diff --git a/src-tauri/src/proxy/handlers.rs b/src-tauri/src/proxy/handlers.rs
index 19e8e3ace..7e13d5150 100644
--- a/src-tauri/src/proxy/handlers.rs
+++ b/src-tauri/src/proxy/handlers.rs
@@ -286,6 +286,13 @@ async fn handle_claude_transform(
     })
 }
 
+fn endpoint_with_query(uri: &axum::http::Uri, endpoint: &str) -> String {
+    match uri.query() {
+        Some(query) => format!("{endpoint}?{query}"),
+        None => endpoint.to_string(),
+    }
+}
+
 // ============================================================================
 // Codex API 处理器
 // ============================================================================
@@ -293,11 +300,13 @@ async fn handle_claude_transform(
 /// 处理 /v1/chat/completions 请求（OpenAI Chat Completions API - Codex CLI）
 pub async fn handle_chat_completions(
     State(state): State<ProxyState>,
+    uri: axum::http::Uri,
     headers: axum::http::HeaderMap,
     Json(body): Json<Value>,
 ) -> Result<axum::response::Response, ProxyError> {
     let mut ctx =
         RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
+    let endpoint = endpoint_with_query(&uri, "/chat/completions");
 
     let is_stream = body
         .get("stream")
@@ -308,7 +317,7 @@ pub async fn handle_chat_completions(
     let result = match forwarder
         .forward_with_retry(
             &AppType::Codex,
-            "/chat/completions",
+            &endpoint,
             body,
             headers,
             ctx.get_providers(),
@@ -334,11 +343,13 @@ pub async fn handle_chat_completions(
 /// 处理 /v1/responses 请求（OpenAI Responses API - Codex CLI 透传）
 pub async fn handle_responses(
     State(state): State<ProxyState>,
+    uri: axum::http::Uri,
     headers: axum::http::HeaderMap,
     Json(body): Json<Value>,
 ) -> Result<axum::response::Response, ProxyError> {
     let mut ctx =
         RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
+    let endpoint = endpoint_with_query(&uri, "/responses");
 
     let is_stream = body
         .get("stream")
@@ -349,7 +360,7 @@ pub async fn handle_responses(
     let result = match forwarder
         .forward_with_retry(
             &AppType::Codex,
-            "/responses",
+            &endpoint,
             body,
             headers,
             ctx.get_providers(),
@@ -375,11 +386,13 @@ pub async fn handle_responses(
 /// 处理 /v1/responses/compact 请求（OpenAI Responses Compact API - Codex CLI 透传）
 pub async fn handle_responses_compact(
     State(state): State<ProxyState>,
+    uri: axum::http::Uri,
     headers: axum::http::HeaderMap,
     Json(body): Json<Value>,
 ) -> Result<axum::response::Response, ProxyError> {
     let mut ctx =
         RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
+    let endpoint = endpoint_with_query(&uri, "/responses/compact");
 
     let is_stream = body
         .get("stream")
@@ -390,7 +403,7 @@ pub async fn handle_responses_compact(
     let result = match forwarder
         .forward_with_retry(
             &AppType::Codex,
-            "/responses/compact",
+            &endpoint,
             body,
             headers,
             ctx.get_providers(),
diff --git a/src-tauri/src/services/stream_check.rs b/src-tauri/src/services/stream_check.rs
index c9b3bc5fa..eb5482e8b 100644
--- a/src-tauri/src/services/stream_check.rs
+++ b/src-tauri/src/services/stream_check.rs
@@ -225,6 +225,7 @@ impl StreamCheckService {
                     &model_to_test,
                     test_prompt,
                     request_timeout,
+                    provider,
                 )
                 .await
             }
@@ -441,18 +442,14 @@ impl StreamCheckService {
         model: &str,
         test_prompt: &str,
         timeout: std::time::Duration,
+        provider: &Provider,
     ) -> Result<(u16, String), AppError> {
-        let base = base_url.trim_end_matches('/');
-        // Codex CLI 的 base_url 语义：base_url 是 API base（可能已包含 /v1 或其他自定义前缀），
-        // Responses 端点为 `/responses`。
-        //
-        // 兼容：如果 base_url 配成纯 origin（如 https://api.openai.com），则需要补 `/v1`。
-        // 优先尝试 `{base}/responses`，若 404 再回退 `{base}/v1/responses`。
-        let urls = if base.ends_with("/v1") {
-            vec![format!("{base}/responses")]
-        } else {
-            vec![format!("{base}/responses"), format!("{base}/v1/responses")]
-        };
+        let is_full_url = provider
+            .meta
+            .as_ref()
+            .and_then(|meta| meta.is_full_url)
+            .unwrap_or(false);
+        let urls = Self::resolve_codex_stream_urls(base_url, is_full_url);
 
         // 解析模型名和推理等级 (支持 model@level 或 model#level 格式)
         let (actual_model, reasoning_effort) = Self::parse_model_with_effort(model);
@@ -743,6 +740,20 @@ impl StreamCheckService {
             format!("{base}/v1/messages")
         }
     }
+
+    fn resolve_codex_stream_urls(base_url: &str, is_full_url: bool) -> Vec<String> {
+        if is_full_url {
+            return vec![base_url.to_string()];
+        }
+
+        let base = base_url.trim_end_matches('/');
+
+        if base.ends_with("/v1") {
+            vec![format!("{base}/responses")]
+        } else {
+            vec![format!("{base}/responses"), format!("{base}/v1/responses")]
+        }
+    }
 }
 
 #[cfg(test)]
@@ -905,4 +916,35 @@ mod tests {
 
         assert_eq!(url, "https://api.anthropic.com/v1/messages");
     }
+
+    #[test]
+    fn test_resolve_codex_stream_urls_for_full_url_mode() {
+        let urls = StreamCheckService::resolve_codex_stream_urls(
+            "https://relay.example/custom/responses",
+            true,
+        );
+
+        assert_eq!(urls, vec!["https://relay.example/custom/responses"]);
+    }
+
+    #[test]
+    fn test_resolve_codex_stream_urls_for_v1_base() {
+        let urls =
+            StreamCheckService::resolve_codex_stream_urls("https://api.openai.com/v1", false);
+
+        assert_eq!(urls, vec!["https://api.openai.com/v1/responses"]);
+    }
+
+    #[test]
+    fn test_resolve_codex_stream_urls_for_origin_base() {
+        let urls = StreamCheckService::resolve_codex_stream_urls("https://api.openai.com", false);
+
+        assert_eq!(
+            urls,
+            vec![
+                "https://api.openai.com/responses",
+                "https://api.openai.com/v1/responses",
+            ]
+        );
+    }
 }
diff --git a/src/components/providers/forms/CodexFormFields.tsx b/src/components/providers/forms/CodexFormFields.tsx
index 694d8b711..38434fc69 100644
--- a/src/components/providers/forms/CodexFormFields.tsx
+++ b/src/components/providers/forms/CodexFormFields.tsx
@@ -22,6 +22,8 @@ interface CodexFormFieldsProps {
   shouldShowSpeedTest: boolean;
   codexBaseUrl: string;
   onBaseUrlChange: (url: string) => void;
+  isFullUrl: boolean;
+  onFullUrlChange: (value: boolean) => void;
   isEndpointModalOpen: boolean;
   onEndpointModalToggle: (open: boolean) => void;
   onCustomEndpointsChange?: (endpoints: string[]) => void;
@@ -49,6 +51,8 @@ export function CodexFormFields({
   shouldShowSpeedTest,
   codexBaseUrl,
   onBaseUrlChange,
+  isFullUrl,
+  onFullUrlChange,
   isEndpointModalOpen,
   onEndpointModalToggle,
   onCustomEndpointsChange,
@@ -93,6 +97,9 @@ export function CodexFormFields({
           onChange={onBaseUrlChange}
           placeholder={t("providerForm.codexApiEndpointPlaceholder")}
           hint={t("providerForm.codexApiHint")}
+          showFullUrlToggle
+          isFullUrl={isFullUrl}
+          onFullUrlChange={onFullUrlChange}
           onManageClick={() => onEndpointModalToggle(true)}
         />
       )}
diff --git a/src/components/providers/forms/ProviderForm.tsx b/src/components/providers/forms/ProviderForm.tsx
index 37fea7707..cead4fc5f 100644
--- a/src/components/providers/forms/ProviderForm.tsx
+++ b/src/components/providers/forms/ProviderForm.tsx
@@ -162,8 +162,9 @@ export function ProviderForm({
   const [endpointAutoSelect, setEndpointAutoSelect] = useState<boolean>(
     () => initialData?.meta?.endpointAutoSelect ?? true,
   );
+  const supportsFullUrl = appId === "claude" || appId === "codex";
   const [localIsFullUrl, setLocalIsFullUrl] = useState<boolean>(() => {
-    if (appId !== "claude") return false;
+    if (!supportsFullUrl) return false;
     return initialData?.meta?.isFullUrl ?? false;
   });
 
@@ -206,7 +207,7 @@ export function ProviderForm({
     }
     setEndpointAutoSelect(initialData?.meta?.endpointAutoSelect ?? true);
     setLocalIsFullUrl(
-      appId === "claude" ? (initialData?.meta?.isFullUrl ?? false) : false,
+      supportsFullUrl ? (initialData?.meta?.isFullUrl ?? false) : false,
     );
     setTestConfig(initialData?.meta?.testConfig ?? { enabled: false });
     setProxyConfig(initialData?.meta?.proxyConfig ?? { enabled: false });
@@ -219,7 +220,7 @@ export function ProviderForm({
         initialData?.meta?.pricingModelSource,
       ),
     });
-  }, [appId, initialData]);
+  }, [appId, initialData, supportsFullUrl]);
 
   const defaultValues: ProviderFormData = useMemo(
     () => ({
@@ -949,7 +950,7 @@ export function ProviderForm({
           ? localApiKeyField
           : undefined,
       isFullUrl:
-        appId === "claude" && category !== "official" && localIsFullUrl
+        supportsFullUrl && category !== "official" && localIsFullUrl
           ? true
           : undefined,
     };
@@ -1432,6 +1433,8 @@ export function ProviderForm({
             shouldShowSpeedTest={shouldShowSpeedTest}
             codexBaseUrl={codexBaseUrl}
             onBaseUrlChange={handleCodexBaseUrlChange}
+            isFullUrl={localIsFullUrl}
+            onFullUrlChange={setLocalIsFullUrl}
             isEndpointModalOpen={isCodexEndpointModalOpen}
             onEndpointModalToggle={setIsCodexEndpointModalOpen}
             onCustomEndpointsChange={
diff --git a/src/hooks/useProviderActions.ts b/src/hooks/useProviderActions.ts
index 2531659b4..4f925d402 100644
--- a/src/hooks/useProviderActions.ts
+++ b/src/hooks/useProviderActions.ts
@@ -139,13 +139,17 @@ export function useProviderActions(activeApp: AppId, isProxyRunning?: boolean) {
   // 切换供应商
   const switchProvider = useCallback(
     async (provider: Provider) => {
-      if (
-        activeApp === "claude" &&
+      const requiresProxyForSwitch =
+        !isProxyRunning &&
         provider.category !== "official" &&
-        (provider.meta?.isFullUrl ||
-          provider.meta?.apiFormat === "openai_chat" ||
-          provider.meta?.apiFormat === "openai_responses") &&
-        !isProxyRunning
+        ((activeApp === "claude" &&
+          (provider.meta?.isFullUrl ||
+            provider.meta?.apiFormat === "openai_chat" ||
+            provider.meta?.apiFormat === "openai_responses")) ||
+          (activeApp === "codex" && provider.meta?.isFullUrl));
+
+      if (
+        requiresProxyForSwitch
       ) {
         toast.warning(
           t("notifications.proxyRequiredForSwitch", {
diff --git a/tests/hooks/useProviderActions.test.tsx b/tests/hooks/useProviderActions.test.tsx
index f85a60bef..d6d858d72 100644
--- a/tests/hooks/useProviderActions.test.tsx
+++ b/tests/hooks/useProviderActions.test.tsx
@@ -213,6 +213,28 @@ describe("useProviderActions", () => {
     expect(settingsApiGetMock).not.toHaveBeenCalled();
   });
 
+  it("blocks switching Codex full URL providers when proxy is not running", async () => {
+    const { wrapper } = createWrapper();
+    const provider = createProvider({
+      category: "custom",
+      meta: {
+        isFullUrl: true,
+      },
+    });
+
+    const { result } = renderHook(() => useProviderActions("codex", false), {
+      wrapper,
+    });
+
+    await act(async () => {
+      await result.current.switchProvider(provider);
+    });
+
+    expect(switchProviderMutateAsync).not.toHaveBeenCalled();
+    expect(toastWarningMock).toHaveBeenCalledTimes(1);
+    expect(settingsApiGetMock).not.toHaveBeenCalled();
+  });
+
   it("should sync plugin config when switching Claude provider with integration enabled", async () => {
     switchProviderMutateAsync.mockResolvedValueOnce(undefined);
     settingsApiGetMock.mockResolvedValueOnce({