Merge pull request #1795 from 0x90000/feat/openai-image-api-sync

feat(openai): 同步生图 API 支持并接入图片计费调度

backend/internal/handler/endpoint.go

@@ -15,10 +15,12 @@ import (
 // ──────────────────────────────────────────────────────────
 
 const (
-	EndpointMessages        = "/v1/messages"
-	EndpointChatCompletions = "/v1/chat/completions"
-	EndpointResponses       = "/v1/responses"
-	EndpointGeminiModels    = "/v1beta/models"
+	EndpointMessages          = "/v1/messages"
+	EndpointChatCompletions   = "/v1/chat/completions"
+	EndpointResponses         = "/v1/responses"
+	EndpointImagesGenerations = "/v1/images/generations"
+	EndpointImagesEdits       = "/v1/images/edits"
+	EndpointGeminiModels      = "/v1beta/models"
 )
 
 // gin.Context keys used by the middleware and helpers below.
@@ -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

@@ -38,13 +38,14 @@ var openAIAdvancedSchedulerSettingCache atomic.Value // *cachedOpenAIAdvancedSch
 var openAIAdvancedSchedulerSettingSF singleflight.Group
 
 type OpenAIAccountScheduleRequest struct {
-	GroupID            *int64
-	SessionHash        string
-	StickyAccountID    int64
-	PreviousResponseID string
-	RequestedModel     string
-	RequiredTransport  OpenAIUpstreamTransport
-	ExcludedIDs        map[int64]struct{}
+	GroupID                 *int64
+	SessionHash             string
+	StickyAccountID         int64
+	PreviousResponseID      string
+	RequestedModel          string
+	RequiredTransport       OpenAIUpstreamTransport
+	RequiredImageCapability OpenAIImagesCapability
+	ExcludedIDs             map[int64]struct{}
 }
 
 type OpenAIAccountScheduleDecision 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)
@@ -937,13 +993,14 @@ func (s *OpenAIGatewayService) SelectAccountWithScheduler(
 	}
 
 	return scheduler.Select(ctx, OpenAIAccountScheduleRequest{
-		GroupID:            groupID,
-		SessionHash:        sessionHash,
-		StickyAccountID:    stickyAccountID,
-		PreviousResponseID: previousResponseID,
-		RequestedModel:     requestedModel,
-		RequiredTransport:  requiredTransport,
-		ExcludedIDs:        excludedIDs,
+		GroupID:                 groupID,
+		SessionHash:             sessionHash,
+		StickyAccountID:         stickyAccountID,
+		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_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) {