fix(merge): 解决与 main 分支的配置冲突

- 合并 main 分支的上游错误日志配置
- 保留调度配置
- 合并 beta header 和 failover 配置

backend/internal/service/account_service.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"time"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 

backend/internal/service/admin_service.go

@@ -488,6 +488,11 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 		subscriptionType = SubscriptionTypeStandard
 	}
 
+	// 限额字段：0 和 nil 都表示"无限制"
+	dailyLimit := normalizeLimit(input.DailyLimitUSD)
+	weeklyLimit := normalizeLimit(input.WeeklyLimitUSD)
+	monthlyLimit := normalizeLimit(input.MonthlyLimitUSD)
+
 	group := &Group{
 		Name:             input.Name,
 		Description:      input.Description,
@@ -496,9 +501,9 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 		IsExclusive:      input.IsExclusive,
 		Status:           StatusActive,
 		SubscriptionType: subscriptionType,
-		DailyLimitUSD:    input.DailyLimitUSD,
-		WeeklyLimitUSD:   input.WeeklyLimitUSD,
-		MonthlyLimitUSD:  input.MonthlyLimitUSD,
+		DailyLimitUSD:    dailyLimit,
+		WeeklyLimitUSD:   weeklyLimit,
+		MonthlyLimitUSD:  monthlyLimit,
 	}
 	if err := s.groupRepo.Create(ctx, group); err != nil {
 		return nil, err
@@ -506,6 +511,14 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 	return group, nil
 }
 
+// normalizeLimit 将 0 或负数转换为 nil（表示无限制）
+func normalizeLimit(limit *float64) *float64 {
+	if limit == nil || *limit <= 0 {
+		return nil
+	}
+	return limit
+}
+
 func (s *adminServiceImpl) UpdateGroup(ctx context.Context, id int64, input *UpdateGroupInput) (*Group, error) {
 	group, err := s.groupRepo.GetByID(ctx, id)
 	if err != nil {
@@ -535,15 +548,15 @@ func (s *adminServiceImpl) UpdateGroup(ctx context.Context, id int64, input *Upd
 	if input.SubscriptionType != "" {
 		group.SubscriptionType = input.SubscriptionType
 	}
-	// 限额字段支持设置为nil（清除限额）或具体值
+	// 限额字段：0 和 nil 都表示"无限制"，正数表示具体限额
 	if input.DailyLimitUSD != nil {
-		group.DailyLimitUSD = input.DailyLimitUSD
+		group.DailyLimitUSD = normalizeLimit(input.DailyLimitUSD)
 	}
 	if input.WeeklyLimitUSD != nil {
-		group.WeeklyLimitUSD = input.WeeklyLimitUSD
+		group.WeeklyLimitUSD = normalizeLimit(input.WeeklyLimitUSD)
 	}
 	if input.MonthlyLimitUSD != nil {
-		group.MonthlyLimitUSD = input.MonthlyLimitUSD
+		group.MonthlyLimitUSD = normalizeLimit(input.MonthlyLimitUSD)
 	}
 
 	if err := s.groupRepo.Update(ctx, group); err != nil {

backend/internal/service/antigravity_gateway_service.go

@@ -358,6 +358,15 @@ func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context,
 		return nil, fmt.Errorf("transform request: %w", err)
 	}
 
+	// 调试：记录转换后的请求体（仅记录前 2000 字符）
+	if bodyJSON, err := json.Marshal(geminiBody); err == nil {
+		truncated := string(bodyJSON)
+		if len(truncated) > 2000 {
+			truncated = truncated[:2000] + "..."
+		}
+		log.Printf("[Debug] Transformed Gemini request: %s", truncated)
+	}
+
 	// 构建上游 action
 	action := "generateContent"
 	if claudeReq.Stream {

backend/internal/service/antigravity_token_refresher.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"fmt"
 	"time"
 )
 
@@ -28,7 +29,7 @@ func (r *AntigravityTokenRefresher) CanRefresh(account *Account) bool {
 }
 
 // NeedsRefresh 检查账户是否需要刷新
-// Antigravity 使用固定的10分钟刷新窗口，忽略全局配置
+// Antigravity 使用固定的15分钟刷新窗口，忽略全局配置
 func (r *AntigravityTokenRefresher) NeedsRefresh(account *Account, _ time.Duration) bool {
 	if !r.CanRefresh(account) {
 		return false
@@ -37,7 +38,13 @@ func (r *AntigravityTokenRefresher) NeedsRefresh(account *Account, _ time.Durati
 	if expiresAt == nil {
 		return false
 	}
-	return time.Until(*expiresAt) < antigravityRefreshWindow
+	timeUntilExpiry := time.Until(*expiresAt)
+	needsRefresh := timeUntilExpiry < antigravityRefreshWindow
+	if needsRefresh {
+		fmt.Printf("[AntigravityTokenRefresher] Account %d needs refresh: expires_at=%s, time_until_expiry=%v, window=%v\n",
+			account.ID, expiresAt.Format("2006-01-02 15:04:05"), timeUntilExpiry, antigravityRefreshWindow)
+	}
+	return needsRefresh
 }
 
 // Refresh 执行 token 刷新

backend/internal/service/api_key_service.go

@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/timezone"
 )

backend/internal/service/auth_service.go

@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 
 	"github.com/golang-jwt/jwt/v5"
 	"golang.org/x/crypto/bcrypt"

backend/internal/service/billing_cache_service.go

@@ -9,7 +9,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 )
 
 // 错误定义

backend/internal/service/email_service.go

@@ -10,7 +10,7 @@ import (
 	"strconv"
 	"time"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 )
 
 var (

backend/internal/service/gateway_service.go

@@ -20,6 +20,7 @@ import (
 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/claude"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/ctxkey"
+	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 
 	"github.com/gin-gonic/gin"
@@ -1061,6 +1062,30 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 
 	// 处理错误响应（不可重试的错误）
 	if resp.StatusCode >= 400 {
+		// 可选：对部分 400 触发 failover（默认关闭以保持语义）
+		if resp.StatusCode == 400 && s.cfg != nil && s.cfg.Gateway.FailoverOn400 {
+			respBody, readErr := io.ReadAll(resp.Body)
+			if readErr != nil {
+				// ReadAll failed, fall back to normal error handling without consuming the stream
+				return s.handleErrorResponse(ctx, resp, c, account)
+			}
+			_ = resp.Body.Close()
+			resp.Body = io.NopCloser(bytes.NewReader(respBody))
+
+			if s.shouldFailoverOn400(respBody) {
+				if s.cfg.Gateway.LogUpstreamErrorBody {
+					log.Printf(
+						"Account %d: 400 error, attempting failover: %s",
+						account.ID,
+						truncateForLog(respBody, s.cfg.Gateway.LogUpstreamErrorBodyMaxBytes),
+					)
+				} else {
+					log.Printf("Account %d: 400 error, attempting failover", account.ID)
+				}
+				s.handleFailoverSideEffects(ctx, resp, account)
+				return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
+			}
+		}
 		return s.handleErrorResponse(ctx, resp, c, account)
 	}
 
@@ -1163,6 +1188,13 @@ func (s *GatewayService) buildUpstreamRequest(ctx context.Context, c *gin.Contex
 	// 处理anthropic-beta header（OAuth账号需要特殊处理）
 	if tokenType == "oauth" {
 		req.Header.Set("anthropic-beta", s.getBetaHeader(modelID, c.GetHeader("anthropic-beta")))
+	} else if s.cfg != nil && s.cfg.Gateway.InjectBetaForApiKey && req.Header.Get("anthropic-beta") == "" {
+		// API-key：仅在请求显式使用 beta 特性且客户端未提供时，按需补齐（默认关闭）
+		if requestNeedsBetaFeatures(body) {
+			if beta := defaultApiKeyBetaHeader(body); beta != "" {
+				req.Header.Set("anthropic-beta", beta)
+			}
+		}
 	}
 
 	return req, nil
@@ -1215,6 +1247,83 @@ func (s *GatewayService) getBetaHeader(modelID string, clientBetaHeader string)
 	return claude.DefaultBetaHeader
 }
 
+func requestNeedsBetaFeatures(body []byte) bool {
+	tools := gjson.GetBytes(body, "tools")
+	if tools.Exists() && tools.IsArray() && len(tools.Array()) > 0 {
+		return true
+	}
+	if strings.EqualFold(gjson.GetBytes(body, "thinking.type").String(), "enabled") {
+		return true
+	}
+	return false
+}
+
+func defaultApiKeyBetaHeader(body []byte) string {
+	modelID := gjson.GetBytes(body, "model").String()
+	if strings.Contains(strings.ToLower(modelID), "haiku") {
+		return claude.ApiKeyHaikuBetaHeader
+	}
+	return claude.ApiKeyBetaHeader
+}
+
+func truncateForLog(b []byte, maxBytes int) string {
+	if maxBytes <= 0 {
+		maxBytes = 2048
+	}
+	if len(b) > maxBytes {
+		b = b[:maxBytes]
+	}
+	s := string(b)
+	// 保持一行，避免污染日志格式
+	s = strings.ReplaceAll(s, "\n", "\\n")
+	s = strings.ReplaceAll(s, "\r", "\\r")
+	return s
+}
+
+func (s *GatewayService) shouldFailoverOn400(respBody []byte) bool {
+	// 只对“可能是兼容性差异导致”的 400 允许切换，避免无意义重试。
+	// 默认保守：无法识别则不切换。
+	msg := strings.ToLower(strings.TrimSpace(extractUpstreamErrorMessage(respBody)))
+	if msg == "" {
+		return false
+	}
+
+	// 缺少/错误的 beta header：换账号/链路可能成功（尤其是混合调度时）。
+	// 更精确匹配 beta 相关的兼容性问题，避免误触发切换。
+	if strings.Contains(msg, "anthropic-beta") ||
+		strings.Contains(msg, "beta feature") ||
+		strings.Contains(msg, "requires beta") {
+		return true
+	}
+
+	// thinking/tool streaming 等兼容性约束（常见于中间转换链路）
+	if strings.Contains(msg, "thinking") || strings.Contains(msg, "thought_signature") || strings.Contains(msg, "signature") {
+		return true
+	}
+	if strings.Contains(msg, "tool_use") || strings.Contains(msg, "tool_result") || strings.Contains(msg, "tools") {
+		return true
+	}
+
+	return false
+}
+
+func extractUpstreamErrorMessage(body []byte) string {
+	// Claude 风格：{"type":"error","error":{"type":"...","message":"..."}}
+	if m := gjson.GetBytes(body, "error.message").String(); strings.TrimSpace(m) != "" {
+		inner := strings.TrimSpace(m)
+		// 有些上游会把完整 JSON 作为字符串塞进 message
+		if strings.HasPrefix(inner, "{") {
+			if innerMsg := gjson.Get(inner, "error.message").String(); strings.TrimSpace(innerMsg) != "" {
+				return innerMsg
+			}
+		}
+		return m
+	}
+
+	// 兜底：尝试顶层 message
+	return gjson.GetBytes(body, "message").String()
+}
+
 func (s *GatewayService) handleErrorResponse(ctx context.Context, resp *http.Response, c *gin.Context, account *Account) (*ForwardResult, error) {
 	body, _ := io.ReadAll(resp.Body)
 
@@ -1227,6 +1336,16 @@ func (s *GatewayService) handleErrorResponse(ctx context.Context, resp *http.Res
 
 	switch resp.StatusCode {
 	case 400:
+		// 仅记录上游错误摘要（避免输出请求内容）；需要时可通过配置打开
+		if s.cfg != nil && s.cfg.Gateway.LogUpstreamErrorBody {
+			log.Printf(
+				"Upstream 400 error (account=%d platform=%s type=%s): %s",
+				account.ID,
+				account.Platform,
+				account.Type,
+				truncateForLog(body, s.cfg.Gateway.LogUpstreamErrorBodyMaxBytes),
+			)
+		}
 		c.Data(http.StatusBadRequest, "application/json", body)
 		return nil, fmt.Errorf("upstream error: %d", resp.StatusCode)
 	case 401:
@@ -1706,6 +1825,18 @@ func (s *GatewayService) ForwardCountTokens(ctx context.Context, c *gin.Context,
 		// 标记账号状态（429/529等）
 		s.rateLimitService.HandleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
 
+		// 记录上游错误摘要便于排障（不回显请求内容）
+		if s.cfg != nil && s.cfg.Gateway.LogUpstreamErrorBody {
+			log.Printf(
+				"count_tokens upstream error %d (account=%d platform=%s type=%s): %s",
+				resp.StatusCode,
+				account.ID,
+				account.Platform,
+				account.Type,
+				truncateForLog(respBody, s.cfg.Gateway.LogUpstreamErrorBodyMaxBytes),
+			)
+		}
+
 		// 返回简化的错误响应
 		errMsg := "Upstream request failed"
 		switch resp.StatusCode {
@@ -1786,6 +1917,13 @@ func (s *GatewayService) buildCountTokensRequest(ctx context.Context, c *gin.Con
 	// OAuth 账号：处理 anthropic-beta header
 	if tokenType == "oauth" {
 		req.Header.Set("anthropic-beta", s.getBetaHeader(modelID, c.GetHeader("anthropic-beta")))
+	} else if s.cfg != nil && s.cfg.Gateway.InjectBetaForApiKey && req.Header.Get("anthropic-beta") == "" {
+		// API-key：与 messages 同步的按需 beta 注入（默认关闭）
+		if requestNeedsBetaFeatures(body) {
+			if beta := defaultApiKeyBetaHeader(body); beta != "" {
+				req.Header.Set("anthropic-beta", beta)
+			}
+		}
 	}
 
 	return req, nil

backend/internal/service/gemini_messages_compat_service.go

@@ -2278,11 +2278,13 @@ func convertClaudeToolsToGeminiTools(tools any) []any {
 				"properties": map[string]any{},
 			}
 		}
+		// 清理 JSON Schema
+		cleanedParams := cleanToolSchema(params)
 
 		funcDecls = append(funcDecls, map[string]any{
 			"name":        name,
 			"description": desc,
-			"parameters":  params,
+			"parameters":  cleanedParams,
 		})
 	}
 
@@ -2296,6 +2298,41 @@ func convertClaudeToolsToGeminiTools(tools any) []any {
 	}
 }
 
+// cleanToolSchema 清理工具的 JSON Schema，移除 Gemini 不支持的字段
+func cleanToolSchema(schema any) any {
+	if schema == nil {
+		return nil
+	}
+
+	switch v := schema.(type) {
+	case map[string]any:
+		cleaned := make(map[string]any)
+		for key, value := range v {
+			// 跳过不支持的字段
+			if key == "$schema" || key == "$id" || key == "$ref" ||
+				key == "additionalProperties" || key == "minLength" ||
+				key == "maxLength" || key == "minItems" || key == "maxItems" {
+				continue
+			}
+			// 递归清理嵌套对象
+			cleaned[key] = cleanToolSchema(value)
+		}
+		// 规范化 type 字段为大写
+		if typeVal, ok := cleaned["type"].(string); ok {
+			cleaned["type"] = strings.ToUpper(typeVal)
+		}
+		return cleaned
+	case []any:
+		cleaned := make([]any, len(v))
+		for i, item := range v {
+			cleaned[i] = cleanToolSchema(item)
+		}
+		return cleaned
+	default:
+		return v
+	}
+}
+
 func convertClaudeGenerationConfig(req map[string]any) map[string]any {
 	out := make(map[string]any)
 	if mt, ok := asInt(req["max_tokens"]); ok && mt > 0 {

backend/internal/service/gemini_messages_compat_service_test.go

@@ -0,0 +1,128 @@
+package service
+
+import (
+	"testing"
+)
+
+// TestConvertClaudeToolsToGeminiTools_CustomType 测试custom类型工具转换
+func TestConvertClaudeToolsToGeminiTools_CustomType(t *testing.T) {
+	tests := []struct {
+		name        string
+		tools       any
+		expectedLen int
+		description string
+	}{
+		{
+			name: "Standard tools",
+			tools: []any{
+				map[string]any{
+					"name":         "get_weather",
+					"description":  "Get weather info",
+					"input_schema": map[string]any{"type": "object"},
+				},
+			},
+			expectedLen: 1,
+			description: "标准工具格式应该正常转换",
+		},
+		{
+			name: "Custom type tool (MCP format)",
+			tools: []any{
+				map[string]any{
+					"type": "custom",
+					"name": "mcp_tool",
+					"custom": map[string]any{
+						"description":  "MCP tool description",
+						"input_schema": map[string]any{"type": "object"},
+					},
+				},
+			},
+			expectedLen: 1,
+			description: "Custom类型工具应该从custom字段读取",
+		},
+		{
+			name: "Mixed standard and custom tools",
+			tools: []any{
+				map[string]any{
+					"name":         "standard_tool",
+					"description":  "Standard",
+					"input_schema": map[string]any{"type": "object"},
+				},
+				map[string]any{
+					"type": "custom",
+					"name": "custom_tool",
+					"custom": map[string]any{
+						"description":  "Custom",
+						"input_schema": map[string]any{"type": "object"},
+					},
+				},
+			},
+			expectedLen: 1,
+			description: "混合工具应该都能正确转换",
+		},
+		{
+			name: "Custom tool without custom field",
+			tools: []any{
+				map[string]any{
+					"type": "custom",
+					"name": "invalid_custom",
+					// 缺少 custom 字段
+				},
+			},
+			expectedLen: 0, // 应该被跳过
+			description: "缺少custom字段的custom工具应该被跳过",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := convertClaudeToolsToGeminiTools(tt.tools)
+
+			if tt.expectedLen == 0 {
+				if result != nil {
+					t.Errorf("%s: expected nil result, got %v", tt.description, result)
+				}
+				return
+			}
+
+			if result == nil {
+				t.Fatalf("%s: expected non-nil result", tt.description)
+			}
+
+			if len(result) != 1 {
+				t.Errorf("%s: expected 1 tool declaration, got %d", tt.description, len(result))
+				return
+			}
+
+			toolDecl, ok := result[0].(map[string]any)
+			if !ok {
+				t.Fatalf("%s: result[0] is not map[string]any", tt.description)
+			}
+
+			funcDecls, ok := toolDecl["functionDeclarations"].([]any)
+			if !ok {
+				t.Fatalf("%s: functionDeclarations is not []any", tt.description)
+			}
+
+			toolsArr, _ := tt.tools.([]any)
+			expectedFuncCount := 0
+			for _, tool := range toolsArr {
+				toolMap, _ := tool.(map[string]any)
+				if toolMap["name"] != "" {
+					// 检查是否为有效的custom工具
+					if toolMap["type"] == "custom" {
+						if toolMap["custom"] != nil {
+							expectedFuncCount++
+						}
+					} else {
+						expectedFuncCount++
+					}
+				}
+			}
+
+			if len(funcDecls) != expectedFuncCount {
+				t.Errorf("%s: expected %d function declarations, got %d",
+					tt.description, expectedFuncCount, len(funcDecls))
+			}
+		})
+	}
+}

backend/internal/service/gemini_oauth_service.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -163,6 +164,45 @@ type GeminiTokenInfo struct {
 	Scope        string `json:"scope,omitempty"`
 	ProjectID    string `json:"project_id,omitempty"`
 	OAuthType    string `json:"oauth_type,omitempty"` // "code_assist" 或 "ai_studio"
+	TierID       string `json:"tier_id,omitempty"`    // Gemini Code Assist tier: LEGACY/PRO/ULTRA
+}
+
+// validateTierID validates tier_id format and length
+func validateTierID(tierID string) error {
+	if tierID == "" {
+		return nil // Empty is allowed
+	}
+	if len(tierID) > 64 {
+		return fmt.Errorf("tier_id exceeds maximum length of 64 characters")
+	}
+	// Allow alphanumeric, underscore, hyphen, and slash (for tier paths)
+	if !regexp.MustCompile(`^[a-zA-Z0-9_/-]+$`).MatchString(tierID) {
+		return fmt.Errorf("tier_id contains invalid characters")
+	}
+	return nil
+}
+
+// extractTierIDFromAllowedTiers extracts tierID from LoadCodeAssist response
+// Prioritizes IsDefault tier, falls back to first non-empty tier
+func extractTierIDFromAllowedTiers(allowedTiers []geminicli.AllowedTier) string {
+	tierID := "LEGACY"
+	// First pass: look for default tier
+	for _, tier := range allowedTiers {
+		if tier.IsDefault && strings.TrimSpace(tier.ID) != "" {
+			tierID = strings.TrimSpace(tier.ID)
+			break
+		}
+	}
+	// Second pass: if still LEGACY, take first non-empty tier
+	if tierID == "LEGACY" {
+		for _, tier := range allowedTiers {
+			if strings.TrimSpace(tier.ID) != "" {
+				tierID = strings.TrimSpace(tier.ID)
+				break
+			}
+		}
+	}
+	return tierID
 }
 
 func (s *GeminiOAuthService) ExchangeCode(ctx context.Context, input *GeminiExchangeCodeInput) (*GeminiTokenInfo, error) {
@@ -223,13 +263,14 @@ func (s *GeminiOAuthService) ExchangeCode(ctx context.Context, input *GeminiExch
 	expiresAt := time.Now().Unix() + tokenResp.ExpiresIn - 300
 
 	projectID := sessionProjectID
+	var tierID string
 
 	// 对于 code_assist 模式，project_id 是必需的
 	// 对于 ai_studio 模式，project_id 是可选的（不影响使用 AI Studio API）
 	if oauthType == "code_assist" {
 		if projectID == "" {
 			var err error
-			projectID, err = s.fetchProjectID(ctx, tokenResp.AccessToken, proxyURL)
+			projectID, tierID, err = s.fetchProjectID(ctx, tokenResp.AccessToken, proxyURL)
 			if err != nil {
 				// 记录警告但不阻断流程，允许后续补充 project_id
 				fmt.Printf("[GeminiOAuth] Warning: Failed to fetch project_id during token exchange: %v\n", err)
@@ -248,6 +289,7 @@ func (s *GeminiOAuthService) ExchangeCode(ctx context.Context, input *GeminiExch
 		ExpiresAt:    expiresAt,
 		Scope:        tokenResp.Scope,
 		ProjectID:    projectID,
+		TierID:       tierID,
 		OAuthType:    oauthType,
 	}, nil
 }
@@ -357,7 +399,7 @@ func (s *GeminiOAuthService) RefreshAccountToken(ctx context.Context, account *A
 	// For Code Assist, project_id is required. Auto-detect if missing.
 	// For AI Studio OAuth, project_id is optional and should not block refresh.
 	if oauthType == "code_assist" && strings.TrimSpace(tokenInfo.ProjectID) == "" {
-		projectID, err := s.fetchProjectID(ctx, tokenInfo.AccessToken, proxyURL)
+		projectID, tierID, err := s.fetchProjectID(ctx, tokenInfo.AccessToken, proxyURL)
 		if err != nil {
 			return nil, fmt.Errorf("failed to auto-detect project_id: %w", err)
 		}
@@ -366,6 +408,7 @@ func (s *GeminiOAuthService) RefreshAccountToken(ctx context.Context, account *A
 			return nil, fmt.Errorf("failed to auto-detect project_id: empty result")
 		}
 		tokenInfo.ProjectID = projectID
+		tokenInfo.TierID = tierID
 	}
 
 	return tokenInfo, nil
@@ -388,6 +431,13 @@ func (s *GeminiOAuthService) BuildAccountCredentials(tokenInfo *GeminiTokenInfo)
 	if tokenInfo.ProjectID != "" {
 		creds["project_id"] = tokenInfo.ProjectID
 	}
+	if tokenInfo.TierID != "" {
+		// Validate tier_id before storing
+		if err := validateTierID(tokenInfo.TierID); err == nil {
+			creds["tier_id"] = tokenInfo.TierID
+		}
+		// Silently skip invalid tier_id (don't block account creation)
+	}
 	if tokenInfo.OAuthType != "" {
 		creds["oauth_type"] = tokenInfo.OAuthType
 	}
@@ -398,34 +448,26 @@ func (s *GeminiOAuthService) Stop() {
 	s.sessionStore.Stop()
 }
 
-func (s *GeminiOAuthService) fetchProjectID(ctx context.Context, accessToken, proxyURL string) (string, error) {
+func (s *GeminiOAuthService) fetchProjectID(ctx context.Context, accessToken, proxyURL string) (string, string, error) {
 	if s.codeAssist == nil {
-		return "", errors.New("code assist client not configured")
+		return "", "", errors.New("code assist client not configured")
 	}
 
 	loadResp, loadErr := s.codeAssist.LoadCodeAssist(ctx, accessToken, proxyURL, nil)
+
+	// Extract tierID from response (works whether CloudAICompanionProject is set or not)
+	tierID := "LEGACY"
+	if loadResp != nil {
+		tierID = extractTierIDFromAllowedTiers(loadResp.AllowedTiers)
+	}
+
+	// If LoadCodeAssist returned a project, use it
 	if loadErr == nil && loadResp != nil && strings.TrimSpace(loadResp.CloudAICompanionProject) != "" {
-		return strings.TrimSpace(loadResp.CloudAICompanionProject), nil
+		return strings.TrimSpace(loadResp.CloudAICompanionProject), tierID, nil
 	}
 
 	// Pick tier from allowedTiers; if no default tier is marked, pick the first non-empty tier ID.
-	tierID := "LEGACY"
-	if loadResp != nil {
-		for _, tier := range loadResp.AllowedTiers {
-			if tier.IsDefault && strings.TrimSpace(tier.ID) != "" {
-				tierID = strings.TrimSpace(tier.ID)
-				break
-			}
-		}
-		if strings.TrimSpace(tierID) == "" || tierID == "LEGACY" {
-			for _, tier := range loadResp.AllowedTiers {
-				if strings.TrimSpace(tier.ID) != "" {
-					tierID = strings.TrimSpace(tier.ID)
-					break
-				}
-			}
-		}
-	}
+	// (tierID already extracted above, reuse it)
 
 	req := &geminicli.OnboardUserRequest{
 		TierID: tierID,
@@ -443,39 +485,39 @@ func (s *GeminiOAuthService) fetchProjectID(ctx context.Context, accessToken, pr
 			// If Code Assist onboarding fails (e.g. INVALID_ARGUMENT), fallback to Cloud Resource Manager projects.
 			fallback, fbErr := fetchProjectIDFromResourceManager(ctx, accessToken, proxyURL)
 			if fbErr == nil && strings.TrimSpace(fallback) != "" {
-				return strings.TrimSpace(fallback), nil
+				return strings.TrimSpace(fallback), tierID, nil
 			}
-			return "", err
+			return "", "", err
 		}
 		if resp.Done {
 			if resp.Response != nil && resp.Response.CloudAICompanionProject != nil {
 				switch v := resp.Response.CloudAICompanionProject.(type) {
 				case string:
-					return strings.TrimSpace(v), nil
+					return strings.TrimSpace(v), tierID, nil
 				case map[string]any:
 					if id, ok := v["id"].(string); ok {
-						return strings.TrimSpace(id), nil
+						return strings.TrimSpace(id), tierID, nil
 					}
 				}
 			}
 
 			fallback, fbErr := fetchProjectIDFromResourceManager(ctx, accessToken, proxyURL)
 			if fbErr == nil && strings.TrimSpace(fallback) != "" {
-				return strings.TrimSpace(fallback), nil
+				return strings.TrimSpace(fallback), tierID, nil
 			}
-			return "", errors.New("onboardUser completed but no project_id returned")
+			return "", "", errors.New("onboardUser completed but no project_id returned")
 		}
 		time.Sleep(2 * time.Second)
 	}
 
 	fallback, fbErr := fetchProjectIDFromResourceManager(ctx, accessToken, proxyURL)
 	if fbErr == nil && strings.TrimSpace(fallback) != "" {
-		return strings.TrimSpace(fallback), nil
+		return strings.TrimSpace(fallback), tierID, nil
 	}
 	if loadErr != nil {
-		return "", fmt.Errorf("loadCodeAssist failed (%v) and onboardUser timeout after %d attempts", loadErr, maxAttempts)
+		return "", "", fmt.Errorf("loadCodeAssist failed (%v) and onboardUser timeout after %d attempts", loadErr, maxAttempts)
 	}
-	return "", fmt.Errorf("onboardUser timeout after %d attempts", maxAttempts)
+	return "", "", fmt.Errorf("onboardUser timeout after %d attempts", maxAttempts)
 }
 
 type googleCloudProject struct {

backend/internal/service/gemini_token_provider.go

@@ -112,7 +112,7 @@ func (p *GeminiTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 			}
 		}
 
-		detected, err := p.geminiOAuthService.fetchProjectID(ctx, accessToken, proxyURL)
+		detected, tierID, err := p.geminiOAuthService.fetchProjectID(ctx, accessToken, proxyURL)
 		if err != nil {
 			log.Printf("[GeminiTokenProvider] Auto-detect project_id failed: %v, fallback to AI Studio API mode", err)
 			return accessToken, nil
@@ -123,6 +123,9 @@ func (p *GeminiTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 				account.Credentials = make(map[string]any)
 			}
 			account.Credentials["project_id"] = detected
+			if tierID != "" {
+				account.Credentials["tier_id"] = tierID
+			}
 			_ = p.accountRepo.Update(ctx, account)
 		}
 	}

backend/internal/service/group_service.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 

backend/internal/service/proxy_service.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 

backend/internal/service/redeem_service.go

@@ -10,7 +10,7 @@ import (
 	"time"
 
 	dbent "github.com/Wei-Shaw/sub2api/ent"
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 

backend/internal/service/setting_service.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 )
 
 var (

backend/internal/service/subscription_service.go

@@ -6,7 +6,7 @@ import (
 	"log"
 	"time"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 
@@ -490,6 +490,7 @@ func (s *SubscriptionService) CheckAndResetWindows(ctx context.Context, sub *Use
 }
 
 // CheckUsageLimits 检查使用限额（返回错误如果超限）
+// 用于中间件的快速预检查，additionalCost 通常为 0
 func (s *SubscriptionService) CheckUsageLimits(ctx context.Context, sub *UserSubscription, group *Group, additionalCost float64) error {
 	if !sub.CheckDailyLimit(group, additionalCost) {
 		return ErrDailyLimitExceeded

backend/internal/service/turnstile_service.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"log"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 )
 
 var (

backend/internal/service/usage_service.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"time"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/usagestats"
 )

backend/internal/service/user_service.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )