refactor(gateway): snapshot usage worker inputs

backend/internal/handler/gateway_handler.go

@@ -510,11 +510,12 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			}
 
 			// 使用量记录通过有界 worker 池提交，避免请求热路径创建无界 goroutine。
+			// ForceCacheBilling 提前拍成标量，避免 worker 闭包保活 failover 状态里的响应体。
+			forceCacheBilling := fs.ForceCacheBilling
 			quotaPlatform := service.QuotaPlatform(c.Request.Context(), apiKey)
 			h.submitUsageRecordTask(c.Request.Context(), func(ctx context.Context) {
 				if err := h.gatewayService.RecordUsage(ctx, &service.RecordUsageInput{
 					Result:             result,
-					ParsedRequest:      parsedReq,
 					QuotaPlatform:      quotaPlatform,
 					APIKey:             apiKey,
 					User:               apiKey.User,
@@ -525,7 +526,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 					UserAgent:          userAgent,
 					IPAddress:          clientIP,
 					RequestPayloadHash: requestPayloadHash,
-					ForceCacheBilling:  fs.ForceCacheBilling,
+					ForceCacheBilling:  forceCacheBilling,
 					APIKeyService:      h.apiKeyService,
 					ChannelUsageFields: channelMapping.ToUsageFields(reqModel, result.UpstreamModel),
 				}); err != nil {
@@ -918,11 +919,12 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			}
 
 			// 使用量记录通过有界 worker 池提交，避免请求热路径创建无界 goroutine。
+			// ForceCacheBilling 提前拍成标量，避免 worker 闭包保活 failover 状态里的响应体。
+			forceCacheBilling := fs.ForceCacheBilling
 			quotaPlatform := service.QuotaPlatform(c.Request.Context(), currentAPIKey)
 			h.submitUsageRecordTask(c.Request.Context(), func(ctx context.Context) {
 				if err := h.gatewayService.RecordUsage(ctx, &service.RecordUsageInput{
 					Result:             result,
-					ParsedRequest:      attemptParsedReq,
 					QuotaPlatform:      quotaPlatform,
 					APIKey:             currentAPIKey,
 					User:               currentAPIKey.User,
@@ -933,7 +935,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 					UserAgent:          userAgent,
 					IPAddress:          clientIP,
 					RequestPayloadHash: requestPayloadHash,
-					ForceCacheBilling:  fs.ForceCacheBilling,
+					ForceCacheBilling:  forceCacheBilling,
 					APIKeyService:      h.apiKeyService,
 					ChannelUsageFields: channelMapping.ToUsageFields(reqModel, result.UpstreamModel),
 				}); err != nil {

backend/internal/handler/gemini_v1beta_handler.go

@@ -527,6 +527,8 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 		requestPayloadHash := service.HashUsageRequestPayload(body)
 		inboundEndpoint := GetInboundEndpoint(c)
 		upstreamEndpoint := GetUpstreamEndpoint(c, account.Platform)
+		// ForceCacheBilling 提前拍成标量，避免 worker 闭包保活 failover 状态里的响应体。
+		forceCacheBilling := fs.ForceCacheBilling
 		quotaPlatform := service.QuotaPlatform(c.Request.Context(), apiKey)
 		h.submitUsageRecordTask(c.Request.Context(), func(ctx context.Context) {
 			if err := h.gatewayService.RecordUsageWithLongContext(ctx, &service.RecordUsageLongContextInput{
@@ -543,7 +545,7 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 				RequestPayloadHash:    requestPayloadHash,
 				LongContextThreshold:  200000, // Gemini 200K 阈值
 				LongContextMultiplier: 2.0,    // 超出部分双倍计费
-				ForceCacheBilling:     fs.ForceCacheBilling,
+				ForceCacheBilling:     forceCacheBilling,
 				APIKeyService:         h.apiKeyService,
 				ChannelUsageFields:    channelMapping.ToUsageFields(reqModel, result.UpstreamModel),
 			}); err != nil {

backend/internal/handler/openai_gateway_handler.go

@@ -1379,6 +1379,7 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 			zap.Int("candidate_count", scheduleDecision.CandidateCount),
 		)
 
+		var requestPayloadHash string
 		hooks := &service.OpenAIWSIngressHooks{
 			InitialRequestModel: reqModel,
 			BeforeRequest: func(turn int, payload []byte, originalModel string) error {
@@ -1464,7 +1465,7 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 						UpstreamEndpoint:   upstreamEndpoint,
 						UserAgent:          userAgent,
 						IPAddress:          clientIP,
-						RequestPayloadHash: service.HashUsageRequestPayload(firstMessage),
+						RequestPayloadHash: requestPayloadHash,
 						APIKeyService:      h.apiKeyService,
 						ChannelUsageFields: channelMappingWS.ToUsageFields(reqModel, result.UpstreamModel),
 					}); err != nil {
@@ -1484,6 +1485,9 @@ func (h *OpenAIGatewayHandler) ResponsesWebSocket(c *gin.Context) {
 			wsFirstMessage = h.gatewayService.ReplaceModelInBody(firstMessage, channelMappingWS.MappedModel)
 		}
 
+		// WebSocket 首包可能很大，hash 必须在 hooks 外算成字符串，避免 AfterTurn 闭包保活请求体。
+		requestPayloadHash = service.HashUsageRequestPayload(wsFirstMessage)
+
 		if err := h.gatewayService.ProxyResponsesWebSocketFromClient(ctx, c, wsConn, account, token, wsFirstMessage, hooks); err != nil {
 			var failoverErr *service.UpstreamFailoverError
 			if errors.As(err, &failoverErr) {

backend/internal/handler/openai_images.go

@@ -73,9 +73,10 @@ func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
 		h.errorResponse(c, http.StatusBadRequest, "invalid_request_error", err.Error())
 		return
 	}
+	requestModel := parsed.Model
 
 	reqLog = reqLog.With(
-		zap.String("model", parsed.Model),
+		zap.String("model", requestModel),
 		zap.Bool("stream", parsed.Stream),
 		zap.Bool("multipart", parsed.Multipart),
 		zap.String("capability", string(parsed.RequiredCapability)),
@@ -85,7 +86,7 @@ func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
 		h.errorResponse(c, http.StatusForbidden, "permission_error", service.ImageGenerationPermissionMessage())
 		return
 	}
-	if decision := h.checkContentModeration(c, reqLog, apiKey, subject, service.ContentModerationProtocolOpenAIImages, parsed.Model, parsed.ModerationBody()); decision != nil && decision.Blocked {
+	if decision := h.checkContentModeration(c, reqLog, apiKey, subject, service.ContentModerationProtocolOpenAIImages, requestModel, parsed.ModerationBody()); decision != nil && decision.Blocked {
 		h.errorResponse(c, contentModerationStatus(decision), contentModerationErrorCode(decision), decision.Message)
 		return
 	}
@@ -98,13 +99,13 @@ func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
 	}
 
 	if parsed.Multipart {
-		setOpsRequestContext(c, parsed.Model, parsed.Stream)
+		setOpsRequestContext(c, requestModel, parsed.Stream)
 	} else {
-		setOpsRequestContext(c, parsed.Model, parsed.Stream)
+		setOpsRequestContext(c, requestModel, parsed.Stream)
 	}
 	setOpsEndpointContext(c, "", int16(service.RequestTypeFromLegacy(parsed.Stream, false)))
 
-	channelMapping, _ := h.gatewayService.ResolveChannelMappingAndRestrict(c.Request.Context(), apiKey.GroupID, parsed.Model)
+	channelMapping, _ := h.gatewayService.ResolveChannelMappingAndRestrict(c.Request.Context(), apiKey.GroupID, requestModel)
 
 	if h.errorPassthroughService != nil {
 		service.BindErrorPassthroughService(c, h.errorPassthroughService)
@@ -147,7 +148,7 @@ func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
 			c.Request.Context(),
 			apiKey.GroupID,
 			sessionHash,
-			parsed.Model,
+			requestModel,
 			failedAccountIDs,
 			parsed.RequiredCapability,
 		)
@@ -324,14 +325,14 @@ func (h *OpenAIGatewayHandler) Images(c *gin.Context) {
 				IPAddress:          clientIP,
 				RequestPayloadHash: requestPayloadHash,
 				APIKeyService:      h.apiKeyService,
-				ChannelUsageFields: channelMapping.ToUsageFields(parsed.Model, upstreamModel),
+				ChannelUsageFields: channelMapping.ToUsageFields(requestModel, 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.String("model", requestModel),
 					zap.Int64("account_id", account.ID),
 				).Error("openai.images.record_usage_failed", zap.Error(err))
 			}

backend/internal/service/gateway_service.go

@@ -4729,6 +4729,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 						if retryErr == nil {
 							if retryResp.StatusCode < 400 {
 								// 重试请求被上游接受后同步 ParsedRequest，保证 usage/日志看到真实请求体。
+								lastWireBody = retryWireBody
 								if err := replaceBody(retryWireBody); err != nil {
 									_ = retryResp.Body.Close()
 									return nil, err
@@ -4769,6 +4770,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 										if retryErr2 == nil {
 											if retryResp2.StatusCode < 400 {
 												// 二阶段工具块降级成功时也必须更新当前 body。
+												lastWireBody = retryWireBody2
 												if err := replaceBody(retryWireBody2); err != nil {
 													_ = retryResp2.Body.Close()
 													return nil, err
@@ -4847,6 +4849,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 							if retryErr == nil {
 								if budgetRetryResp.StatusCode < 400 {
 									// budget 修正请求成功后，ParsedRequest 也要描述被接受的修正版。
+									lastWireBody = budgetWireBody
 									if err := replaceBody(budgetWireBody); err != nil {
 										_ = budgetRetryResp.Body.Close()
 										return nil, err
@@ -8228,10 +8231,10 @@ func (s *GatewayService) getUserGroupRateMultiplier(ctx context.Context, userID,
 	return resolver.Resolve(ctx, userID, groupID, groupDefaultMultiplier)
 }
 
-// RecordUsageInput 记录使用量的输入参数
+// RecordUsageInput 记录使用量的输入参数。
+// 异步 worker 只接收计费所需快照，不能持有 ParsedRequest/RequestBodyRef 这类大请求体引用。
 type RecordUsageInput struct {
 	Result             *ForwardResult
-	ParsedRequest      *ParsedRequest
 	APIKey             *APIKey
 	User               *User
 	Account            *Account
@@ -8709,15 +8712,8 @@ func writeUsageLogBestEffort(ctx context.Context, repo UsageLogRepository, usage
 	}
 }
 
-// recordUsageOpts 内部选项，参数化 RecordUsage 与 RecordUsageWithLongContext 的差异点。
+// recordUsageOpts 内部选项，参数化普通计费与长上下文计费的差异点。
 type recordUsageOpts struct {
-	// Claude Max 策略所需的 ParsedRequest（可选，仅 Claude 路径传入）
-	ParsedRequest *ParsedRequest
-
-	// EnableClaudePath 启用 Claude 路径特有逻辑：
-	// - Claude Max 缓存计费策略
-	EnableClaudePath bool
-
 	// 长上下文计费（仅 Gemini 路径需要）
 	LongContextThreshold  int
 	LongContextMultiplier float64
@@ -8740,9 +8736,7 @@ func (s *GatewayService) RecordUsage(ctx context.Context, input *RecordUsageInpu
 		APIKeyService:      input.APIKeyService,
 		QuotaPlatform:      input.QuotaPlatform,
 		ChannelUsageFields: input.ChannelUsageFields,
-	}, &recordUsageOpts{
+	}, &recordUsageOpts{})
-		EnableClaudePath: true,
-	})
 }
 
 // RecordUsageLongContextInput 记录使用量的输入参数（支持长上下文双倍计费）
@@ -8808,9 +8802,7 @@ type recordUsageCoreInput struct {
 }
 
 // recordUsageCore 是 RecordUsage 和 RecordUsageWithLongContext 的统一实现。
-// opts 中的字段控制两者之间的差异行为：
+// LongContextThreshold > 0 时 Token 计费回退走 CalculateCostWithLongContext。
-// - ParsedRequest != nil → 启用 Claude Max 缓存计费策略
-// - LongContextThreshold > 0 → Token 计费回退走 CalculateCostWithLongContext
 func (s *GatewayService) recordUsageCore(ctx context.Context, input *recordUsageCoreInput, opts *recordUsageOpts) error {
 	result := input.Result
 	apiKey := input.APIKey