阶段4：隔离第三方请求并补充负向验收

保持 OSS、签名下载、Provider、搜索、loopback 和更新下载使用独立 Client。

为搜索、loopback 和更新下载提取独立构造点，保留原有 no_proxy、timeout 和 redirect 配置。

新增 OSS/签名传输、搜索、loopback 和更新下载的无标记请求捕获测试。

为 Codex Provider 代理转发增加无主站标记断言。

更新 Issue 226 阶段方案与验收计划，记录阶段 4 完成。

apps/ai-game-creator-shell/src-tauri/src/agent/codex_provider_proxy.rs

@@ -252,6 +252,10 @@ mod tests {
                 .and_then(|value| value.to_str().ok()),
             Some("Bearer fixture-provider-key")
         );
+        assert!(
+            headers.get("x-genarrative-client").is_none(),
+            "Provider 请求不得携带 AGC 主站标记"
+        );
         Response::builder()
             .status(StatusCode::OK)
             .header("content-type", "application/json")

apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs

@@ -2181,6 +2181,15 @@ async fn bridge_browser_playtest(root: &Path, arguments: &Value) -> Value {
     }
 }
 
+fn build_controlled_search_client() -> Result<reqwest::Client, String> {
+    reqwest::Client::builder()
+        .no_proxy()
+        .timeout(std::time::Duration::from_secs(20))
+        .redirect(reqwest::redirect::Policy::none())
+        .build()
+        .map_err(|_| "创建 AGC 受控搜索连接失败".to_string())
+}
+
 async fn bridge_web_search(root: &Path, arguments: &Value) -> Value {
     let result = async {
         enforce_project_permission_policy(root, "project.search")?;
@@ -2190,12 +2199,7 @@ async fn bridge_web_search(root: &Path, arguments: &Value) -> Value {
             DIRECT_TOOL_BRIDGE_MAX_SEARCH_QUERY_CHARS,
         )?;
         let max_results = bridge_search_max_results(arguments)?;
-        let client = reqwest::Client::builder()
-            .no_proxy()
-            .timeout(std::time::Duration::from_secs(20))
-            .redirect(reqwest::redirect::Policy::none())
-            .build()
-            .map_err(|_| "创建 AGC 受控搜索连接失败".to_string())?;
+        let client = build_controlled_search_client()?;
         let response = client
             .get(DIRECT_TOOL_BRIDGE_SEARCH_URL)
             .query(&[("q", query.as_str())])
@@ -2321,6 +2325,45 @@ pub(crate) async fn start_direct_tool_bridge(root: &Path) -> Result<DirectToolBr
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::io::{Read, Write};
+
+    #[tokio::test]
+    async fn controlled_search_client_omits_agc_marker() {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").expect("bind search fixture");
+        let address = listener.local_addr().expect("search fixture address");
+        let server = std::thread::spawn(move || {
+            let (mut stream, _) = listener.accept().expect("accept search request");
+            stream
+                .set_read_timeout(Some(std::time::Duration::from_secs(2)))
+                .expect("set search fixture timeout");
+            let mut bytes = Vec::new();
+            let mut buffer = [0_u8; 1024];
+            while !bytes.windows(4).any(|window| window == b"\r\n\r\n") {
+                let read = stream.read(&mut buffer).expect("read search request");
+                assert!(read > 0, "search request closed before headers");
+                bytes.extend_from_slice(&buffer[..read]);
+            }
+            stream
+                .write_all(
+                    b"HTTP/1.1 204 No Content\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+                )
+                .expect("write search response");
+            String::from_utf8_lossy(&bytes).into_owned()
+        });
+
+        let client = build_controlled_search_client().expect("build search client");
+        let response = client
+            .get(format!("http://{address}/search"))
+            .send()
+            .await
+            .expect("send search request");
+        let request = server.join().expect("join search fixture");
+
+        assert_eq!(response.status(), reqwest::StatusCode::NO_CONTENT);
+        assert!(!request
+            .to_ascii_lowercase()
+            .contains("x-genarrative-client:"));
+    }
 
     #[test]
     fn bridge_argument_bounds_are_deterministic() {

apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs

@@ -819,15 +819,19 @@ fn direct_tool_bridge_url() -> Result<String, String> {
     Ok(value)
 }
 
+fn build_direct_tool_bridge_client() -> Result<reqwest::Client, String> {
+    reqwest::Client::builder()
+        .no_proxy()
+        .timeout(std::time::Duration::from_secs(1_800))
+        .redirect(reqwest::redirect::Policy::none())
+        .build()
+        .map_err(|_| "创建客户端工具桥连接失败".to_string())
+}
+
 async fn call_client_tool_bridge(tool: &str, arguments: &Value) -> Value {
     let result = async {
         let url = direct_tool_bridge_url()?;
-        let client = reqwest::Client::builder()
-            .no_proxy()
-            .timeout(std::time::Duration::from_secs(1_800))
-            .redirect(reqwest::redirect::Policy::none())
-            .build()
-            .map_err(|_| "创建客户端工具桥连接失败".to_string())?;
+        let client = build_direct_tool_bridge_client()?;
         let response = client
             .post(url)
             .json(&json!({ "tool": tool, "arguments": arguments }))
@@ -1147,6 +1151,46 @@ async fn run_direct_tools_mcp_stdio() -> Result<(), String> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::io::{Read, Write};
+
+    #[tokio::test]
+    async fn loopback_tool_bridge_client_omits_agc_marker() {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").expect("bind loopback fixture");
+        let address = listener.local_addr().expect("loopback fixture address");
+        let server = std::thread::spawn(move || {
+            let (mut stream, _) = listener.accept().expect("accept loopback request");
+            stream
+                .set_read_timeout(Some(std::time::Duration::from_secs(2)))
+                .expect("set loopback fixture timeout");
+            let mut bytes = Vec::new();
+            let mut buffer = [0_u8; 1024];
+            while !bytes.windows(4).any(|window| window == b"\r\n\r\n") {
+                let read = stream.read(&mut buffer).expect("read loopback request");
+                assert!(read > 0, "loopback request closed before headers");
+                bytes.extend_from_slice(&buffer[..read]);
+            }
+            stream
+                .write_all(
+                    b"HTTP/1.1 204 No Content\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+                )
+                .expect("write loopback response");
+            String::from_utf8_lossy(&bytes).into_owned()
+        });
+
+        let client = build_direct_tool_bridge_client().expect("build loopback client");
+        let response = client
+            .post(format!("http://{address}/tool-test"))
+            .json(&json!({ "tool": "fixture", "arguments": {} }))
+            .send()
+            .await
+            .expect("send loopback request");
+        let request = server.join().expect("join loopback fixture");
+
+        assert_eq!(response.status(), reqwest::StatusCode::NO_CONTENT);
+        assert!(!request
+            .to_ascii_lowercase()
+            .contains("x-genarrative-client:"));
+    }
 
     #[test]
     fn direct_tools_mode_requires_the_exact_private_flag() {

apps/ai-game-creator-shell/src-tauri/src/assets.rs

@@ -2082,6 +2082,42 @@ mod tests {
         String::from_utf8_lossy(&bytes).into_owned()
     }
 
+    #[tokio::test]
+    async fn external_asset_transfer_client_omits_agc_marker() {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").expect("bind transfer fixture");
+        let base_url = format!(
+            "http://{}",
+            listener.local_addr().expect("transfer address")
+        );
+        let upload_url = url::Url::parse(&format!("{base_url}/upload")).expect("upload URL");
+        let server = std::thread::spawn(move || {
+            let (mut stream, _) = listener.accept().expect("accept transfer request");
+            let request = read_asset_test_request(&mut stream);
+            stream
+                .write_all(
+                    b"HTTP/1.1 204 No Content\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+                )
+                .expect("write transfer response");
+            request
+        });
+
+        let client = build_external_asset_download_client(&upload_url, &base_url, true)
+            .await
+            .expect("build external asset transfer client");
+        let response = client
+            .post(upload_url)
+            .body("fixture-upload")
+            .send()
+            .await
+            .expect("send transfer request");
+        let request = server.join().expect("join transfer fixture");
+
+        assert_eq!(response.status(), reqwest::StatusCode::NO_CONTENT);
+        assert!(!request
+            .to_ascii_lowercase()
+            .contains("x-genarrative-client:"));
+    }
+
     #[test]
     fn canvas_download_accepts_supported_image_magic() {
         let cases: [(&str, &str, &[u8]); 4] = [

apps/ai-game-creator-shell/src-tauri/src/main.rs

@@ -50,6 +50,10 @@ const AGC_UPDATE_OSS_HOST: &str = "agc-dev.oss-rg-china-mainland.aliyuncs.com";
 const AGC_UPDATE_MAX_DOWNLOAD_BYTES: u64 = 512 * 1024 * 1024;
 const AGC_UPDATE_DOWNLOAD_PROGRESS_EVENT: &str = "agc-update-download-progress";
 
+fn build_agc_update_download_client() -> reqwest::Client {
+    reqwest::Client::new()
+}
+
 #[derive(Clone, Debug, Serialize)]
 #[serde(rename_all = "camelCase")]
 struct AgcUpdateDownloadProgress {
@@ -118,7 +122,7 @@ async fn download_agc_update(
     if filename.is_empty() || filename.len() > 128 {
         return Err("更新文件名无效".to_string());
     }
-    let response = reqwest::Client::new()
+    let response = build_agc_update_download_client()
         .get(parsed)
         .send()
         .await
@@ -2656,6 +2660,50 @@ mod diagnostic_log_tests {
     }
 }
 
+#[cfg(test)]
+mod update_client_tests {
+    use super::*;
+    use std::io::{Read, Write};
+
+    #[tokio::test]
+    async fn update_download_client_omits_agc_marker() {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").expect("bind update fixture");
+        let address = listener.local_addr().expect("update fixture address");
+        let server = std::thread::spawn(move || {
+            let (mut stream, _) = listener.accept().expect("accept update request");
+            stream
+                .set_read_timeout(Some(std::time::Duration::from_secs(2)))
+                .expect("set update fixture timeout");
+            let mut bytes = Vec::new();
+            let mut buffer = [0_u8; 1024];
+            while !bytes.windows(4).any(|window| window == b"\r\n\r\n") {
+                let read = stream.read(&mut buffer).expect("read update request");
+                assert!(read > 0, "update request closed before headers");
+                bytes.extend_from_slice(&buffer[..read]);
+            }
+            stream
+                .write_all(
+                    b"HTTP/1.1 204 No Content\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+                )
+                .expect("write update response");
+            String::from_utf8_lossy(&bytes).into_owned()
+        });
+
+        let client = build_agc_update_download_client();
+        let response = client
+            .get(format!("http://{address}/update.exe"))
+            .send()
+            .await
+            .expect("send update request");
+        let request = server.join().expect("join update fixture");
+
+        assert_eq!(response.status(), reqwest::StatusCode::NO_CONTENT);
+        assert!(!request
+            .to_ascii_lowercase()
+            .contains("x-genarrative-client:"));
+    }
+}
+
 #[cfg(test)]
 mod tests;
 pub mod ui_editor;

local-docs/【实施方案】Issue226-AGC客户端主站请求统一标记-2026-09-01.md

@@ -6,7 +6,7 @@
 - `#226 添加客户端特殊标识`：本方案实际实施范围
 - `#225 添加客户端埋点统计`：主站接收、落库和后台统计，本文只冻结交接契约，不在本次实施
 
-状态：阶段 3 已完成，待阶段 4 实施<br>
+状态：阶段 4 已完成，待阶段 5 实施<br>
 本方案包含 #226 客户端代码修改，不包含 #225 主站接收、落库和后台统计代码
 
 ## 1. 一句话交付结果
@@ -237,6 +237,14 @@ let client = agc_main_site_client_builder()
 - 阶段 3 请求捕获验证：`sync_canvas_project_assets_downloads_external_resources`（1 test passed）确认账号态项目请求和 `assets/read-url` 带标记，签名媒体下载不带标记。
 - 阶段 3 验证命令：`cargo test --locked --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml http_client -- --nocapture`（2 tests passed）；`cargo test --locked --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml sync_canvas_project_assets_downloads_external_resources -- --nocapture`（1 test passed）；`cargo fmt --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml -- --check`、`npm run check:encoding` 和 `git diff --check` 均通过。
 
+### 6.6 阶段 4 实施记录
+
+- 保持第三方请求的独立 Client 边界：`build_external_asset_download_client`、Codex Provider 代理、受控搜索、loopback 工具桥和更新下载均未接入主站 factory。
+- 为搜索、loopback 和更新下载提取独立的 Client 构造点，保留原有 `no_proxy`、timeout 和 redirect 配置，并明确验证这些 Client 不携带 `X-Genarrative-Client`。
+- 新增 OSS/签名传输 Client、受控搜索 Client、loopback 工具桥 Client 和更新下载 Client 的本地 TCP 负向测试；Provider 代理转发测试增加无标记断言。
+- 阶段 4 验证结果：`omits_agc_marker` 负向测试 4 个通过；Provider 代理测试 1 个通过；阶段 3 的画板同步请求捕获测试继续作为签名 URL 媒体下载无标记证据。
+- 未修改主站 API、`ExternalEditorBindingAccess` 路由映射、认证语义、OSS/Provider/搜索/loopback/更新的网络安全策略或 #225 代码。
+
 ## 7. 调用语义和现有路由边界
 
 本次不改变 `ExternalEditorBindingAccess` 的职责：

local-docs/【实施计划】Issue226-AGC客户端主站请求标记分阶段验收-2026-09-01.md

@@ -6,7 +6,7 @@
 - `#226 添加客户端特殊标识`：本计划全部实施范围
 - `#225 添加客户端埋点统计`：只接收交接契约，不在本计划实现
 
-当前状态：阶段 3 已完成；阶段 4 尚未开始。阶段 0 的证据与验收记录见
+当前状态：阶段 4 已完成；阶段 5 尚未开始。阶段 0 的证据与验收记录见
 [【阶段验收】Issue226阶段0现状基线与契约冻结-2026-09-01.md](C:/projects/narrative/Genarrative/local-docs/【阶段验收】Issue226阶段0现状基线与契约冻结-2026-09-01.md)。
 
 ## 1. 交付目标
@@ -284,6 +284,15 @@ fn agc_main_site_client_builder() -> reqwest::ClientBuilder;
 - 没有出现“为了复用 factory，把第三方请求也带上 Header”的情况。
 - 负向测试失败时能定位到具体请求类别，而不是只报告一个总失败。
 
+### 8.4 阶段 4 实施记录
+
+- `build_external_asset_download_client` 的 OSS/签名传输 Client 保持独立；新增 `external_asset_transfer_client_omits_agc_marker` 本地 TCP 测试。
+- 受控搜索 Client 提取为独立构造点，新增 `controlled_search_client_omits_agc_marker` 测试。
+- loopback 工具桥 Client 提取为独立构造点，新增 `loopback_tool_bridge_client_omits_agc_marker` 测试。
+- 更新下载保留独立裸 Client，新增 `update_download_client_omits_agc_marker` 测试。
+- Codex Provider 代理转发测试增加 `x-genarrative-client` 缺失断言；阶段 3 的画板同步测试继续确认签名媒体下载无标记。
+- 阶段 4 验证命令：`cargo test --locked --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml omits_agc_marker -- --nocapture`（4 tests passed）；`cargo test --locked --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml loopback_proxy_strips_false_codex_limit_headers_and_requires_bearer -- --nocapture`（1 test passed）；`cargo fmt --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml -- --check` 和 `git diff --check` 通过。
+
 ## 9. 阶段 5：账号态、External 态和语义回归
 
 ### 9.1 工作内容