diff --git a/backend/internal/service/account_usage_service.go b/backend/internal/service/account_usage_service.go
index 12cb87dd..2fa5f707 100644
--- a/backend/internal/service/account_usage_service.go
+++ b/backend/internal/service/account_usage_service.go
@@ -96,6 +96,7 @@ const (
 	apiCacheTTL         = 3 * time.Minute
 	windowStatsCacheTTL = 1 * time.Minute
 	openAIProbeCacheTTL = 10 * time.Minute
+	openAICodexProbeVersion = "0.104.0"
 )
 
 // UsageCache 封装账户使用量相关的缓存
@@ -400,7 +401,7 @@ func (s *AccountUsageService) probeOpenAICodexSnapshot(ctx context.Context, acco
 	req.Header.Set("Accept", "text/event-stream")
 	req.Header.Set("OpenAI-Beta", "responses=experimental")
 	req.Header.Set("Originator", "codex_cli_rs")
-	req.Header.Set("Version", codexCLIVersion)
+	req.Header.Set("Version", openAICodexProbeVersion)
 	req.Header.Set("User-Agent", codexCLIUserAgent)
 	if s.identityCache != nil {
 		if fp, fpErr := s.identityCache.GetFingerprint(reqCtx, account.ID); fpErr == nil && fp != nil && strings.TrimSpace(fp.UserAgent) != "" {
diff --git a/backend/internal/service/openai_gateway_service_test.go b/backend/internal/service/openai_gateway_service_test.go
index 6c8f4f52..c8efe6b3 100644
--- a/backend/internal/service/openai_gateway_service_test.go
+++ b/backend/internal/service/openai_gateway_service_test.go
@@ -1288,90 +1288,6 @@ func TestOpenAIUpdateCodexUsageSnapshotFromHeaders(t *testing.T) {
 	}
 }
 
-func TestOpenAIResponsesRequestPathSuffix(t *testing.T) {
-	gin.SetMode(gin.TestMode)
-	rec := httptest.NewRecorder()
-	c, _ := gin.CreateTestContext(rec)
-
-	tests := []struct {
-		name string
-		path string
-		want string
-	}{
-		{name: "exact v1 responses", path: "/v1/responses", want: ""},
-		{name: "compact v1 responses", path: "/v1/responses/compact", want: "/compact"},
-		{name: "compact alias responses", path: "/responses/compact/", want: "/compact"},
-		{name: "nested suffix", path: "/openai/v1/responses/compact/detail", want: "/compact/detail"},
-		{name: "unrelated path", path: "/v1/chat/completions", want: ""},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c.Request = httptest.NewRequest(http.MethodPost, tt.path, nil)
-			require.Equal(t, tt.want, openAIResponsesRequestPathSuffix(c))
-		})
-	}
-}
-
-func TestOpenAIBuildUpstreamRequestOpenAIPassthroughPreservesCompactPath(t *testing.T) {
-	gin.SetMode(gin.TestMode)
-	rec := httptest.NewRecorder()
-	c, _ := gin.CreateTestContext(rec)
-	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
-
-	svc := &OpenAIGatewayService{}
-	account := &Account{Type: AccountTypeOAuth}
-
-	req, err := svc.buildUpstreamRequestOpenAIPassthrough(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token")
-	require.NoError(t, err)
-	require.Equal(t, chatgptCodexURL+"/compact", req.URL.String())
-	require.Equal(t, "application/json", req.Header.Get("Accept"))
-	require.Equal(t, codexCLIVersion, req.Header.Get("Version"))
-	require.NotEmpty(t, req.Header.Get("Session_Id"))
-}
-
-func TestOpenAIBuildUpstreamRequestCompactForcesJSONAcceptForOAuth(t *testing.T) {
-	gin.SetMode(gin.TestMode)
-	rec := httptest.NewRecorder()
-	c, _ := gin.CreateTestContext(rec)
-	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
-
-	svc := &OpenAIGatewayService{}
-	account := &Account{
-		Type:        AccountTypeOAuth,
-		Credentials: map[string]any{"chatgpt_account_id": "chatgpt-acc"},
-	}
-
-	req, err := svc.buildUpstreamRequest(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token", false, "", true)
-	require.NoError(t, err)
-	require.Equal(t, chatgptCodexURL+"/compact", req.URL.String())
-	require.Equal(t, "application/json", req.Header.Get("Accept"))
-	require.Equal(t, codexCLIVersion, req.Header.Get("Version"))
-	require.NotEmpty(t, req.Header.Get("Session_Id"))
-}
-
-func TestOpenAIBuildUpstreamRequestPreservesCompactPathForAPIKeyBaseURL(t *testing.T) {
-	gin.SetMode(gin.TestMode)
-	rec := httptest.NewRecorder()
-	c, _ := gin.CreateTestContext(rec)
-	c.Request = httptest.NewRequest(http.MethodPost, "/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
-
-	svc := &OpenAIGatewayService{cfg: &config.Config{
-		Security: config.SecurityConfig{
-			URLAllowlist: config.URLAllowlistConfig{Enabled: false},
-		},
-	}}
-	account := &Account{
-		Type:        AccountTypeAPIKey,
-		Platform:    PlatformOpenAI,
-		Credentials: map[string]any{"base_url": "https://example.com/v1"},
-	}
-
-	req, err := svc.buildUpstreamRequest(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token", false, "", false)
-	require.NoError(t, err)
-	require.Equal(t, "https://example.com/v1/responses/compact", req.URL.String())
-}
-
 // ==================== P1-08 修复：model 替换性能优化测试 =============
 func TestReplaceModelInSSELine(t *testing.T) {
 	svc := &OpenAIGatewayService{}