from app.mcp import mcp
from app.core import settings
from mcp.server.fastmcp import Context
from typing import Any
from urllib.parse import urlparse
import httpx
ALLOWED_METHODS = {"GET", "HEAD"}
def _is_domain_allowed(url: str) -> bool:
if not settings.allowed_fetch_domains:
return True
domain = urlparse(url).netloc
return any(domain.endswith(allowed) for allowed in settings.allowed_fetch_domains)
@mcp.tool()
async def fetch_url(url: str, method: str = "GET", ctx: Context = None) -> dict[str, Any]:
"""
Execute HTTP requests to external URLs.
Args:
url: URL to fetch
method: HTTP method (GET, HEAD)
Returns:
Status code, headers and content (truncated if too long)
"""
if not settings.enable_fetch_tool:
return {"success": False, "error": "Tool fetch_url disabled"}
method = method.upper()
if method not in ALLOWED_METHODS:
return {"success": False, "error": f"Only {ALLOWED_METHODS} are supported"}
if not url.startswith(("http://", "https://")):
return {"success": False, "error": "URL must start with http:// or https://"}
if not _is_domain_allowed(url):
return {"success": False, "error": f"Domain not allowed. Allowed: {settings.allowed_fetch_domains}"}
client: httpx.AsyncClient | None = None
should_close = False
try:
if ctx and hasattr(ctx, 'request_context') and ctx.request_context.lifespan_context:
client = ctx.request_context.lifespan_context.http_client
else:
client = httpx.AsyncClient(timeout=settings.http_timeout)
should_close = True
response = await client.request(method, url)
content = None
content_length = None
if method == "GET":
content = response.text[:settings.max_url_content]
content_length = len(response.text)
return {
"success": True,
"url": url,
"method": method,
"status_code": response.status_code,
"headers": dict(response.headers),
"content_preview": content,
"content_length": content_length
}
except httpx.TimeoutException:
return {"success": False, "error": "Request timeout"}
except httpx.RequestError as e:
return {"success": False, "error": f"Request failed: {e}"}
finally:
if should_close and client:
await client.aclose()
