diff --git a/backend/internal/service/gemini_chat_completions_compat_service.go b/backend/internal/service/gemini_chat_completions_compat_service.go
index 228f0153e..e76fbcee1 100644
--- a/backend/internal/service/gemini_chat_completions_compat_service.go
+++ b/backend/internal/service/gemini_chat_completions_compat_service.go
@@ -215,7 +215,9 @@ func (s *GeminiMessagesCompatService) forwardClaudeBodyAsChatCompletions(
 		if s.rateLimitService != nil {
 			policy = s.rateLimitService.CheckErrorPolicy(ctx, account, resp.StatusCode, respBody, mappedModel)
 		}
-		if policy != ErrorPolicyTempUnscheduled {
+		// 与 messages 兼容层一致：只有 None / Matched 才走账号状态处理。
+		// Skipped（池模式、或自定义错误码未命中）与 TempUnscheduled 已由策略层裁决完毕。
+		if policy == ErrorPolicyNone || policy == ErrorPolicyMatched {
 			s.handleGeminiUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
 		}
 		evBody := unwrapIfNeeded(account.Type == AccountTypeOAuth, respBody)
diff --git a/backend/internal/service/gemini_error_policy_test.go b/backend/internal/service/gemini_error_policy_test.go
index e71bd141b..46024077a 100644
--- a/backend/internal/service/gemini_error_policy_test.go
+++ b/backend/internal/service/gemini_error_policy_test.go
@@ -489,6 +489,105 @@ func TestHandleGeminiUpstreamError_GoogleOneCapacityExhaustedUsesTierCooldown(t
 	require.True(t, repo.lastRateLimitReset.Before(after.Add(5*time.Minute).Add(2*time.Second)))
 }
 
+// ---------------------------------------------------------------------------
+// TestHandleGeminiUpstreamError_PoolMode429 — 池模式账号的 429 不写账号级限流。
+//
+// 429 的标记点在重试循环内（handleClaudeCompat / forwardNativeGemini /
+// chat completions 三条路径），先于 CheckErrorPolicy 执行，池模式豁免只能落在
+// handleGeminiUpstreamError 自身；否则一次上游 429 会把账号锁到 PST 午夜，
+// 即便重试已经成功返回客户端。
+// ---------------------------------------------------------------------------
+
+func TestHandleGeminiUpstreamError_PoolMode429(t *testing.T) {
+	// 中转上游的真实 429 文案：不含 "per day"，也没有 quotaResetDelay，
+	// 解析失败后 apikey 账号会落到 PST 午夜兜底。
+	body := []byte(`{"error":{"code":429,"message":"You have exhausted your capacity on this model. Your quota will reset after 6h53m10s."}}`)
+
+	tests := []struct {
+		name              string
+		account           *Account
+		expectRateLimited bool
+	}{
+		{
+			name: "pool_mode_apikey_stays_in_pool",
+			account: &Account{
+				ID:          600,
+				Platform:    PlatformGemini,
+				Type:        AccountTypeAPIKey,
+				Credentials: map[string]any{"pool_mode": true},
+			},
+			expectRateLimited: false,
+		},
+		{
+			name: "custom_error_codes_hit_overrides_pool_mode",
+			account: &Account{
+				ID:       601,
+				Platform: PlatformGemini,
+				Type:     AccountTypeAPIKey,
+				Credentials: map[string]any{
+					"pool_mode":                  true,
+					"custom_error_codes_enabled": true,
+					"custom_error_codes":         []any{float64(429)},
+				},
+			},
+			expectRateLimited: true,
+		},
+		{
+			name: "custom_error_codes_miss_skips",
+			account: &Account{
+				ID:       602,
+				Platform: PlatformGemini,
+				Type:     AccountTypeAPIKey,
+				Credentials: map[string]any{
+					"pool_mode":                  true,
+					"custom_error_codes_enabled": true,
+					"custom_error_codes":         []any{float64(500)},
+				},
+			},
+			expectRateLimited: false,
+		},
+		{
+			name: "non_pool_apikey_still_rate_limited",
+			account: &Account{
+				ID:       603,
+				Platform: PlatformGemini,
+				Type:     AccountTypeAPIKey,
+			},
+			expectRateLimited: true,
+		},
+		{
+			name: "oauth_account_ignores_pool_mode_flag",
+			account: &Account{
+				ID:          604,
+				Platform:    PlatformGemini,
+				Type:        AccountTypeOAuth,
+				Credentials: map[string]any{"pool_mode": true},
+			},
+			expectRateLimited: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			repo := &rateLimit429AccountRepoStub{}
+			svc := &GeminiMessagesCompatService{
+				accountRepo:      repo,
+				rateLimitService: NewRateLimitService(repo, nil, &config.Config{}, nil, nil),
+			}
+
+			svc.handleGeminiUpstreamError(context.Background(), tt.account, http.StatusTooManyRequests, http.Header{}, body)
+
+			if !tt.expectRateLimited {
+				require.Zero(t, repo.rateLimitCalls, "池模式账号不应被标记账号级限流")
+				return
+			}
+			require.Equal(t, 1, repo.rateLimitCalls)
+			require.Equal(t, tt.account.ID, repo.lastRateLimitID)
+			require.True(t, repo.lastRateLimitReset.After(time.Now()))
+		})
+	}
+}
+
 type geminiErrorPolicyRepo struct {
 	mockAccountRepoForGemini
 	setErrorCalls            int
diff --git a/backend/internal/service/gemini_messages_compat_service.go b/backend/internal/service/gemini_messages_compat_service.go
index fcedf9a21..e62a24223 100644
--- a/backend/internal/service/gemini_messages_compat_service.go
+++ b/backend/internal/service/gemini_messages_compat_service.go
@@ -2959,6 +2959,11 @@ func (s *GeminiMessagesCompatService) handleGeminiUpstreamError(ctx context.Cont
 	if statusCode != 429 {
 		return
 	}
+	// 池模式账号不写账号级限流：账号留在池内，由 failover / 同号重试消化 429。
+	// 自定义错误码优先级高于池模式，开启后仍按其命中结果标记。
+	if account.IsPoolMode() && !account.IsCustomErrorCodesEnabled() {
+		return
+	}
 
 	oauthType := account.GeminiOAuthType()
 	tierID := account.GeminiTierID()