Max Isbey
b8a107d16c
create_mcp_http_client followed every redirect, so everything configured on a client (headers, auth, request bodies) was re-sent to whatever host a Location header named. Clients built by the factory now follow redirects within the same origin (scheme, host, and port), plus http-to-https upgrades of the same host on default ports, and raise the new RedirectError for anything else - before the next request is sent. - transports resolve a refused redirect in-band: requests get a JSON-RPC error naming the target and the remedy, notifications are delivered to the session's message handler; the standalone GET stream stops retrying an endpoint that keeps redirecting - caller-supplied clients that follow no redirects get the same clear error on POST, GET stream, and SSE connect instead of an opaque content-type error - OAuth discovery, registration, token, refresh, and the identity-assertion token exchange fail loudly on redirect responses instead of silently trying the next URL or abandoning the discovery chain - RedirectError and create_mcp_http_client are exported from the top-level mcp package; migration.md documents the behavior change; docs and examples configure clients through the factory, and the general-purpose fetch example uses a browser-like client of its own
A simple MCP server that exposes a website fetching tool.
Usage
Start the server using either stdio (default) or Streamable HTTP transport:
# Using stdio transport (default)
uv run mcp-simple-tool
# Using Streamable HTTP transport on custom port
uv run mcp-simple-tool --transport streamable-http --port 8000
The server exposes a tool named "fetch" that accepts one required argument:
url: The URL of the website to fetch
Example
Using the MCP client, you can use the tool like this using the STDIO transport:
import asyncio
from mcp.client.session import ClientSession
from mcp.client.stdio import StdioServerParameters, stdio_client
async def main():
async with stdio_client(
StdioServerParameters(command="uv", args=["run", "mcp-simple-tool"])
) as (read, write):
async with ClientSession(read, write) as session:
await session.initialize()
# List available tools
tools = await session.list_tools()
print(tools)
# Call the fetch tool
result = await session.call_tool("fetch", {"url": "https://example.com"})
print(result)
asyncio.run(main())