diff --git a/backend/internal/service/antigravity_quota_fetcher.go b/backend/internal/service/antigravity_quota_fetcher.go
index 07eb563d0..ec7571adf 100644
--- a/backend/internal/service/antigravity_quota_fetcher.go
+++ b/backend/internal/service/antigravity_quota_fetcher.go
@@ -2,6 +2,9 @@ package service
 
 import (
 	"context"
+	"fmt"
+	"log"
+	"strings"
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/pkg/antigravity"
@@ -22,13 +25,24 @@ func (f *AntigravityQuotaFetcher) CanFetch(account *Account) bool {
 	if account.Platform != PlatformAntigravity {
 		return false
 	}
-	accessToken := account.GetCredential("access_token")
-	return accessToken != ""
+	if account.Type != AccountTypeOAuth {
+		return false
+	}
+	if account.GetCredential("access_token") != "" {
+		return true
+	}
+	return account.GetCredential("refresh_token") != ""
 }
 
 // FetchQuota 获取 Antigravity 账户额度信息
 func (f *AntigravityQuotaFetcher) FetchQuota(ctx context.Context, account *Account, proxyURL string) (*QuotaResult, error) {
-	accessToken := account.GetCredential("access_token")
+	accessToken, err := f.resolveAccessToken(ctx, account, proxyURL)
+	if err != nil {
+		return nil, err
+	}
+	if accessToken == "" {
+		return nil, fmt.Errorf("no antigravity access_token available")
+	}
 	projectID := account.GetCredential("project_id")
 
 	client := antigravity.NewClient(proxyURL)
@@ -48,6 +62,38 @@ func (f *AntigravityQuotaFetcher) FetchQuota(ctx context.Context, account *Accou
 	}, nil
 }
 
+func (f *AntigravityQuotaFetcher) resolveAccessToken(ctx context.Context, account *Account, proxyURL string) (string, error) {
+	accessToken := strings.TrimSpace(account.GetCredential("access_token"))
+	expiresAt := account.GetCredentialAsTime("expires_at")
+	if accessToken != "" && (expiresAt == nil || time.Until(*expiresAt) > 3*time.Minute) {
+		return accessToken, nil
+	}
+
+	refreshToken := strings.TrimSpace(account.GetCredential("refresh_token"))
+	if refreshToken == "" {
+		if accessToken != "" {
+			return accessToken, nil
+		}
+		return "", fmt.Errorf("no antigravity refresh_token available")
+	}
+
+	client := antigravity.NewClient(proxyURL)
+	refreshResp, err := client.RefreshToken(ctx, refreshToken)
+	if err != nil {
+		if accessToken != "" {
+			log.Printf("[antigravity] token refresh failed during quota fetch, fallback to existing access_token: %v", err)
+			return accessToken, nil
+		}
+		return "", fmt.Errorf("refresh access_token failed: %w", err)
+	}
+
+	if strings.TrimSpace(refreshResp.AccessToken) == "" {
+		return "", fmt.Errorf("refreshed access_token is empty")
+	}
+
+	return refreshResp.AccessToken, nil
+}
+
 // buildUsageInfo 将 API 响应转换为 UsageInfo
 func (f *AntigravityQuotaFetcher) buildUsageInfo(modelsResp *antigravity.FetchAvailableModelsResponse) *UsageInfo {
 	now := time.Now()
diff --git a/backend/internal/service/token_refresh_service.go b/backend/internal/service/token_refresh_service.go
index a37e0d0ac..6a13e8164 100644
--- a/backend/internal/service/token_refresh_service.go
+++ b/backend/internal/service/token_refresh_service.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 )
 
 // TokenRefreshService OAuth token自动刷新服务
@@ -150,6 +151,16 @@ func (s *TokenRefreshService) processRefresh() {
 
 			// 检查是否需要刷新
 			if !refresher.NeedsRefresh(account, refreshWindow) {
+				if account.Platform == PlatformAntigravity && account.Status == StatusError {
+					errMsg := strings.ToLower(account.ErrorMessage)
+					if strings.Contains(errMsg, "token refresh failed") || strings.Contains(errMsg, "invalid_client") {
+						if clearErr := s.accountRepo.ClearError(ctx, account.ID); clearErr != nil {
+							slog.Warn("token_refresh.clear_stale_error_failed", "account_id", account.ID, "error", clearErr)
+						} else {
+							slog.Info("token_refresh.cleared_stale_antigravity_error", "account_id", account.ID)
+						}
+					}
+				}
 				break // 不需要刷新，跳过
 			}
 
@@ -195,7 +206,40 @@ func (s *TokenRefreshService) processRefresh() {
 // listActiveAccounts 获取所有active状态的账号
 // 使用ListActive确保刷新所有活跃账号的token（包括临时禁用的）
 func (s *TokenRefreshService) listActiveAccounts(ctx context.Context) ([]Account, error) {
-	return s.accountRepo.ListActive(ctx)
+	active, err := s.accountRepo.ListActive(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	// Antigravity 历史 refresh 错误账号也需要纳入刷新：
+	// client_secret 修复后，这些账号应可自动恢复为 active。
+	merged := make([]Account, 0, len(active)+8)
+	seen := make(map[int64]struct{}, len(active)+8)
+	for _, acc := range active {
+		merged = append(merged, acc)
+		seen[acc.ID] = struct{}{}
+	}
+
+	params := pagination.PaginationParams{Page: 1, PageSize: 100}
+	for {
+		errAccounts, pageInfo, listErr := s.accountRepo.ListWithFilters(ctx, params, PlatformAntigravity, "", StatusError, "", 0)
+		if listErr != nil {
+			return nil, listErr
+		}
+		for _, acc := range errAccounts {
+			if _, ok := seen[acc.ID]; ok {
+				continue
+			}
+			merged = append(merged, acc)
+			seen[acc.ID] = struct{}{}
+		}
+		if pageInfo == nil || params.Page >= pageInfo.Pages || len(errAccounts) == 0 {
+			break
+		}
+		params.Page++
+	}
+
+	return merged, nil
 }
 
 // refreshWithRetry 带重试的刷新
@@ -218,17 +262,23 @@ func (s *TokenRefreshService) refreshWithRetry(ctx context.Context, account *Acc
 		}
 
 		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 {
-					slog.Warn("token_refresh.clear_account_error_failed",
-						"account_id", account.ID,
-						"error", clearErr,
-					)
-				} else {
-					slog.Info("token_refresh.cleared_missing_project_id_error", "account_id", account.ID)
+			// Antigravity 账户：刷新成功后清理历史 refresh 错误状态。
+			// 常见场景：client_secret 修复后，旧的 invalid_client 错误会残留在账号状态中。
+			if account.Platform == PlatformAntigravity && account.Status == StatusError {
+				errMsg := strings.ToLower(account.ErrorMessage)
+				if strings.Contains(errMsg, "missing_project_id:") ||
+					strings.Contains(errMsg, "token refresh failed") ||
+					strings.Contains(errMsg, "invalid_client") {
+					if clearErr := s.accountRepo.ClearError(ctx, account.ID); clearErr != nil {
+						slog.Warn("token_refresh.clear_account_error_failed",
+							"account_id", account.ID,
+							"error", clearErr,
+						)
+					} else {
+						slog.Info("token_refresh.cleared_antigravity_error", "account_id", account.ID)
+						account.Status = StatusActive
+						account.ErrorMessage = ""
+					}
 				}
 			}
 			// 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）