Merge branch 'main' of https://github.com/mt21625457/aicodex2api

backend/internal/config/config.go

@@ -258,8 +258,43 @@ type GatewayConfig struct {
 	// 是否允许对部分 400 错误触发 failover（默认关闭以避免改变语义）
 	FailoverOn400 bool `mapstructure:"failover_on_400"`
 
+	// 账户切换最大次数（遇到上游错误时切换到其他账户的次数上限）
+	MaxAccountSwitches int `mapstructure:"max_account_switches"`
+	// Gemini 账户切换最大次数（Gemini 平台单独配置，因 API 限制更严格）
+	MaxAccountSwitchesGemini int `mapstructure:"max_account_switches_gemini"`
+
+	// Antigravity 429 fallback 限流时间（分钟），解析重置时间失败时使用
+	AntigravityFallbackCooldownMinutes int `mapstructure:"antigravity_fallback_cooldown_minutes"`
+
 	// Scheduling: 账号调度相关配置
 	Scheduling GatewaySchedulingConfig `mapstructure:"scheduling"`
+
+	// TLSFingerprint: TLS指纹伪装配置
+	TLSFingerprint TLSFingerprintConfig `mapstructure:"tls_fingerprint"`
+}
+
+// TLSFingerprintConfig TLS指纹伪装配置
+// 用于模拟 Claude CLI (Node.js) 的 TLS 握手特征，避免被识别为非官方客户端
+type TLSFingerprintConfig struct {
+	// Enabled: 是否全局启用TLS指纹功能
+	Enabled bool `mapstructure:"enabled"`
+	// Profiles: 预定义的TLS指纹配置模板
+	// key 为模板名称，如 "claude_cli_v2", "chrome_120" 等
+	Profiles map[string]TLSProfileConfig `mapstructure:"profiles"`
+}
+
+// TLSProfileConfig 单个TLS指纹模板的配置
+type TLSProfileConfig struct {
+	// Name: 模板显示名称
+	Name string `mapstructure:"name"`
+	// EnableGREASE: 是否启用GREASE扩展（Chrome使用，Node.js不使用）
+	EnableGREASE bool `mapstructure:"enable_grease"`
+	// CipherSuites: TLS加密套件列表（空则使用内置默认值）
+	CipherSuites []uint16 `mapstructure:"cipher_suites"`
+	// Curves: 椭圆曲线列表（空则使用内置默认值）
+	Curves []uint16 `mapstructure:"curves"`
+	// PointFormats: 点格式列表（空则使用内置默认值）
+	PointFormats []uint8 `mapstructure:"point_formats"`
 }
 
 // GatewaySchedulingConfig accounts scheduling configuration.
@@ -272,6 +307,9 @@ type GatewaySchedulingConfig struct {
 	FallbackWaitTimeout time.Duration `mapstructure:"fallback_wait_timeout"`
 	FallbackMaxWaiting  int           `mapstructure:"fallback_max_waiting"`
 
+	// 兜底层账户选择策略: "last_used"(按最后使用时间排序，默认) 或 "random"(随机)
+	FallbackSelectionMode string `mapstructure:"fallback_selection_mode"`
+
 	// 负载计算
 	LoadBatchEnabled bool `mapstructure:"load_batch_enabled"`
 
@@ -781,6 +819,9 @@ func setDefaults() {
 	viper.SetDefault("gateway.log_upstream_error_body_max_bytes", 2048)
 	viper.SetDefault("gateway.inject_beta_for_apikey", false)
 	viper.SetDefault("gateway.failover_on_400", false)
+	viper.SetDefault("gateway.max_account_switches", 10)
+	viper.SetDefault("gateway.max_account_switches_gemini", 3)
+	viper.SetDefault("gateway.antigravity_fallback_cooldown_minutes", 1)
 	viper.SetDefault("gateway.max_body_size", int64(100*1024*1024))
 	viper.SetDefault("gateway.connection_pool_isolation", ConnectionPoolIsolationAccountProxy)
 	// HTTP 上游连接池配置（针对 5000+ 并发用户优化）
@@ -793,11 +834,12 @@ func setDefaults() {
 	viper.SetDefault("gateway.concurrency_slot_ttl_minutes", 30) // 并发槽位过期时间（支持超长请求）
 	viper.SetDefault("gateway.stream_data_interval_timeout", 180)
 	viper.SetDefault("gateway.stream_keepalive_interval", 10)
-	viper.SetDefault("gateway.max_line_size", 10*1024*1024)
+	viper.SetDefault("gateway.max_line_size", 40*1024*1024)
 	viper.SetDefault("gateway.scheduling.sticky_session_max_waiting", 3)
 	viper.SetDefault("gateway.scheduling.sticky_session_wait_timeout", 120*time.Second)
 	viper.SetDefault("gateway.scheduling.fallback_wait_timeout", 30*time.Second)
 	viper.SetDefault("gateway.scheduling.fallback_max_waiting", 100)
+	viper.SetDefault("gateway.scheduling.fallback_selection_mode", "last_used")
 	viper.SetDefault("gateway.scheduling.load_batch_enabled", true)
 	viper.SetDefault("gateway.scheduling.slot_cleanup_interval", 30*time.Second)
 	viper.SetDefault("gateway.scheduling.db_fallback_enabled", true)
@@ -809,6 +851,8 @@ func setDefaults() {
 	viper.SetDefault("gateway.scheduling.outbox_lag_rebuild_failures", 3)
 	viper.SetDefault("gateway.scheduling.outbox_backlog_rebuild_rows", 10000)
 	viper.SetDefault("gateway.scheduling.full_rebuild_interval_seconds", 300)
+	// TLS指纹伪装配置（默认关闭，需要账号级别单独启用）
+	viper.SetDefault("gateway.tls_fingerprint.enabled", true)
 	viper.SetDefault("concurrency.ping_interval", 10)
 
 	// TokenRefresh

backend/internal/handler/admin/account_handler.go

@@ -173,6 +173,7 @@ func (h *AccountHandler) List(c *gin.Context) {
 	// 识别需要查询窗口费用和会话数的账号（Anthropic OAuth/SetupToken 且启用了相应功能）
 	windowCostAccountIDs := make([]int64, 0)
 	sessionLimitAccountIDs := make([]int64, 0)
+	sessionIdleTimeouts := make(map[int64]time.Duration) // 各账号的会话空闲超时配置
 	for i := range accounts {
 		acc := &accounts[i]
 		if acc.IsAnthropicOAuthOrSetupToken() {
@@ -181,6 +182,7 @@ func (h *AccountHandler) List(c *gin.Context) {
 			}
 			if acc.GetMaxSessions() > 0 {
 				sessionLimitAccountIDs = append(sessionLimitAccountIDs, acc.ID)
+				sessionIdleTimeouts[acc.ID] = time.Duration(acc.GetSessionIdleTimeoutMinutes()) * time.Minute
 			}
 		}
 	}
@@ -189,9 +191,9 @@ func (h *AccountHandler) List(c *gin.Context) {
 	var windowCosts map[int64]float64
 	var activeSessions map[int64]int
 
-	// 获取活跃会话数（批量查询）
+	// 获取活跃会话数（批量查询，传入各账号的 idleTimeout 配置）
 	if len(sessionLimitAccountIDs) > 0 && h.sessionLimitCache != nil {
-		activeSessions, _ = h.sessionLimitCache.GetActiveSessionCountBatch(c.Request.Context(), sessionLimitAccountIDs)
+		activeSessions, _ = h.sessionLimitCache.GetActiveSessionCountBatch(c.Request.Context(), sessionLimitAccountIDs, sessionIdleTimeouts)
 		if activeSessions == nil {
 			activeSessions = make(map[int64]int)
 		}
@@ -211,12 +213,8 @@ func (h *AccountHandler) List(c *gin.Context) {
 			}
 			accCopy := acc // 闭包捕获
 			g.Go(func() error {
-				var startTime time.Time
-				if accCopy.SessionWindowStart != nil {
-					startTime = *accCopy.SessionWindowStart
-				} else {
-					startTime = time.Now().Add(-5 * time.Hour)
-				}
+				// 使用统一的窗口开始时间计算逻辑（考虑窗口过期情况）
+				startTime := accCopy.GetCurrentWindowStartTime()
 				stats, err := h.accountUsageService.GetAccountWindowStats(gctx, accCopy.ID, startTime)
 				if err == nil && stats != nil {
 					mu.Lock()
@@ -545,6 +543,36 @@ func (h *AccountHandler) Refresh(c *gin.Context) {
 				newCredentials[k] = v
 			}
 		}
+
+		// 如果 project_id 获取失败，先更新凭证，再标记账户为 error
+		if tokenInfo.ProjectIDMissing {
+			// 先更新凭证
+			_, updateErr := h.adminService.UpdateAccount(c.Request.Context(), accountID, &service.UpdateAccountInput{
+				Credentials: newCredentials,
+			})
+			if updateErr != nil {
+				response.InternalError(c, "Failed to update credentials: "+updateErr.Error())
+				return
+			}
+			// 标记账户为 error
+			if setErr := h.adminService.SetAccountError(c.Request.Context(), accountID, "missing_project_id: 账户缺少project id，可能无法使用Antigravity"); setErr != nil {
+				response.InternalError(c, "Failed to set account error: "+setErr.Error())
+				return
+			}
+			response.Success(c, gin.H{
+				"message": "Token refreshed but project_id is missing, account marked as error",
+				"warning": "missing_project_id",
+			})
+			return
+		}
+
+		// 成功获取到 project_id，如果之前是 missing_project_id 错误则清除
+		if account.Status == service.StatusError && strings.Contains(account.ErrorMessage, "missing_project_id:") {
+			if _, clearErr := h.adminService.ClearAccountError(c.Request.Context(), accountID); clearErr != nil {
+				response.InternalError(c, "Failed to clear account error: "+clearErr.Error())
+				return
+			}
+		}
 	} else {
 		// Use Anthropic/Claude OAuth service to refresh token
 		tokenInfo, err := h.oauthService.RefreshAccountToken(c.Request.Context(), account)

backend/internal/handler/admin/admin_service_stub_test.go

@@ -200,6 +200,10 @@ func (s *stubAdminService) ClearAccountError(ctx context.Context, id int64) (*se
 	return &account, nil
 }
 
+func (s *stubAdminService) SetAccountError(ctx context.Context, id int64, errorMsg string) error {
+	return nil
+}
+
 func (s *stubAdminService) SetAccountSchedulable(ctx context.Context, id int64, schedulable bool) (*service.Account, error) {
 	account := service.Account{ID: id, Name: "account", Status: service.StatusActive, Schedulable: schedulable}
 	return &account, nil

backend/internal/handler/dto/mappers.go

@@ -161,6 +161,16 @@ func AccountFromServiceShallow(a *service.Account) *Account {
 		if idleTimeout := a.GetSessionIdleTimeoutMinutes(); idleTimeout > 0 {
 			out.SessionIdleTimeoutMin = &idleTimeout
 		}
+		// TLS指纹伪装开关
+		if a.IsTLSFingerprintEnabled() {
+			enabled := true
+			out.EnableTLSFingerprint = &enabled
+		}
+		// 会话ID伪装开关
+		if a.IsSessionIDMaskingEnabled() {
+			enabled := true
+			out.EnableSessionIDMasking = &enabled
+		}
 	}
 
 	return out

backend/internal/handler/dto/types.go

@@ -112,6 +112,15 @@ type Account struct {
 	MaxSessions           *int `json:"max_sessions,omitempty"`
 	SessionIdleTimeoutMin *int `json:"session_idle_timeout_minutes,omitempty"`
 
+	// TLS指纹伪装（仅 Anthropic OAuth/SetupToken 账号有效）
+	// 从 extra 字段提取，方便前端显示和编辑
+	EnableTLSFingerprint *bool `json:"enable_tls_fingerprint,omitempty"`
+
+	// 会话ID伪装（仅 Anthropic OAuth/SetupToken 账号有效）
+	// 启用后将在15分钟内固定 metadata.user_id 中的 session ID
+	// 从 extra 字段提取，方便前端显示和编辑
+	EnableSessionIDMasking *bool `json:"session_id_masking_enabled,omitempty"`
+
 	Proxy         *Proxy         `json:"proxy,omitempty"`
 	AccountGroups []AccountGroup `json:"account_groups,omitempty"`
 

backend/internal/handler/gateway_handler.go

@@ -31,6 +31,8 @@ type GatewayHandler struct {
 	userService               *service.UserService
 	billingCacheService       *service.BillingCacheService
 	concurrencyHelper         *ConcurrencyHelper
+	maxAccountSwitches        int
+	maxAccountSwitchesGemini  int
 }
 
 // NewGatewayHandler creates a new GatewayHandler
@@ -44,8 +46,16 @@ func NewGatewayHandler(
 	cfg *config.Config,
 ) *GatewayHandler {
 	pingInterval := time.Duration(0)
+	maxAccountSwitches := 10
+	maxAccountSwitchesGemini := 3
 	if cfg != nil {
 		pingInterval = time.Duration(cfg.Concurrency.PingInterval) * time.Second
+		if cfg.Gateway.MaxAccountSwitches > 0 {
+			maxAccountSwitches = cfg.Gateway.MaxAccountSwitches
+		}
+		if cfg.Gateway.MaxAccountSwitchesGemini > 0 {
+			maxAccountSwitchesGemini = cfg.Gateway.MaxAccountSwitchesGemini
+		}
 	}
 	return &GatewayHandler{
 		gatewayService:            gatewayService,
@@ -54,6 +64,8 @@ func NewGatewayHandler(
 		userService:               userService,
 		billingCacheService:       billingCacheService,
 		concurrencyHelper:         NewConcurrencyHelper(concurrencyService, SSEPingFormatClaude, pingInterval),
+		maxAccountSwitches:        maxAccountSwitches,
+		maxAccountSwitchesGemini:  maxAccountSwitchesGemini,
 	}
 }
 
@@ -179,7 +191,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 	}
 
 	if platform == service.PlatformGemini {
-		const maxAccountSwitches = 3
+		maxAccountSwitches := h.maxAccountSwitchesGemini
 		switchCount := 0
 		failedAccountIDs := make(map[int64]struct{})
 		lastFailoverStatus := 0
@@ -313,7 +325,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 		}
 	}
 
-	const maxAccountSwitches = 10
+	maxAccountSwitches := h.maxAccountSwitches
 	switchCount := 0
 	failedAccountIDs := make(map[int64]struct{})
 	lastFailoverStatus := 0

backend/internal/handler/gemini_v1beta_handler.go

@@ -220,7 +220,7 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 	if sessionHash != "" {
 		sessionKey = "gemini:" + sessionHash
 	}
-	const maxAccountSwitches = 3
+	maxAccountSwitches := h.maxAccountSwitchesGemini
 	switchCount := 0
 	failedAccountIDs := make(map[int64]struct{})
 	lastFailoverStatus := 0

backend/internal/handler/openai_gateway_handler.go

@@ -25,6 +25,7 @@ type OpenAIGatewayHandler struct {
 	gatewayService      *service.OpenAIGatewayService
 	billingCacheService *service.BillingCacheService
 	concurrencyHelper   *ConcurrencyHelper
+	maxAccountSwitches  int
 }
 
 // NewOpenAIGatewayHandler creates a new OpenAIGatewayHandler
@@ -35,13 +36,18 @@ func NewOpenAIGatewayHandler(
 	cfg *config.Config,
 ) *OpenAIGatewayHandler {
 	pingInterval := time.Duration(0)
+	maxAccountSwitches := 3
 	if cfg != nil {
 		pingInterval = time.Duration(cfg.Concurrency.PingInterval) * time.Second
+		if cfg.Gateway.MaxAccountSwitches > 0 {
+			maxAccountSwitches = cfg.Gateway.MaxAccountSwitches
+		}
 	}
 	return &OpenAIGatewayHandler{
 		gatewayService:      gatewayService,
 		billingCacheService: billingCacheService,
 		concurrencyHelper:   NewConcurrencyHelper(concurrencyService, SSEPingFormatComment, pingInterval),
+		maxAccountSwitches:  maxAccountSwitches,
 	}
 }
 
@@ -189,7 +195,7 @@ func (h *OpenAIGatewayHandler) Responses(c *gin.Context) {
 	// Generate session hash (header first; fallback to prompt_cache_key)
 	sessionHash := h.gatewayService.GenerateSessionHash(c, reqBody)
 
-	const maxAccountSwitches = 3
+	maxAccountSwitches := h.maxAccountSwitches
 	switchCount := 0
 	failedAccountIDs := make(map[int64]struct{})
 	lastFailoverStatus := 0

backend/internal/pkg/antigravity/client.go

@@ -16,15 +16,6 @@ import (
 	"time"
 )
 
-// resolveHost 从 URL 解析 host
-func resolveHost(urlStr string) string {
-	parsed, err := url.Parse(urlStr)
-	if err != nil {
-		return ""
-	}
-	return parsed.Host
-}
-
 // NewAPIRequestWithURL 使用指定的 base URL 创建 Antigravity API 请求（v1internal 端点）
 func NewAPIRequestWithURL(ctx context.Context, baseURL, action, accessToken string, body []byte) (*http.Request, error) {
 	// 构建 URL，流式请求添加 ?alt=sse 参数
@@ -39,23 +30,11 @@ func NewAPIRequestWithURL(ctx context.Context, baseURL, action, accessToken stri
 		return nil, err
 	}
 
-	// 基础 Headers
+	// 基础 Headers（与 Antigravity-Manager 保持一致，只设置这 3 个）
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Authorization", "Bearer "+accessToken)
 	req.Header.Set("User-Agent", UserAgent)
 
-	// Accept Header 根据请求类型设置
-	if isStream {
-		req.Header.Set("Accept", "text/event-stream")
-	} else {
-		req.Header.Set("Accept", "application/json")
-	}
-
-	// 显式设置 Host Header
-	if host := resolveHost(apiURL); host != "" {
-		req.Host = host
-	}
-
 	return req, nil
 }
 
@@ -195,12 +174,15 @@ func isConnectionError(err error) bool {
 }
 
 // shouldFallbackToNextURL 判断是否应切换到下一个 URL
-// 仅连接错误和 HTTP 429 触发 URL 降级
+// 与 Antigravity-Manager 保持一致：连接错误、429、408、404、5xx 触发 URL 降级
 func shouldFallbackToNextURL(err error, statusCode int) bool {
 	if isConnectionError(err) {
 		return true
 	}
-	return statusCode == http.StatusTooManyRequests
+	return statusCode == http.StatusTooManyRequests ||
+		statusCode == http.StatusRequestTimeout ||
+		statusCode == http.StatusNotFound ||
+		statusCode >= 500
 }
 
 // ExchangeCode 用 authorization code 交换 token
@@ -321,11 +303,8 @@ func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadC
 		return nil, nil, fmt.Errorf("序列化请求失败: %w", err)
 	}
 
-	// 获取可用的 URL 列表
-	availableURLs := DefaultURLAvailability.GetAvailableURLs()
-	if len(availableURLs) == 0 {
-		availableURLs = BaseURLs // 所有 URL 都不可用时，重试所有
-	}
+	// 固定顺序：prod -> daily
+	availableURLs := BaseURLs
 
 	var lastErr error
 	for urlIdx, baseURL := range availableURLs {
@@ -343,7 +322,6 @@ func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadC
 		if err != nil {
 			lastErr = fmt.Errorf("loadCodeAssist 请求失败: %w", err)
 			if shouldFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
-				DefaultURLAvailability.MarkUnavailable(baseURL)
 				log.Printf("[antigravity] loadCodeAssist URL fallback: %s -> %s", baseURL, availableURLs[urlIdx+1])
 				continue
 			}
@@ -358,7 +336,6 @@ func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadC
 
 		// 检查是否需要 URL 降级
 		if shouldFallbackToNextURL(nil, resp.StatusCode) && urlIdx < len(availableURLs)-1 {
-			DefaultURLAvailability.MarkUnavailable(baseURL)
 			log.Printf("[antigravity] loadCodeAssist URL fallback (HTTP %d): %s -> %s", resp.StatusCode, baseURL, availableURLs[urlIdx+1])
 			continue
 		}
@@ -376,6 +353,8 @@ func (c *Client) LoadCodeAssist(ctx context.Context, accessToken string) (*LoadC
 		var rawResp map[string]any
 		_ = json.Unmarshal(respBodyBytes, &rawResp)
 
+		// 标记成功的 URL，下次优先使用
+		DefaultURLAvailability.MarkSuccess(baseURL)
 		return &loadResp, rawResp, nil
 	}
 
@@ -412,11 +391,8 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 		return nil, nil, fmt.Errorf("序列化请求失败: %w", err)
 	}
 
-	// 获取可用的 URL 列表
-	availableURLs := DefaultURLAvailability.GetAvailableURLs()
-	if len(availableURLs) == 0 {
-		availableURLs = BaseURLs // 所有 URL 都不可用时，重试所有
-	}
+	// 固定顺序：prod -> daily
+	availableURLs := BaseURLs
 
 	var lastErr error
 	for urlIdx, baseURL := range availableURLs {
@@ -434,7 +410,6 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 		if err != nil {
 			lastErr = fmt.Errorf("fetchAvailableModels 请求失败: %w", err)
 			if shouldFallbackToNextURL(err, 0) && urlIdx < len(availableURLs)-1 {
-				DefaultURLAvailability.MarkUnavailable(baseURL)
 				log.Printf("[antigravity] fetchAvailableModels URL fallback: %s -> %s", baseURL, availableURLs[urlIdx+1])
 				continue
 			}
@@ -449,7 +424,6 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 
 		// 检查是否需要 URL 降级
 		if shouldFallbackToNextURL(nil, resp.StatusCode) && urlIdx < len(availableURLs)-1 {
-			DefaultURLAvailability.MarkUnavailable(baseURL)
 			log.Printf("[antigravity] fetchAvailableModels URL fallback (HTTP %d): %s -> %s", resp.StatusCode, baseURL, availableURLs[urlIdx+1])
 			continue
 		}
@@ -467,6 +441,8 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 		var rawResp map[string]any
 		_ = json.Unmarshal(respBodyBytes, &rawResp)
 
+		// 标记成功的 URL，下次优先使用
+		DefaultURLAvailability.MarkSuccess(baseURL)
 		return &modelsResp, rawResp, nil
 	}
 

backend/internal/pkg/antigravity/gemini_types.go

@@ -143,9 +143,10 @@ type GeminiResponse struct {
 
 // GeminiCandidate Gemini 候选响应
 type GeminiCandidate struct {
-	Content      *GeminiContent `json:"content,omitempty"`
-	FinishReason string         `json:"finishReason,omitempty"`
-	Index        int            `json:"index,omitempty"`
+	Content           *GeminiContent           `json:"content,omitempty"`
+	FinishReason      string                   `json:"finishReason,omitempty"`
+	Index             int                      `json:"index,omitempty"`
+	GroundingMetadata *GeminiGroundingMetadata `json:"groundingMetadata,omitempty"`
 }
 
 // GeminiUsageMetadata Gemini 用量元数据
@@ -156,6 +157,23 @@ type GeminiUsageMetadata struct {
 	TotalTokenCount         int `json:"totalTokenCount,omitempty"`
 }
 
+// GeminiGroundingMetadata Gemini grounding 元数据（Web Search）
+type GeminiGroundingMetadata struct {
+	WebSearchQueries []string               `json:"webSearchQueries,omitempty"`
+	GroundingChunks  []GeminiGroundingChunk `json:"groundingChunks,omitempty"`
+}
+
+// GeminiGroundingChunk Gemini grounding chunk
+type GeminiGroundingChunk struct {
+	Web *GeminiGroundingWeb `json:"web,omitempty"`
+}
+
+// GeminiGroundingWeb Gemini grounding web 信息
+type GeminiGroundingWeb struct {
+	Title string `json:"title,omitempty"`
+	URI   string `json:"uri,omitempty"`
+}
+
 // DefaultSafetySettings 默认安全设置（关闭所有过滤）
 var DefaultSafetySettings = []GeminiSafetySetting{
 	{Category: "HARM_CATEGORY_HARASSMENT", Threshold: "OFF"},

backend/internal/pkg/antigravity/oauth.go

@@ -32,8 +32,8 @@ const (
 		"https://www.googleapis.com/auth/cclog " +
 		"https://www.googleapis.com/auth/experimentsandconfigs"
 
-	// User-Agent（模拟官方客户端）
-	UserAgent = "antigravity/1.104.0 darwin/arm64"
+	// User-Agent（与 Antigravity-Manager 保持一致）
+	UserAgent = "antigravity/1.11.9 windows/amd64"
 
 	// Session 过期时间
 	SessionTTL = 30 * time.Minute
@@ -42,22 +42,21 @@ const (
 	URLAvailabilityTTL = 5 * time.Minute
 )
 
-// BaseURLs 定义 Antigravity API 端点，按优先级排序
-// fallback 顺序: sandbox → daily → prod
+// BaseURLs 定义 Antigravity API 端点（与 Antigravity-Manager 保持一致）
 var BaseURLs = []string{
-	"https://daily-cloudcode-pa.sandbox.googleapis.com", // sandbox
-	"https://daily-cloudcode-pa.googleapis.com",         // daily
-	"https://cloudcode-pa.googleapis.com",               // prod
+	"https://cloudcode-pa.googleapis.com",               // prod (优先)
+	"https://daily-cloudcode-pa.sandbox.googleapis.com", // daily sandbox (备用)
 }
 
 // BaseURL 默认 URL（保持向后兼容）
 var BaseURL = BaseURLs[0]
 
-// URLAvailability 管理 URL 可用性状态（带 TTL 自动恢复）
+// URLAvailability 管理 URL 可用性状态（带 TTL 自动恢复和动态优先级）
 type URLAvailability struct {
 	mu          sync.RWMutex
 	unavailable map[string]time.Time // URL -> 恢复时间
 	ttl         time.Duration
+	lastSuccess string // 最近成功请求的 URL，优先使用
 }
 
 // DefaultURLAvailability 全局 URL 可用性管理器
@@ -78,6 +77,15 @@ func (u *URLAvailability) MarkUnavailable(url string) {
 	u.unavailable[url] = time.Now().Add(u.ttl)
 }
 
+// MarkSuccess 标记 URL 请求成功，将其设为优先使用
+func (u *URLAvailability) MarkSuccess(url string) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	u.lastSuccess = url
+	// 成功后清除该 URL 的不可用标记
+	delete(u.unavailable, url)
+}
+
 // IsAvailable 检查 URL 是否可用
 func (u *URLAvailability) IsAvailable(url string) bool {
 	u.mu.RLock()
@@ -89,14 +97,29 @@ func (u *URLAvailability) IsAvailable(url string) bool {
 	return time.Now().After(expiry)
 }
 
-// GetAvailableURLs 返回可用的 URL 列表（保持优先级顺序）
+// GetAvailableURLs 返回可用的 URL 列表
+// 最近成功的 URL 优先，其他按默认顺序
 func (u *URLAvailability) GetAvailableURLs() []string {
 	u.mu.RLock()
 	defer u.mu.RUnlock()
 
 	now := time.Now()
 	result := make([]string, 0, len(BaseURLs))
+
+	// 如果有最近成功的 URL 且可用，放在最前面
+	if u.lastSuccess != "" {
+		expiry, exists := u.unavailable[u.lastSuccess]
+		if !exists || now.After(expiry) {
+			result = append(result, u.lastSuccess)
+		}
+	}
+
+	// 添加其他可用的 URL（按默认顺序）
 	for _, url := range BaseURLs {
+		// 跳过已添加的 lastSuccess
+		if url == u.lastSuccess {
+			continue
+		}
 		expiry, exists := u.unavailable[url]
 		if !exists || now.After(expiry) {
 			result = append(result, url)
@@ -240,24 +263,3 @@ func BuildAuthorizationURL(state, codeChallenge string) string {
 
 	return fmt.Sprintf("%s?%s", AuthorizeURL, params.Encode())
 }
-
-// GenerateMockProjectID 生成随机 project_id（当 API 不返回时使用）
-// 格式：{形容词}-{名词}-{5位随机字符}
-func GenerateMockProjectID() string {
-	adjectives := []string{"useful", "bright", "swift", "calm", "bold"}
-	nouns := []string{"fuze", "wave", "spark", "flow", "core"}
-
-	randBytes, _ := GenerateRandomBytes(7)
-
-	adj := adjectives[int(randBytes[0])%len(adjectives)]
-	noun := nouns[int(randBytes[1])%len(nouns)]
-
-	// 生成 5 位随机字符（a-z0-9）
-	const charset = "abcdefghijklmnopqrstuvwxyz0123456789"
-	suffix := make([]byte, 5)
-	for i := 0; i < 5; i++ {
-		suffix[i] = charset[int(randBytes[i+2])%len(charset)]
-	}
-
-	return fmt.Sprintf("%s-%s-%s", adj, noun, string(suffix))
-}

backend/internal/pkg/antigravity/request_transformer.go

@@ -54,6 +54,9 @@ func DefaultTransformOptions() TransformOptions {
 	}
 }
 
+// webSearchFallbackModel web_search 请求使用的降级模型
+const webSearchFallbackModel = "gemini-2.5-flash"
+
 // TransformClaudeToGemini 将 Claude 请求转换为 v1internal Gemini 格式
 func TransformClaudeToGemini(claudeReq *ClaudeRequest, projectID, mappedModel string) ([]byte, error) {
 	return TransformClaudeToGeminiWithOptions(claudeReq, projectID, mappedModel, DefaultTransformOptions())
@@ -64,12 +67,23 @@ func TransformClaudeToGeminiWithOptions(claudeReq *ClaudeRequest, projectID, map
 	// 用于存储 tool_use id -> name 映射
 	toolIDToName := make(map[string]string)
 
+	// 检测是否有 web_search 工具
+	hasWebSearchTool := hasWebSearchTool(claudeReq.Tools)
+	requestType := "agent"
+	targetModel := mappedModel
+	if hasWebSearchTool {
+		requestType = "web_search"
+		if targetModel != webSearchFallbackModel {
+			targetModel = webSearchFallbackModel
+		}
+	}
+
 	// 检测是否启用 thinking
 	isThinkingEnabled := claudeReq.Thinking != nil && claudeReq.Thinking.Type == "enabled"
 
 	// 只有 Gemini 模型支持 dummy thought workaround
 	// Claude 模型通过 Vertex/Google API 需要有效的 thought signatures
-	allowDummyThought := strings.HasPrefix(mappedModel, "gemini-")
+	allowDummyThought := strings.HasPrefix(targetModel, "gemini-")
 
 	// 1. 构建 contents
 	contents, strippedThinking, err := buildContents(claudeReq.Messages, toolIDToName, isThinkingEnabled, allowDummyThought)
@@ -78,7 +92,7 @@ func TransformClaudeToGeminiWithOptions(claudeReq *ClaudeRequest, projectID, map
 	}
 
 	// 2. 构建 systemInstruction
-	systemInstruction := buildSystemInstruction(claudeReq.System, claudeReq.Model, opts)
+	systemInstruction := buildSystemInstruction(claudeReq.System, claudeReq.Model, opts, claudeReq.Tools)
 
 	// 3. 构建 generationConfig
 	reqForConfig := claudeReq
@@ -89,6 +103,11 @@ func TransformClaudeToGeminiWithOptions(claudeReq *ClaudeRequest, projectID, map
 		reqCopy.Thinking = nil
 		reqForConfig = &reqCopy
 	}
+	if targetModel != "" && targetModel != reqForConfig.Model {
+		reqCopy := *reqForConfig
+		reqCopy.Model = targetModel
+		reqForConfig = &reqCopy
+	}
 	generationConfig := buildGenerationConfig(reqForConfig)
 
 	// 4. 构建 tools
@@ -127,8 +146,8 @@ func TransformClaudeToGeminiWithOptions(claudeReq *ClaudeRequest, projectID, map
 		Project:     projectID,
 		RequestID:   "agent-" + uuid.New().String(),
 		UserAgent:   "antigravity", // 固定值，与官方客户端一致
-		RequestType: "agent",
-		Model:       mappedModel,
+		RequestType: requestType,
+		Model:       targetModel,
 		Request:     innerRequest,
 	}
 
@@ -154,8 +173,40 @@ func GetDefaultIdentityPatch() string {
 	return antigravityIdentity
 }
 
-// buildSystemInstruction 构建 systemInstruction
-func buildSystemInstruction(system json.RawMessage, modelName string, opts TransformOptions) *GeminiContent {
+// mcpXMLProtocol MCP XML 工具调用协议（与 Antigravity-Manager 保持一致）
+const mcpXMLProtocol = `
+==== MCP XML 工具调用协议 (Workaround) ====
+当你需要调用名称以 ` + "`mcp__`" + ` 开头的 MCP 工具时：
+1) 优先尝试 XML 格式调用：输出 ` + "`<mcp__tool_name>{\"arg\":\"value\"}</mcp__tool_name>`" + `。
+2) 必须直接输出 XML 块，无需 markdown 包装，内容为 JSON 格式的入参。
+3) 这种方式具有更高的连通性和容错性，适用于大型结果返回场景。
+===========================================`
+
+// hasMCPTools 检测是否有 mcp__ 前缀的工具
+func hasMCPTools(tools []ClaudeTool) bool {
+	for _, tool := range tools {
+		if strings.HasPrefix(tool.Name, "mcp__") {
+			return true
+		}
+	}
+	return false
+}
+
+// filterOpenCodePrompt 过滤 OpenCode 默认提示词，只保留用户自定义指令
+func filterOpenCodePrompt(text string) string {
+	if !strings.Contains(text, "You are an interactive CLI tool") {
+		return text
+	}
+	// 提取 "Instructions from:" 及之后的部分
+	if idx := strings.Index(text, "Instructions from:"); idx >= 0 {
+		return text[idx:]
+	}
+	// 如果没有自定义指令，返回空
+	return ""
+}
+
+// buildSystemInstruction 构建 systemInstruction（与 Antigravity-Manager 保持一致）
+func buildSystemInstruction(system json.RawMessage, modelName string, opts TransformOptions, tools []ClaudeTool) *GeminiContent {
 	var parts []GeminiPart
 
 	// 先解析用户的 system prompt，检测是否已包含 Antigravity identity
@@ -167,10 +218,14 @@ func buildSystemInstruction(system json.RawMessage, modelName string, opts Trans
 		var sysStr string
 		if err := json.Unmarshal(system, &sysStr); err == nil {
 			if strings.TrimSpace(sysStr) != "" {
-				userSystemParts = append(userSystemParts, GeminiPart{Text: sysStr})
 				if strings.Contains(sysStr, "You are Antigravity") {
 					userHasAntigravityIdentity = true
 				}
+				// 过滤 OpenCode 默认提示词
+				filtered := filterOpenCodePrompt(sysStr)
+				if filtered != "" {
+					userSystemParts = append(userSystemParts, GeminiPart{Text: filtered})
+				}
 			}
 		} else {
 			// 尝试解析为数组
@@ -178,10 +233,14 @@ func buildSystemInstruction(system json.RawMessage, modelName string, opts Trans
 			if err := json.Unmarshal(system, &sysBlocks); err == nil {
 				for _, block := range sysBlocks {
 					if block.Type == "text" && strings.TrimSpace(block.Text) != "" {
-						userSystemParts = append(userSystemParts, GeminiPart{Text: block.Text})
 						if strings.Contains(block.Text, "You are Antigravity") {
 							userHasAntigravityIdentity = true
 						}
+						// 过滤 OpenCode 默认提示词
+						filtered := filterOpenCodePrompt(block.Text)
+						if filtered != "" {
+							userSystemParts = append(userSystemParts, GeminiPart{Text: filtered})
+						}
 					}
 				}
 			}
@@ -200,6 +259,16 @@ func buildSystemInstruction(system json.RawMessage, modelName string, opts Trans
 	// 添加用户的 system prompt
 	parts = append(parts, userSystemParts...)
 
+	// 检测是否有 MCP 工具，如有则注入 XML 调用协议
+	if hasMCPTools(tools) {
+		parts = append(parts, GeminiPart{Text: mcpXMLProtocol})
+	}
+
+	// 如果用户没有提供 Antigravity 身份，添加结束标记
+	if !userHasAntigravityIdentity {
+		parts = append(parts, GeminiPart{Text: "\n--- [SYSTEM_PROMPT_END] ---"})
+	}
+
 	if len(parts) == 0 {
 		return nil
 	}
@@ -429,6 +498,11 @@ func buildGenerationConfig(req *ClaudeRequest) *GeminiGenerationConfig {
 		StopSequences:   DefaultStopSequences,
 	}
 
+	// 如果请求中指定了 MaxTokens，使用请求值
+	if req.MaxTokens > 0 {
+		config.MaxOutputTokens = req.MaxTokens
+	}
+
 	// Thinking 配置
 	if req.Thinking != nil && req.Thinking.Type == "enabled" {
 		config.ThinkingConfig = &GeminiThinkingConfig{
@@ -458,37 +532,43 @@ func buildGenerationConfig(req *ClaudeRequest) *GeminiGenerationConfig {
 	return config
 }
 
+func hasWebSearchTool(tools []ClaudeTool) bool {
+	for _, tool := range tools {
+		if isWebSearchTool(tool) {
+			return true
+		}
+	}
+	return false
+}
+
+func isWebSearchTool(tool ClaudeTool) bool {
+	if strings.HasPrefix(tool.Type, "web_search") || tool.Type == "google_search" {
+		return true
+	}
+
+	name := strings.TrimSpace(tool.Name)
+	switch name {
+	case "web_search", "google_search", "web_search_20250305":
+		return true
+	default:
+		return false
+	}
+}
+
 // buildTools 构建 tools
 func buildTools(tools []ClaudeTool) []GeminiToolDeclaration {
 	if len(tools) == 0 {
 		return nil
 	}
 
-	// 检查是否有 web_search 工具
-	hasWebSearch := false
-	for _, tool := range tools {
-		if tool.Name == "web_search" {
-			hasWebSearch = true
-			break
-		}
-	}
-
-	if hasWebSearch {
-		// Web Search 工具映射
-		return []GeminiToolDeclaration{{
-			GoogleSearch: &GeminiGoogleSearch{
-				EnhancedContent: &GeminiEnhancedContent{
-					ImageSearch: &GeminiImageSearch{
-						MaxResultCount: 5,
-					},
-				},
-			},
-		}}
-	}
+	hasWebSearch := hasWebSearchTool(tools)
 
 	// 普通工具
 	var funcDecls []GeminiFunctionDecl
 	for _, tool := range tools {
+		if isWebSearchTool(tool) {
+			continue
+		}
 		// 跳过无效工具名称
 		if strings.TrimSpace(tool.Name) == "" {
 			log.Printf("Warning: skipping tool with empty name")
@@ -531,7 +611,20 @@ func buildTools(tools []ClaudeTool) []GeminiToolDeclaration {
 	}
 
 	if len(funcDecls) == 0 {
-		return nil
+		if !hasWebSearch {
+			return nil
+		}
+
+		// Web Search 工具映射
+		return []GeminiToolDeclaration{{
+			GoogleSearch: &GeminiGoogleSearch{
+				EnhancedContent: &GeminiEnhancedContent{
+					ImageSearch: &GeminiImageSearch{
+						MaxResultCount: 5,
+					},
+				},
+			},
+		}}
 	}
 
 	return []GeminiToolDeclaration{{

backend/internal/pkg/antigravity/response_transformer.go

@@ -3,6 +3,7 @@ package antigravity
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 )
 
 // TransformGeminiToClaude 将 Gemini 响应转换为 Claude 格式（非流式）
@@ -63,6 +64,12 @@ func (p *NonStreamingProcessor) Process(geminiResp *GeminiResponse, responseID,
 		p.processPart(&part)
 	}
 
+	if len(geminiResp.Candidates) > 0 {
+		if grounding := geminiResp.Candidates[0].GroundingMetadata; grounding != nil {
+			p.processGrounding(grounding)
+		}
+	}
+
 	// 刷新剩余内容
 	p.flushThinking()
 	p.flushText()
@@ -190,6 +197,18 @@ func (p *NonStreamingProcessor) processPart(part *GeminiPart) {
 	}
 }
 
+func (p *NonStreamingProcessor) processGrounding(grounding *GeminiGroundingMetadata) {
+	groundingText := buildGroundingText(grounding)
+	if groundingText == "" {
+		return
+	}
+
+	p.flushThinking()
+	p.flushText()
+	p.textBuilder += groundingText
+	p.flushText()
+}
+
 // flushText 刷新 text builder
 func (p *NonStreamingProcessor) flushText() {
 	if p.textBuilder == "" {
@@ -262,6 +281,44 @@ func (p *NonStreamingProcessor) buildResponse(geminiResp *GeminiResponse, respon
 	}
 }
 
+func buildGroundingText(grounding *GeminiGroundingMetadata) string {
+	if grounding == nil {
+		return ""
+	}
+
+	var builder strings.Builder
+
+	if len(grounding.WebSearchQueries) > 0 {
+		_, _ = builder.WriteString("\n\n---\nWeb search queries: ")
+		_, _ = builder.WriteString(strings.Join(grounding.WebSearchQueries, ", "))
+	}
+
+	if len(grounding.GroundingChunks) > 0 {
+		var links []string
+		for i, chunk := range grounding.GroundingChunks {
+			if chunk.Web == nil {
+				continue
+			}
+			title := strings.TrimSpace(chunk.Web.Title)
+			if title == "" {
+				title = "Source"
+			}
+			uri := strings.TrimSpace(chunk.Web.URI)
+			if uri == "" {
+				uri = "#"
+			}
+			links = append(links, fmt.Sprintf("[%d] [%s](%s)", i+1, title, uri))
+		}
+
+		if len(links) > 0 {
+			_, _ = builder.WriteString("\n\nSources:\n")
+			_, _ = builder.WriteString(strings.Join(links, "\n"))
+		}
+	}
+
+	return builder.String()
+}
+
 // generateRandomID 生成随机 ID
 func generateRandomID() string {
 	const chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

backend/internal/pkg/antigravity/stream_transformer.go

@@ -27,6 +27,8 @@ type StreamingProcessor struct {
 	pendingSignature  string
 	trailingSignature string
 	originalModel     string
+	webSearchQueries  []string
+	groundingChunks   []GeminiGroundingChunk
 
 	// 累计 usage
 	inputTokens     int
@@ -93,6 +95,10 @@ func (p *StreamingProcessor) ProcessLine(line string) []byte {
 		}
 	}
 
+	if len(geminiResp.Candidates) > 0 {
+		p.captureGrounding(geminiResp.Candidates[0].GroundingMetadata)
+	}
+
 	// 检查是否结束
 	if len(geminiResp.Candidates) > 0 {
 		finishReason := geminiResp.Candidates[0].FinishReason
@@ -200,6 +206,20 @@ func (p *StreamingProcessor) processPart(part *GeminiPart) []byte {
 	return result.Bytes()
 }
 
+func (p *StreamingProcessor) captureGrounding(grounding *GeminiGroundingMetadata) {
+	if grounding == nil {
+		return
+	}
+
+	if len(grounding.WebSearchQueries) > 0 && len(p.webSearchQueries) == 0 {
+		p.webSearchQueries = append([]string(nil), grounding.WebSearchQueries...)
+	}
+
+	if len(grounding.GroundingChunks) > 0 && len(p.groundingChunks) == 0 {
+		p.groundingChunks = append([]GeminiGroundingChunk(nil), grounding.GroundingChunks...)
+	}
+}
+
 // processThinking 处理 thinking
 func (p *StreamingProcessor) processThinking(text, signature string) []byte {
 	var result bytes.Buffer
@@ -417,6 +437,23 @@ func (p *StreamingProcessor) emitFinish(finishReason string) []byte {
 		p.trailingSignature = ""
 	}
 
+	if len(p.webSearchQueries) > 0 || len(p.groundingChunks) > 0 {
+		groundingText := buildGroundingText(&GeminiGroundingMetadata{
+			WebSearchQueries: p.webSearchQueries,
+			GroundingChunks:  p.groundingChunks,
+		})
+		if groundingText != "" {
+			_, _ = result.Write(p.startBlock(BlockTypeText, map[string]any{
+				"type": "text",
+				"text": "",
+			}))
+			_, _ = result.Write(p.emitDelta("text_delta", map[string]any{
+				"text": groundingText,
+			}))
+			_, _ = result.Write(p.endBlock())
+		}
+	}
+
 	// 确定 stop_reason
 	stopReason := "end_turn"
 	if p.usedTool {

backend/internal/pkg/response/response.go

@@ -162,11 +162,11 @@ func ParsePagination(c *gin.Context) (page, pageSize int) {
 
 	// 支持 page_size 和 limit 两种参数名
 	if ps := c.Query("page_size"); ps != "" {
-		if val, err := parseInt(ps); err == nil && val > 0 && val <= 100 {
+		if val, err := parseInt(ps); err == nil && val > 0 && val <= 1000 {
 			pageSize = val
 		}
 	} else if l := c.Query("limit"); l != "" {
-		if val, err := parseInt(l); err == nil && val > 0 && val <= 100 {
+		if val, err := parseInt(l); err == nil && val > 0 && val <= 1000 {
 			pageSize = val
 		}
 	}

backend/internal/pkg/tlsfingerprint/dialer.go

@@ -0,0 +1,568 @@
+// Package tlsfingerprint provides TLS fingerprint simulation for HTTP clients.
+// It uses the utls library to create TLS connections that mimic Node.js/Claude Code clients.
+package tlsfingerprint
+
+import (
+	"bufio"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"log/slog"
+	"net"
+	"net/http"
+	"net/url"
+
+	utls "github.com/refraction-networking/utls"
+	"golang.org/x/net/proxy"
+)
+
+// Profile contains TLS fingerprint configuration.
+type Profile struct {
+	Name         string // Profile name for identification
+	CipherSuites []uint16
+	Curves       []uint16
+	PointFormats []uint8
+	EnableGREASE bool
+}
+
+// Dialer creates TLS connections with custom fingerprints.
+type Dialer struct {
+	profile    *Profile
+	baseDialer func(ctx context.Context, network, addr string) (net.Conn, error)
+}
+
+// HTTPProxyDialer creates TLS connections through HTTP/HTTPS proxies with custom fingerprints.
+// It handles the CONNECT tunnel establishment before performing TLS handshake.
+type HTTPProxyDialer struct {
+	profile  *Profile
+	proxyURL *url.URL
+}
+
+// SOCKS5ProxyDialer creates TLS connections through SOCKS5 proxies with custom fingerprints.
+// It uses golang.org/x/net/proxy to establish the SOCKS5 tunnel.
+type SOCKS5ProxyDialer struct {
+	profile  *Profile
+	proxyURL *url.URL
+}
+
+// Default TLS fingerprint values captured from Claude CLI 2.x (Node.js 20.x + OpenSSL 3.x)
+// Captured using: tshark -i lo -f "tcp port 8443" -Y "tls.handshake.type == 1" -V
+// JA3 Hash: 1a28e69016765d92e3b381168d68922c
+//
+// Note: JA3/JA4 may have slight variations due to:
+// - Session ticket presence/absence
+// - Extension negotiation state
+var (
+	// defaultCipherSuites contains all 59 cipher suites from Claude CLI
+	// Order is critical for JA3 fingerprint matching
+	defaultCipherSuites = []uint16{
+		// TLS 1.3 cipher suites (MUST be first)
+		0x1302, // TLS_AES_256_GCM_SHA384
+		0x1303, // TLS_CHACHA20_POLY1305_SHA256
+		0x1301, // TLS_AES_128_GCM_SHA256
+
+		// ECDHE + AES-GCM
+		0xc02f, // TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
+		0xc02b, // TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
+		0xc030, // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
+		0xc02c, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
+
+		// DHE + AES-GCM
+		0x009e, // TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
+
+		// ECDHE/DHE + AES-CBC-SHA256/384
+		0xc027, // TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
+		0x0067, // TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
+		0xc028, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
+		0x006b, // TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
+
+		// DHE-DSS/RSA + AES-GCM
+		0x00a3, // TLS_DHE_DSS_WITH_AES_256_GCM_SHA384
+		0x009f, // TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
+
+		// ChaCha20-Poly1305
+		0xcca9, // TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
+		0xcca8, // TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+		0xccaa, // TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+
+		// AES-CCM (256-bit)
+		0xc0af, // TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8
+		0xc0ad, // TLS_ECDHE_ECDSA_WITH_AES_256_CCM
+		0xc0a3, // TLS_DHE_RSA_WITH_AES_256_CCM_8
+		0xc09f, // TLS_DHE_RSA_WITH_AES_256_CCM
+
+		// ARIA (256-bit)
+		0xc05d, // TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384
+		0xc061, // TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
+		0xc057, // TLS_DHE_DSS_WITH_ARIA_256_GCM_SHA384
+		0xc053, // TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
+
+		// DHE-DSS + AES-GCM (128-bit)
+		0x00a2, // TLS_DHE_DSS_WITH_AES_128_GCM_SHA256
+
+		// AES-CCM (128-bit)
+		0xc0ae, // TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8
+		0xc0ac, // TLS_ECDHE_ECDSA_WITH_AES_128_CCM
+		0xc0a2, // TLS_DHE_RSA_WITH_AES_128_CCM_8
+		0xc09e, // TLS_DHE_RSA_WITH_AES_128_CCM
+
+		// ARIA (128-bit)
+		0xc05c, // TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256
+		0xc060, // TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
+		0xc056, // TLS_DHE_DSS_WITH_ARIA_128_GCM_SHA256
+		0xc052, // TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
+
+		// ECDHE/DHE + AES-CBC-SHA384/256 (more)
+		0xc024, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
+		0x006a, // TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
+		0xc023, // TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
+		0x0040, // TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
+
+		// ECDHE/DHE + AES-CBC-SHA (legacy)
+		0xc00a, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
+		0xc014, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
+		0x0039, // TLS_DHE_RSA_WITH_AES_256_CBC_SHA
+		0x0038, // TLS_DHE_DSS_WITH_AES_256_CBC_SHA
+		0xc009, // TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
+		0xc013, // TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
+		0x0033, // TLS_DHE_RSA_WITH_AES_128_CBC_SHA
+		0x0032, // TLS_DHE_DSS_WITH_AES_128_CBC_SHA
+
+		// RSA + AES-GCM/CCM/ARIA (non-PFS, 256-bit)
+		0x009d, // TLS_RSA_WITH_AES_256_GCM_SHA384
+		0xc0a1, // TLS_RSA_WITH_AES_256_CCM_8
+		0xc09d, // TLS_RSA_WITH_AES_256_CCM
+		0xc051, // TLS_RSA_WITH_ARIA_256_GCM_SHA384
+
+		// RSA + AES-GCM/CCM/ARIA (non-PFS, 128-bit)
+		0x009c, // TLS_RSA_WITH_AES_128_GCM_SHA256
+		0xc0a0, // TLS_RSA_WITH_AES_128_CCM_8
+		0xc09c, // TLS_RSA_WITH_AES_128_CCM
+		0xc050, // TLS_RSA_WITH_ARIA_128_GCM_SHA256
+
+		// RSA + AES-CBC (non-PFS, legacy)
+		0x003d, // TLS_RSA_WITH_AES_256_CBC_SHA256
+		0x003c, // TLS_RSA_WITH_AES_128_CBC_SHA256
+		0x0035, // TLS_RSA_WITH_AES_256_CBC_SHA
+		0x002f, // TLS_RSA_WITH_AES_128_CBC_SHA
+
+		// Renegotiation indication
+		0x00ff, // TLS_EMPTY_RENEGOTIATION_INFO_SCSV
+	}
+
+	// defaultCurves contains the 10 supported groups from Claude CLI (including FFDHE)
+	defaultCurves = []utls.CurveID{
+		utls.X25519,          // 0x001d
+		utls.CurveP256,       // 0x0017 (secp256r1)
+		utls.CurveID(0x001e), // x448
+		utls.CurveP521,       // 0x0019 (secp521r1)
+		utls.CurveP384,       // 0x0018 (secp384r1)
+		utls.CurveID(0x0100), // ffdhe2048
+		utls.CurveID(0x0101), // ffdhe3072
+		utls.CurveID(0x0102), // ffdhe4096
+		utls.CurveID(0x0103), // ffdhe6144
+		utls.CurveID(0x0104), // ffdhe8192
+	}
+
+	// defaultPointFormats contains all 3 point formats from Claude CLI
+	defaultPointFormats = []uint8{
+		0, // uncompressed
+		1, // ansiX962_compressed_prime
+		2, // ansiX962_compressed_char2
+	}
+
+	// defaultSignatureAlgorithms contains the 20 signature algorithms from Claude CLI
+	defaultSignatureAlgorithms = []utls.SignatureScheme{
+		0x0403, // ecdsa_secp256r1_sha256
+		0x0503, // ecdsa_secp384r1_sha384
+		0x0603, // ecdsa_secp521r1_sha512
+		0x0807, // ed25519
+		0x0808, // ed448
+		0x0809, // rsa_pss_pss_sha256
+		0x080a, // rsa_pss_pss_sha384
+		0x080b, // rsa_pss_pss_sha512
+		0x0804, // rsa_pss_rsae_sha256
+		0x0805, // rsa_pss_rsae_sha384
+		0x0806, // rsa_pss_rsae_sha512
+		0x0401, // rsa_pkcs1_sha256
+		0x0501, // rsa_pkcs1_sha384
+		0x0601, // rsa_pkcs1_sha512
+		0x0303, // ecdsa_sha224
+		0x0301, // rsa_pkcs1_sha224
+		0x0302, // dsa_sha224
+		0x0402, // dsa_sha256
+		0x0502, // dsa_sha384
+		0x0602, // dsa_sha512
+	}
+)
+
+// NewDialer creates a new TLS fingerprint dialer.
+// baseDialer is used for TCP connection establishment (supports proxy scenarios).
+// If baseDialer is nil, direct TCP dial is used.
+func NewDialer(profile *Profile, baseDialer func(ctx context.Context, network, addr string) (net.Conn, error)) *Dialer {
+	if baseDialer == nil {
+		baseDialer = (&net.Dialer{}).DialContext
+	}
+	return &Dialer{profile: profile, baseDialer: baseDialer}
+}
+
+// NewHTTPProxyDialer creates a new TLS fingerprint dialer that works through HTTP/HTTPS proxies.
+// It establishes a CONNECT tunnel before performing TLS handshake with custom fingerprint.
+func NewHTTPProxyDialer(profile *Profile, proxyURL *url.URL) *HTTPProxyDialer {
+	return &HTTPProxyDialer{profile: profile, proxyURL: proxyURL}
+}
+
+// NewSOCKS5ProxyDialer creates a new TLS fingerprint dialer that works through SOCKS5 proxies.
+// It establishes a SOCKS5 tunnel before performing TLS handshake with custom fingerprint.
+func NewSOCKS5ProxyDialer(profile *Profile, proxyURL *url.URL) *SOCKS5ProxyDialer {
+	return &SOCKS5ProxyDialer{profile: profile, proxyURL: proxyURL}
+}
+
+// DialTLSContext establishes a TLS connection through SOCKS5 proxy with the configured fingerprint.
+// Flow: SOCKS5 CONNECT to target -> TLS handshake with utls on the tunnel
+func (d *SOCKS5ProxyDialer) DialTLSContext(ctx context.Context, network, addr string) (net.Conn, error) {
+	slog.Debug("tls_fingerprint_socks5_connecting", "proxy", d.proxyURL.Host, "target", addr)
+
+	// Step 1: Create SOCKS5 dialer
+	var auth *proxy.Auth
+	if d.proxyURL.User != nil {
+		username := d.proxyURL.User.Username()
+		password, _ := d.proxyURL.User.Password()
+		auth = &proxy.Auth{
+			User:     username,
+			Password: password,
+		}
+	}
+
+	// Determine proxy address
+	proxyAddr := d.proxyURL.Host
+	if d.proxyURL.Port() == "" {
+		proxyAddr = net.JoinHostPort(d.proxyURL.Hostname(), "1080") // Default SOCKS5 port
+	}
+
+	socksDialer, err := proxy.SOCKS5("tcp", proxyAddr, auth, proxy.Direct)
+	if err != nil {
+		slog.Debug("tls_fingerprint_socks5_dialer_failed", "error", err)
+		return nil, fmt.Errorf("create SOCKS5 dialer: %w", err)
+	}
+
+	// Step 2: Establish SOCKS5 tunnel to target
+	slog.Debug("tls_fingerprint_socks5_establishing_tunnel", "target", addr)
+	conn, err := socksDialer.Dial("tcp", addr)
+	if err != nil {
+		slog.Debug("tls_fingerprint_socks5_connect_failed", "error", err)
+		return nil, fmt.Errorf("SOCKS5 connect: %w", err)
+	}
+	slog.Debug("tls_fingerprint_socks5_tunnel_established")
+
+	// Step 3: Perform TLS handshake on the tunnel with utls fingerprint
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		host = addr
+	}
+	slog.Debug("tls_fingerprint_socks5_starting_handshake", "host", host)
+
+	// Build ClientHello specification from profile (Node.js/Claude CLI fingerprint)
+	spec := buildClientHelloSpecFromProfile(d.profile)
+	slog.Debug("tls_fingerprint_socks5_clienthello_spec",
+		"cipher_suites", len(spec.CipherSuites),
+		"extensions", len(spec.Extensions),
+		"compression_methods", spec.CompressionMethods,
+		"tls_vers_max", fmt.Sprintf("0x%04x", spec.TLSVersMax),
+		"tls_vers_min", fmt.Sprintf("0x%04x", spec.TLSVersMin))
+
+	if d.profile != nil {
+		slog.Debug("tls_fingerprint_socks5_using_profile", "name", d.profile.Name, "grease", d.profile.EnableGREASE)
+	}
+
+	// Create uTLS connection on the tunnel
+	tlsConn := utls.UClient(conn, &utls.Config{
+		ServerName: host,
+	}, utls.HelloCustom)
+
+	if err := tlsConn.ApplyPreset(spec); err != nil {
+		slog.Debug("tls_fingerprint_socks5_apply_preset_failed", "error", err)
+		_ = conn.Close()
+		return nil, fmt.Errorf("apply TLS preset: %w", err)
+	}
+
+	if err := tlsConn.Handshake(); err != nil {
+		slog.Debug("tls_fingerprint_socks5_handshake_failed", "error", err)
+		_ = conn.Close()
+		return nil, fmt.Errorf("TLS handshake failed: %w", err)
+	}
+
+	state := tlsConn.ConnectionState()
+	slog.Debug("tls_fingerprint_socks5_handshake_success",
+		"version", fmt.Sprintf("0x%04x", state.Version),
+		"cipher_suite", fmt.Sprintf("0x%04x", state.CipherSuite),
+		"alpn", state.NegotiatedProtocol)
+
+	return tlsConn, nil
+}
+
+// DialTLSContext establishes a TLS connection through HTTP proxy with the configured fingerprint.
+// Flow: TCP connect to proxy -> CONNECT tunnel -> TLS handshake with utls
+func (d *HTTPProxyDialer) DialTLSContext(ctx context.Context, network, addr string) (net.Conn, error) {
+	slog.Debug("tls_fingerprint_http_proxy_connecting", "proxy", d.proxyURL.Host, "target", addr)
+
+	// Step 1: TCP connect to proxy server
+	var proxyAddr string
+	if d.proxyURL.Port() != "" {
+		proxyAddr = d.proxyURL.Host
+	} else {
+		// Default ports
+		if d.proxyURL.Scheme == "https" {
+			proxyAddr = net.JoinHostPort(d.proxyURL.Hostname(), "443")
+		} else {
+			proxyAddr = net.JoinHostPort(d.proxyURL.Hostname(), "80")
+		}
+	}
+
+	dialer := &net.Dialer{}
+	conn, err := dialer.DialContext(ctx, "tcp", proxyAddr)
+	if err != nil {
+		slog.Debug("tls_fingerprint_http_proxy_connect_failed", "error", err)
+		return nil, fmt.Errorf("connect to proxy: %w", err)
+	}
+	slog.Debug("tls_fingerprint_http_proxy_connected", "proxy_addr", proxyAddr)
+
+	// Step 2: Send CONNECT request to establish tunnel
+	req := &http.Request{
+		Method: "CONNECT",
+		URL:    &url.URL{Opaque: addr},
+		Host:   addr,
+		Header: make(http.Header),
+	}
+
+	// Add proxy authentication if present
+	if d.proxyURL.User != nil {
+		username := d.proxyURL.User.Username()
+		password, _ := d.proxyURL.User.Password()
+		auth := base64.StdEncoding.EncodeToString([]byte(username + ":" + password))
+		req.Header.Set("Proxy-Authorization", "Basic "+auth)
+	}
+
+	slog.Debug("tls_fingerprint_http_proxy_sending_connect", "target", addr)
+	if err := req.Write(conn); err != nil {
+		_ = conn.Close()
+		slog.Debug("tls_fingerprint_http_proxy_write_failed", "error", err)
+		return nil, fmt.Errorf("write CONNECT request: %w", err)
+	}
+
+	// Step 3: Read CONNECT response
+	br := bufio.NewReader(conn)
+	resp, err := http.ReadResponse(br, req)
+	if err != nil {
+		_ = conn.Close()
+		slog.Debug("tls_fingerprint_http_proxy_read_response_failed", "error", err)
+		return nil, fmt.Errorf("read CONNECT response: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		_ = conn.Close()
+		slog.Debug("tls_fingerprint_http_proxy_connect_failed_status", "status_code", resp.StatusCode, "status", resp.Status)
+		return nil, fmt.Errorf("proxy CONNECT failed: %s", resp.Status)
+	}
+	slog.Debug("tls_fingerprint_http_proxy_tunnel_established")
+
+	// Step 4: Perform TLS handshake on the tunnel with utls fingerprint
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		host = addr
+	}
+	slog.Debug("tls_fingerprint_http_proxy_starting_handshake", "host", host)
+
+	// Build ClientHello specification (reuse the shared method)
+	spec := buildClientHelloSpecFromProfile(d.profile)
+	slog.Debug("tls_fingerprint_http_proxy_clienthello_spec",
+		"cipher_suites", len(spec.CipherSuites),
+		"extensions", len(spec.Extensions))
+
+	if d.profile != nil {
+		slog.Debug("tls_fingerprint_http_proxy_using_profile", "name", d.profile.Name, "grease", d.profile.EnableGREASE)
+	}
+
+	// Create uTLS connection on the tunnel
+	// Note: TLS 1.3 cipher suites are handled automatically by utls when TLS 1.3 is in SupportedVersions
+	tlsConn := utls.UClient(conn, &utls.Config{
+		ServerName: host,
+	}, utls.HelloCustom)
+
+	if err := tlsConn.ApplyPreset(spec); err != nil {
+		slog.Debug("tls_fingerprint_http_proxy_apply_preset_failed", "error", err)
+		_ = conn.Close()
+		return nil, fmt.Errorf("apply TLS preset: %w", err)
+	}
+
+	if err := tlsConn.HandshakeContext(ctx); err != nil {
+		slog.Debug("tls_fingerprint_http_proxy_handshake_failed", "error", err)
+		_ = conn.Close()
+		return nil, fmt.Errorf("TLS handshake failed: %w", err)
+	}
+
+	state := tlsConn.ConnectionState()
+	slog.Debug("tls_fingerprint_http_proxy_handshake_success",
+		"version", fmt.Sprintf("0x%04x", state.Version),
+		"cipher_suite", fmt.Sprintf("0x%04x", state.CipherSuite),
+		"alpn", state.NegotiatedProtocol)
+
+	return tlsConn, nil
+}
+
+// DialTLSContext establishes a TLS connection with the configured fingerprint.
+// This method is designed to be used as http.Transport.DialTLSContext.
+func (d *Dialer) DialTLSContext(ctx context.Context, network, addr string) (net.Conn, error) {
+	// Establish TCP connection using base dialer (supports proxy)
+	slog.Debug("tls_fingerprint_dialing_tcp", "addr", addr)
+	conn, err := d.baseDialer(ctx, network, addr)
+	if err != nil {
+		slog.Debug("tls_fingerprint_tcp_dial_failed", "error", err)
+		return nil, err
+	}
+	slog.Debug("tls_fingerprint_tcp_connected", "addr", addr)
+
+	// Extract hostname for SNI
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		host = addr
+	}
+	slog.Debug("tls_fingerprint_sni_hostname", "host", host)
+
+	// Build ClientHello specification
+	spec := d.buildClientHelloSpec()
+	slog.Debug("tls_fingerprint_clienthello_spec",
+		"cipher_suites", len(spec.CipherSuites),
+		"extensions", len(spec.Extensions))
+
+	// Log profile info
+	if d.profile != nil {
+		slog.Debug("tls_fingerprint_using_profile", "name", d.profile.Name, "grease", d.profile.EnableGREASE)
+	} else {
+		slog.Debug("tls_fingerprint_using_default_profile")
+	}
+
+	// Create uTLS connection
+	// Note: TLS 1.3 cipher suites are handled automatically by utls when TLS 1.3 is in SupportedVersions
+	tlsConn := utls.UClient(conn, &utls.Config{
+		ServerName: host,
+	}, utls.HelloCustom)
+
+	// Apply fingerprint
+	if err := tlsConn.ApplyPreset(spec); err != nil {
+		slog.Debug("tls_fingerprint_apply_preset_failed", "error", err)
+		_ = conn.Close()
+		return nil, err
+	}
+	slog.Debug("tls_fingerprint_preset_applied")
+
+	// Perform TLS handshake
+	if err := tlsConn.HandshakeContext(ctx); err != nil {
+		slog.Debug("tls_fingerprint_handshake_failed",
+			"error", err,
+			"local_addr", conn.LocalAddr(),
+			"remote_addr", conn.RemoteAddr())
+		_ = conn.Close()
+		return nil, fmt.Errorf("TLS handshake failed: %w", err)
+	}
+
+	// Log successful handshake details
+	state := tlsConn.ConnectionState()
+	slog.Debug("tls_fingerprint_handshake_success",
+		"version", fmt.Sprintf("0x%04x", state.Version),
+		"cipher_suite", fmt.Sprintf("0x%04x", state.CipherSuite),
+		"alpn", state.NegotiatedProtocol)
+
+	return tlsConn, nil
+}
+
+// buildClientHelloSpec constructs the ClientHello specification based on the profile.
+func (d *Dialer) buildClientHelloSpec() *utls.ClientHelloSpec {
+	return buildClientHelloSpecFromProfile(d.profile)
+}
+
+// toUTLSCurves converts uint16 slice to utls.CurveID slice.
+func toUTLSCurves(curves []uint16) []utls.CurveID {
+	result := make([]utls.CurveID, len(curves))
+	for i, c := range curves {
+		result[i] = utls.CurveID(c)
+	}
+	return result
+}
+
+// buildClientHelloSpecFromProfile constructs ClientHelloSpec from a Profile.
+// This is a standalone function that can be used by both Dialer and HTTPProxyDialer.
+func buildClientHelloSpecFromProfile(profile *Profile) *utls.ClientHelloSpec {
+	// Get cipher suites
+	var cipherSuites []uint16
+	if profile != nil && len(profile.CipherSuites) > 0 {
+		cipherSuites = profile.CipherSuites
+	} else {
+		cipherSuites = defaultCipherSuites
+	}
+
+	// Get curves
+	var curves []utls.CurveID
+	if profile != nil && len(profile.Curves) > 0 {
+		curves = toUTLSCurves(profile.Curves)
+	} else {
+		curves = defaultCurves
+	}
+
+	// Get point formats
+	var pointFormats []uint8
+	if profile != nil && len(profile.PointFormats) > 0 {
+		pointFormats = profile.PointFormats
+	} else {
+		pointFormats = defaultPointFormats
+	}
+
+	// Check if GREASE is enabled
+	enableGREASE := profile != nil && profile.EnableGREASE
+
+	extensions := make([]utls.TLSExtension, 0, 16)
+
+	if enableGREASE {
+		extensions = append(extensions, &utls.UtlsGREASEExtension{})
+	}
+
+	// SNI extension - MUST be explicitly added for HelloCustom mode
+	// utls will populate the server name from Config.ServerName
+	extensions = append(extensions, &utls.SNIExtension{})
+
+	// Claude CLI extension order (captured from tshark):
+	// server_name(0), ec_point_formats(11), supported_groups(10), session_ticket(35),
+	// alpn(16), encrypt_then_mac(22), extended_master_secret(23),
+	// signature_algorithms(13), supported_versions(43),
+	// psk_key_exchange_modes(45), key_share(51)
+	extensions = append(extensions,
+		&utls.SupportedPointsExtension{SupportedPoints: pointFormats},
+		&utls.SupportedCurvesExtension{Curves: curves},
+		&utls.SessionTicketExtension{},
+		&utls.ALPNExtension{AlpnProtocols: []string{"http/1.1"}},
+		&utls.GenericExtension{Id: 22},
+		&utls.ExtendedMasterSecretExtension{},
+		&utls.SignatureAlgorithmsExtension{SupportedSignatureAlgorithms: defaultSignatureAlgorithms},
+		&utls.SupportedVersionsExtension{Versions: []uint16{
+			utls.VersionTLS13,
+			utls.VersionTLS12,
+		}},
+		&utls.PSKKeyExchangeModesExtension{Modes: []uint8{utls.PskModeDHE}},
+		&utls.KeyShareExtension{KeyShares: []utls.KeyShare{
+			{Group: utls.X25519},
+		}},
+	)
+
+	if enableGREASE {
+		extensions = append(extensions, &utls.UtlsGREASEExtension{})
+	}
+
+	return &utls.ClientHelloSpec{
+		CipherSuites:       cipherSuites,
+		CompressionMethods: []uint8{0}, // null compression only (standard)
+		Extensions:         extensions,
+		TLSVersMax:         utls.VersionTLS13,
+		TLSVersMin:         utls.VersionTLS10,
+	}
+}

backend/internal/pkg/tlsfingerprint/dialer_test.go

@@ -0,0 +1,307 @@
+// Package tlsfingerprint provides TLS fingerprint simulation for HTTP clients.
+//
+// Integration tests for verifying TLS fingerprint correctness.
+// These tests make actual network requests and should be run manually.
+//
+// Run with: go test -v ./internal/pkg/tlsfingerprint/...
+// Run integration tests: go test -v -run TestJA3 ./internal/pkg/tlsfingerprint/...
+package tlsfingerprint
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+)
+
+// FingerprintResponse represents the response from tls.peet.ws/api/all.
+type FingerprintResponse struct {
+	IP    string  `json:"ip"`
+	TLS   TLSInfo `json:"tls"`
+	HTTP2 any     `json:"http2"`
+}
+
+// TLSInfo contains TLS fingerprint details.
+type TLSInfo struct {
+	JA3           string `json:"ja3"`
+	JA3Hash       string `json:"ja3_hash"`
+	JA4           string `json:"ja4"`
+	PeetPrint     string `json:"peetprint"`
+	PeetPrintHash string `json:"peetprint_hash"`
+	ClientRandom  string `json:"client_random"`
+	SessionID     string `json:"session_id"`
+}
+
+// TestDialerBasicConnection tests that the dialer can establish TLS connections.
+func TestDialerBasicConnection(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping network test in short mode")
+	}
+
+	// Create a dialer with default profile
+	profile := &Profile{
+		Name:         "Test Profile",
+		EnableGREASE: false,
+	}
+	dialer := NewDialer(profile, nil)
+
+	// Create HTTP client with custom TLS dialer
+	client := &http.Client{
+		Transport: &http.Transport{
+			DialTLSContext: dialer.DialTLSContext,
+		},
+		Timeout: 30 * time.Second,
+	}
+
+	// Make a request to a known HTTPS endpoint
+	resp, err := client.Get("https://www.google.com")
+	if err != nil {
+		t.Fatalf("failed to connect: %v", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Errorf("expected status 200, got %d", resp.StatusCode)
+	}
+}
+
+// TestJA3Fingerprint verifies the JA3/JA4 fingerprint matches expected value.
+// This test uses tls.peet.ws to verify the fingerprint.
+// Expected JA3 hash: 1a28e69016765d92e3b381168d68922c (Claude CLI / Node.js 20.x)
+// Expected JA4: t13d5911h1_a33745022dd6_1f22a2ca17c4 (d=domain) or t13i5911h1_... (i=IP)
+func TestJA3Fingerprint(t *testing.T) {
+	// Skip if network is unavailable or if running in short mode
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	profile := &Profile{
+		Name:         "Claude CLI Test",
+		EnableGREASE: false,
+	}
+	dialer := NewDialer(profile, nil)
+
+	client := &http.Client{
+		Transport: &http.Transport{
+			DialTLSContext: dialer.DialTLSContext,
+		},
+		Timeout: 30 * time.Second,
+	}
+
+	// Use tls.peet.ws fingerprint detection API
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(ctx, "GET", "https://tls.peet.ws/api/all", nil)
+	if err != nil {
+		t.Fatalf("failed to create request: %v", err)
+	}
+	req.Header.Set("User-Agent", "Claude Code/2.0.0 Node.js/20.0.0")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		t.Fatalf("failed to get fingerprint: %v", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatalf("failed to read response: %v", err)
+	}
+
+	var fpResp FingerprintResponse
+	if err := json.Unmarshal(body, &fpResp); err != nil {
+		t.Logf("Response body: %s", string(body))
+		t.Fatalf("failed to parse fingerprint response: %v", err)
+	}
+
+	// Log all fingerprint information
+	t.Logf("JA3: %s", fpResp.TLS.JA3)
+	t.Logf("JA3 Hash: %s", fpResp.TLS.JA3Hash)
+	t.Logf("JA4: %s", fpResp.TLS.JA4)
+	t.Logf("PeetPrint: %s", fpResp.TLS.PeetPrint)
+	t.Logf("PeetPrint Hash: %s", fpResp.TLS.PeetPrintHash)
+
+	// Verify JA3 hash matches expected value
+	expectedJA3Hash := "1a28e69016765d92e3b381168d68922c"
+	if fpResp.TLS.JA3Hash == expectedJA3Hash {
+		t.Logf("✓ JA3 hash matches expected value: %s", expectedJA3Hash)
+	} else {
+		t.Errorf("✗ JA3 hash mismatch: got %s, expected %s", fpResp.TLS.JA3Hash, expectedJA3Hash)
+	}
+
+	// Verify JA4 fingerprint
+	// JA4 format: t[version][sni][cipher_count][ext_count][alpn]_[cipher_hash]_[ext_hash]
+	// Expected: t13d5910h1 (d=domain) or t13i5910h1 (i=IP)
+	// The suffix _a33745022dd6_1f22a2ca17c4 should match
+	expectedJA4Suffix := "_a33745022dd6_1f22a2ca17c4"
+	if strings.HasSuffix(fpResp.TLS.JA4, expectedJA4Suffix) {
+		t.Logf("✓ JA4 suffix matches expected value: %s", expectedJA4Suffix)
+	} else {
+		t.Errorf("✗ JA4 suffix mismatch: got %s, expected suffix %s", fpResp.TLS.JA4, expectedJA4Suffix)
+	}
+
+	// Verify JA4 prefix (t13d5911h1 or t13i5911h1)
+	// d = domain (SNI present), i = IP (no SNI)
+	// Since we connect to tls.peet.ws (domain), we expect 'd'
+	expectedJA4Prefix := "t13d5911h1"
+	if strings.HasPrefix(fpResp.TLS.JA4, expectedJA4Prefix) {
+		t.Logf("✓ JA4 prefix matches: %s (t13=TLS1.3, d=domain, 59=ciphers, 11=extensions, h1=HTTP/1.1)", expectedJA4Prefix)
+	} else {
+		// Also accept 'i' variant for IP connections
+		altPrefix := "t13i5911h1"
+		if strings.HasPrefix(fpResp.TLS.JA4, altPrefix) {
+			t.Logf("✓ JA4 prefix matches (IP variant): %s", altPrefix)
+		} else {
+			t.Errorf("✗ JA4 prefix mismatch: got %s, expected %s or %s", fpResp.TLS.JA4, expectedJA4Prefix, altPrefix)
+		}
+	}
+
+	// Verify JA3 contains expected cipher suites (TLS 1.3 ciphers at the beginning)
+	if strings.Contains(fpResp.TLS.JA3, "4866-4867-4865") {
+		t.Logf("✓ JA3 contains expected TLS 1.3 cipher suites")
+	} else {
+		t.Logf("Warning: JA3 does not contain expected TLS 1.3 cipher suites")
+	}
+
+	// Verify extension list (should be 11 extensions including SNI)
+	// Expected: 0-11-10-35-16-22-23-13-43-45-51
+	expectedExtensions := "0-11-10-35-16-22-23-13-43-45-51"
+	if strings.Contains(fpResp.TLS.JA3, expectedExtensions) {
+		t.Logf("✓ JA3 contains expected extension list: %s", expectedExtensions)
+	} else {
+		t.Logf("Warning: JA3 extension list may differ")
+	}
+}
+
+// TestDialerWithProfile tests that different profiles produce different fingerprints.
+func TestDialerWithProfile(t *testing.T) {
+	// Create two dialers with different profiles
+	profile1 := &Profile{
+		Name:         "Profile 1 - No GREASE",
+		EnableGREASE: false,
+	}
+	profile2 := &Profile{
+		Name:         "Profile 2 - With GREASE",
+		EnableGREASE: true,
+	}
+
+	dialer1 := NewDialer(profile1, nil)
+	dialer2 := NewDialer(profile2, nil)
+
+	// Build specs and compare
+	// Note: We can't directly compare JA3 without making network requests
+	// but we can verify the specs are different
+	spec1 := dialer1.buildClientHelloSpec()
+	spec2 := dialer2.buildClientHelloSpec()
+
+	// Profile with GREASE should have more extensions
+	if len(spec2.Extensions) <= len(spec1.Extensions) {
+		t.Error("expected GREASE profile to have more extensions")
+	}
+}
+
+// TestHTTPProxyDialerBasic tests HTTP proxy dialer creation.
+// Note: This is a unit test - actual proxy testing requires a proxy server.
+func TestHTTPProxyDialerBasic(t *testing.T) {
+	profile := &Profile{
+		Name:         "Test Profile",
+		EnableGREASE: false,
+	}
+
+	// Test that dialer is created without panic
+	proxyURL := mustParseURL("http://proxy.example.com:8080")
+	dialer := NewHTTPProxyDialer(profile, proxyURL)
+
+	if dialer == nil {
+		t.Fatal("expected dialer to be created")
+	}
+	if dialer.profile != profile {
+		t.Error("expected profile to be set")
+	}
+	if dialer.proxyURL != proxyURL {
+		t.Error("expected proxyURL to be set")
+	}
+}
+
+// TestSOCKS5ProxyDialerBasic tests SOCKS5 proxy dialer creation.
+// Note: This is a unit test - actual proxy testing requires a proxy server.
+func TestSOCKS5ProxyDialerBasic(t *testing.T) {
+	profile := &Profile{
+		Name:         "Test Profile",
+		EnableGREASE: false,
+	}
+
+	// Test that dialer is created without panic
+	proxyURL := mustParseURL("socks5://proxy.example.com:1080")
+	dialer := NewSOCKS5ProxyDialer(profile, proxyURL)
+
+	if dialer == nil {
+		t.Fatal("expected dialer to be created")
+	}
+	if dialer.profile != profile {
+		t.Error("expected profile to be set")
+	}
+	if dialer.proxyURL != proxyURL {
+		t.Error("expected proxyURL to be set")
+	}
+}
+
+// TestBuildClientHelloSpec tests ClientHello spec construction.
+func TestBuildClientHelloSpec(t *testing.T) {
+	// Test with nil profile (should use defaults)
+	spec := buildClientHelloSpecFromProfile(nil)
+
+	if len(spec.CipherSuites) == 0 {
+		t.Error("expected cipher suites to be set")
+	}
+	if len(spec.Extensions) == 0 {
+		t.Error("expected extensions to be set")
+	}
+
+	// Verify default cipher suites are used
+	if len(spec.CipherSuites) != len(defaultCipherSuites) {
+		t.Errorf("expected %d cipher suites, got %d", len(defaultCipherSuites), len(spec.CipherSuites))
+	}
+
+	// Test with custom profile
+	customProfile := &Profile{
+		Name:         "Custom",
+		EnableGREASE: false,
+		CipherSuites: []uint16{0x1301, 0x1302},
+	}
+	spec = buildClientHelloSpecFromProfile(customProfile)
+
+	if len(spec.CipherSuites) != 2 {
+		t.Errorf("expected 2 cipher suites, got %d", len(spec.CipherSuites))
+	}
+}
+
+// TestToUTLSCurves tests curve ID conversion.
+func TestToUTLSCurves(t *testing.T) {
+	input := []uint16{0x001d, 0x0017, 0x0018}
+	result := toUTLSCurves(input)
+
+	if len(result) != len(input) {
+		t.Errorf("expected %d curves, got %d", len(input), len(result))
+	}
+
+	for i, curve := range result {
+		if uint16(curve) != input[i] {
+			t.Errorf("curve %d: expected 0x%04x, got 0x%04x", i, input[i], uint16(curve))
+		}
+	}
+}
+
+// Helper function to parse URL without error handling.
+func mustParseURL(rawURL string) *url.URL {
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}

backend/internal/pkg/tlsfingerprint/registry.go

@@ -0,0 +1,171 @@
+// Package tlsfingerprint provides TLS fingerprint simulation for HTTP clients.
+package tlsfingerprint
+
+import (
+	"log/slog"
+	"sort"
+	"sync"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+)
+
+// DefaultProfileName is the name of the built-in Claude CLI profile.
+const DefaultProfileName = "claude_cli_v2"
+
+// Registry manages TLS fingerprint profiles.
+// It holds a collection of profiles that can be used for TLS fingerprint simulation.
+// Profiles are selected based on account ID using modulo operation.
+type Registry struct {
+	mu           sync.RWMutex
+	profiles     map[string]*Profile
+	profileNames []string // Sorted list of profile names for deterministic selection
+}
+
+// NewRegistry creates a new TLS fingerprint profile registry.
+// It initializes with the built-in default profile.
+func NewRegistry() *Registry {
+	r := &Registry{
+		profiles:     make(map[string]*Profile),
+		profileNames: make([]string, 0),
+	}
+
+	// Register the built-in default profile
+	r.registerBuiltinProfile()
+
+	return r
+}
+
+// NewRegistryFromConfig creates a new registry and loads profiles from config.
+// If the config has custom profiles defined, they will be merged with the built-in default.
+func NewRegistryFromConfig(cfg *config.TLSFingerprintConfig) *Registry {
+	r := NewRegistry()
+
+	if cfg == nil || !cfg.Enabled {
+		slog.Debug("tls_registry_disabled", "reason", "disabled or no config")
+		return r
+	}
+
+	// Load custom profiles from config
+	for name, profileCfg := range cfg.Profiles {
+		profile := &Profile{
+			Name:         profileCfg.Name,
+			EnableGREASE: profileCfg.EnableGREASE,
+			CipherSuites: profileCfg.CipherSuites,
+			Curves:       profileCfg.Curves,
+			PointFormats: profileCfg.PointFormats,
+		}
+
+		// If the profile has empty values, they will use defaults in dialer
+		r.RegisterProfile(name, profile)
+		slog.Debug("tls_registry_loaded_profile", "key", name, "name", profileCfg.Name)
+	}
+
+	slog.Debug("tls_registry_initialized", "profile_count", len(r.profileNames), "profiles", r.profileNames)
+	return r
+}
+
+// registerBuiltinProfile adds the default Claude CLI profile to the registry.
+func (r *Registry) registerBuiltinProfile() {
+	defaultProfile := &Profile{
+		Name:         "Claude CLI 2.x (Node.js 20.x + OpenSSL 3.x)",
+		EnableGREASE: false, // Node.js does not use GREASE
+		// Empty slices will cause dialer to use built-in defaults
+		CipherSuites: nil,
+		Curves:       nil,
+		PointFormats: nil,
+	}
+	r.RegisterProfile(DefaultProfileName, defaultProfile)
+}
+
+// RegisterProfile adds or updates a profile in the registry.
+func (r *Registry) RegisterProfile(name string, profile *Profile) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	// Check if this is a new profile
+	_, exists := r.profiles[name]
+	r.profiles[name] = profile
+
+	if !exists {
+		r.profileNames = append(r.profileNames, name)
+		// Keep names sorted for deterministic selection
+		sort.Strings(r.profileNames)
+	}
+}
+
+// GetProfile returns a profile by name.
+// Returns nil if the profile does not exist.
+func (r *Registry) GetProfile(name string) *Profile {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return r.profiles[name]
+}
+
+// GetDefaultProfile returns the built-in default profile.
+func (r *Registry) GetDefaultProfile() *Profile {
+	return r.GetProfile(DefaultProfileName)
+}
+
+// GetProfileByAccountID returns a profile for the given account ID.
+// The profile is selected using: profileNames[accountID % len(profiles)]
+// This ensures deterministic profile assignment for each account.
+func (r *Registry) GetProfileByAccountID(accountID int64) *Profile {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	if len(r.profileNames) == 0 {
+		return nil
+	}
+
+	// Use modulo to select profile index
+	// Use absolute value to handle negative IDs (though unlikely)
+	idx := accountID
+	if idx < 0 {
+		idx = -idx
+	}
+	selectedIndex := int(idx % int64(len(r.profileNames)))
+	selectedName := r.profileNames[selectedIndex]
+
+	return r.profiles[selectedName]
+}
+
+// ProfileCount returns the number of registered profiles.
+func (r *Registry) ProfileCount() int {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return len(r.profiles)
+}
+
+// ProfileNames returns a sorted list of all registered profile names.
+func (r *Registry) ProfileNames() []string {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	// Return a copy to prevent modification
+	names := make([]string, len(r.profileNames))
+	copy(names, r.profileNames)
+	return names
+}
+
+// Global registry instance for convenience
+var globalRegistry *Registry
+var globalRegistryOnce sync.Once
+
+// GlobalRegistry returns the global TLS fingerprint registry.
+// The registry is lazily initialized with the default profile.
+func GlobalRegistry() *Registry {
+	globalRegistryOnce.Do(func() {
+		globalRegistry = NewRegistry()
+	})
+	return globalRegistry
+}
+
+// InitGlobalRegistry initializes the global registry with configuration.
+// This should be called during application startup.
+// It is safe to call multiple times; subsequent calls will update the registry.
+func InitGlobalRegistry(cfg *config.TLSFingerprintConfig) *Registry {
+	globalRegistryOnce.Do(func() {
+		globalRegistry = NewRegistryFromConfig(cfg)
+	})
+	return globalRegistry
+}

backend/internal/pkg/tlsfingerprint/registry_test.go

@@ -0,0 +1,243 @@
+package tlsfingerprint
+
+import (
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+)
+
+func TestNewRegistry(t *testing.T) {
+	r := NewRegistry()
+
+	// Should have exactly one profile (the default)
+	if r.ProfileCount() != 1 {
+		t.Errorf("expected 1 profile, got %d", r.ProfileCount())
+	}
+
+	// Should have the default profile
+	profile := r.GetDefaultProfile()
+	if profile == nil {
+		t.Error("expected default profile to exist")
+	}
+
+	// Default profile name should be in the list
+	names := r.ProfileNames()
+	if len(names) != 1 || names[0] != DefaultProfileName {
+		t.Errorf("expected profile names to be [%s], got %v", DefaultProfileName, names)
+	}
+}
+
+func TestRegisterProfile(t *testing.T) {
+	r := NewRegistry()
+
+	// Register a new profile
+	customProfile := &Profile{
+		Name:         "Custom Profile",
+		EnableGREASE: true,
+	}
+	r.RegisterProfile("custom", customProfile)
+
+	// Should now have 2 profiles
+	if r.ProfileCount() != 2 {
+		t.Errorf("expected 2 profiles, got %d", r.ProfileCount())
+	}
+
+	// Should be able to retrieve the custom profile
+	retrieved := r.GetProfile("custom")
+	if retrieved == nil {
+		t.Fatal("expected custom profile to exist")
+	}
+	if retrieved.Name != "Custom Profile" {
+		t.Errorf("expected profile name 'Custom Profile', got '%s'", retrieved.Name)
+	}
+	if !retrieved.EnableGREASE {
+		t.Error("expected EnableGREASE to be true")
+	}
+}
+
+func TestGetProfile(t *testing.T) {
+	r := NewRegistry()
+
+	// Get existing profile
+	profile := r.GetProfile(DefaultProfileName)
+	if profile == nil {
+		t.Error("expected default profile to exist")
+	}
+
+	// Get non-existing profile
+	nonExistent := r.GetProfile("nonexistent")
+	if nonExistent != nil {
+		t.Error("expected nil for non-existent profile")
+	}
+}
+
+func TestGetProfileByAccountID(t *testing.T) {
+	r := NewRegistry()
+
+	// With only default profile, all account IDs should return the same profile
+	for i := int64(0); i < 10; i++ {
+		profile := r.GetProfileByAccountID(i)
+		if profile == nil {
+			t.Errorf("expected profile for account %d, got nil", i)
+		}
+	}
+
+	// Add more profiles
+	r.RegisterProfile("profile_a", &Profile{Name: "Profile A"})
+	r.RegisterProfile("profile_b", &Profile{Name: "Profile B"})
+
+	// Now we have 3 profiles: claude_cli_v2, profile_a, profile_b
+	// Names are sorted, so order is: claude_cli_v2, profile_a, profile_b
+	expectedOrder := []string{DefaultProfileName, "profile_a", "profile_b"}
+	names := r.ProfileNames()
+	for i, name := range expectedOrder {
+		if names[i] != name {
+			t.Errorf("expected name at index %d to be %s, got %s", i, name, names[i])
+		}
+	}
+
+	// Test modulo selection
+	// Account ID 0 % 3 = 0 -> claude_cli_v2
+	// Account ID 1 % 3 = 1 -> profile_a
+	// Account ID 2 % 3 = 2 -> profile_b
+	// Account ID 3 % 3 = 0 -> claude_cli_v2
+	testCases := []struct {
+		accountID    int64
+		expectedName string
+	}{
+		{0, "Claude CLI 2.x (Node.js 20.x + OpenSSL 3.x)"},
+		{1, "Profile A"},
+		{2, "Profile B"},
+		{3, "Claude CLI 2.x (Node.js 20.x + OpenSSL 3.x)"},
+		{4, "Profile A"},
+		{5, "Profile B"},
+		{100, "Profile A"}, // 100 % 3 = 1
+		{-1, "Profile A"},  // |-1| % 3 = 1
+		{-3, "Claude CLI 2.x (Node.js 20.x + OpenSSL 3.x)"}, // |-3| % 3 = 0
+	}
+
+	for _, tc := range testCases {
+		profile := r.GetProfileByAccountID(tc.accountID)
+		if profile == nil {
+			t.Errorf("expected profile for account %d, got nil", tc.accountID)
+			continue
+		}
+		if profile.Name != tc.expectedName {
+			t.Errorf("account %d: expected profile name '%s', got '%s'", tc.accountID, tc.expectedName, profile.Name)
+		}
+	}
+}
+
+func TestNewRegistryFromConfig(t *testing.T) {
+	// Test with nil config
+	r := NewRegistryFromConfig(nil)
+	if r.ProfileCount() != 1 {
+		t.Errorf("expected 1 profile with nil config, got %d", r.ProfileCount())
+	}
+
+	// Test with disabled config
+	disabledCfg := &config.TLSFingerprintConfig{
+		Enabled: false,
+	}
+	r = NewRegistryFromConfig(disabledCfg)
+	if r.ProfileCount() != 1 {
+		t.Errorf("expected 1 profile with disabled config, got %d", r.ProfileCount())
+	}
+
+	// Test with enabled config and custom profiles
+	enabledCfg := &config.TLSFingerprintConfig{
+		Enabled: true,
+		Profiles: map[string]config.TLSProfileConfig{
+			"custom1": {
+				Name:         "Custom Profile 1",
+				EnableGREASE: true,
+			},
+			"custom2": {
+				Name:         "Custom Profile 2",
+				EnableGREASE: false,
+			},
+		},
+	}
+	r = NewRegistryFromConfig(enabledCfg)
+
+	// Should have 3 profiles: default + 2 custom
+	if r.ProfileCount() != 3 {
+		t.Errorf("expected 3 profiles, got %d", r.ProfileCount())
+	}
+
+	// Check custom profiles exist
+	custom1 := r.GetProfile("custom1")
+	if custom1 == nil || custom1.Name != "Custom Profile 1" {
+		t.Error("expected custom1 profile to exist with correct name")
+	}
+	custom2 := r.GetProfile("custom2")
+	if custom2 == nil || custom2.Name != "Custom Profile 2" {
+		t.Error("expected custom2 profile to exist with correct name")
+	}
+}
+
+func TestProfileNames(t *testing.T) {
+	r := NewRegistry()
+
+	// Add profiles in non-alphabetical order
+	r.RegisterProfile("zebra", &Profile{Name: "Zebra"})
+	r.RegisterProfile("alpha", &Profile{Name: "Alpha"})
+	r.RegisterProfile("beta", &Profile{Name: "Beta"})
+
+	names := r.ProfileNames()
+
+	// Should be sorted alphabetically
+	expected := []string{"alpha", "beta", DefaultProfileName, "zebra"}
+	if len(names) != len(expected) {
+		t.Errorf("expected %d names, got %d", len(expected), len(names))
+	}
+	for i, name := range expected {
+		if names[i] != name {
+			t.Errorf("expected name at index %d to be %s, got %s", i, name, names[i])
+		}
+	}
+
+	// Test that returned slice is a copy (modifying it shouldn't affect registry)
+	names[0] = "modified"
+	originalNames := r.ProfileNames()
+	if originalNames[0] == "modified" {
+		t.Error("modifying returned slice should not affect registry")
+	}
+}
+
+func TestConcurrentAccess(t *testing.T) {
+	r := NewRegistry()
+
+	// Run concurrent reads and writes
+	done := make(chan bool)
+
+	// Writers
+	for i := 0; i < 10; i++ {
+		go func(id int) {
+			for j := 0; j < 100; j++ {
+				r.RegisterProfile("concurrent"+string(rune('0'+id)), &Profile{Name: "Concurrent"})
+			}
+			done <- true
+		}(i)
+	}
+
+	// Readers
+	for i := 0; i < 10; i++ {
+		go func(id int) {
+			for j := 0; j < 100; j++ {
+				_ = r.ProfileCount()
+				_ = r.ProfileNames()
+				_ = r.GetProfileByAccountID(int64(id * j))
+				_ = r.GetProfile(DefaultProfileName)
+			}
+			done <- true
+		}(i)
+	}
+
+	// Wait for all goroutines
+	for i := 0; i < 20; i++ {
+		<-done
+	}
+
+	// Test should pass without data races (run with -race flag)
+}

backend/internal/repository/account_repo.go

@@ -575,6 +575,15 @@ func (r *accountRepository) syncSchedulerAccountSnapshot(ctx context.Context, ac
 	}
 }
 
+func (r *accountRepository) ClearError(ctx context.Context, id int64) error {
+	_, err := r.client.Account.Update().
+		Where(dbaccount.IDEQ(id)).
+		SetStatus(service.StatusActive).
+		SetErrorMessage("").
+		Save(ctx)
+	return err
+}
+
 func (r *accountRepository) AddToGroup(ctx context.Context, accountID, groupID int64, priority int) error {
 	_, err := r.client.AccountGroup.Create().
 		SetAccountID(accountID).
@@ -993,7 +1002,16 @@ func (r *accountRepository) UpdateSessionWindow(ctx context.Context, id int64, s
 		builder.SetSessionWindowEnd(*end)
 	}
 	_, err := builder.Save(ctx)
-	return err
+	if err != nil {
+		return err
+	}
+	// 触发调度器缓存更新（仅当窗口时间有变化时）
+	if start != nil || end != nil {
+		if err := enqueueSchedulerOutbox(ctx, r.sql, service.SchedulerOutboxEventAccountChanged, &id, nil, nil); err != nil {
+			log.Printf("[SchedulerOutbox] enqueue session window update failed: account=%d err=%v", id, err)
+		}
+	}
+	return nil
 }
 
 func (r *accountRepository) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {

backend/internal/repository/api_key_cache.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"log"
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/service"
@@ -12,9 +13,10 @@ import (
 )
 
 const (
-	apiKeyRateLimitKeyPrefix = "apikey:ratelimit:"
-	apiKeyRateLimitDuration  = 24 * time.Hour
-	apiKeyAuthCachePrefix    = "apikey:auth:"
+	apiKeyRateLimitKeyPrefix   = "apikey:ratelimit:"
+	apiKeyRateLimitDuration    = 24 * time.Hour
+	apiKeyAuthCachePrefix      = "apikey:auth:"
+	authCacheInvalidateChannel = "auth:cache:invalidate"
 )
 
 // apiKeyRateLimitKey generates the Redis key for API key creation rate limiting.
@@ -91,3 +93,45 @@ func (c *apiKeyCache) SetAuthCache(ctx context.Context, key string, entry *servi
 func (c *apiKeyCache) DeleteAuthCache(ctx context.Context, key string) error {
 	return c.rdb.Del(ctx, apiKeyAuthCacheKey(key)).Err()
 }
+
+// PublishAuthCacheInvalidation publishes a cache invalidation message to all instances
+func (c *apiKeyCache) PublishAuthCacheInvalidation(ctx context.Context, cacheKey string) error {
+	return c.rdb.Publish(ctx, authCacheInvalidateChannel, cacheKey).Err()
+}
+
+// SubscribeAuthCacheInvalidation subscribes to cache invalidation messages
+func (c *apiKeyCache) SubscribeAuthCacheInvalidation(ctx context.Context, handler func(cacheKey string)) error {
+	pubsub := c.rdb.Subscribe(ctx, authCacheInvalidateChannel)
+
+	// Verify subscription is working
+	_, err := pubsub.Receive(ctx)
+	if err != nil {
+		_ = pubsub.Close()
+		return fmt.Errorf("subscribe to auth cache invalidation: %w", err)
+	}
+
+	go func() {
+		defer func() {
+			if err := pubsub.Close(); err != nil {
+				log.Printf("Warning: failed to close auth cache invalidation pubsub: %v", err)
+			}
+		}()
+
+		ch := pubsub.Channel()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case msg, ok := <-ch:
+				if !ok {
+					return
+				}
+				if msg != nil {
+					handler(msg.Payload)
+				}
+			}
+		}
+	}()
+
+	return nil
+}

backend/internal/repository/http_upstream.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log/slog"
 	"net"
 	"net/http"
 	"net/url"
@@ -14,6 +15,7 @@ import (
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/proxyutil"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/tlsfingerprint"
 	"github.com/Wei-Shaw/sub2api/internal/service"
 	"github.com/Wei-Shaw/sub2api/internal/util/urlvalidator"
 )
@@ -150,6 +152,172 @@ func (s *httpUpstreamService) Do(req *http.Request, proxyURL string, accountID i
 	return resp, nil
 }
 
+// DoWithTLS 执行带 TLS 指纹伪装的 HTTP 请求
+// 根据 enableTLSFingerprint 参数决定是否使用 TLS 指纹
+//
+// 参数:
+//   - req: HTTP 请求对象
+//   - proxyURL: 代理地址，空字符串表示直连
+//   - accountID: 账户 ID，用于账户级隔离和 TLS 指纹模板选择
+//   - accountConcurrency: 账户并发限制，用于动态调整连接池大小
+//   - enableTLSFingerprint: 是否启用 TLS 指纹伪装
+//
+// TLS 指纹说明:
+//   - 当 enableTLSFingerprint=true 时，使用 utls 库模拟 Claude CLI 的 TLS 指纹
+//   - 指纹模板根据 accountID % len(profiles) 自动选择
+//   - 支持直连、HTTP/HTTPS 代理、SOCKS5 代理三种场景
+func (s *httpUpstreamService) DoWithTLS(req *http.Request, proxyURL string, accountID int64, accountConcurrency int, enableTLSFingerprint bool) (*http.Response, error) {
+	// 如果未启用 TLS 指纹，直接使用标准请求路径
+	if !enableTLSFingerprint {
+		return s.Do(req, proxyURL, accountID, accountConcurrency)
+	}
+
+	// TLS 指纹已启用，记录调试日志
+	targetHost := ""
+	if req != nil && req.URL != nil {
+		targetHost = req.URL.Host
+	}
+	proxyInfo := "direct"
+	if proxyURL != "" {
+		proxyInfo = proxyURL
+	}
+	slog.Debug("tls_fingerprint_enabled", "account_id", accountID, "target", targetHost, "proxy", proxyInfo)
+
+	if err := s.validateRequestHost(req); err != nil {
+		return nil, err
+	}
+
+	// 获取 TLS 指纹 Profile
+	registry := tlsfingerprint.GlobalRegistry()
+	profile := registry.GetProfileByAccountID(accountID)
+	if profile == nil {
+		// 如果获取不到 profile，回退到普通请求
+		slog.Debug("tls_fingerprint_no_profile", "account_id", accountID, "fallback", "standard_request")
+		return s.Do(req, proxyURL, accountID, accountConcurrency)
+	}
+
+	slog.Debug("tls_fingerprint_using_profile", "account_id", accountID, "profile", profile.Name, "grease", profile.EnableGREASE)
+
+	// 获取或创建带 TLS 指纹的客户端
+	entry, err := s.acquireClientWithTLS(proxyURL, accountID, accountConcurrency, profile)
+	if err != nil {
+		slog.Debug("tls_fingerprint_acquire_client_failed", "account_id", accountID, "error", err)
+		return nil, err
+	}
+
+	// 执行请求
+	resp, err := entry.client.Do(req)
+	if err != nil {
+		// 请求失败，立即减少计数
+		atomic.AddInt64(&entry.inFlight, -1)
+		atomic.StoreInt64(&entry.lastUsed, time.Now().UnixNano())
+		slog.Debug("tls_fingerprint_request_failed", "account_id", accountID, "error", err)
+		return nil, err
+	}
+
+	slog.Debug("tls_fingerprint_request_success", "account_id", accountID, "status", resp.StatusCode)
+
+	// 包装响应体，在关闭时自动减少计数并更新时间戳
+	resp.Body = wrapTrackedBody(resp.Body, func() {
+		atomic.AddInt64(&entry.inFlight, -1)
+		atomic.StoreInt64(&entry.lastUsed, time.Now().UnixNano())
+	})
+
+	return resp, nil
+}
+
+// acquireClientWithTLS 获取或创建带 TLS 指纹的客户端
+func (s *httpUpstreamService) acquireClientWithTLS(proxyURL string, accountID int64, accountConcurrency int, profile *tlsfingerprint.Profile) (*upstreamClientEntry, error) {
+	return s.getClientEntryWithTLS(proxyURL, accountID, accountConcurrency, profile, true, true)
+}
+
+// getClientEntryWithTLS 获取或创建带 TLS 指纹的客户端条目
+// TLS 指纹客户端使用独立的缓存键，与普通客户端隔离
+func (s *httpUpstreamService) getClientEntryWithTLS(proxyURL string, accountID int64, accountConcurrency int, profile *tlsfingerprint.Profile, markInFlight bool, enforceLimit bool) (*upstreamClientEntry, error) {
+	isolation := s.getIsolationMode()
+	proxyKey, parsedProxy := normalizeProxyURL(proxyURL)
+	// TLS 指纹客户端使用独立的缓存键，加 "tls:" 前缀
+	cacheKey := "tls:" + buildCacheKey(isolation, proxyKey, accountID)
+	poolKey := s.buildPoolKey(isolation, accountConcurrency) + ":tls"
+
+	now := time.Now()
+	nowUnix := now.UnixNano()
+
+	// 读锁快速路径
+	s.mu.RLock()
+	if entry, ok := s.clients[cacheKey]; ok && s.shouldReuseEntry(entry, isolation, proxyKey, poolKey) {
+		atomic.StoreInt64(&entry.lastUsed, nowUnix)
+		if markInFlight {
+			atomic.AddInt64(&entry.inFlight, 1)
+		}
+		s.mu.RUnlock()
+		slog.Debug("tls_fingerprint_reusing_client", "account_id", accountID, "cache_key", cacheKey)
+		return entry, nil
+	}
+	s.mu.RUnlock()
+
+	// 写锁慢路径
+	s.mu.Lock()
+	if entry, ok := s.clients[cacheKey]; ok {
+		if s.shouldReuseEntry(entry, isolation, proxyKey, poolKey) {
+			atomic.StoreInt64(&entry.lastUsed, nowUnix)
+			if markInFlight {
+				atomic.AddInt64(&entry.inFlight, 1)
+			}
+			s.mu.Unlock()
+			slog.Debug("tls_fingerprint_reusing_client", "account_id", accountID, "cache_key", cacheKey)
+			return entry, nil
+		}
+		slog.Debug("tls_fingerprint_evicting_stale_client",
+			"account_id", accountID,
+			"cache_key", cacheKey,
+			"proxy_changed", entry.proxyKey != proxyKey,
+			"pool_changed", entry.poolKey != poolKey)
+		s.removeClientLocked(cacheKey, entry)
+	}
+
+	// 超出缓存上限时尝试淘汰
+	if enforceLimit && s.maxUpstreamClients() > 0 {
+		s.evictIdleLocked(now)
+		if len(s.clients) >= s.maxUpstreamClients() {
+			if !s.evictOldestIdleLocked() {
+				s.mu.Unlock()
+				return nil, errUpstreamClientLimitReached
+			}
+		}
+	}
+
+	// 创建带 TLS 指纹的 Transport
+	slog.Debug("tls_fingerprint_creating_new_client", "account_id", accountID, "cache_key", cacheKey, "proxy", proxyKey)
+	settings := s.resolvePoolSettings(isolation, accountConcurrency)
+	transport, err := buildUpstreamTransportWithTLSFingerprint(settings, parsedProxy, profile)
+	if err != nil {
+		s.mu.Unlock()
+		return nil, fmt.Errorf("build TLS fingerprint transport: %w", err)
+	}
+
+	client := &http.Client{Transport: transport}
+	if s.shouldValidateResolvedIP() {
+		client.CheckRedirect = s.redirectChecker
+	}
+
+	entry := &upstreamClientEntry{
+		client:   client,
+		proxyKey: proxyKey,
+		poolKey:  poolKey,
+	}
+	atomic.StoreInt64(&entry.lastUsed, nowUnix)
+	if markInFlight {
+		atomic.StoreInt64(&entry.inFlight, 1)
+	}
+	s.clients[cacheKey] = entry
+
+	s.evictIdleLocked(now)
+	s.evictOverLimitLocked()
+	s.mu.Unlock()
+	return entry, nil
+}
+
 func (s *httpUpstreamService) shouldValidateResolvedIP() bool {
 	if s.cfg == nil {
 		return false
@@ -618,6 +786,64 @@ func buildUpstreamTransport(settings poolSettings, proxyURL *url.URL) (*http.Tra
 	return transport, nil
 }
 
+// buildUpstreamTransportWithTLSFingerprint 构建带 TLS 指纹伪装的 Transport
+// 使用 utls 库模拟 Claude CLI 的 TLS 指纹
+//
+// 参数:
+//   - settings: 连接池配置
+//   - proxyURL: 代理 URL（nil 表示直连）
+//   - profile: TLS 指纹配置
+//
+// 返回:
+//   - *http.Transport: 配置好的 Transport 实例
+//   - error: 配置错误
+//
+// 代理类型处理:
+//   - nil/空: 直连，使用 TLSFingerprintDialer
+//   - http/https: HTTP 代理，使用 HTTPProxyDialer（CONNECT 隧道 + utls 握手）
+//   - socks5: SOCKS5 代理，使用 SOCKS5ProxyDialer（SOCKS5 隧道 + utls 握手）
+func buildUpstreamTransportWithTLSFingerprint(settings poolSettings, proxyURL *url.URL, profile *tlsfingerprint.Profile) (*http.Transport, error) {
+	transport := &http.Transport{
+		MaxIdleConns:          settings.maxIdleConns,
+		MaxIdleConnsPerHost:   settings.maxIdleConnsPerHost,
+		MaxConnsPerHost:       settings.maxConnsPerHost,
+		IdleConnTimeout:       settings.idleConnTimeout,
+		ResponseHeaderTimeout: settings.responseHeaderTimeout,
+		// 禁用默认的 TLS，我们使用自定义的 DialTLSContext
+		ForceAttemptHTTP2: false,
+	}
+
+	// 根据代理类型选择合适的 TLS 指纹 Dialer
+	if proxyURL == nil {
+		// 直连：使用 TLSFingerprintDialer
+		slog.Debug("tls_fingerprint_transport_direct")
+		dialer := tlsfingerprint.NewDialer(profile, nil)
+		transport.DialTLSContext = dialer.DialTLSContext
+	} else {
+		scheme := strings.ToLower(proxyURL.Scheme)
+		switch scheme {
+		case "socks5", "socks5h":
+			// SOCKS5 代理：使用 SOCKS5ProxyDialer
+			slog.Debug("tls_fingerprint_transport_socks5", "proxy", proxyURL.Host)
+			socks5Dialer := tlsfingerprint.NewSOCKS5ProxyDialer(profile, proxyURL)
+			transport.DialTLSContext = socks5Dialer.DialTLSContext
+		case "http", "https":
+			// HTTP/HTTPS 代理：使用 HTTPProxyDialer（CONNECT 隧道）
+			slog.Debug("tls_fingerprint_transport_http_connect", "proxy", proxyURL.Host)
+			httpDialer := tlsfingerprint.NewHTTPProxyDialer(profile, proxyURL)
+			transport.DialTLSContext = httpDialer.DialTLSContext
+		default:
+			// 未知代理类型，回退到普通代理配置（无 TLS 指纹）
+			slog.Debug("tls_fingerprint_transport_unknown_scheme_fallback", "scheme", scheme)
+			if err := proxyutil.ConfigureTransportProxy(transport, proxyURL); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return transport, nil
+}
+
 // trackedBody 带跟踪功能的响应体包装器
 // 在 Close 时执行回调，用于更新请求计数
 type trackedBody struct {

backend/internal/repository/identity_cache.go

@@ -11,8 +11,10 @@ import (
 )
 
 const (
-	fingerprintKeyPrefix = "fingerprint:"
-	fingerprintTTL       = 24 * time.Hour
+	fingerprintKeyPrefix   = "fingerprint:"
+	fingerprintTTL         = 24 * time.Hour
+	maskedSessionKeyPrefix = "masked_session:"
+	maskedSessionTTL       = 15 * time.Minute
 )
 
 // fingerprintKey generates the Redis key for account fingerprint cache.
@@ -20,6 +22,11 @@ func fingerprintKey(accountID int64) string {
 	return fmt.Sprintf("%s%d", fingerprintKeyPrefix, accountID)
 }
 
+// maskedSessionKey generates the Redis key for masked session ID cache.
+func maskedSessionKey(accountID int64) string {
+	return fmt.Sprintf("%s%d", maskedSessionKeyPrefix, accountID)
+}
+
 type identityCache struct {
 	rdb *redis.Client
 }
@@ -49,3 +56,20 @@ func (c *identityCache) SetFingerprint(ctx context.Context, accountID int64, fp
 	}
 	return c.rdb.Set(ctx, key, val, fingerprintTTL).Err()
 }
+
+func (c *identityCache) GetMaskedSessionID(ctx context.Context, accountID int64) (string, error) {
+	key := maskedSessionKey(accountID)
+	val, err := c.rdb.Get(ctx, key).Result()
+	if err != nil {
+		if err == redis.Nil {
+			return "", nil
+		}
+		return "", err
+	}
+	return val, nil
+}
+
+func (c *identityCache) SetMaskedSessionID(ctx context.Context, accountID int64, sessionID string) error {
+	key := maskedSessionKey(accountID)
+	return c.rdb.Set(ctx, key, sessionID, maskedSessionTTL).Err()
+}

backend/internal/repository/session_limit_cache.go

@@ -217,7 +217,7 @@ func (c *sessionLimitCache) GetActiveSessionCount(ctx context.Context, accountID
 }
 
 // GetActiveSessionCountBatch 批量获取多个账号的活跃会话数
-func (c *sessionLimitCache) GetActiveSessionCountBatch(ctx context.Context, accountIDs []int64) (map[int64]int, error) {
+func (c *sessionLimitCache) GetActiveSessionCountBatch(ctx context.Context, accountIDs []int64, idleTimeouts map[int64]time.Duration) (map[int64]int, error) {
 	if len(accountIDs) == 0 {
 		return make(map[int64]int), nil
 	}
@@ -226,11 +226,18 @@ func (c *sessionLimitCache) GetActiveSessionCountBatch(ctx context.Context, acco
 
 	// 使用 pipeline 批量执行
 	pipe := c.rdb.Pipeline()
-	idleTimeoutSeconds := int(c.defaultIdleTimeout.Seconds())
 
 	cmds := make(map[int64]*redis.Cmd, len(accountIDs))
 	for _, accountID := range accountIDs {
 		key := sessionLimitKey(accountID)
+		// 使用各账号自己的 idleTimeout，如果没有则用默认值
+		idleTimeout := c.defaultIdleTimeout
+		if idleTimeouts != nil {
+			if t, ok := idleTimeouts[accountID]; ok && t > 0 {
+				idleTimeout = t
+			}
+		}
+		idleTimeoutSeconds := int(idleTimeout.Seconds())
 		cmds[accountID] = getActiveSessionCountScript.Run(ctx, pipe, []string{key}, idleTimeoutSeconds)
 	}
 

backend/internal/server/api_contract_test.go

@@ -618,6 +618,14 @@ func (stubApiKeyCache) DeleteAuthCache(ctx context.Context, key string) error {
 	return nil
 }
 
+func (stubApiKeyCache) PublishAuthCacheInvalidation(ctx context.Context, cacheKey string) error {
+	return nil
+}
+
+func (stubApiKeyCache) SubscribeAuthCacheInvalidation(ctx context.Context, handler func(cacheKey string)) error {
+	return nil
+}
+
 type stubGroupRepo struct{}
 
 func (stubGroupRepo) Create(ctx context.Context, group *service.Group) error {
@@ -736,6 +744,10 @@ func (s *stubAccountRepo) SetError(ctx context.Context, id int64, errorMsg strin
 	return errors.New("not implemented")
 }
 
+func (s *stubAccountRepo) ClearError(ctx context.Context, id int64) error {
+	return errors.New("not implemented")
+}
+
 func (s *stubAccountRepo) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
 	return errors.New("not implemented")
 }

backend/internal/service/account.go

@@ -576,6 +576,44 @@ func (a *Account) IsAnthropicOAuthOrSetupToken() bool {
 	return a.Platform == PlatformAnthropic && (a.Type == AccountTypeOAuth || a.Type == AccountTypeSetupToken)
 }
 
+// IsTLSFingerprintEnabled 检查是否启用 TLS 指纹伪装
+// 仅适用于 Anthropic OAuth/SetupToken 类型账号
+// 启用后将模拟 Claude Code (Node.js) 客户端的 TLS 握手特征
+func (a *Account) IsTLSFingerprintEnabled() bool {
+	// 仅支持 Anthropic OAuth/SetupToken 账号
+	if !a.IsAnthropicOAuthOrSetupToken() {
+		return false
+	}
+	if a.Extra == nil {
+		return false
+	}
+	if v, ok := a.Extra["enable_tls_fingerprint"]; ok {
+		if enabled, ok := v.(bool); ok {
+			return enabled
+		}
+	}
+	return false
+}
+
+// IsSessionIDMaskingEnabled 检查是否启用会话ID伪装
+// 仅适用于 Anthropic OAuth/SetupToken 类型账号
+// 启用后将在一段时间内（15分钟）固定 metadata.user_id 中的 session ID，
+// 使上游认为请求来自同一个会话
+func (a *Account) IsSessionIDMaskingEnabled() bool {
+	if !a.IsAnthropicOAuthOrSetupToken() {
+		return false
+	}
+	if a.Extra == nil {
+		return false
+	}
+	if v, ok := a.Extra["session_id_masking_enabled"]; ok {
+		if enabled, ok := v.(bool); ok {
+			return enabled
+		}
+	}
+	return false
+}
+
 // GetWindowCostLimit 获取 5h 窗口费用阈值（美元）
 // 返回 0 表示未启用
 func (a *Account) GetWindowCostLimit() float64 {
@@ -652,6 +690,23 @@ func (a *Account) CheckWindowCostSchedulability(currentWindowCost float64) Windo
 	return WindowCostNotSchedulable
 }
 
+// GetCurrentWindowStartTime 获取当前有效的窗口开始时间
+// 逻辑：
+// 1. 如果窗口未过期（SessionWindowEnd 存在且在当前时间之后），使用记录的 SessionWindowStart
+// 2. 否则（窗口过期或未设置），使用新的预测窗口开始时间（从当前整点开始）
+func (a *Account) GetCurrentWindowStartTime() time.Time {
+	now := time.Now()
+
+	// 窗口未过期，使用记录的窗口开始时间
+	if a.SessionWindowStart != nil && a.SessionWindowEnd != nil && now.Before(*a.SessionWindowEnd) {
+		return *a.SessionWindowStart
+	}
+
+	// 窗口已过期或未设置，预测新的窗口开始时间（从当前整点开始）
+	// 与 ratelimit_service.go 中 UpdateSessionWindow 的预测逻辑保持一致
+	return time.Date(now.Year(), now.Month(), now.Day(), now.Hour(), 0, 0, 0, now.Location())
+}
+
 // parseExtraFloat64 从 extra 字段解析 float64 值
 func parseExtraFloat64(value any) float64 {
 	switch v := value.(type) {

backend/internal/service/account_service.go

@@ -37,6 +37,7 @@ type AccountRepository interface {
 	UpdateLastUsed(ctx context.Context, id int64) error
 	BatchUpdateLastUsed(ctx context.Context, updates map[int64]time.Time) error
 	SetError(ctx context.Context, id int64, errorMsg string) error
+	ClearError(ctx context.Context, id int64) error
 	SetSchedulable(ctx context.Context, id int64, schedulable bool) error
 	AutoPauseExpiredAccounts(ctx context.Context, now time.Time) (int64, error)
 	BindGroups(ctx context.Context, accountID int64, groupIDs []int64) error

backend/internal/service/account_service_delete_test.go

@@ -99,6 +99,10 @@ func (s *accountRepoStub) SetError(ctx context.Context, id int64, errorMsg strin
 	panic("unexpected SetError call")
 }
 
+func (s *accountRepoStub) ClearError(ctx context.Context, id int64) error {
+	panic("unexpected ClearError call")
+}
+
 func (s *accountRepoStub) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
 	panic("unexpected SetSchedulable call")
 }

backend/internal/service/account_test_service.go

@@ -265,7 +265,7 @@ func (s *AccountTestService) testClaudeAccountConnection(c *gin.Context, account
 		proxyURL = account.Proxy.URL()
 	}
 
-	resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
+	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 	if err != nil {
 		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
 	}
@@ -375,7 +375,7 @@ func (s *AccountTestService) testOpenAIAccountConnection(c *gin.Context, account
 		proxyURL = account.Proxy.URL()
 	}
 
-	resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
+	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 	if err != nil {
 		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
 	}
@@ -446,7 +446,7 @@ func (s *AccountTestService) testGeminiAccountConnection(c *gin.Context, account
 		proxyURL = account.Proxy.URL()
 	}
 
-	resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
+	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 	if err != nil {
 		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
 	}

backend/internal/service/account_usage_service.go

@@ -369,12 +369,8 @@ func (s *AccountUsageService) addWindowStats(ctx context.Context, account *Accou
 
 	// 如果没有缓存，从数据库查询
 	if windowStats == nil {
-		var startTime time.Time
-		if account.SessionWindowStart != nil {
-			startTime = *account.SessionWindowStart
-		} else {
-			startTime = time.Now().Add(-5 * time.Hour)
-		}
+		// 使用统一的窗口开始时间计算逻辑（考虑窗口过期情况）
+		startTime := account.GetCurrentWindowStartTime()
 
 		stats, err := s.usageLogRepo.GetAccountWindowStats(ctx, account.ID, startTime)
 		if err != nil {

backend/internal/service/admin_service.go

@@ -42,6 +42,7 @@ type AdminService interface {
 	DeleteAccount(ctx context.Context, id int64) error
 	RefreshAccountCredentials(ctx context.Context, id int64) (*Account, error)
 	ClearAccountError(ctx context.Context, id int64) (*Account, error)
+	SetAccountError(ctx context.Context, id int64, errorMsg string) error
 	SetAccountSchedulable(ctx context.Context, id int64, schedulable bool) (*Account, error)
 	BulkUpdateAccounts(ctx context.Context, input *BulkUpdateAccountsInput) (*BulkUpdateAccountsResult, error)
 
@@ -1101,6 +1102,10 @@ func (s *adminServiceImpl) ClearAccountError(ctx context.Context, id int64) (*Ac
 	return account, nil
 }
 
+func (s *adminServiceImpl) SetAccountError(ctx context.Context, id int64, errorMsg string) error {
+	return s.accountRepo.SetError(ctx, id, errorMsg)
+}
+
 func (s *adminServiceImpl) SetAccountSchedulable(ctx context.Context, id int64, schedulable bool) (*Account, error) {
 	if err := s.accountRepo.SetSchedulable(ctx, id, schedulable); err != nil {
 		return nil, err

backend/internal/service/antigravity_oauth_service.go

@@ -82,13 +82,14 @@ type AntigravityExchangeCodeInput struct {
 
 // AntigravityTokenInfo token 信息
 type AntigravityTokenInfo struct {
-	AccessToken  string `json:"access_token"`
-	RefreshToken string `json:"refresh_token"`
-	ExpiresIn    int64  `json:"expires_in"`
-	ExpiresAt    int64  `json:"expires_at"`
-	TokenType    string `json:"token_type"`
-	Email        string `json:"email,omitempty"`
-	ProjectID    string `json:"project_id,omitempty"`
+	AccessToken      string `json:"access_token"`
+	RefreshToken     string `json:"refresh_token"`
+	ExpiresIn        int64  `json:"expires_in"`
+	ExpiresAt        int64  `json:"expires_at"`
+	TokenType        string `json:"token_type"`
+	Email            string `json:"email,omitempty"`
+	ProjectID        string `json:"project_id,omitempty"`
+	ProjectIDMissing bool   `json:"-"` // LoadCodeAssist 未返回 project_id
 }
 
 // ExchangeCode 用 authorization code 交换 token
@@ -149,12 +150,6 @@ func (s *AntigravityOAuthService) ExchangeCode(ctx context.Context, input *Antig
 		result.ProjectID = loadResp.CloudAICompanionProject
 	}
 
-	// 兜底：随机生成 project_id
-	if result.ProjectID == "" {
-		result.ProjectID = antigravity.GenerateMockProjectID()
-		fmt.Printf("[AntigravityOAuth] 使用随机生成的 project_id: %s\n", result.ProjectID)
-	}
-
 	return result, nil
 }
 
@@ -236,16 +231,24 @@ func (s *AntigravityOAuthService) RefreshAccountToken(ctx context.Context, accou
 		return nil, err
 	}
 
-	// 保留原有的 project_id 和 email
-	existingProjectID := strings.TrimSpace(account.GetCredential("project_id"))
-	if existingProjectID != "" {
-		tokenInfo.ProjectID = existingProjectID
-	}
+	// 保留原有的 email
 	existingEmail := strings.TrimSpace(account.GetCredential("email"))
 	if existingEmail != "" {
 		tokenInfo.Email = existingEmail
 	}
 
+	// 每次刷新都调用 LoadCodeAssist 获取 project_id
+	client := antigravity.NewClient(proxyURL)
+	loadResp, _, err := client.LoadCodeAssist(ctx, tokenInfo.AccessToken)
+	if err != nil || loadResp == nil || loadResp.CloudAICompanionProject == "" {
+		// LoadCodeAssist 失败或返回空，保留原有 project_id，标记缺失
+		existingProjectID := strings.TrimSpace(account.GetCredential("project_id"))
+		tokenInfo.ProjectID = existingProjectID
+		tokenInfo.ProjectIDMissing = true
+	} else {
+		tokenInfo.ProjectID = loadResp.CloudAICompanionProject
+	}
+
 	return tokenInfo, nil
 }
 

backend/internal/service/antigravity_quota_fetcher.go

@@ -31,11 +31,6 @@ func (f *AntigravityQuotaFetcher) FetchQuota(ctx context.Context, account *Accou
 	accessToken := account.GetCredential("access_token")
 	projectID := account.GetCredential("project_id")
 
-	// 如果没有 project_id，生成一个随机的
-	if projectID == "" {
-		projectID = antigravity.GenerateMockProjectID()
-	}
-
 	client := antigravity.NewClient(proxyURL)
 
 	// 调用 API 获取配额

backend/internal/service/antigravity_rate_limit_test.go

@@ -0,0 +1,190 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/antigravity"
+	"github.com/stretchr/testify/require"
+)
+
+type stubAntigravityUpstream struct {
+	firstBase  string
+	secondBase string
+	calls      []string
+}
+
+func (s *stubAntigravityUpstream) Do(req *http.Request, proxyURL string, accountID int64, accountConcurrency int) (*http.Response, error) {
+	url := req.URL.String()
+	s.calls = append(s.calls, url)
+	if strings.HasPrefix(url, s.firstBase) {
+		return &http.Response{
+			StatusCode: http.StatusTooManyRequests,
+			Header:     http.Header{},
+			Body:       io.NopCloser(strings.NewReader(`{"error":{"message":"Resource has been exhausted"}}`)),
+		}, nil
+	}
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     http.Header{},
+		Body:       io.NopCloser(strings.NewReader("ok")),
+	}, nil
+}
+
+func (s *stubAntigravityUpstream) DoWithTLS(req *http.Request, proxyURL string, accountID int64, accountConcurrency int, enableTLSFingerprint bool) (*http.Response, error) {
+	return s.Do(req, proxyURL, accountID, accountConcurrency)
+}
+
+type scopeLimitCall struct {
+	accountID int64
+	scope     AntigravityQuotaScope
+	resetAt   time.Time
+}
+
+type rateLimitCall struct {
+	accountID int64
+	resetAt   time.Time
+}
+
+type stubAntigravityAccountRepo struct {
+	AccountRepository
+	scopeCalls []scopeLimitCall
+	rateCalls  []rateLimitCall
+}
+
+func (s *stubAntigravityAccountRepo) SetAntigravityQuotaScopeLimit(ctx context.Context, id int64, scope AntigravityQuotaScope, resetAt time.Time) error {
+	s.scopeCalls = append(s.scopeCalls, scopeLimitCall{accountID: id, scope: scope, resetAt: resetAt})
+	return nil
+}
+
+func (s *stubAntigravityAccountRepo) SetRateLimited(ctx context.Context, id int64, resetAt time.Time) error {
+	s.rateCalls = append(s.rateCalls, rateLimitCall{accountID: id, resetAt: resetAt})
+	return nil
+}
+
+func TestAntigravityRetryLoop_URLFallback_UsesLatestSuccess(t *testing.T) {
+	oldBaseURLs := append([]string(nil), antigravity.BaseURLs...)
+	oldAvailability := antigravity.DefaultURLAvailability
+	defer func() {
+		antigravity.BaseURLs = oldBaseURLs
+		antigravity.DefaultURLAvailability = oldAvailability
+	}()
+
+	base1 := "https://ag-1.test"
+	base2 := "https://ag-2.test"
+	antigravity.BaseURLs = []string{base1, base2}
+	antigravity.DefaultURLAvailability = antigravity.NewURLAvailability(time.Minute)
+
+	upstream := &stubAntigravityUpstream{firstBase: base1, secondBase: base2}
+	account := &Account{
+		ID:          1,
+		Name:        "acc-1",
+		Platform:    PlatformAntigravity,
+		Schedulable: true,
+		Status:      StatusActive,
+		Concurrency: 1,
+	}
+
+	var handleErrorCalled bool
+	result, err := antigravityRetryLoop(antigravityRetryLoopParams{
+		prefix:      "[test]",
+		ctx:         context.Background(),
+		account:     account,
+		proxyURL:    "",
+		accessToken: "token",
+		action:      "generateContent",
+		body:        []byte(`{"input":"test"}`),
+		quotaScope:  AntigravityQuotaScopeClaude,
+		httpUpstream: upstream,
+		handleError: func(ctx context.Context, prefix string, account *Account, statusCode int, headers http.Header, body []byte, quotaScope AntigravityQuotaScope) {
+			handleErrorCalled = true
+		},
+	})
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, result.resp)
+	defer func() { _ = result.resp.Body.Close() }()
+	require.Equal(t, http.StatusOK, result.resp.StatusCode)
+	require.False(t, handleErrorCalled)
+	require.Len(t, upstream.calls, 2)
+	require.True(t, strings.HasPrefix(upstream.calls[0], base1))
+	require.True(t, strings.HasPrefix(upstream.calls[1], base2))
+
+	available := antigravity.DefaultURLAvailability.GetAvailableURLs()
+	require.NotEmpty(t, available)
+	require.Equal(t, base2, available[0])
+}
+
+func TestAntigravityHandleUpstreamError_UsesScopeLimitWhenEnabled(t *testing.T) {
+	t.Setenv(antigravityScopeRateLimitEnv, "true")
+	repo := &stubAntigravityAccountRepo{}
+	svc := &AntigravityGatewayService{accountRepo: repo}
+	account := &Account{ID: 9, Name: "acc-9", Platform: PlatformAntigravity}
+
+	body := buildGeminiRateLimitBody("3s")
+	svc.handleUpstreamError(context.Background(), "[test]", account, http.StatusTooManyRequests, http.Header{}, body, AntigravityQuotaScopeClaude)
+
+	require.Len(t, repo.scopeCalls, 1)
+	require.Empty(t, repo.rateCalls)
+	call := repo.scopeCalls[0]
+	require.Equal(t, account.ID, call.accountID)
+	require.Equal(t, AntigravityQuotaScopeClaude, call.scope)
+	require.WithinDuration(t, time.Now().Add(3*time.Second), call.resetAt, 2*time.Second)
+}
+
+func TestAntigravityHandleUpstreamError_UsesAccountLimitWhenScopeDisabled(t *testing.T) {
+	t.Setenv(antigravityScopeRateLimitEnv, "false")
+	repo := &stubAntigravityAccountRepo{}
+	svc := &AntigravityGatewayService{accountRepo: repo}
+	account := &Account{ID: 10, Name: "acc-10", Platform: PlatformAntigravity}
+
+	body := buildGeminiRateLimitBody("2s")
+	svc.handleUpstreamError(context.Background(), "[test]", account, http.StatusTooManyRequests, http.Header{}, body, AntigravityQuotaScopeClaude)
+
+	require.Len(t, repo.rateCalls, 1)
+	require.Empty(t, repo.scopeCalls)
+	call := repo.rateCalls[0]
+	require.Equal(t, account.ID, call.accountID)
+	require.WithinDuration(t, time.Now().Add(2*time.Second), call.resetAt, 2*time.Second)
+}
+
+func TestAccountIsSchedulableForModel_AntigravityRateLimits(t *testing.T) {
+	now := time.Now()
+	future := now.Add(10 * time.Minute)
+
+	account := &Account{
+		ID:          1,
+		Name:        "acc",
+		Platform:    PlatformAntigravity,
+		Status:      StatusActive,
+		Schedulable: true,
+	}
+
+	account.RateLimitResetAt = &future
+	require.False(t, account.IsSchedulableForModel("claude-sonnet-4-5"))
+	require.False(t, account.IsSchedulableForModel("gemini-3-flash"))
+
+	account.RateLimitResetAt = nil
+	account.Extra = map[string]any{
+		antigravityQuotaScopesKey: map[string]any{
+			"claude": map[string]any{
+				"rate_limit_reset_at": future.Format(time.RFC3339),
+			},
+		},
+	}
+
+	require.False(t, account.IsSchedulableForModel("claude-sonnet-4-5"))
+	require.True(t, account.IsSchedulableForModel("gemini-3-flash"))
+}
+
+func buildGeminiRateLimitBody(delay string) []byte {
+	return []byte(fmt.Sprintf(`{"error":{"message":"too many requests","details":[{"metadata":{"quotaResetDelay":%q}}]}}`, delay))
+}

backend/internal/service/antigravity_token_refresher.go

@@ -61,5 +61,10 @@ func (r *AntigravityTokenRefresher) Refresh(ctx context.Context, account *Accoun
 		}
 	}
 
+	// 如果 project_id 获取失败，返回 credentials 但同时返回错误让账户被标记
+	if tokenInfo.ProjectIDMissing {
+		return newCredentials, fmt.Errorf("missing_project_id: 账户缺少project id，可能无法使用Antigravity")
+	}
+
 	return newCredentials, nil
 }

backend/internal/service/api_key_auth_cache_impl.go

@@ -94,6 +94,20 @@ func (s *APIKeyService) initAuthCache(cfg *config.Config) {
 	s.authCacheL1 = cache
 }
 
+// StartAuthCacheInvalidationSubscriber starts the Pub/Sub subscriber for L1 cache invalidation.
+// This should be called after the service is fully initialized.
+func (s *APIKeyService) StartAuthCacheInvalidationSubscriber(ctx context.Context) {
+	if s.cache == nil || s.authCacheL1 == nil {
+		return
+	}
+	if err := s.cache.SubscribeAuthCacheInvalidation(ctx, func(cacheKey string) {
+		s.authCacheL1.Del(cacheKey)
+	}); err != nil {
+		// Log but don't fail - L1 cache will still work, just without cross-instance invalidation
+		println("[Service] Warning: failed to start auth cache invalidation subscriber:", err.Error())
+	}
+}
+
 func (s *APIKeyService) authCacheKey(key string) string {
 	sum := sha256.Sum256([]byte(key))
 	return hex.EncodeToString(sum[:])
@@ -149,6 +163,8 @@ func (s *APIKeyService) deleteAuthCache(ctx context.Context, cacheKey string) {
 		return
 	}
 	_ = s.cache.DeleteAuthCache(ctx, cacheKey)
+	// Publish invalidation message to other instances
+	_ = s.cache.PublishAuthCacheInvalidation(ctx, cacheKey)
 }
 
 func (s *APIKeyService) loadAuthCacheEntry(ctx context.Context, key, cacheKey string) (*APIKeyAuthCacheEntry, error) {

backend/internal/service/api_key_service.go

@@ -65,6 +65,10 @@ type APIKeyCache interface {
 	GetAuthCache(ctx context.Context, key string) (*APIKeyAuthCacheEntry, error)
 	SetAuthCache(ctx context.Context, key string, entry *APIKeyAuthCacheEntry, ttl time.Duration) error
 	DeleteAuthCache(ctx context.Context, key string) error
+
+	// Pub/Sub for L1 cache invalidation across instances
+	PublishAuthCacheInvalidation(ctx context.Context, cacheKey string) error
+	SubscribeAuthCacheInvalidation(ctx context.Context, handler func(cacheKey string)) error
 }
 
 // APIKeyAuthCacheInvalidator 提供认证缓存失效能力

backend/internal/service/api_key_service_cache_test.go

@@ -142,6 +142,14 @@ func (s *authCacheStub) DeleteAuthCache(ctx context.Context, key string) error {
 	return nil
 }
 
+func (s *authCacheStub) PublishAuthCacheInvalidation(ctx context.Context, cacheKey string) error {
+	return nil
+}
+
+func (s *authCacheStub) SubscribeAuthCacheInvalidation(ctx context.Context, handler func(cacheKey string)) error {
+	return nil
+}
+
 func TestAPIKeyService_GetByKey_UsesL2Cache(t *testing.T) {
 	cache := &authCacheStub{}
 	repo := &authRepoStub{

backend/internal/service/api_key_service_delete_test.go

@@ -168,6 +168,14 @@ func (s *apiKeyCacheStub) DeleteAuthCache(ctx context.Context, key string) error
 	return nil
 }
 
+func (s *apiKeyCacheStub) PublishAuthCacheInvalidation(ctx context.Context, cacheKey string) error {
+	return nil
+}
+
+func (s *apiKeyCacheStub) SubscribeAuthCacheInvalidation(ctx context.Context, handler func(cacheKey string)) error {
+	return nil
+}
+
 // TestApiKeyService_Delete_OwnerMismatch 测试非所有者尝试删除时返回权限错误。
 // 预期行为：
 //   - GetKeyAndOwnerID 返回所有者 ID 为 1

backend/internal/service/gateway_multiplatform_test.go

@@ -105,6 +105,9 @@ func (m *mockAccountRepoForPlatform) BatchUpdateLastUsed(ctx context.Context, up
 func (m *mockAccountRepoForPlatform) SetError(ctx context.Context, id int64, errorMsg string) error {
 	return nil
 }
+func (m *mockAccountRepoForPlatform) ClearError(ctx context.Context, id int64) error {
+	return nil
+}
 func (m *mockAccountRepoForPlatform) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
 	return nil
 }

backend/internal/service/gateway_service.go

@@ -11,6 +11,8 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"log/slog"
+	mathrand "math/rand"
 	"net/http"
 	"os"
 	"regexp"
@@ -445,11 +447,20 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 }
 
 // SelectAccountWithLoadAwareness selects account with load-awareness and wait plan.
-// metadataUserID: 原始 metadata.user_id 字段（用于提取会话 UUID 进行会话数量限制）
+// metadataUserID: 已废弃参数，会话限制现在统一使用 sessionHash
 func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}, metadataUserID string) (*AccountSelectionResult, error) {
+	// 调试日志：记录调度入口参数
+	excludedIDsList := make([]int64, 0, len(excludedIDs))
+	for id := range excludedIDs {
+		excludedIDsList = append(excludedIDsList, id)
+	}
+	slog.Debug("account_scheduling_starting",
+		"group_id", derefGroupID(groupID),
+		"model", requestedModel,
+		"session", shortSessionHash(sessionHash),
+		"excluded_ids", excludedIDsList)
+
 	cfg := s.schedulingConfig()
-	// 提取会话 UUID（用于会话数量限制）
-	sessionUUID := extractSessionUUID(metadataUserID)
 
 	var stickyAccountID int64
 	if sessionHash != "" && s.cache != nil {
@@ -475,41 +486,63 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	}
 
 	if s.concurrencyService == nil || !cfg.LoadBatchEnabled {
-		account, err := s.SelectAccountForModelWithExclusions(ctx, groupID, sessionHash, requestedModel, excludedIDs)
-		if err != nil {
-			return nil, err
+		// 复制排除列表，用于会话限制拒绝时的重试
+		localExcluded := make(map[int64]struct{})
+		for k, v := range excludedIDs {
+			localExcluded[k] = v
 		}
-		result, err := s.tryAcquireAccountSlot(ctx, account.ID, account.Concurrency)
-		if err == nil && result.Acquired {
-			return &AccountSelectionResult{
-				Account:     account,
-				Acquired:    true,
-				ReleaseFunc: result.ReleaseFunc,
-			}, nil
-		}
-		if stickyAccountID > 0 && stickyAccountID == account.ID && s.concurrencyService != nil {
-			waitingCount, _ := s.concurrencyService.GetAccountWaitingCount(ctx, account.ID)
-			if waitingCount < cfg.StickySessionMaxWaiting {
+
+		for {
+			account, err := s.SelectAccountForModelWithExclusions(ctx, groupID, sessionHash, requestedModel, localExcluded)
+			if err != nil {
+				return nil, err
+			}
+
+			result, err := s.tryAcquireAccountSlot(ctx, account.ID, account.Concurrency)
+			if err == nil && result.Acquired {
+				// 获取槽位后检查会话限制（使用 sessionHash 作为会话标识符）
+				if !s.checkAndRegisterSession(ctx, account, sessionHash) {
+					result.ReleaseFunc()                   // 释放槽位
+					localExcluded[account.ID] = struct{}{} // 排除此账号
+					continue                               // 重新选择
+				}
 				return &AccountSelectionResult{
-					Account: account,
-					WaitPlan: &AccountWaitPlan{
-						AccountID:      account.ID,
-						MaxConcurrency: account.Concurrency,
-						Timeout:        cfg.StickySessionWaitTimeout,
-						MaxWaiting:     cfg.StickySessionMaxWaiting,
-					},
+					Account:     account,
+					Acquired:    true,
+					ReleaseFunc: result.ReleaseFunc,
 				}, nil
 			}
+
+			// 对于等待计划的情况，也需要先检查会话限制
+			if !s.checkAndRegisterSession(ctx, account, sessionHash) {
+				localExcluded[account.ID] = struct{}{}
+				continue
+			}
+
+			if stickyAccountID > 0 && stickyAccountID == account.ID && s.concurrencyService != nil {
+				waitingCount, _ := s.concurrencyService.GetAccountWaitingCount(ctx, account.ID)
+				if waitingCount < cfg.StickySessionMaxWaiting {
+					return &AccountSelectionResult{
+						Account: account,
+						WaitPlan: &AccountWaitPlan{
+							AccountID:      account.ID,
+							MaxConcurrency: account.Concurrency,
+							Timeout:        cfg.StickySessionWaitTimeout,
+							MaxWaiting:     cfg.StickySessionMaxWaiting,
+						},
+					}, nil
+				}
+			}
+			return &AccountSelectionResult{
+				Account: account,
+				WaitPlan: &AccountWaitPlan{
+					AccountID:      account.ID,
+					MaxConcurrency: account.Concurrency,
+					Timeout:        cfg.FallbackWaitTimeout,
+					MaxWaiting:     cfg.FallbackMaxWaiting,
+				},
+			}, nil
 		}
-		return &AccountSelectionResult{
-			Account: account,
-			WaitPlan: &AccountWaitPlan{
-				AccountID:      account.ID,
-				MaxConcurrency: account.Concurrency,
-				Timeout:        cfg.FallbackWaitTimeout,
-				MaxWaiting:     cfg.FallbackMaxWaiting,
-			},
-		}, nil
 	}
 
 	platform, hasForcePlatform, err := s.resolvePlatform(ctx, groupID, group)
@@ -625,7 +658,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 							result, err := s.tryAcquireAccountSlot(ctx, stickyAccountID, stickyAccount.Concurrency)
 							if err == nil && result.Acquired {
 								// 会话数量限制检查
-								if !s.checkAndRegisterSession(ctx, stickyAccount, sessionUUID) {
+								if !s.checkAndRegisterSession(ctx, stickyAccount, sessionHash) {
 									result.ReleaseFunc() // 释放槽位
 									// 继续到负载感知选择
 								} else {
@@ -643,15 +676,20 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 
 							waitingCount, _ := s.concurrencyService.GetAccountWaitingCount(ctx, stickyAccountID)
 							if waitingCount < cfg.StickySessionMaxWaiting {
-								return &AccountSelectionResult{
-									Account: stickyAccount,
-									WaitPlan: &AccountWaitPlan{
-										AccountID:      stickyAccountID,
-										MaxConcurrency: stickyAccount.Concurrency,
-										Timeout:        cfg.StickySessionWaitTimeout,
-										MaxWaiting:     cfg.StickySessionMaxWaiting,
-									},
-								}, nil
+								// 会话数量限制检查（等待计划也需要占用会话配额）
+								if !s.checkAndRegisterSession(ctx, stickyAccount, sessionHash) {
+									// 会话限制已满，继续到负载感知选择
+								} else {
+									return &AccountSelectionResult{
+										Account: stickyAccount,
+										WaitPlan: &AccountWaitPlan{
+											AccountID:      stickyAccountID,
+											MaxConcurrency: stickyAccount.Concurrency,
+											Timeout:        cfg.StickySessionWaitTimeout,
+											MaxWaiting:     cfg.StickySessionMaxWaiting,
+										},
+									}, nil
+								}
 							}
 							// 粘性账号槽位满且等待队列已满，继续使用负载感知选择
 						}
@@ -714,7 +752,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 					result, err := s.tryAcquireAccountSlot(ctx, item.account.ID, item.account.Concurrency)
 					if err == nil && result.Acquired {
 						// 会话数量限制检查
-						if !s.checkAndRegisterSession(ctx, item.account, sessionUUID) {
+						if !s.checkAndRegisterSession(ctx, item.account, sessionHash) {
 							result.ReleaseFunc() // 释放槽位，继续尝试下一个账号
 							continue
 						}
@@ -732,20 +770,26 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 					}
 				}
 
-				// 5. 所有路由账号槽位满，返回等待计划（选择负载最低的）
-				acc := routingAvailable[0].account
-				if s.debugModelRoutingEnabled() {
-					log.Printf("[ModelRoutingDebug] routed wait: group_id=%v model=%s session=%s account=%d", derefGroupID(groupID), requestedModel, shortSessionHash(sessionHash), acc.ID)
+				// 5. 所有路由账号槽位满，尝试返回等待计划（选择负载最低的）
+				// 遍历找到第一个满足会话限制的账号
+				for _, item := range routingAvailable {
+					if !s.checkAndRegisterSession(ctx, item.account, sessionHash) {
+						continue // 会话限制已满，尝试下一个
+					}
+					if s.debugModelRoutingEnabled() {
+						log.Printf("[ModelRoutingDebug] routed wait: group_id=%v model=%s session=%s account=%d", derefGroupID(groupID), requestedModel, shortSessionHash(sessionHash), item.account.ID)
+					}
+					return &AccountSelectionResult{
+						Account: item.account,
+						WaitPlan: &AccountWaitPlan{
+							AccountID:      item.account.ID,
+							MaxConcurrency: item.account.Concurrency,
+							Timeout:        cfg.StickySessionWaitTimeout,
+							MaxWaiting:     cfg.StickySessionMaxWaiting,
+						},
+					}, nil
 				}
-				return &AccountSelectionResult{
-					Account: acc,
-					WaitPlan: &AccountWaitPlan{
-						AccountID:      acc.ID,
-						MaxConcurrency: acc.Concurrency,
-						Timeout:        cfg.StickySessionWaitTimeout,
-						MaxWaiting:     cfg.StickySessionMaxWaiting,
-					},
-				}, nil
+				// 所有路由账号会话限制都已满，继续到 Layer 2 回退
 			}
 			// 路由列表中的账号都不可用（负载率 >= 100），继续到 Layer 2 回退
 			log.Printf("[ModelRouting] All routed accounts unavailable for model=%s, falling back to normal selection", requestedModel)
@@ -773,7 +817,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 					if err == nil && result.Acquired {
 						// 会话数量限制检查
 						// Session count limit check
-						if !s.checkAndRegisterSession(ctx, account, sessionUUID) {
+						if !s.checkAndRegisterSession(ctx, account, sessionHash) {
 							result.ReleaseFunc() // 释放槽位，继续到 Layer 2
 						} else {
 							_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), sessionHash, stickySessionTTL)
@@ -787,15 +831,22 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 
 					waitingCount, _ := s.concurrencyService.GetAccountWaitingCount(ctx, accountID)
 					if waitingCount < cfg.StickySessionMaxWaiting {
-						return &AccountSelectionResult{
-							Account: account,
-							WaitPlan: &AccountWaitPlan{
-								AccountID:      accountID,
-								MaxConcurrency: account.Concurrency,
-								Timeout:        cfg.StickySessionWaitTimeout,
-								MaxWaiting:     cfg.StickySessionMaxWaiting,
-							},
-						}, nil
+						// 会话数量限制检查（等待计划也需要占用会话配额）
+						// Session count limit check (wait plan also requires session quota)
+						if !s.checkAndRegisterSession(ctx, account, sessionHash) {
+							// 会话限制已满，继续到 Layer 2
+							// Session limit full, continue to Layer 2
+						} else {
+							return &AccountSelectionResult{
+								Account: account,
+								WaitPlan: &AccountWaitPlan{
+									AccountID:      accountID,
+									MaxConcurrency: account.Concurrency,
+									Timeout:        cfg.StickySessionWaitTimeout,
+									MaxWaiting:     cfg.StickySessionMaxWaiting,
+								},
+							}, nil
+						}
 					}
 				}
 			}
@@ -845,7 +896,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 
 	loadMap, err := s.concurrencyService.GetAccountsLoadBatch(ctx, accountLoads)
 	if err != nil {
-		if result, ok := s.tryAcquireByLegacyOrder(ctx, candidates, groupID, sessionHash, preferOAuth, sessionUUID); ok {
+		if result, ok := s.tryAcquireByLegacyOrder(ctx, candidates, groupID, sessionHash, preferOAuth); ok {
 			return result, nil
 		}
 	} else {
@@ -895,7 +946,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 				result, err := s.tryAcquireAccountSlot(ctx, item.account.ID, item.account.Concurrency)
 				if err == nil && result.Acquired {
 					// 会话数量限制检查
-					if !s.checkAndRegisterSession(ctx, item.account, sessionUUID) {
+					if !s.checkAndRegisterSession(ctx, item.account, sessionHash) {
 						result.ReleaseFunc() // 释放槽位，继续尝试下一个账号
 						continue
 					}
@@ -913,8 +964,12 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	}
 
 	// ============ Layer 3: 兜底排队 ============
-	sortAccountsByPriorityAndLastUsed(candidates, preferOAuth)
+	s.sortCandidatesForFallback(candidates, preferOAuth, cfg.FallbackSelectionMode)
 	for _, acc := range candidates {
+		// 会话数量限制检查（等待计划也需要占用会话配额）
+		if !s.checkAndRegisterSession(ctx, acc, sessionHash) {
+			continue // 会话限制已满，尝试下一个账号
+		}
 		return &AccountSelectionResult{
 			Account: acc,
 			WaitPlan: &AccountWaitPlan{
@@ -928,7 +983,7 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	return nil, errors.New("no available accounts")
 }
 
-func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates []*Account, groupID *int64, sessionHash string, preferOAuth bool, sessionUUID string) (*AccountSelectionResult, bool) {
+func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates []*Account, groupID *int64, sessionHash string, preferOAuth bool) (*AccountSelectionResult, bool) {
 	ordered := append([]*Account(nil), candidates...)
 	sortAccountsByPriorityAndLastUsed(ordered, preferOAuth)
 
@@ -936,7 +991,7 @@ func (s *GatewayService) tryAcquireByLegacyOrder(ctx context.Context, candidates
 		result, err := s.tryAcquireAccountSlot(ctx, acc.ID, acc.Concurrency)
 		if err == nil && result.Acquired {
 			// 会话数量限制检查
-			if !s.checkAndRegisterSession(ctx, acc, sessionUUID) {
+			if !s.checkAndRegisterSession(ctx, acc, sessionHash) {
 				result.ReleaseFunc() // 释放槽位，继续尝试下一个账号
 				continue
 			}
@@ -1093,7 +1148,24 @@ func (s *GatewayService) resolvePlatform(ctx context.Context, groupID *int64, gr
 
 func (s *GatewayService) listSchedulableAccounts(ctx context.Context, groupID *int64, platform string, hasForcePlatform bool) ([]Account, bool, error) {
 	if s.schedulerSnapshot != nil {
-		return s.schedulerSnapshot.ListSchedulableAccounts(ctx, groupID, platform, hasForcePlatform)
+		accounts, useMixed, err := s.schedulerSnapshot.ListSchedulableAccounts(ctx, groupID, platform, hasForcePlatform)
+		if err == nil {
+			slog.Debug("account_scheduling_list_snapshot",
+				"group_id", derefGroupID(groupID),
+				"platform", platform,
+				"use_mixed", useMixed,
+				"count", len(accounts))
+			for _, acc := range accounts {
+				slog.Debug("account_scheduling_account_detail",
+					"account_id", acc.ID,
+					"name", acc.Name,
+					"platform", acc.Platform,
+					"type", acc.Type,
+					"status", acc.Status,
+					"tls_fingerprint", acc.IsTLSFingerprintEnabled())
+			}
+		}
+		return accounts, useMixed, err
 	}
 	useMixed := (platform == PlatformAnthropic || platform == PlatformGemini) && !hasForcePlatform
 	if useMixed {
@@ -1106,6 +1178,10 @@ func (s *GatewayService) listSchedulableAccounts(ctx context.Context, groupID *i
 			accounts, err = s.accountRepo.ListSchedulableByPlatforms(ctx, platforms)
 		}
 		if err != nil {
+			slog.Debug("account_scheduling_list_failed",
+				"group_id", derefGroupID(groupID),
+				"platform", platform,
+				"error", err)
 			return nil, useMixed, err
 		}
 		filtered := make([]Account, 0, len(accounts))
@@ -1115,6 +1191,20 @@ func (s *GatewayService) listSchedulableAccounts(ctx context.Context, groupID *i
 			}
 			filtered = append(filtered, acc)
 		}
+		slog.Debug("account_scheduling_list_mixed",
+			"group_id", derefGroupID(groupID),
+			"platform", platform,
+			"raw_count", len(accounts),
+			"filtered_count", len(filtered))
+		for _, acc := range filtered {
+			slog.Debug("account_scheduling_account_detail",
+				"account_id", acc.ID,
+				"name", acc.Name,
+				"platform", acc.Platform,
+				"type", acc.Type,
+				"status", acc.Status,
+				"tls_fingerprint", acc.IsTLSFingerprintEnabled())
+		}
 		return filtered, useMixed, nil
 	}
 
@@ -1129,8 +1219,25 @@ func (s *GatewayService) listSchedulableAccounts(ctx context.Context, groupID *i
 		accounts, err = s.accountRepo.ListSchedulableByPlatform(ctx, platform)
 	}
 	if err != nil {
+		slog.Debug("account_scheduling_list_failed",
+			"group_id", derefGroupID(groupID),
+			"platform", platform,
+			"error", err)
 		return nil, useMixed, err
 	}
+	slog.Debug("account_scheduling_list_single",
+		"group_id", derefGroupID(groupID),
+		"platform", platform,
+		"count", len(accounts))
+	for _, acc := range accounts {
+		slog.Debug("account_scheduling_account_detail",
+			"account_id", acc.ID,
+			"name", acc.Name,
+			"platform", acc.Platform,
+			"type", acc.Type,
+			"status", acc.Status,
+			"tls_fingerprint", acc.IsTLSFingerprintEnabled())
+	}
 	return accounts, useMixed, nil
 }
 
@@ -1196,12 +1303,8 @@ func (s *GatewayService) isAccountSchedulableForWindowCost(ctx context.Context,
 
 	// 缓存未命中，从数据库查询
 	{
-		var startTime time.Time
-		if account.SessionWindowStart != nil {
-			startTime = *account.SessionWindowStart
-		} else {
-			startTime = time.Now().Add(-5 * time.Hour)
-		}
+		// 使用统一的窗口开始时间计算逻辑（考虑窗口过期情况）
+		startTime := account.GetCurrentWindowStartTime()
 
 		stats, err := s.usageLogRepo.GetAccountWindowStats(ctx, account.ID, startTime)
 		if err != nil {
@@ -1234,15 +1337,16 @@ checkSchedulability:
 
 // checkAndRegisterSession 检查并注册会话，用于会话数量限制
 // 仅适用于 Anthropic OAuth/SetupToken 账号
+// sessionID: 会话标识符（使用粘性会话的 hash）
 // 返回 true 表示允许（在限制内或会话已存在），false 表示拒绝（超出限制且是新会话）
-func (s *GatewayService) checkAndRegisterSession(ctx context.Context, account *Account, sessionUUID string) bool {
+func (s *GatewayService) checkAndRegisterSession(ctx context.Context, account *Account, sessionID string) bool {
 	// 只检查 Anthropic OAuth/SetupToken 账号
 	if !account.IsAnthropicOAuthOrSetupToken() {
 		return true
 	}
 
 	maxSessions := account.GetMaxSessions()
-	if maxSessions <= 0 || sessionUUID == "" {
+	if maxSessions <= 0 || sessionID == "" {
 		return true // 未启用会话限制或无会话ID
 	}
 
@@ -1252,7 +1356,7 @@ func (s *GatewayService) checkAndRegisterSession(ctx context.Context, account *A
 
 	idleTimeout := time.Duration(account.GetSessionIdleTimeoutMinutes()) * time.Minute
 
-	allowed, err := s.sessionLimitCache.RegisterSession(ctx, account.ID, sessionUUID, maxSessions, idleTimeout)
+	allowed, err := s.sessionLimitCache.RegisterSession(ctx, account.ID, sessionID, maxSessions, idleTimeout)
 	if err != nil {
 		// 失败开放：缓存错误时允许通过
 		return true
@@ -1260,18 +1364,6 @@ func (s *GatewayService) checkAndRegisterSession(ctx context.Context, account *A
 	return allowed
 }
 
-// extractSessionUUID 从 metadata.user_id 中提取会话 UUID
-// 格式: user_{64位hex}_account__session_{uuid}
-func extractSessionUUID(metadataUserID string) string {
-	if metadataUserID == "" {
-		return ""
-	}
-	if match := sessionIDRegex.FindStringSubmatch(metadataUserID); len(match) > 1 {
-		return match[1]
-	}
-	return ""
-}
-
 func (s *GatewayService) getSchedulableAccount(ctx context.Context, accountID int64) (*Account, error) {
 	if s.schedulerSnapshot != nil {
 		return s.schedulerSnapshot.GetAccount(ctx, accountID)
@@ -1301,6 +1393,56 @@ func sortAccountsByPriorityAndLastUsed(accounts []*Account, preferOAuth bool) {
 	})
 }
 
+// sortCandidatesForFallback 根据配置选择排序策略
+// mode: "last_used"(按最后使用时间) 或 "random"(随机)
+func (s *GatewayService) sortCandidatesForFallback(accounts []*Account, preferOAuth bool, mode string) {
+	if mode == "random" {
+		// 先按优先级排序，然后在同优先级内随机打乱
+		sortAccountsByPriorityOnly(accounts, preferOAuth)
+		shuffleWithinPriority(accounts)
+	} else {
+		// 默认按最后使用时间排序
+		sortAccountsByPriorityAndLastUsed(accounts, preferOAuth)
+	}
+}
+
+// sortAccountsByPriorityOnly 仅按优先级排序
+func sortAccountsByPriorityOnly(accounts []*Account, preferOAuth bool) {
+	sort.SliceStable(accounts, func(i, j int) bool {
+		a, b := accounts[i], accounts[j]
+		if a.Priority != b.Priority {
+			return a.Priority < b.Priority
+		}
+		if preferOAuth && a.Type != b.Type {
+			return a.Type == AccountTypeOAuth
+		}
+		return false
+	})
+}
+
+// shuffleWithinPriority 在同优先级内随机打乱顺序
+func shuffleWithinPriority(accounts []*Account) {
+	if len(accounts) <= 1 {
+		return
+	}
+	r := mathrand.New(mathrand.NewSource(time.Now().UnixNano()))
+	start := 0
+	for start < len(accounts) {
+		priority := accounts[start].Priority
+		end := start + 1
+		for end < len(accounts) && accounts[end].Priority == priority {
+			end++
+		}
+		// 对 [start, end) 范围内的账户随机打乱
+		if end-start > 1 {
+			r.Shuffle(end-start, func(i, j int) {
+				accounts[start+i], accounts[start+j] = accounts[start+j], accounts[start+i]
+			})
+		}
+		start = end
+	}
+}
+
 // selectAccountForModelWithPlatform 选择单平台账户（完全隔离）
 func (s *GatewayService) selectAccountForModelWithPlatform(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}, platform string) (*Account, error) {
 	preferOAuth := platform == PlatformGemini
@@ -2158,6 +2300,10 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 		proxyURL = account.Proxy.URL()
 	}
 
+	// 调试日志：记录即将转发的账号信息
+	log.Printf("[Forward] Using account: ID=%d Name=%s Platform=%s Type=%s TLSFingerprint=%v Proxy=%s",
+		account.ID, account.Name, account.Platform, account.Type, account.IsTLSFingerprintEnabled(), proxyURL)
+
 	// 重试循环
 	var resp *http.Response
 	retryStart := time.Now()
@@ -2172,7 +2318,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 		}
 
 		// 发送请求
-		resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+		resp, err = s.httpUpstream.DoWithTLS(upstreamReq, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 		if err != nil {
 			if resp != nil && resp.Body != nil {
 				_ = resp.Body.Close()
@@ -2246,7 +2392,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 					filteredBody := FilterThinkingBlocksForRetry(body)
 					retryReq, buildErr := s.buildUpstreamRequest(ctx, c, account, filteredBody, token, tokenType, reqModel)
 					if buildErr == nil {
-						retryResp, retryErr := s.httpUpstream.Do(retryReq, proxyURL, account.ID, account.Concurrency)
+						retryResp, retryErr := s.httpUpstream.DoWithTLS(retryReq, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 						if retryErr == nil {
 							if retryResp.StatusCode < 400 {
 								log.Printf("Account %d: signature error retry succeeded (thinking downgraded)", account.ID)
@@ -2278,7 +2424,7 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 									filteredBody2 := FilterSignatureSensitiveBlocksForRetry(body)
 									retryReq2, buildErr2 := s.buildUpstreamRequest(ctx, c, account, filteredBody2, token, tokenType, reqModel)
 									if buildErr2 == nil {
-										retryResp2, retryErr2 := s.httpUpstream.Do(retryReq2, proxyURL, account.ID, account.Concurrency)
+										retryResp2, retryErr2 := s.httpUpstream.DoWithTLS(retryReq2, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 										if retryErr2 == nil {
 											resp = retryResp2
 											break
@@ -2393,6 +2539,10 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 			_ = resp.Body.Close()
 			resp.Body = io.NopCloser(bytes.NewReader(respBody))
 
+			// 调试日志：打印重试耗尽后的错误响应
+			log.Printf("[Forward] Upstream error (retry exhausted, failover): Account=%d(%s) Status=%d RequestID=%s Body=%s",
+				account.ID, account.Name, resp.StatusCode, resp.Header.Get("x-request-id"), truncateString(string(respBody), 1000))
+
 			s.handleRetryExhaustedSideEffects(ctx, resp, account)
 			appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
 				Platform:           account.Platform,
@@ -2420,6 +2570,10 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 		_ = resp.Body.Close()
 		resp.Body = io.NopCloser(bytes.NewReader(respBody))
 
+		// 调试日志：打印上游错误响应
+		log.Printf("[Forward] Upstream error (failover): Account=%d(%s) Status=%d RequestID=%s Body=%s",
+			account.ID, account.Name, resp.StatusCode, resp.Header.Get("x-request-id"), truncateString(string(respBody), 1000))
+
 		s.handleFailoverSideEffects(ctx, resp, account)
 		appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
 			Platform:           account.Platform,
@@ -2549,9 +2703,10 @@ func (s *GatewayService) buildUpstreamRequest(ctx context.Context, c *gin.Contex
 			fingerprint = fp
 
 			// 2. 重写metadata.user_id（需要指纹中的ClientID和账号的account_uuid）
+			// 如果启用了会话ID伪装，会在重写后替换 session 部分为固定值
 			accountUUID := account.GetExtraString("account_uuid")
 			if accountUUID != "" && fp.ClientID != "" {
-				if newBody, err := s.identityService.RewriteUserID(body, account.ID, accountUUID, fp.ClientID); err == nil && len(newBody) > 0 {
+				if newBody, err := s.identityService.RewriteUserIDWithMasking(ctx, body, account, accountUUID, fp.ClientID); err == nil && len(newBody) > 0 {
 					body = newBody
 				}
 			}
@@ -2770,6 +2925,10 @@ func extractUpstreamErrorMessage(body []byte) string {
 func (s *GatewayService) handleErrorResponse(ctx context.Context, resp *http.Response, c *gin.Context, account *Account) (*ForwardResult, error) {
 	body, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
 
+	// 调试日志：打印上游错误响应
+	log.Printf("[Forward] Upstream error (non-retryable): Account=%d(%s) Status=%d RequestID=%s Body=%s",
+		account.ID, account.Name, resp.StatusCode, resp.Header.Get("x-request-id"), truncateString(string(body), 1000))
+
 	upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(body))
 	upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
 
@@ -3478,7 +3637,7 @@ func (s *GatewayService) ForwardCountTokens(ctx context.Context, c *gin.Context,
 	}
 
 	// 发送请求
-	resp, err := s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+	resp, err := s.httpUpstream.DoWithTLS(upstreamReq, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 	if err != nil {
 		setOpsUpstreamError(c, 0, sanitizeUpstreamErrorMessage(err.Error()), "")
 		s.countTokensError(c, http.StatusBadGateway, "upstream_error", "Request failed")
@@ -3500,7 +3659,7 @@ func (s *GatewayService) ForwardCountTokens(ctx context.Context, c *gin.Context,
 		filteredBody := FilterThinkingBlocksForRetry(body)
 		retryReq, buildErr := s.buildCountTokensRequest(ctx, c, account, filteredBody, token, tokenType, reqModel)
 		if buildErr == nil {
-			retryResp, retryErr := s.httpUpstream.Do(retryReq, proxyURL, account.ID, account.Concurrency)
+			retryResp, retryErr := s.httpUpstream.DoWithTLS(retryReq, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
 			if retryErr == nil {
 				resp = retryResp
 				respBody, err = io.ReadAll(resp.Body)
@@ -3578,12 +3737,13 @@ func (s *GatewayService) buildCountTokensRequest(ctx context.Context, c *gin.Con
 	}
 
 	// OAuth 账号：应用统一指纹和重写 userID
+	// 如果启用了会话ID伪装，会在重写后替换 session 部分为固定值
 	if account.IsOAuth() && s.identityService != nil {
 		fp, err := s.identityService.GetOrCreateFingerprint(ctx, account.ID, c.Request.Header)
 		if err == nil {
 			accountUUID := account.GetExtraString("account_uuid")
 			if accountUUID != "" && fp.ClientID != "" {
-				if newBody, err := s.identityService.RewriteUserID(body, account.ID, accountUUID, fp.ClientID); err == nil && len(newBody) > 0 {
+				if newBody, err := s.identityService.RewriteUserIDWithMasking(ctx, body, account, accountUUID, fp.ClientID); err == nil && len(newBody) > 0 {
 					body = newBody
 				}
 			}

backend/internal/service/gemini_multiplatform_test.go

@@ -90,6 +90,9 @@ func (m *mockAccountRepoForGemini) BatchUpdateLastUsed(ctx context.Context, upda
 func (m *mockAccountRepoForGemini) SetError(ctx context.Context, id int64, errorMsg string) error {
 	return nil
 }
+func (m *mockAccountRepoForGemini) ClearError(ctx context.Context, id int64) error {
+	return nil
+}
 func (m *mockAccountRepoForGemini) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
 	return nil
 }

backend/internal/service/http_upstream_port.go

@@ -10,6 +10,7 @@ import "net/http"
 // - 支持可选代理配置
 // - 支持账户级连接池隔离
 // - 实现类负责连接池管理和复用
+// - 支持可选的 TLS 指纹伪装
 type HTTPUpstream interface {
 	// Do 执行 HTTP 请求
 	//
@@ -27,4 +28,28 @@ type HTTPUpstream interface {
 	//   - 调用方必须关闭 resp.Body，否则会导致连接泄漏
 	//   - 响应体可能已被包装以跟踪请求生命周期
 	Do(req *http.Request, proxyURL string, accountID int64, accountConcurrency int) (*http.Response, error)
+
+	// DoWithTLS 执行带 TLS 指纹伪装的 HTTP 请求
+	//
+	// 参数:
+	//   - req: HTTP 请求对象，由调用方构建
+	//   - proxyURL: 代理服务器地址，空字符串表示直连
+	//   - accountID: 账户 ID，用于连接池隔离和 TLS 指纹模板选择
+	//   - accountConcurrency: 账户并发限制，用于动态调整连接池大小
+	//   - enableTLSFingerprint: 是否启用 TLS 指纹伪装
+	//
+	// 返回:
+	//   - *http.Response: HTTP 响应，调用方必须关闭 Body
+	//   - error: 请求错误（网络错误、超时等）
+	//
+	// TLS 指纹说明:
+	//   - 当 enableTLSFingerprint=true 时，使用 utls 库模拟 Claude CLI 的 TLS 指纹
+	//   - TLS 指纹模板根据 accountID % len(profiles) 自动选择
+	//   - 支持直连、HTTP/HTTPS 代理、SOCKS5 代理三种场景
+	//   - 如果 enableTLSFingerprint=false，行为与 Do 方法相同
+	//
+	// 注意:
+	//   - 调用方必须关闭 resp.Body，否则会导致连接泄漏
+	//   - TLS 指纹客户端与普通客户端使用不同的缓存键，互不影响
+	DoWithTLS(req *http.Request, proxyURL string, accountID int64, accountConcurrency int, enableTLSFingerprint bool) (*http.Response, error)
 }

backend/internal/service/identity_service.go

@@ -8,9 +8,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"log/slog"
 	"net/http"
 	"regexp"
 	"strconv"
+	"strings"
 	"time"
 )
 
@@ -49,6 +51,13 @@ type Fingerprint struct {
 type IdentityCache interface {
 	GetFingerprint(ctx context.Context, accountID int64) (*Fingerprint, error)
 	SetFingerprint(ctx context.Context, accountID int64, fp *Fingerprint) error
+	// GetMaskedSessionID 获取固定的会话ID（用于会话ID伪装功能）
+	// 返回的 sessionID 是一个 UUID 格式的字符串
+	// 如果不存在或已过期（15分钟无请求），返回空字符串
+	GetMaskedSessionID(ctx context.Context, accountID int64) (string, error)
+	// SetMaskedSessionID 设置固定的会话ID，TTL 为 15 分钟
+	// 每次调用都会刷新 TTL
+	SetMaskedSessionID(ctx context.Context, accountID int64, sessionID string) error
 }
 
 // IdentityService 管理OAuth账号的请求身份指纹
@@ -203,6 +212,94 @@ func (s *IdentityService) RewriteUserID(body []byte, accountID int64, accountUUI
 	return json.Marshal(reqMap)
 }
 
+// RewriteUserIDWithMasking 重写body中的metadata.user_id，支持会话ID伪装
+// 如果账号启用了会话ID伪装（session_id_masking_enabled），
+// 则在完成常规重写后，将 session 部分替换为固定的伪装ID（15分钟内保持不变）
+func (s *IdentityService) RewriteUserIDWithMasking(ctx context.Context, body []byte, account *Account, accountUUID, cachedClientID string) ([]byte, error) {
+	// 先执行常规的 RewriteUserID 逻辑
+	newBody, err := s.RewriteUserID(body, account.ID, accountUUID, cachedClientID)
+	if err != nil {
+		return newBody, err
+	}
+
+	// 检查是否启用会话ID伪装
+	if !account.IsSessionIDMaskingEnabled() {
+		return newBody, nil
+	}
+
+	// 解析重写后的 body，提取 user_id
+	var reqMap map[string]any
+	if err := json.Unmarshal(newBody, &reqMap); err != nil {
+		return newBody, nil
+	}
+
+	metadata, ok := reqMap["metadata"].(map[string]any)
+	if !ok {
+		return newBody, nil
+	}
+
+	userID, ok := metadata["user_id"].(string)
+	if !ok || userID == "" {
+		return newBody, nil
+	}
+
+	// 查找 _session_ 的位置，替换其后的内容
+	const sessionMarker = "_session_"
+	idx := strings.LastIndex(userID, sessionMarker)
+	if idx == -1 {
+		return newBody, nil
+	}
+
+	// 获取或生成固定的伪装 session ID
+	maskedSessionID, err := s.cache.GetMaskedSessionID(ctx, account.ID)
+	if err != nil {
+		log.Printf("Warning: failed to get masked session ID for account %d: %v", account.ID, err)
+		return newBody, nil
+	}
+
+	if maskedSessionID == "" {
+		// 首次或已过期，生成新的伪装 session ID
+		maskedSessionID = generateRandomUUID()
+		log.Printf("Generated new masked session ID for account %d: %s", account.ID, maskedSessionID)
+	}
+
+	// 刷新 TTL（每次请求都刷新，保持 15 分钟有效期）
+	if err := s.cache.SetMaskedSessionID(ctx, account.ID, maskedSessionID); err != nil {
+		log.Printf("Warning: failed to set masked session ID for account %d: %v", account.ID, err)
+	}
+
+	// 替换 session 部分：保留 _session_ 之前的内容，替换之后的内容
+	newUserID := userID[:idx+len(sessionMarker)] + maskedSessionID
+
+	slog.Debug("session_id_masking_applied",
+		"account_id", account.ID,
+		"before", userID,
+		"after", newUserID,
+	)
+
+	metadata["user_id"] = newUserID
+	reqMap["metadata"] = metadata
+
+	return json.Marshal(reqMap)
+}
+
+// generateRandomUUID 生成随机 UUID v4 格式字符串
+func generateRandomUUID() string {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
+		// fallback: 使用时间戳生成
+		h := sha256.Sum256([]byte(fmt.Sprintf("%d", time.Now().UnixNano())))
+		b = h[:16]
+	}
+
+	// 设置 UUID v4 版本和变体位
+	b[6] = (b[6] & 0x0f) | 0x40
+	b[8] = (b[8] & 0x3f) | 0x80
+
+	return fmt.Sprintf("%x-%x-%x-%x-%x",
+		b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
+}
+
 // generateClientID 生成64位十六进制客户端ID（32字节随机数）
 func generateClientID() string {
 	b := make([]byte, 32)

backend/internal/service/ratelimit_service.go

@@ -73,10 +73,14 @@ func (s *RateLimitService) HandleUpstreamError(ctx context.Context, account *Acc
 		return false
 	}
 
-	tempMatched := false
+	// 先尝试临时不可调度规则（401除外）
+	// 如果匹配成功，直接返回，不执行后续禁用逻辑
 	if statusCode != 401 {
-		tempMatched = s.tryTempUnschedulable(ctx, account, statusCode, responseBody)
+		if s.tryTempUnschedulable(ctx, account, statusCode, responseBody) {
+			return true
+		}
 	}
+
 	upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(responseBody))
 	upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
 	if upstreamMsg != "" {
@@ -84,6 +88,14 @@ func (s *RateLimitService) HandleUpstreamError(ctx context.Context, account *Acc
 	}
 
 	switch statusCode {
+	case 400:
+		// 只有当错误信息包含 "organization has been disabled" 时才禁用
+		if strings.Contains(strings.ToLower(upstreamMsg), "organization has been disabled") {
+			msg := "Organization disabled (400): " + upstreamMsg
+			s.handleAuthError(ctx, account, msg)
+			shouldDisable = true
+		}
+		// 其他 400 错误（如参数问题）不处理，不禁用账号
 	case 401:
 		// 对所有 OAuth 账号在 401 错误时调用缓存失效并强制下次刷新
 		if account.Type == AccountTypeOAuth {
@@ -148,9 +160,6 @@ func (s *RateLimitService) HandleUpstreamError(ctx context.Context, account *Acc
 		}
 	}
 
-	if tempMatched {
-		return true
-	}
 	return shouldDisable
 }
 

backend/internal/service/session_limit_cache.go

@@ -38,8 +38,9 @@ type SessionLimitCache interface {
 	GetActiveSessionCount(ctx context.Context, accountID int64) (int, error)
 
 	// GetActiveSessionCountBatch 批量获取多个账号的活跃会话数
+	// idleTimeouts: 每个账号的空闲超时时间配置，key 为 accountID；若为 nil 或某账号不在其中，则使用默认超时
 	// 返回 map[accountID]count，查询失败的账号不在 map 中
-	GetActiveSessionCountBatch(ctx context.Context, accountIDs []int64) (map[int64]int, error)
+	GetActiveSessionCountBatch(ctx context.Context, accountIDs []int64, idleTimeouts map[int64]time.Duration) (map[int64]int, error)
 
 	// IsSessionActive 检查特定会话是否活跃（未过期）
 	IsSessionActive(ctx context.Context, accountID int64, sessionUUID string) (bool, error)

backend/internal/service/token_refresh_service.go

@@ -166,11 +166,25 @@ func (s *TokenRefreshService) refreshWithRetry(ctx context.Context, account *Acc
 
 	for attempt := 1; attempt <= s.cfg.MaxRetries; attempt++ {
 		newCredentials, err := refresher.Refresh(ctx, account)
-		if err == nil {
-			// 刷新成功，更新账号credentials
+
+		// 如果有新凭证，先更新（即使有错误也要保存 token）
+		if newCredentials != nil {
 			account.Credentials = newCredentials
-			if err := s.accountRepo.Update(ctx, account); err != nil {
-				return fmt.Errorf("failed to save credentials: %w", err)
+			if saveErr := s.accountRepo.Update(ctx, account); saveErr != nil {
+				return fmt.Errorf("failed to save credentials: %w", saveErr)
+			}
+		}
+
+		if err == nil {
+			// Antigravity 账户：如果之前是因为缺少 project_id 而标记为 error，现在成功获取到了，清除错误状态
+			if account.Platform == PlatformAntigravity &&
+				account.Status == StatusError &&
+				strings.Contains(account.ErrorMessage, "missing_project_id:") {
+				if clearErr := s.accountRepo.ClearError(ctx, account.ID); clearErr != nil {
+					log.Printf("[TokenRefresh] Failed to clear error status for account %d: %v", account.ID, clearErr)
+				} else {
+					log.Printf("[TokenRefresh] Account %d: cleared missing_project_id error", account.ID)
+				}
 			}
 			// 对所有 OAuth 账号调用缓存失效（InvalidateToken 内部根据平台判断是否需要处理）
 			if s.cacheInvalidator != nil && account.Type == AccountTypeOAuth {
@@ -230,6 +244,7 @@ func isNonRetryableRefreshError(err error) bool {
 		"invalid_client",      // 客户端配置错误
 		"unauthorized_client", // 客户端未授权
 		"access_denied",       // 访问被拒绝
+		"missing_project_id",  // 缺少 project_id
 	}
 	for _, needle := range nonRetryable {
 		if strings.Contains(msg, needle) {

backend/internal/service/wire.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	"context"
 	"database/sql"
 	"time"
 
@@ -196,6 +197,8 @@ func ProvideOpsScheduledReportService(
 
 // ProvideAPIKeyAuthCacheInvalidator 提供 API Key 认证缓存失效能力
 func ProvideAPIKeyAuthCacheInvalidator(apiKeyService *APIKeyService) APIKeyAuthCacheInvalidator {
+	// Start Pub/Sub subscriber for L1 cache invalidation across instances
+	apiKeyService.StartAuthCacheInvalidationSubscriber(context.Background())
 	return apiKeyService
 }