		if err == nil {
+			return cost
+		}
+		logger.LegacyPrintf("service.openai_gateway", "Calculate image channel cost failed: %v", err)
+	}
+
+	var groupConfig *ImagePriceConfig
+	if apiKey != nil && apiKey.Group != nil {
+		groupConfig = &ImagePriceConfig{
+			Price1K: apiKey.Group.ImagePrice1K,
+			Price2K: apiKey.Group.ImagePrice2K,
+			Price4K: apiKey.Group.ImagePrice4K,
+		}
+	}
+	return s.billingService.CalculateImageCost(billingModel, result.ImageSize, result.ImageCount, groupConfig, multiplier)
+}
+
+func (s *OpenAIGatewayService) resolveOpenAIChannelPricing(ctx context.Context, billingModel string, apiKey *APIKey) *ResolvedPricing {
+	if s.resolver == nil || apiKey == nil || apiKey.Group == nil {
+		return nil
+	}
+	gid := apiKey.Group.ID
+	resolved := s.resolver.Resolve(ctx, PricingInput{Model: billingModel, GroupID: &gid})
+	if resolved.Source == PricingSourceChannel {
+		return resolved
+	}
+	return nil
+}
+
+func hasOpenAIImageUsageTokens(result *OpenAIForwardResult) bool {
+	if result == nil {
+		return false
+	}
+	return result.Usage.InputTokens > 0 ||
+		result.Usage.OutputTokens > 0 ||
+		result.Usage.CacheCreationInputTokens > 0 ||
+		result.Usage.CacheReadInputTokens > 0 ||
+		result.Usage.ImageOutputTokens > 0
+}
+
 // ParseCodexRateLimitHeaders extracts Codex usage limits from response headers.
 // Exported for use in ratelimit_service when handling OpenAI 429 responses.
 func ParseCodexRateLimitHeaders(headers http.Header) *OpenAICodexUsageSnapshot {

backend/internal/service/openai_images.go

+package service
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"crypto/sha3"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/textproto"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/proxyurl"
+	"github.com/Wei-Shaw/sub2api/internal/util/responseheaders"
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"github.com/imroc/req/v3"
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+)
+
+const (
+	openAIImagesGenerationsEndpoint = "/v1/images/generations"
+	openAIImagesEditsEndpoint       = "/v1/images/edits"
+
+	openAIImagesGenerationsURL = "https://api.openai.com/v1/images/generations"
+	openAIImagesEditsURL       = "https://api.openai.com/v1/images/edits"
+
+	openAIChatGPTStartURL               = "https://chatgpt.com/"
+	openAIChatGPTFilesURL               = "https://chatgpt.com/backend-api/files"
+	openAIChatGPTConversationInitURL    = "https://chatgpt.com/backend-api/conversation/init"
+	openAIChatGPTConversationURL        = "https://chatgpt.com/backend-api/f/conversation"
+	openAIChatGPTConversationPrepareURL = "https://chatgpt.com/backend-api/f/conversation/prepare"
+	openAIChatGPTChatRequirementsURL    = "https://chatgpt.com/backend-api/sentinel/chat-requirements"
+
+	openAIImageBackendUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36"
+	openAIImageRequirementsDiff = "0fffff"
+)
+
+type OpenAIImagesCapability string
+
+const (
+	OpenAIImagesCapabilityBasic  OpenAIImagesCapability = "images-basic"
+	OpenAIImagesCapabilityNative OpenAIImagesCapability = "images-native"
+)
+
+type OpenAIImagesUpload struct {
+	FieldName   string
+	FileName    string
+	ContentType string
+	Data        []byte
+	Width       int
+	Height      int
+}
+
+type OpenAIImagesRequest struct {
+	Endpoint           string
+	ContentType        string
+	Multipart          bool
+	Model              string
+	ExplicitModel      bool
+	Prompt             string
+	Stream             bool
+	N                  int
+	Size               string
+	ExplicitSize       bool
+	SizeTier           string
+	ResponseFormat     string
+	HasMask            bool
+	HasNativeOptions   bool
+	RequiredCapability OpenAIImagesCapability
+	Uploads            []OpenAIImagesUpload
+	Body               []byte
+	bodyHash           string
+}
+
+func (r *OpenAIImagesRequest) IsEdits() bool {
+	return r != nil && r.Endpoint == openAIImagesEditsEndpoint
+}
+
+func (r *OpenAIImagesRequest) StickySessionSeed() string {
+	if r == nil {
+		return ""
+	}
+	parts := []string{
+		"openai-images",
+		strings.TrimSpace(r.Endpoint),
+		strings.TrimSpace(r.Model),
+		strings.TrimSpace(r.Size),
+		strings.TrimSpace(r.Prompt),
+	}
+	seed := strings.Join(parts, "|")
+	if strings.TrimSpace(r.Prompt) == "" && r.bodyHash != "" {
+		seed += "|body=" + r.bodyHash
+	}
+	return seed
+}
+
+func (s *OpenAIGatewayService) ParseOpenAIImagesRequest(c *gin.Context, body []byte) (*OpenAIImagesRequest, error) {
+	if c == nil || c.Request == nil {
+		return nil, fmt.Errorf("missing request context")
+	}
+	endpoint := normalizeOpenAIImagesEndpointPath(c.Request.URL.Path)
+	if endpoint == "" {
+		return nil, fmt.Errorf("unsupported images endpoint")
+	}
+
+	contentType := strings.TrimSpace(c.GetHeader("Content-Type"))
+	req := &OpenAIImagesRequest{
+		Endpoint:    endpoint,
+		ContentType: contentType,
+		N:           1,
+		Body:        body,
+	}
+	if len(body) > 0 {
+		sum := sha256.Sum256(body)
+		req.bodyHash = hex.EncodeToString(sum[:8])
+	}
+
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err == nil && strings.EqualFold(mediaType, "multipart/form-data") {
+		req.Multipart = true
+		if parseErr := parseOpenAIImagesMultipartRequest(body, contentType, req); parseErr != nil {
+			return nil, parseErr
+		}
+	} else {
+		if len(body) == 0 {
+			return nil, fmt.Errorf("request body is empty")
+		}
+		if !gjson.ValidBytes(body) {
+			return nil, fmt.Errorf("failed to parse request body")
+		}
+		if parseErr := parseOpenAIImagesJSONRequest(body, req); parseErr != nil {
+			return nil, parseErr
+		}
+	}
+
+	applyOpenAIImagesDefaults(req)
+	req.SizeTier = normalizeOpenAIImageSizeTier(req.Size)
+	req.RequiredCapability = classifyOpenAIImagesCapability(req)
+	return req, nil
+}
+
+func parseOpenAIImagesJSONRequest(body []byte, req *OpenAIImagesRequest) error {
+	if modelResult := gjson.GetBytes(body, "model"); modelResult.Exists() {
+		req.Model = strings.TrimSpace(modelResult.String())
+		req.ExplicitModel = req.Model != ""
+	}
+	req.Prompt = strings.TrimSpace(gjson.GetBytes(body, "prompt").String())
+
+	if streamResult := gjson.GetBytes(body, "stream"); streamResult.Exists() {
+		if streamResult.Type != gjson.True && streamResult.Type != gjson.False {
+			return fmt.Errorf("invalid stream field type")
+		}
+		req.Stream = streamResult.Bool()
+	}
+
+	if nResult := gjson.GetBytes(body, "n"); nResult.Exists() {
+		if nResult.Type != gjson.Number {
+			return fmt.Errorf("invalid n field type")
+		}
+		req.N = int(nResult.Int())
+		if req.N <= 0 {
+			return fmt.Errorf("n must be greater than 0")
+		}
+	}
+
+	if sizeResult := gjson.GetBytes(body, "size"); sizeResult.Exists() {
+		req.Size = strings.TrimSpace(sizeResult.String())
+		req.ExplicitSize = req.Size != ""
+	}
+	req.ResponseFormat = strings.ToLower(strings.TrimSpace(gjson.GetBytes(body, "response_format").String()))
+	req.HasMask = gjson.GetBytes(body, "mask").Exists()
+	req.HasNativeOptions = hasOpenAINativeImageOptions(func(path string) bool {
+		return gjson.GetBytes(body, path).Exists()
+	})
+	return nil
+}
+
+func parseOpenAIImagesMultipartRequest(body []byte, contentType string, req *OpenAIImagesRequest) error {
+	_, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return fmt.Errorf("invalid multipart content-type: %w", err)
+	}
+	boundary := strings.TrimSpace(params["boundary"])
+	if boundary == "" {
+		return fmt.Errorf("multipart boundary is required")
+	}
+
+	reader := multipart.NewReader(bytes.NewReader(body), boundary)
+	for {
+		part, err := reader.NextPart()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("read multipart body: %w", err)
+		}
+		name := strings.TrimSpace(part.FormName())
+		if name == "" {
+			_ = part.Close()
+			continue
+		}
+
+		data, err := io.ReadAll(part)
+		_ = part.Close()
+		if err != nil {
+			return fmt.Errorf("read multipart field %s: %w", name, err)
+		}
+
+		fileName := strings.TrimSpace(part.FileName())
+		if fileName != "" {
+			partContentType := strings.TrimSpace(part.Header.Get("Content-Type"))
+			if name == "mask" && len(data) > 0 {
+				req.HasMask = true
+			}
+			if name == "image" || strings.HasPrefix(name, "image[") {
+				width, height := parseOpenAIImageDimensions(part.Header)
+				req.Uploads = append(req.Uploads, OpenAIImagesUpload{
+					FieldName:   name,
+					FileName:    fileName,
+					ContentType: partContentType,
+					Data:        data,
+					Width:       width,
+					Height:      height,
+				})
+			}
+			continue
+		}
+
+		value := strings.TrimSpace(string(data))
+		switch name {
+		case "model":
+			req.Model = value
+			req.ExplicitModel = value != ""
+		case "prompt":
+			req.Prompt = value
+		case "size":
+			req.Size = value
+			req.ExplicitSize = value != ""
+		case "response_format":
+			req.ResponseFormat = strings.ToLower(value)
+		case "stream":
+			parsed, err := strconv.ParseBool(value)
+			if err != nil {
+				return fmt.Errorf("invalid stream field value")
+			}
+			req.Stream = parsed
+		case "n":
+			n, err := strconv.Atoi(value)
+			if err != nil || n <= 0 {
+				return fmt.Errorf("n must be a positive integer")
+			}
+			req.N = n
+		default:
+			if isOpenAINativeImageOption(name) && value != "" {
+				req.HasNativeOptions = true
+			}
+		}
+	}
+
+	if len(req.Uploads) == 0 && req.IsEdits() {
+		return fmt.Errorf("image file is required")
+	}
+	return nil
+}
+
+func parseOpenAIImageDimensions(_ textproto.MIMEHeader) (int, int) {
+	return 0, 0
+}
+
+func applyOpenAIImagesDefaults(req *OpenAIImagesRequest) {
+	if req == nil {
+		return
+	}
+	if req.N <= 0 {
+		req.N = 1
+	}
+	if strings.TrimSpace(req.Model) != "" {
+		req.Model = strings.TrimSpace(req.Model)
+		return
+	}
+	req.Model = "gpt-image-2"
+}
+
+func normalizeOpenAIImagesEndpointPath(path string) string {
+	trimmed := strings.TrimSpace(path)
+	switch {
+	case strings.Contains(trimmed, "/images/generations"):
+		return openAIImagesGenerationsEndpoint
+	case strings.Contains(trimmed, "/images/edits"):
+		return openAIImagesEditsEndpoint
+	default:
+		return ""
+	}
+}
+
+func classifyOpenAIImagesCapability(req *OpenAIImagesRequest) OpenAIImagesCapability {
+	if req == nil {
+		return OpenAIImagesCapabilityNative
+	}
+	if req.ExplicitModel || req.ExplicitSize {
+		return OpenAIImagesCapabilityNative
+	}
+	model := strings.ToLower(strings.TrimSpace(req.Model))
+	if !strings.HasPrefix(model, "gpt-image-") {
+		return OpenAIImagesCapabilityNative
+	}
+	if req.Stream || req.N != 1 || req.HasMask || req.HasNativeOptions {
+		return OpenAIImagesCapabilityNative
+	}
+	if req.IsEdits() && !req.Multipart {
+		return OpenAIImagesCapabilityNative
+	}
+	if req.ResponseFormat != "" && req.ResponseFormat != "b64_json" {
+		return OpenAIImagesCapabilityNative
+	}
+	return OpenAIImagesCapabilityBasic
+}
+
+func hasOpenAINativeImageOptions(exists func(path string) bool) bool {
+	for _, path := range []string{
+		"background",
+		"quality",
+		"style",
+		"output_format",
+		"output_compression",
+		"moderation",
+	} {
+		if exists(path) {
+			return true
+		}
+	}
+	return false
+}
+
+func isOpenAINativeImageOption(name string) bool {
+	switch strings.TrimSpace(strings.ToLower(name)) {
+	case "background", "quality", "style", "output_format", "output_compression", "moderation":
+		return true
+	default:
+		return false
+	}
+}
+
+func normalizeOpenAIImageSizeTier(size string) string {
+	switch strings.ToLower(strings.TrimSpace(size)) {
+	case "1024x1024":
+		return "1K"
+	case "1536x1024", "1024x1536", "1792x1024", "1024x1792", "", "auto":
+		return "2K"
+	default:
+		return "2K"
+	}
+}
+
+func (s *OpenAIGatewayService) ForwardImages(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	parsed *OpenAIImagesRequest,
+	channelMappedModel string,
+) (*OpenAIForwardResult, error) {
+	if parsed == nil {
+		return nil, fmt.Errorf("parsed images request is required")
+	}
+	switch account.Type {
+	case AccountTypeAPIKey:
+		return s.forwardOpenAIImagesAPIKey(ctx, c, account, body, parsed, channelMappedModel)
+	case AccountTypeOAuth:
+		return s.forwardOpenAIImagesOAuth(ctx, c, account, parsed, channelMappedModel)
+	default:
+		return nil, fmt.Errorf("unsupported account type: %s", account.Type)
+	}
+}
+
+func (s *OpenAIGatewayService) forwardOpenAIImagesAPIKey(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	parsed *OpenAIImagesRequest,
+	channelMappedModel string,
+) (*OpenAIForwardResult, error) {
+	startTime := time.Now()
+	requestModel := strings.TrimSpace(parsed.Model)
+	if mapped := strings.TrimSpace(channelMappedModel); mapped != "" {
+		requestModel = mapped
+	}
+	upstreamModel := account.GetMappedModel(requestModel)
+	forwardBody, forwardContentType, err := rewriteOpenAIImagesModel(body, parsed.ContentType, upstreamModel)
+	if err != nil {
+		return nil, err
+	}
+	if !parsed.Multipart {
+		setOpsUpstreamRequestBody(c, forwardBody)
+	}
+
+	token, _, err := s.GetAccessToken(ctx, account)
+	if err != nil {
+		return nil, err
+	}
+	upstreamReq, err := s.buildOpenAIImagesRequest(ctx, c, account, forwardBody, forwardContentType, token, parsed.Endpoint)
+	if err != nil {
+		return nil, err
+	}
+
+	proxyURL := ""
+	if account.ProxyID != nil && account.Proxy != nil {
+		proxyURL = account.Proxy.URL()
+	}
+	upstreamStart := time.Now()
+	resp, err := s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+	SetOpsLatencyMs(c, OpsUpstreamLatencyMsKey, time.Since(upstreamStart).Milliseconds())
+	if err != nil {
+		safeErr := sanitizeUpstreamErrorMessage(err.Error())
+		setOpsUpstreamError(c, 0, safeErr, "")
+		appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+			Platform:           account.Platform,
+			AccountID:          account.ID,
+			AccountName:        account.Name,
+			UpstreamStatusCode: 0,
+			UpstreamURL:        safeUpstreamURL(upstreamReq.URL.String()),
+			Kind:               "request_error",
+			Message:            safeErr,
+		})
+		return nil, fmt.Errorf("upstream request failed: %s", safeErr)
+	}
+	if resp.StatusCode >= 400 {
+		respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+		_ = resp.Body.Close()
+		resp.Body = io.NopCloser(bytes.NewReader(respBody))
+		upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(respBody))
+		upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
+		if s.shouldFailoverOpenAIUpstreamResponse(resp.StatusCode, upstreamMsg, respBody) {
+			appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+				Platform:           account.Platform,
+				AccountID:          account.ID,
+				AccountName:        account.Name,
+				UpstreamStatusCode: resp.StatusCode,
+				UpstreamRequestID:  resp.Header.Get("x-request-id"),
+				UpstreamURL:        safeUpstreamURL(upstreamReq.URL.String()),
+				Kind:               "failover",
+				Message:            upstreamMsg,
+			})
+			s.handleFailoverSideEffects(ctx, resp, account)
+			return nil, &UpstreamFailoverError{
+				StatusCode:             resp.StatusCode,
+				ResponseBody:           respBody,
+				RetryableOnSameAccount: account.IsPoolMode() && isPoolModeRetryableStatus(resp.StatusCode),
+			}
+		}
+		return s.handleErrorResponse(ctx, resp, c, account, forwardBody)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	var usage OpenAIUsage
+	imageCount := parsed.N
+	var firstTokenMs *int
+	if parsed.Stream {
+		streamUsage, streamCount, ttft, err := s.handleOpenAIImagesStreamingResponse(resp, c, startTime)
+		if err != nil {
+			return nil, err
+		}
+		usage = streamUsage
+		imageCount = streamCount
+		firstTokenMs = ttft
+	} else {
+		nonStreamUsage, nonStreamCount, err := s.handleOpenAIImagesNonStreamingResponse(resp, c)
+		if err != nil {
+			return nil, err
+		}
+		usage = nonStreamUsage
+		if nonStreamCount > 0 {
+			imageCount = nonStreamCount
+		}
+	}
+	return &OpenAIForwardResult{
+		RequestID:       resp.Header.Get("x-request-id"),
+		Usage:           usage,
+		Model:           requestModel,
+		UpstreamModel:   upstreamModel,
+		Stream:          parsed.Stream,
+		ResponseHeaders: resp.Header.Clone(),
+		Duration:        time.Since(startTime),
+		FirstTokenMs:    firstTokenMs,
+		ImageCount:      imageCount,
+		ImageSize:       parsed.SizeTier,
+	}, nil
+}
+
+func (s *OpenAIGatewayService) buildOpenAIImagesRequest(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	contentType string,
+	token string,
+	endpoint string,
+) (*http.Request, error) {
+	targetURL := openAIImagesGenerationsURL
+	if endpoint == openAIImagesEditsEndpoint {
+		targetURL = openAIImagesEditsURL
+	}
+	baseURL := account.GetOpenAIBaseURL()
+	if baseURL != "" {
+		validatedURL, err := s.validateUpstreamBaseURL(baseURL)
+		if err != nil {
+			return nil, err
+		}
+		targetURL = buildOpenAIImagesURL(validatedURL, endpoint)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, targetURL, bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	for key, values := range c.Request.Header {
+		if !openaiPassthroughAllowedHeaders[strings.ToLower(key)] {
+			continue
+		}
+		for _, value := range values {
+			req.Header.Add(key, value)
+		}
+	}
+	customUA := account.GetOpenAIUserAgent()
+	if customUA != "" {
+		req.Header.Set("User-Agent", customUA)
+	}
+	if strings.TrimSpace(contentType) != "" {
+		req.Header.Set("Content-Type", contentType)
+	}
+	return req, nil
+}
+
+func buildOpenAIImagesURL(base string, endpoint string) string {
+	normalized := strings.TrimRight(strings.TrimSpace(base), "/")
+	relative := strings.TrimPrefix(strings.TrimSpace(endpoint), "/v1")
+	if strings.HasSuffix(normalized, endpoint) || strings.HasSuffix(normalized, relative) {
+		return normalized
+	}
+	if strings.HasSuffix(normalized, "/v1") {
+		return normalized + relative
+	}
+	return normalized + endpoint
+}
+
+func rewriteOpenAIImagesModel(body []byte, contentType string, model string) ([]byte, string, error) {
+	model = strings.TrimSpace(model)
+	if model == "" {
+		return body, contentType, nil
+	}
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err == nil && strings.EqualFold(mediaType, "multipart/form-data") {
+		rewrittenBody, rewrittenType, rewriteErr := rewriteOpenAIImagesMultipartModel(body, contentType, model)
+		return rewrittenBody, rewrittenType, rewriteErr
+	}
+	rewritten, err := sjson.SetBytes(body, "model", model)
+	if err != nil {
+		return nil, "", fmt.Errorf("rewrite image request model: %w", err)
+	}
+	return rewritten, contentType, nil
+}
+
+func rewriteOpenAIImagesMultipartModel(body []byte, contentType string, model string) ([]byte, string, error) {
+	_, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return nil, "", fmt.Errorf("parse multipart content-type: %w", err)
+	}
+	boundary := strings.TrimSpace(params["boundary"])
+	if boundary == "" {
+		return nil, "", fmt.Errorf("multipart boundary is required")
+	}
+
+	reader := multipart.NewReader(bytes.NewReader(body), boundary)
+	var buffer bytes.Buffer
+	writer := multipart.NewWriter(&buffer)
+	modelWritten := false
+
+	for {
+		part, err := reader.NextPart()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, "", fmt.Errorf("read multipart body: %w", err)
+		}
+
+		formName := strings.TrimSpace(part.FormName())
+		partHeader := cloneMultipartHeader(part.Header)
+		target, err := writer.CreatePart(partHeader)
+		if err != nil {
+			_ = part.Close()
+			return nil, "", fmt.Errorf("create multipart part: %w", err)
+		}
+
+		if formName == "model" && part.FileName() == "" {
+			if _, err := target.Write([]byte(model)); err != nil {
+				_ = part.Close()
+				return nil, "", fmt.Errorf("rewrite multipart model: %w", err)
+			}
+			modelWritten = true
+			_ = part.Close()
+			continue
+		}
+		if _, err := io.Copy(target, part); err != nil {
+			_ = part.Close()
+			return nil, "", fmt.Errorf("copy multipart part: %w", err)
+		}
+		_ = part.Close()
+	}
+
+	if !modelWritten {
+		if err := writer.WriteField("model", model); err != nil {
+			return nil, "", fmt.Errorf("append multipart model field: %w", err)
+		}
+	}
+	if err := writer.Close(); err != nil {
+		return nil, "", fmt.Errorf("finalize multipart body: %w", err)
+	}
+	return buffer.Bytes(), writer.FormDataContentType(), nil
+}
+
+func cloneMultipartHeader(src textproto.MIMEHeader) textproto.MIMEHeader {
+	dst := make(textproto.MIMEHeader, len(src))
+	for key, values := range src {
+		copied := make([]string, len(values))
+		copy(copied, values)
+		dst[key] = copied
+	}
+	return dst
+}
+
+func (s *OpenAIGatewayService) handleOpenAIImagesNonStreamingResponse(resp *http.Response, c *gin.Context) (OpenAIUsage, int, error) {
+	body, err := ReadUpstreamResponseBody(resp.Body, s.cfg, c, openAITooLargeError)
+	if err != nil {
+		return OpenAIUsage{}, 0, err
+	}
+	responseheaders.WriteFilteredHeaders(c.Writer.Header(), resp.Header, s.responseHeaderFilter)
+	contentType := "application/json"
+	if s.cfg != nil && !s.cfg.Security.ResponseHeaders.Enabled {
+		if upstreamType := resp.Header.Get("Content-Type"); upstreamType != "" {
+			contentType = upstreamType
+		}
+	}
+	c.Data(resp.StatusCode, contentType, body)
+
+	usage, _ := extractOpenAIUsageFromJSONBytes(body)
+	return usage, extractOpenAIImageCountFromJSONBytes(body), nil
+}
+
+func (s *OpenAIGatewayService) handleOpenAIImagesStreamingResponse(
+	resp *http.Response,
+	c *gin.Context,
+	startTime time.Time,
+) (OpenAIUsage, int, *int, error) {
+	responseheaders.WriteFilteredHeaders(c.Writer.Header(), resp.Header, s.responseHeaderFilter)
+	contentType := strings.TrimSpace(resp.Header.Get("Content-Type"))
+	if contentType == "" {
+		contentType = "text/event-stream"
+	}
+	c.Status(resp.StatusCode)
+	c.Header("Content-Type", contentType)
+
+	flusher, ok := c.Writer.(http.Flusher)
+	if !ok {
+		return OpenAIUsage{}, 0, nil, fmt.Errorf("streaming is not supported by response writer")
+	}
+
+	reader := bufio.NewReader(resp.Body)
+	usage := OpenAIUsage{}
+	imageCount := 0
+	var firstTokenMs *int
+
+	for {
+		line, err := reader.ReadBytes('\n')
+		if len(line) > 0 {
+			if firstTokenMs == nil {
+				ms := int(time.Since(startTime).Milliseconds())
+				firstTokenMs = &ms
+			}
+			if _, writeErr := c.Writer.Write(line); writeErr != nil {
+				return OpenAIUsage{}, 0, firstTokenMs, writeErr
+			}
+			flusher.Flush()
+
+			if data, ok := extractOpenAISSEDataLine(strings.TrimRight(string(line), "\r\n")); ok && data != "" && data != "[DONE]" {
+				dataBytes := []byte(data)
+				mergeOpenAIUsage(&usage, dataBytes)
+				if count := extractOpenAIImageCountFromJSONBytes(dataBytes); count > imageCount {
+					imageCount = count
+				}
+			}
+		}
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return OpenAIUsage{}, 0, firstTokenMs, err
+		}
+	}
+	return usage, imageCount, firstTokenMs, nil
+}
+
+func mergeOpenAIUsage(dst *OpenAIUsage, body []byte) {
+	if dst == nil {
+		return
+	}
+	if parsed, ok := extractOpenAIUsageFromJSONBytes(body); ok {
+		if parsed.InputTokens > 0 {
+			dst.InputTokens = parsed.InputTokens
+		}
+		if parsed.OutputTokens > 0 {
+			dst.OutputTokens = parsed.OutputTokens
+		}
+		if parsed.CacheReadInputTokens > 0 {
+			dst.CacheReadInputTokens = parsed.CacheReadInputTokens
+		}
+		if parsed.ImageOutputTokens > 0 {
+			dst.ImageOutputTokens = parsed.ImageOutputTokens
+		}
+	}
+}
+
+func extractOpenAIImageCountFromJSONBytes(body []byte) int {
+	if len(body) == 0 || !gjson.ValidBytes(body) {
+		return 0
+	}
+	data := gjson.GetBytes(body, "data")
+	if data.Exists() && data.IsArray() {
+		return len(data.Array())
+	}
+	return 0
+}
+
+func (s *OpenAIGatewayService) forwardOpenAIImagesOAuth(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	parsed *OpenAIImagesRequest,
+	channelMappedModel string,
+) (*OpenAIForwardResult, error) {
+	startTime := time.Now()
+	requestModel := strings.TrimSpace(parsed.Model)
+	if mapped := strings.TrimSpace(channelMappedModel); mapped != "" {
+		requestModel = mapped
+	}
+
+	token, _, err := s.GetAccessToken(ctx, account)
+	if err != nil {
+		return nil, err
+	}
+	client, err := newOpenAIBackendAPIClient(resolveOpenAIProxyURL(account))
+	if err != nil {
+		return nil, err
+	}
+	headers, err := s.buildOpenAIBackendAPIHeaders(account, token)
+	if err != nil {
+		return nil, err
+	}
+	if bootstrapErr := bootstrapOpenAIBackendAPI(ctx, client, headers); bootstrapErr != nil {
+		logger.LegacyPrintf("service.openai_gateway", "OpenAI image bootstrap failed: %v", bootstrapErr)
+	}
+
+	chatReqs, err := fetchOpenAIChatRequirements(ctx, client, headers)
+	if err != nil {
+		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, err)
+	}
+	if chatReqs.Arkose.Required {
+		return nil, s.wrapOpenAIImageBackendError(
+			ctx,
+			c,
+			account,
+			newOpenAIImageSyntheticStatusError(
+				http.StatusForbidden,
+				"chat-requirements requires unsupported challenge (arkose)",
+				openAIChatGPTChatRequirementsURL,
+			),
+		)
+	}
+
+	parentMessageID := uuid.NewString()
+	proofToken := generateOpenAIProofToken(chatReqs.ProofOfWork.Required, chatReqs.ProofOfWork.Seed, chatReqs.ProofOfWork.Difficulty, headers.Get("User-Agent"))
+	_ = initializeOpenAIImageConversation(ctx, client, headers)
+	conduitToken, err := prepareOpenAIImageConversation(ctx, client, headers, parsed.Prompt, parentMessageID, chatReqs.Token, proofToken)
+	if err != nil {
+		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, err)
+	}
+
+	uploads, err := uploadOpenAIImageFiles(ctx, client, headers, parsed.Uploads)
+	if err != nil {
+		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, err)
+	}
+
+	convReq := buildOpenAIImageConversationRequest(parsed, parentMessageID, uploads)
+	if parsedContent, err := json.Marshal(convReq); err == nil {
+		setOpsUpstreamRequestBody(c, parsedContent)
+	}
+	convHeaders := cloneHTTPHeader(headers)
+	convHeaders.Set("Accept", "text/event-stream")
+	convHeaders.Set("Content-Type", "application/json")
+	convHeaders.Set("openai-sentinel-chat-requirements-token", chatReqs.Token)
+	if conduitToken != "" {
+		convHeaders.Set("x-conduit-token", conduitToken)
+	}
+	if proofToken != "" {
+		convHeaders.Set("openai-sentinel-proof-token", proofToken)
+	}
+
+	resp, err := client.R().
+		SetContext(ctx).
+		DisableAutoReadResponse().
+		SetHeaders(headerToMap(convHeaders)).
+		SetBodyJsonMarshal(convReq).
+		Post(openAIChatGPTConversationURL)
+	if err != nil {
+		return nil, fmt.Errorf("openai image conversation request failed: %w", err)
+	}
+	defer func() {
+		if resp != nil && resp.Body != nil {
+			_ = resp.Body.Close()
+		}
+	}()
+	if resp.StatusCode >= 400 {
+		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, handleOpenAIImageBackendError(resp))
+	}
+
+	conversationID, pointerInfos, usage, firstTokenMs, err := readOpenAIImageConversationStream(resp, startTime)
+	if err != nil {
+		return nil, err
+	}
+	pointerInfos = mergeOpenAIImagePointerInfos(pointerInfos, nil)
+	if conversationID != "" && !hasOpenAIFileServicePointerInfos(pointerInfos) {
+		polledPointers, pollErr := pollOpenAIImageConversation(ctx, client, headers, conversationID)
+		if pollErr != nil {
+			return nil, s.wrapOpenAIImageBackendError(ctx, c, account, pollErr)
+		}
+		pointerInfos = mergeOpenAIImagePointerInfos(pointerInfos, polledPointers)
+	}
+	pointerInfos = preferOpenAIFileServicePointerInfos(pointerInfos)
+	if len(pointerInfos) == 0 {
+		return nil, fmt.Errorf("openai image conversation returned no downloadable images")
+	}
+
+	responseBody, imageCount, err := buildOpenAIImageResponse(ctx, client, headers, conversationID, pointerInfos)
+	if err != nil {
+		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, err)
+	}
+
+	c.Data(http.StatusOK, "application/json; charset=utf-8", responseBody)
+	return &OpenAIForwardResult{
+		RequestID:     resp.Header.Get("x-request-id"),
+		Usage:         usage,
+		Model:         requestModel,
+		UpstreamModel: requestModel,
+		Stream:        false,
+		Duration:      time.Since(startTime),
+		FirstTokenMs:  firstTokenMs,
+		ImageCount:    imageCount,
+		ImageSize:     parsed.SizeTier,
+	}, nil
+}
+
+func resolveOpenAIProxyURL(account *Account) string {
+	if account != nil && account.ProxyID != nil && account.Proxy != nil {
+		return account.Proxy.URL()
+	}
+	return ""
+}
+
+func newOpenAIBackendAPIClient(proxyURL string) (*req.Client, error) {
+	client := req.C().
+		SetTimeout(180 * time.Second).
+		ImpersonateChrome()
+	trimmed, _, err := proxyurl.Parse(proxyURL)
+	if err != nil {
+		return nil, err
+	}
+	if trimmed != "" {
+		client.SetProxyURL(trimmed)
+	}
+	return client, nil
+}
+
+func (s *OpenAIGatewayService) buildOpenAIBackendAPIHeaders(account *Account, token string) (http.Header, error) {
+	deviceID, sessionID := s.ensureOpenAIImageSessionCredentials(context.Background(), account)
+	headers := make(http.Header)
+	headers.Set("Authorization", "Bearer "+token)
+	headers.Set("Accept", "application/json")
+	headers.Set("Origin", "https://chatgpt.com")
+	headers.Set("Referer", "https://chatgpt.com/")
+	headers.Set("Sec-Fetch-Dest", "empty")
+	headers.Set("Sec-Fetch-Mode", "cors")
+	headers.Set("Sec-Fetch-Site", "same-origin")
+	headers.Set("User-Agent", openAIImageBackendUserAgent)
+	if customUA := strings.TrimSpace(account.GetOpenAIUserAgent()); customUA != "" {
+		headers.Set("User-Agent", customUA)
+	}
+	if chatgptAccountID := strings.TrimSpace(account.GetChatGPTAccountID()); chatgptAccountID != "" {
+		headers.Set("chatgpt-account-id", chatgptAccountID)
+	}
+	if deviceID != "" {
+		headers.Set("oai-device-id", deviceID)
+		headers.Set("Cookie", "oai-did="+deviceID)
+	}
+	if sessionID != "" {
+		headers.Set("oai-session-id", sessionID)
+	}
+	return headers, nil
+}
+
+func (s *OpenAIGatewayService) ensureOpenAIImageSessionCredentials(ctx context.Context, account *Account) (string, string) {
+	if account == nil {
+		return "", ""
+	}
+	deviceID := account.GetOpenAIDeviceID()
+	sessionID := account.GetOpenAISessionID()
+	if deviceID != "" && sessionID != "" {
+		return deviceID, sessionID
+	}
+
+	updates := map[string]any{}
+	if deviceID == "" {
+		deviceID = uuid.NewString()
+		updates["openai_device_id"] = deviceID
+	}
+	if sessionID == "" {
+		sessionID = uuid.NewString()
+		updates["openai_session_id"] = sessionID
+	}
+	if account.Extra == nil {
+		account.Extra = map[string]any{}
+	}
+	for key, value := range updates {
+		account.Extra[key] = value
+	}
+	if len(updates) == 0 || s == nil || s.accountRepo == nil {
+		return deviceID, sessionID
+	}
+
+	updateCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+	if err := s.accountRepo.UpdateExtra(updateCtx, account.ID, updates); err != nil {
+		logger.LegacyPrintf("service.openai_gateway", "persist openai image session creds failed: account=%d err=%v", account.ID, err)
+	}
+	return deviceID, sessionID
+}
+
+func bootstrapOpenAIBackendAPI(ctx context.Context, client *req.Client, headers http.Header) error {
+	resp, err := client.R().
+		SetContext(ctx).
+		DisableAutoReadResponse().
+		SetHeaders(headerToMap(headers)).
+		Get(openAIChatGPTStartURL)
+	if err != nil {
+		return err
+	}
+	if resp != nil && resp.Body != nil {
+		_, _ = io.Copy(io.Discard, resp.Body)
+		_ = resp.Body.Close()
+	}
+	return nil
+}
+
+func initializeOpenAIImageConversation(ctx context.Context, client *req.Client, headers http.Header) error {
+	payload := map[string]any{
+		"gizmo_id":                nil,
+		"requested_default_model": nil,
+		"conversation_id":         nil,
+		"timezone_offset_min":     openAITimezoneOffsetMinutes(),
+		"system_hints":            []string{"picture_v2"},
+	}
+	resp, err := client.R().
+		SetContext(ctx).
+		SetHeaders(headerToMap(headers)).
+		SetBodyJsonMarshal(payload).
+		Post(openAIChatGPTConversationInitURL)
+	if err != nil {
+		return err
+	}
+	if !resp.IsSuccessState() {
+		return newOpenAIImageStatusError(resp, "conversation init failed")
+	}
+	return nil
+}
+
+type openAIChatRequirements struct {
+	Token     string `json:"token"`
+	Turnstile struct {
+		Required bool `json:"required"`
+	} `json:"turnstile"`
+	Arkose struct {
+		Required bool `json:"required"`
+	} `json:"arkose"`
+	ProofOfWork struct {
+		Required   bool   `json:"required"`
+		Seed       string `json:"seed"`
+		Difficulty string `json:"difficulty"`
+	} `json:"proofofwork"`
+}
+
+func fetchOpenAIChatRequirements(ctx context.Context, client *req.Client, headers http.Header) (*openAIChatRequirements, error) {
+	var lastErr error
+	for _, payload := range []map[string]any{
+		{"p": nil},
+		{"p": generateOpenAIRequirementsToken(headers.Get("User-Agent"))},
+	} {
+		var result openAIChatRequirements
+		resp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(headerToMap(headers)).
+			SetBodyJsonMarshal(payload).
+			SetSuccessResult(&result).
+			Post(openAIChatGPTChatRequirementsURL)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		if resp.IsSuccessState() && strings.TrimSpace(result.Token) != "" {
+			return &result, nil
+		}
+		lastErr = newOpenAIImageStatusError(resp, "chat-requirements failed")
+	}
+	if lastErr == nil {
+		lastErr = fmt.Errorf("chat-requirements failed")
+	}
+	return nil, lastErr
+}
+
+func prepareOpenAIImageConversation(
+	ctx context.Context,
+	client *req.Client,
+	headers http.Header,
+	prompt string,
+	parentMessageID string,
+	chatToken string,
+	proofToken string,
+) (string, error) {
+	messageID := uuid.NewString()
+	payload := map[string]any{
+		"action":                "next",
+		"client_prepare_state":  "success",
+		"fork_from_shared_post": false,
+		"parent_message_id":     parentMessageID,
+		"model":                 "auto",
+		"timezone_offset_min":   openAITimezoneOffsetMinutes(),
+		"timezone":              openAITimezoneName(),
+		"conversation_mode":     map[string]any{"kind": "primary_assistant"},
+		"system_hints":          []string{"picture_v2"},
+		"supports_buffering":    true,
+		"supported_encodings":   []string{"v1"},
+		"partial_query": map[string]any{
+			"id":     messageID,
+			"author": map[string]any{"role": "user"},
+			"content": map[string]any{
+				"content_type": "text",
+				"parts":        []string{coalesceOpenAIFileName(prompt, "Generate an image.")},
+			},
+		},
+		"client_contextual_info": map[string]any{
+			"app_name": "chatgpt.com",
+		},
+	}
+	prepareHeaders := cloneHTTPHeader(headers)
+	prepareHeaders.Set("Accept", "*/*")
+	prepareHeaders.Set("Content-Type", "application/json")
+	if strings.TrimSpace(chatToken) != "" {
+		prepareHeaders.Set("openai-sentinel-chat-requirements-token", strings.TrimSpace(chatToken))
+	}
+	if strings.TrimSpace(proofToken) != "" {
+		prepareHeaders.Set("openai-sentinel-proof-token", strings.TrimSpace(proofToken))
+	}
+	var result struct {
+		ConduitToken string `json:"conduit_token"`
+	}
+	resp, err := client.R().
+		SetContext(ctx).
+		SetHeaders(headerToMap(prepareHeaders)).
+		SetBodyJsonMarshal(payload).
+		SetSuccessResult(&result).
+		Post(openAIChatGPTConversationPrepareURL)
+	if err != nil {
+		return "", err
+	}
+	if !resp.IsSuccessState() {
+		return "", newOpenAIImageStatusError(resp, "conversation prepare failed")
+	}
+	return strings.TrimSpace(result.ConduitToken), nil
+}
+
+type openAIUploadedImage struct {
+	FileID   string
+	FileName string
+	FileSize int
+	MimeType string
+	Width    int
+	Height   int
+}
+
+func uploadOpenAIImageFiles(ctx context.Context, client *req.Client, headers http.Header, uploads []OpenAIImagesUpload) ([]openAIUploadedImage, error) {
+	if len(uploads) == 0 {
+		return nil, nil
+	}
+	results := make([]openAIUploadedImage, 0, len(uploads))
+	for i := range uploads {
+		item := uploads[i]
+		fileName := coalesceOpenAIFileName(item.FileName, "image.png")
+		payload := map[string]any{
+			"file_name": fileName,
+			"file_size": len(item.Data),
+			"use_case":  "multimodal",
+		}
+		var created struct {
+			FileID    string `json:"file_id"`
+			UploadURL string `json:"upload_url"`
+		}
+		resp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(headerToMap(headers)).
+			SetBodyJsonMarshal(payload).
+			SetSuccessResult(&created).
+			Post(openAIChatGPTFilesURL)
+		if err != nil {
+			return nil, err
+		}
+		if !resp.IsSuccessState() || strings.TrimSpace(created.FileID) == "" || strings.TrimSpace(created.UploadURL) == "" {
+			return nil, newOpenAIImageStatusError(resp, "create upload slot failed")
+		}
+
+		uploadHeaders := map[string]string{
+			"Content-Type":   coalesceOpenAIFileName(item.ContentType, "application/octet-stream"),
+			"Origin":         "https://chatgpt.com",
+			"x-ms-blob-type": "BlockBlob",
+			"x-ms-version":   "2020-04-08",
+			"User-Agent":     headers.Get("User-Agent"),
+		}
+		putResp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(uploadHeaders).
+			SetBody(item.Data).
+			DisableAutoReadResponse().
+			Put(created.UploadURL)
+		if err != nil {
+			return nil, err
+		}
+		if putResp.Response != nil && putResp.Response.Body != nil {
+			_, _ = io.Copy(io.Discard, putResp.Response.Body)
+			_ = putResp.Response.Body.Close()
+		}
+		if putResp.StatusCode < 200 || putResp.StatusCode >= 300 {
+			return nil, newOpenAIImageStatusError(putResp, "upload image bytes failed")
+		}
+
+		uploadedResp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(headerToMap(headers)).
+			SetBodyJsonMarshal(map[string]any{}).
+			Post(fmt.Sprintf("%s/%s/uploaded", openAIChatGPTFilesURL, created.FileID))
+		if err != nil {
+			return nil, err
+		}
+		if !uploadedResp.IsSuccessState() {
+			return nil, newOpenAIImageStatusError(uploadedResp, "mark upload complete failed")
+		}
+
+		results = append(results, openAIUploadedImage{
+			FileID:   created.FileID,
+			FileName: fileName,
+			FileSize: len(item.Data),
+			MimeType: coalesceOpenAIFileName(item.ContentType, "application/octet-stream"),
+			Width:    item.Width,
+			Height:   item.Height,
+		})
+	}
+	return results, nil
+}
+
+func coalesceOpenAIFileName(value string, fallback string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return fallback
+	}
+	return value
+}
+
+func buildOpenAIImageConversationRequest(parsed *OpenAIImagesRequest, parentMessageID string, uploads []openAIUploadedImage) map[string]any {
+	parts := []any{coalesceOpenAIFileName(parsed.Prompt, "Generate an image.")}
+	attachments := make([]map[string]any, 0, len(uploads))
+	if len(uploads) > 0 {
+		parts = make([]any, 0, len(uploads)+1)
+		for _, upload := range uploads {
+			parts = append(parts, map[string]any{
+				"content_type":  "image_asset_pointer",
+				"asset_pointer": "file-service://" + upload.FileID,
+				"size_bytes":    upload.FileSize,
+				"width":         upload.Width,
+				"height":        upload.Height,
+			})
+			attachment := map[string]any{
+				"id":       upload.FileID,
+				"mimeType": upload.MimeType,
+				"name":     upload.FileName,
+				"size":     upload.FileSize,
+			}
+			if upload.Width > 0 {
+				attachment["width"] = upload.Width
+			}
+			if upload.Height > 0 {
+				attachment["height"] = upload.Height
+			}
+			attachments = append(attachments, attachment)
+		}
+		parts = append(parts, coalesceOpenAIFileName(parsed.Prompt, "Edit this image."))
+	}
+
+	contentType := "text"
+	if len(uploads) > 0 {
+		contentType = "multimodal_text"
+	}
+	metadata := map[string]any{
+		"developer_mode_connector_ids": []any{},
+		"selected_github_repos":        []any{},
+		"selected_all_github_repos":    false,
+		"system_hints":                 []string{"picture_v2"},
+		"serialization_metadata": map[string]any{
+			"custom_symbol_offsets": []any{},
+		},
+	}
+	message := map[string]any{
+		"id":     uuid.NewString(),
+		"author": map[string]any{"role": "user"},
+		"content": map[string]any{
+			"content_type": contentType,
+			"parts":        parts,
+		},
+		"metadata":    metadata,
+		"create_time": float64(time.Now().UnixMilli()) / 1000,
+	}
+	if len(attachments) > 0 {
+		metadata["attachments"] = attachments
+	}
+
+	return map[string]any{
+		"action":                               "next",
+		"client_prepare_state":                 "sent",
+		"parent_message_id":                    parentMessageID,
+		"model":                                "auto",
+		"timezone_offset_min":                  openAITimezoneOffsetMinutes(),
+		"timezone":                             openAITimezoneName(),
+		"conversation_mode":                    map[string]any{"kind": "primary_assistant"},
+		"enable_message_followups":             true,
+		"system_hints":                         []string{"picture_v2"},
+		"supports_buffering":                   true,
+		"supported_encodings":                  []string{"v1"},
+		"paragen_cot_summary_display_override": "allow",
+		"force_parallel_switch":                "auto",
+		"client_contextual_info": map[string]any{
+			"is_dark_mode":      false,
+			"time_since_loaded": 200,
+			"page_height":       900,
+			"page_width":        1440,
+			"pixel_ratio":       1,
+			"screen_height":     1080,
+			"screen_width":      1920,
+			"app_name":          "chatgpt.com",
+		},
+		"messages": []any{message},
+	}
+}
+
+type openAIImagePointerInfo struct {
+	Pointer string
+	Prompt  string
+}
+
+type openAIImageToolMessage struct {
+	MessageID    string
+	CreateTime   float64
+	PointerInfos []openAIImagePointerInfo
+}
+
+func readOpenAIImageConversationStream(resp *req.Response, startTime time.Time) (string, []openAIImagePointerInfo, OpenAIUsage, *int, error) {
+	if resp == nil || resp.Response == nil || resp.Response.Body == nil {
+		return "", nil, OpenAIUsage{}, nil, fmt.Errorf("empty conversation response")
+	}
+	reader := bufio.NewReader(resp.Response.Body)
+	var (
+		conversationID string
+		firstTokenMs   *int
+		usage          OpenAIUsage
+		pointers       []openAIImagePointerInfo
+	)
+
+	for {
+		line, err := reader.ReadString('\n')
+		if strings.TrimSpace(line) != "" && firstTokenMs == nil {
+			ms := int(time.Since(startTime).Milliseconds())
+			firstTokenMs = &ms
+		}
+		if data, ok := extractOpenAISSEDataLine(strings.TrimRight(line, "\r\n")); ok && data != "" && data != "[DONE]" {
+			dataBytes := []byte(data)
+			if conversationID == "" {
+				conversationID = strings.TrimSpace(gjson.GetBytes(dataBytes, "v.conversation_id").String())
+				if conversationID == "" {
+					conversationID = strings.TrimSpace(gjson.GetBytes(dataBytes, "conversation_id").String())
+				}
+			}
+			mergeOpenAIUsage(&usage, dataBytes)
+			pointers = mergeOpenAIImagePointerInfos(pointers, collectOpenAIImagePointers(dataBytes))
+		}
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return "", nil, OpenAIUsage{}, firstTokenMs, err
+		}
+	}
+	return conversationID, pointers, usage, firstTokenMs, nil
+}
+
+func collectOpenAIImagePointers(body []byte) []openAIImagePointerInfo {
+	if len(body) == 0 {
+		return nil
+	}
+	matches := openAIImagePointerMatches(body)
+	if len(matches) == 0 {
+		return nil
+	}
+	prompt := ""
+	for _, path := range []string{
+		"message.metadata.dalle.prompt",
+		"metadata.dalle.prompt",
+		"revised_prompt",
+	} {
+		if value := strings.TrimSpace(gjson.GetBytes(body, path).String()); value != "" {
+			prompt = value
+			break
+		}
+	}
+	out := make([]openAIImagePointerInfo, 0, len(matches))
+	for _, pointer := range matches {
+		out = append(out, openAIImagePointerInfo{Pointer: pointer, Prompt: prompt})
+	}
+	return out
+}
+
+func openAIImagePointerMatches(body []byte) []string {
+	raw := string(body)
+	matches := make([]string, 0, 4)
+	for _, prefix := range []string{"file-service://", "sediment://"} {
+		start := 0
+		for {
+			idx := strings.Index(raw[start:], prefix)
+			if idx < 0 {
+				break
+			}
+			idx += start
+			end := idx + len(prefix)
+			for end < len(raw) {
+				ch := raw[end]
+				if ch != '-' && ch != '_' &&
+					(ch < '0' || ch > '9') &&
+					(ch < 'a' || ch > 'z') &&
+					(ch < 'A' || ch > 'Z') {
+					break
+				}
+				end++
+			}
+			matches = append(matches, raw[idx:end])
+			start = end
+		}
+	}
+	return dedupeStrings(matches)
+}
+
+func mergeOpenAIImagePointerInfos(existing []openAIImagePointerInfo, next []openAIImagePointerInfo) []openAIImagePointerInfo {
+	if len(next) == 0 {
+		return existing
+	}
+	seen := make(map[string]openAIImagePointerInfo, len(existing)+len(next))
+	out := make([]openAIImagePointerInfo, 0, len(existing)+len(next))
+	for _, item := range existing {
+		seen[item.Pointer] = item
+		out = append(out, item)
+	}
+	for _, item := range next {
+		if existingItem, ok := seen[item.Pointer]; ok {
+			if existingItem.Prompt == "" && item.Prompt != "" {
+				for i := range out {
+					if out[i].Pointer == item.Pointer {
+						out[i].Prompt = item.Prompt
+						break
+					}
+				}
+			}
+			continue
+		}
+		seen[item.Pointer] = item
+		out = append(out, item)
+	}
+	return out
+}
+
+func hasOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) bool {
+	for _, item := range items {
+		if strings.HasPrefix(item.Pointer, "file-service://") {
+			return true
+		}
+	}
+	return false
+}
+
+func preferOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) []openAIImagePointerInfo {
+	if !hasOpenAIFileServicePointerInfos(items) {
+		return items
+	}
+	out := make([]openAIImagePointerInfo, 0, len(items))
+	for _, item := range items {
+		if strings.HasPrefix(item.Pointer, "file-service://") {
+			out = append(out, item)
+		}
+	}
+	return out
+}
+
+func extractOpenAIImageToolMessages(mapping map[string]any) []openAIImageToolMessage {
+	if len(mapping) == 0 {
+		return nil
+	}
+	out := make([]openAIImageToolMessage, 0, 4)
+	for messageID, raw := range mapping {
+		node, _ := raw.(map[string]any)
+		if node == nil {
+			continue
+		}
+		message, _ := node["message"].(map[string]any)
+		if message == nil {
+			continue
+		}
+		author, _ := message["author"].(map[string]any)
+		metadata, _ := message["metadata"].(map[string]any)
+		content, _ := message["content"].(map[string]any)
+		if author == nil || metadata == nil || content == nil {
+			continue
+		}
+		if role, _ := author["role"].(string); role != "tool" {
+			continue
+		}
+		if asyncTaskType, _ := metadata["async_task_type"].(string); asyncTaskType != "image_gen" {
+			continue
+		}
+		if contentType, _ := content["content_type"].(string); contentType != "multimodal_text" {
+			continue
+		}
+		prompt := ""
+		if title, _ := metadata["image_gen_title"].(string); strings.TrimSpace(title) != "" {
+			prompt = strings.TrimSpace(title)
+		}
+		item := openAIImageToolMessage{MessageID: messageID}
+		if createTime, ok := message["create_time"].(float64); ok {
+			item.CreateTime = createTime
+		}
+		parts, _ := content["parts"].([]any)
+		for _, part := range parts {
+			switch value := part.(type) {
+			case map[string]any:
+				if assetPointer, _ := value["asset_pointer"].(string); strings.TrimSpace(assetPointer) != "" {
+					for _, pointer := range openAIImagePointerMatches([]byte(assetPointer)) {
+						item.PointerInfos = append(item.PointerInfos, openAIImagePointerInfo{
+							Pointer: pointer,
+							Prompt:  prompt,
+						})
+					}
+				}
+			case string:
+				for _, pointer := range openAIImagePointerMatches([]byte(value)) {
+					item.PointerInfos = append(item.PointerInfos, openAIImagePointerInfo{
+						Pointer: pointer,
+						Prompt:  prompt,
+					})
+				}
+			}
+		}
+		if len(item.PointerInfos) == 0 {
+			continue
+		}
+		item.PointerInfos = mergeOpenAIImagePointerInfos(nil, item.PointerInfos)
+		out = append(out, item)
+	}
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].CreateTime < out[j].CreateTime
+	})
+	return out
+}
+
+func pollOpenAIImageConversation(ctx context.Context, client *req.Client, headers http.Header, conversationID string) ([]openAIImagePointerInfo, error) {
+	conversationID = strings.TrimSpace(conversationID)
+	if conversationID == "" {
+		return nil, nil
+	}
+	deadline := time.Now().Add(90 * time.Second)
+	interval := 3 * time.Second
+	previewWait := 15 * time.Second
+	var (
+		lastErr     error
+		firstToolAt time.Time
+	)
+	for time.Now().Before(deadline) {
+		resp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(headerToMap(headers)).
+			DisableAutoReadResponse().
+			Get(fmt.Sprintf("https://chatgpt.com/backend-api/conversation/%s", conversationID))
+		if err != nil {
+			lastErr = err
+		} else {
+			if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+				body, readErr := io.ReadAll(resp.Response.Body)
+				_ = resp.Response.Body.Close()
+				if readErr != nil {
+					lastErr = readErr
+					goto waitNextPoll
+				}
+				pointers := mergeOpenAIImagePointerInfos(nil, collectOpenAIImagePointers(body))
+				var decoded map[string]any
+				if err := json.Unmarshal(body, &decoded); err == nil {
+					if mapping, _ := decoded["mapping"].(map[string]any); len(mapping) > 0 {
+						toolMessages := extractOpenAIImageToolMessages(mapping)
+						if len(toolMessages) > 0 && firstToolAt.IsZero() {
+							firstToolAt = time.Now()
+						}
+						for _, msg := range toolMessages {
+							pointers = mergeOpenAIImagePointerInfos(pointers, msg.PointerInfos)
+						}
+					}
+				}
+				if hasOpenAIFileServicePointerInfos(pointers) {
+					return preferOpenAIFileServicePointerInfos(pointers), nil
+				}
+				if len(pointers) > 0 && !firstToolAt.IsZero() && time.Since(firstToolAt) >= previewWait {
+					return pointers, nil
+				}
+			} else {
+				statusErr := newOpenAIImageStatusError(resp, "conversation poll failed")
+				if isOpenAIImageTransientConversationNotFoundError(statusErr) {
+					lastErr = statusErr
+					goto waitNextPoll
+				}
+				return nil, statusErr
+			}
+		}
+
+	waitNextPoll:
+		timer := time.NewTimer(interval)
+		select {
+		case <-ctx.Done():
+			if !timer.Stop() {
+				<-timer.C
+			}
+			return nil, ctx.Err()
+		case <-timer.C:
+		}
+	}
+	return nil, lastErr
+}
+
+func buildOpenAIImageResponse(
+	ctx context.Context,
+	client *req.Client,
+	headers http.Header,
+	conversationID string,
+	pointers []openAIImagePointerInfo,
+) ([]byte, int, error) {
+	type responseItem struct {
+		B64JSON       string `json:"b64_json"`
+		RevisedPrompt string `json:"revised_prompt,omitempty"`
+	}
+	items := make([]responseItem, 0, len(pointers))
+	for _, pointer := range pointers {
+		downloadURL, err := fetchOpenAIImageDownloadURL(ctx, client, headers, conversationID, pointer.Pointer)
+		if err != nil {
+			return nil, 0, err
+		}
+		data, err := downloadOpenAIImageBytes(ctx, client, headers, downloadURL)
+		if err != nil {
+			return nil, 0, err
+		}
+		items = append(items, responseItem{
+			B64JSON:       base64.StdEncoding.EncodeToString(data),
+			RevisedPrompt: pointer.Prompt,
+		})
+	}
+	payload := map[string]any{
+		"created": time.Now().Unix(),
+		"data":    items,
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return nil, 0, err
+	}
+	return body, len(items), nil
+}
+
+func fetchOpenAIImageDownloadURL(
+	ctx context.Context,
+	client *req.Client,
+	headers http.Header,
+	conversationID string,
+	pointer string,
+) (string, error) {
+	url := ""
+	allowConversationRetry := false
+	switch {
+	case strings.HasPrefix(pointer, "file-service://"):
+		fileID := strings.TrimPrefix(pointer, "file-service://")
+		url = fmt.Sprintf("%s/%s/download", openAIChatGPTFilesURL, fileID)
+	case strings.HasPrefix(pointer, "sediment://"):
+		attachmentID := strings.TrimPrefix(pointer, "sediment://")
+		url = fmt.Sprintf("https://chatgpt.com/backend-api/conversation/%s/attachment/%s/download", conversationID, attachmentID)
+		allowConversationRetry = true
+	default:
+		return "", fmt.Errorf("unsupported image pointer: %s", pointer)
+	}
+
+	var lastErr error
+	for attempt := 0; attempt < 8; attempt++ {
+		var result struct {
+			DownloadURL string `json:"download_url"`
+		}
+		resp, err := client.R().
+			SetContext(ctx).
+			SetHeaders(headerToMap(headers)).
+			SetSuccessResult(&result).
+			Get(url)
+		if err != nil {
+			lastErr = err
+		} else if resp.IsSuccessState() && strings.TrimSpace(result.DownloadURL) != "" {
+			return strings.TrimSpace(result.DownloadURL), nil
+		} else {
+			statusErr := newOpenAIImageStatusError(resp, "fetch image download url failed")
+			if !allowConversationRetry || !isOpenAIImageTransientConversationNotFoundError(statusErr) {
+				return "", statusErr
+			}
+			lastErr = statusErr
+		}
+		if attempt == 7 {
+			break
+		}
+		timer := time.NewTimer(750 * time.Millisecond)
+		select {
+		case <-ctx.Done():
+			if !timer.Stop() {
+				<-timer.C
+			}
+			return "", ctx.Err()
+		case <-timer.C:
+		}
+	}
+	if lastErr == nil {
+		lastErr = fmt.Errorf("fetch image download url failed")
+	}
+	return "", lastErr
+}
+
+func downloadOpenAIImageBytes(ctx context.Context, client *req.Client, headers http.Header, downloadURL string) ([]byte, error) {
+	request := client.R().
+		SetContext(ctx).
+		DisableAutoReadResponse()
+
+	if strings.HasPrefix(downloadURL, openAIChatGPTStartURL) {
+		downloadHeaders := cloneHTTPHeader(headers)
+		downloadHeaders.Set("Accept", "image/*,*/*;q=0.8")
+		downloadHeaders.Del("Content-Type")
+		request.SetHeaders(headerToMap(downloadHeaders))
+	} else {
+		userAgent := strings.TrimSpace(headers.Get("User-Agent"))
+		if userAgent == "" {
+			userAgent = openAIImageBackendUserAgent
+		}
+		request.SetHeader("User-Agent", userAgent)
+	}
+
+	resp, err := request.Get(downloadURL)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if resp != nil && resp.Body != nil {
+			_ = resp.Body.Close()
+		}
+	}()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, newOpenAIImageStatusError(resp, "download image bytes failed")
+	}
+	return io.ReadAll(resp.Body)
+}
+
+func handleOpenAIImageBackendError(resp *req.Response) error {
+	return newOpenAIImageStatusError(resp, "backend-api request failed")
+}
+
+type openAIImageStatusError struct {
+	StatusCode      int
+	Message         string
+	ResponseBody    []byte
+	ResponseHeaders http.Header
+	RequestID       string
+	URL             string
+}
+
+func (e *openAIImageStatusError) Error() string {
+	if e == nil {
+		return "openai image backend request failed"
+	}
+	if e.Message != "" {
+		return e.Message
+	}
+	if e.StatusCode > 0 {
+		return fmt.Sprintf("openai image backend request failed: status %d", e.StatusCode)
+	}
+	return "openai image backend request failed"
+}
+
+func newOpenAIImageStatusError(resp *req.Response, fallback string) error {
+	if resp == nil {
+		if strings.TrimSpace(fallback) == "" {
+			fallback = "openai image backend request failed"
+		}
+		return fmt.Errorf("%s", fallback)
+	}
+
+	statusCode := resp.StatusCode
+	headers := http.Header(nil)
+	requestID := ""
+	requestURL := ""
+	body := []byte(nil)
+
+	if resp.Response != nil {
+		headers = resp.Response.Header.Clone()
+		requestID = strings.TrimSpace(resp.Response.Header.Get("x-request-id"))
+		if resp.Response.Request != nil && resp.Response.Request.URL != nil {
+			requestURL = resp.Response.Request.URL.String()
+		}
+		if resp.Response.Body != nil {
+			body, _ = io.ReadAll(io.LimitReader(resp.Response.Body, 2<<20))
+			_ = resp.Response.Body.Close()
+		}
+	}
+
+	message := sanitizeUpstreamErrorMessage(extractUpstreamErrorMessage(body))
+	if message == "" {
+		prefix := strings.TrimSpace(fallback)
+		if prefix == "" {
+			prefix = "openai image backend request failed"
+		}
+		message = fmt.Sprintf("%s: status %d", prefix, statusCode)
+	}
+
+	return &openAIImageStatusError{
+		StatusCode:      statusCode,
+		Message:         message,
+		ResponseBody:    body,
+		ResponseHeaders: headers,
+		RequestID:       requestID,
+		URL:             requestURL,
+	}
+}
+
+func newOpenAIImageSyntheticStatusError(statusCode int, message string, requestURL string) *openAIImageStatusError {
+	message = sanitizeUpstreamErrorMessage(strings.TrimSpace(message))
+	if message == "" {
+		message = "openai image backend request failed"
+	}
+	var body []byte
+	if payload, err := json.Marshal(map[string]string{"detail": message}); err == nil {
+		body = payload
+	}
+	return &openAIImageStatusError{
+		StatusCode:   statusCode,
+		Message:      message,
+		ResponseBody: body,
+		URL:          strings.TrimSpace(requestURL),
+	}
+}
+
+func isOpenAIImageTransientConversationNotFoundError(err error) bool {
+	statusErr, ok := err.(*openAIImageStatusError)
+	if !ok || statusErr == nil || statusErr.StatusCode != http.StatusNotFound {
+		return false
+	}
+	msg := strings.ToLower(strings.TrimSpace(statusErr.Message))
+	if strings.Contains(msg, "conversation_not_found") {
+		return true
+	}
+	if strings.Contains(msg, "conversation") && strings.Contains(msg, "not found") {
+		return true
+	}
+	bodyMsg := strings.ToLower(strings.TrimSpace(extractUpstreamErrorMessage(statusErr.ResponseBody)))
+	if strings.Contains(bodyMsg, "conversation_not_found") {
+		return true
+	}
+	return strings.Contains(bodyMsg, "conversation") && strings.Contains(bodyMsg, "not found")
+}
+
+func (s *OpenAIGatewayService) wrapOpenAIImageBackendError(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	err error,
+) error {
+	var statusErr *openAIImageStatusError
+	if !errors.As(err, &statusErr) || statusErr == nil {
+		return err
+	}
+
+	upstreamMsg := sanitizeUpstreamErrorMessage(statusErr.Message)
+	appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+		Platform:           account.Platform,
+		AccountID:          account.ID,
+		AccountName:        account.Name,
+		UpstreamStatusCode: statusErr.StatusCode,
+		UpstreamRequestID:  statusErr.RequestID,
+		UpstreamURL:        safeUpstreamURL(statusErr.URL),
+		Kind:               "request_error",
+		Message:            upstreamMsg,
+	})
+	setOpsUpstreamError(c, statusErr.StatusCode, upstreamMsg, "")
+
+	if s.shouldFailoverOpenAIUpstreamResponse(statusErr.StatusCode, upstreamMsg, statusErr.ResponseBody) {
+		if s.rateLimitService != nil {
+			s.rateLimitService.HandleUpstreamError(ctx, account, statusErr.StatusCode, statusErr.ResponseHeaders, statusErr.ResponseBody)
+		}
+		appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+			Platform:           account.Platform,
+			AccountID:          account.ID,
+			AccountName:        account.Name,
+			UpstreamStatusCode: statusErr.StatusCode,
+			UpstreamRequestID:  statusErr.RequestID,
+			UpstreamURL:        safeUpstreamURL(statusErr.URL),
+			Kind:               "failover",
+			Message:            upstreamMsg,
+		})
+		retryableOnSameAccount := account.IsPoolMode() && isPoolModeRetryableStatus(statusErr.StatusCode)
+		if strings.Contains(strings.ToLower(statusErr.Message), "unsupported challenge") {
+			retryableOnSameAccount = false
+		}
+		return &UpstreamFailoverError{
+			StatusCode:             statusErr.StatusCode,
+			ResponseBody:           statusErr.ResponseBody,
+			RetryableOnSameAccount: retryableOnSameAccount,
+		}
+	}
+
+	return statusErr
+}
+
+func cloneHTTPHeader(src http.Header) http.Header {
+	dst := make(http.Header, len(src))
+	for key, values := range src {
+		copied := make([]string, len(values))
+		copy(copied, values)
+		dst[key] = copied
+	}
+	return dst
+}
+
+func headerToMap(header http.Header) map[string]string {
+	if len(header) == 0 {
+		return nil
+	}
+	result := make(map[string]string, len(header))
+	for key, values := range header {
+		if len(values) == 0 {
+			continue
+		}
+		result[key] = values[0]
+	}
+	return result
+}
+
+func openAITimezoneOffsetMinutes() int {
+	_, offset := time.Now().Zone()
+	return offset / 60
+}
+
+func openAITimezoneName() string {
+	return time.Now().Location().String()
+}
+
+func generateOpenAIRequirementsToken(userAgent string) string {
+	config := []any{
+		"core" + strconv.Itoa(3008),
+		time.Now().UTC().Format(time.RFC1123),
+		nil,
+		0.123456,
+		coalesceOpenAIFileName(strings.TrimSpace(userAgent), openAIImageBackendUserAgent),
+		nil,
+		"prod-openai-images",
+		"en-US",
+		"en-US,en",
+		0,
+		"navigator.webdriver",
+		"location",
+		"document.body",
+		float64(time.Now().UnixMilli()) / 1000,
+		uuid.NewString(),
+		"",
+		8,
+		time.Now().Unix(),
+	}
+	answer, solved := generateOpenAIChallengeAnswer(strconv.FormatInt(time.Now().UnixNano(), 10), openAIImageRequirementsDiff, config)
+	if solved {
+		return "gAAAAAC" + answer
+	}
+	return ""
+}
+
+func generateOpenAIChallengeAnswer(seed string, difficulty string, config []any) (string, bool) {
+	diffBytes, err := hex.DecodeString(difficulty)
+	if err != nil {
+		return "", false
+	}
+	p1 := []byte(jsonCompactSlice(config[:3], true))
+	p2 := []byte(jsonCompactSlice(config[4:9], false))
+	p3 := []byte(jsonCompactSlice(config[10:], false))
+	seedBytes := []byte(seed)
+
+	for i := 0; i < 100000; i++ {
+		payload := fmt.Sprintf("%s%d,%s,%d,%s", p1, i, p2, i>>1, p3)
+		encoded := base64.StdEncoding.EncodeToString([]byte(payload))
+		sum := sha3.Sum512(append(seedBytes, []byte(encoded)...))
+		if bytes.Compare(sum[:len(diffBytes)], diffBytes) <= 0 {
+			return encoded, true
+		}
+	}
+	return "", false
+}
+
+func jsonCompactSlice(values []any, trimSuffixComma bool) string {
+	raw, _ := json.Marshal(values)
+	text := string(raw)
+	if trimSuffixComma {
+		return strings.TrimSuffix(text, "]")
+	}
+	return strings.TrimPrefix(text, "[")
+}
+
+func generateOpenAIProofToken(required bool, seed string, difficulty string, userAgent string) string {
+	if !required || strings.TrimSpace(seed) == "" || strings.TrimSpace(difficulty) == "" {
+		return ""
+	}
+	screen := 3008
+	if len(seed)%2 == 0 {
+		screen = 4010
+	}
+	proofToken := []any{
+		screen,
+		time.Now().UTC().Format(time.RFC1123),
+		nil,
+		0,
+		coalesceOpenAIFileName(strings.TrimSpace(userAgent), openAIImageBackendUserAgent),
+		"https://chatgpt.com/",
+		"dpl=openai-images",
+		"en",
+		"en-US",
+		nil,
+		"plugins[object PluginArray]",
+		"_reactListening",
+		"alert",
+	}
+	diffLen := len(difficulty)
+	for i := 0; i < 100000; i++ {
+		proofToken[3] = i
+		raw, _ := json.Marshal(proofToken)
+		encoded := base64.StdEncoding.EncodeToString(raw)
+		sum := sha3.Sum512([]byte(seed + encoded))
+		if strings.Compare(hex.EncodeToString(sum[:])[:diffLen], difficulty) <= 0 {
+			return "gAAAAAB" + encoded
+		}
+	}
+	fallbackBase := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%q", seed)))
+	return "gAAAAABwQ8Lk5FbGpA2NcR9dShT6gYjU7VxZ4D" + fallbackBase
+}
+
+func dedupeStrings(values []string) []string {
+	if len(values) == 0 {
+		return nil
+	}
+	seen := make(map[string]struct{}, len(values))
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		if _, ok := seen[value]; ok {
+			continue
+		}
+		seen[value] = struct{}{}
+		out = append(out, value)
+	}
+	return out
+}

backend/internal/service/openai_images_test.go

+package service
+
+import (
+	"bytes"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOpenAIGatewayServiceParseOpenAIImagesRequest_JSON(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"model":"gpt-image-2","prompt":"draw a cat","size":"1024x1024","quality":"high","stream":true}`)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/images/generations", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = req
+
+	svc := &OpenAIGatewayService{}
+	parsed, err := svc.ParseOpenAIImagesRequest(c, body)
+	require.NoError(t, err)
+	require.NotNil(t, parsed)
+	require.Equal(t, "/v1/images/generations", parsed.Endpoint)
+	require.Equal(t, "gpt-image-2", parsed.Model)
+	require.Equal(t, "draw a cat", parsed.Prompt)
+	require.True(t, parsed.Stream)
+	require.Equal(t, "1024x1024", parsed.Size)
+	require.Equal(t, "1K", parsed.SizeTier)
+	require.Equal(t, OpenAIImagesCapabilityNative, parsed.RequiredCapability)
+	require.False(t, parsed.Multipart)
+}
+
+func TestOpenAIGatewayServiceParseOpenAIImagesRequest_MultipartEdit(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var body bytes.Buffer
+	writer := multipart.NewWriter(&body)
+	require.NoError(t, writer.WriteField("model", "gpt-image-2"))
+	require.NoError(t, writer.WriteField("prompt", "replace background"))
+	require.NoError(t, writer.WriteField("size", "1536x1024"))
+	part, err := writer.CreateFormFile("image", "source.png")
+	require.NoError(t, err)
+	_, err = part.Write([]byte("fake-image-bytes"))
+	require.NoError(t, err)
+	require.NoError(t, writer.Close())
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/images/edits", bytes.NewReader(body.Bytes()))
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = req
+
+	svc := &OpenAIGatewayService{}
+	parsed, err := svc.ParseOpenAIImagesRequest(c, body.Bytes())
+	require.NoError(t, err)
+	require.NotNil(t, parsed)
+	require.Equal(t, "/v1/images/edits", parsed.Endpoint)
+	require.True(t, parsed.Multipart)
+	require.Equal(t, "gpt-image-2", parsed.Model)
+	require.Equal(t, "replace background", parsed.Prompt)
+	require.Equal(t, "1536x1024", parsed.Size)
+	require.Equal(t, "2K", parsed.SizeTier)
+	require.Len(t, parsed.Uploads, 1)
+	require.Equal(t, OpenAIImagesCapabilityNative, parsed.RequiredCapability)
+}
+
+func TestOpenAIGatewayServiceParseOpenAIImagesRequest_PromptOnlyDefaultsRemainBasic(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"prompt":"draw a cat"}`)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/images/generations", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = req
+
+	svc := &OpenAIGatewayService{}
+	parsed, err := svc.ParseOpenAIImagesRequest(c, body)
+	require.NoError(t, err)
+	require.NotNil(t, parsed)
+	require.Equal(t, "gpt-image-2", parsed.Model)
+	require.Equal(t, OpenAIImagesCapabilityBasic, parsed.RequiredCapability)
+}
+
+func TestOpenAIGatewayServiceParseOpenAIImagesRequest_ExplicitSizeRequiresNativeCapability(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"prompt":"draw a cat","size":"1024x1024"}`)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/images/generations", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = req
+
+	svc := &OpenAIGatewayService{}
+	parsed, err := svc.ParseOpenAIImagesRequest(c, body)
+	require.NoError(t, err)
+	require.NotNil(t, parsed)
+	require.Equal(t, OpenAIImagesCapabilityNative, parsed.RequiredCapability)
+}

backend/internal/service/ops_retry.go

@@ -388,7 +388,7 @@ func (s *OpsService) executeRetry(ctx context.Context, errorLog *OpsErrorLogDeta
 func detectOpsRetryType(path string) opsRetryRequestType {
 	p := strings.ToLower(strings.TrimSpace(path))
 	switch {
-	case strings.Contains(p, "/responses"):
+	case strings.Contains(p, "/responses"), strings.Contains(p, "/images/"):
 		return opsRetryTypeOpenAI
 	case strings.Contains(p, "/v1beta/"):
 		return opsRetryTypeGeminiV1B

backend/internal/web/embed_on.go

@@ -305,7 +305,8 @@ func shouldBypassEmbeddedFrontend(path string) bool {
 		strings.HasPrefix(trimmed, "/setup/") ||
 		trimmed == "/health" ||
 		trimmed == "/responses" ||
-		strings.HasPrefix(trimmed, "/responses/")
+		strings.HasPrefix(trimmed, "/responses/") ||
+		strings.HasPrefix(trimmed, "/images/")
 }
 
 func serveIndexHTML(c *gin.Context, fsys fs.FS) {