fix(fetch): fix fetchurl tool incorrect output when fetching via service fails

CHANGELOG.md

@@ -9,6 +9,10 @@ Internal builds may append content to the Unreleased section.
 Only write entries that are worth mentioning to users.
 -->
 
+## [Unreleased]
+
+- Tool: Fix FetchURL tool incorrect output when fetching via service fails
+
 ## [0.62] - 2025-12-08
 
 - ACP: Fix tool results (including Shell tool output) not being displayed in ACP clients like Zed

src/kimi_cli/tools/web/fetch.py

@@ -29,15 +29,17 @@ def __init__(self, config: Config):
 
     @override
     async def __call__(self, params: Params) -> ToolReturnValue:
-        builder = ToolResultBuilder(max_line_length=None)
-
         if self._service_config:
-            result = await self._fetch_with_service(params, builder)
-            if isinstance(result, ToolOk):
-                return result
-            logger.warning("Failed to fetch URL via service: {error}", error=result.message)
+            ret = await self._fetch_with_service(params)
+            if isinstance(ret, ToolOk):
+                return ret
+            logger.warning("Failed to fetch URL via service: {error}", error=ret.message)
             # fallback to local fetch if service fetch fails
+        return await self.fetch_with_http_get(params)
 
+    @staticmethod
+    async def fetch_with_http_get(params: Params) -> ToolReturnValue:
+        builder = ToolResultBuilder()
         try:
             async with (
                 new_client_session() as session,
@@ -103,14 +105,13 @@ async def __call__(self, params: Params) -> ToolReturnValue:
         builder.write(extracted_text)
         return builder.ok("The returned content is the main text content extracted from the page.")
 
-    async def _fetch_with_service(
-        self, params: Params, builder: ToolResultBuilder
-    ) -> ToolReturnValue:
+    async def _fetch_with_service(self, params: Params) -> ToolReturnValue:
         assert self._service_config is not None
 
         tool_call = get_current_tool_call_or_none()
         assert tool_call is not None, "Tool call is expected to be set"
 
+        builder = ToolResultBuilder()
         headers = {
             "User-Agent": USER_AGENT,
             "Authorization": f"Bearer {self._service_config.api_key.get_secret_value()}",
@@ -119,20 +120,31 @@ async def _fetch_with_service(
             **(self._service_config.custom_headers or {}),
         }
 
-        async with (
-            new_client_session() as session,
-            session.post(
-                self._service_config.base_url,
-                headers=headers,
-                json={"url": params.url},
-            ) as response,
-        ):
-            if response.status != 200:
-                return builder.error(
-                    f"Failed to fetch URL via service. Status: {response.status}.",
-                    brief="Failed to fetch URL via fetch service",
-                )
+        try:
+            async with (
+                new_client_session() as session,
+                session.post(
+                    self._service_config.base_url,
+                    headers=headers,
+                    json={"url": params.url},
+                ) as response,
+            ):
+                if response.status != 200:
+                    return builder.error(
+                        f"Failed to fetch URL via service. Status: {response.status}.",
+                        brief="Failed to fetch URL via fetch service",
+                    )
 
-            content = await response.text()
-            builder.write(content)
-            return builder.ok("The returned content is the main content extracted from the page.")
+                content = await response.text()
+                builder.write(content)
+                return builder.ok(
+                    "The returned content is the main content extracted from the page."
+                )
+        except aiohttp.ClientError as e:
+            return builder.error(
+                (
+                    f"Failed to fetch URL via service due to network error: {str(e)}. "
+                    "This may indicate the service is unreachable."
+                ),
+                brief="Network error when calling fetch service",
+            )