python-sdk VS specification

Today's example was modelcontextprotocol/python-sdk#2657. I opened it eleven days ago. A small fix on the v1.x backport branch: when a client POSTs a JSON-RPC request whose id matches one already in flight on the same session, reject the duplicate with 409 Conflict instead of silently overwriting the prior _request_streams entry. The MCP base protocol explicitly forbids reusing a request ID within a session; the silent-overwrite behavior left the first request hanging forever.

If you'd rather hand-roll it, the Python SDK and TypeScript SDK are both solid and the protocol itself is small enough to read in an afternoon.

数据来源：MCP Python SDK — FastMCP — 23,020 ⭐

GitHub - modelcontextprotocol/python-sdk: The official Python SDK for Model Context Protocol servers and clients

These are the tests that catch the kinds of misleading errors, state leakage, and contract drift seen in modelcontextprotocol/typescript-sdk #699, modelcontextprotocol/python-sdk #756, and modelcontextprotocol/typescript-sdk #451 before users do. A server with only happy-path coverage is usually one incident away from rediscovering Sloth, Wrath, or Pride the hard way.

The MCP fault taxonomy paper cites a Graphiti MCP issue in which returning full embedding vectors increased output from approximately 5K tokens to more than 250K tokens, reportedly driving a 50x increase in cost. The pattern also appears in runtime excess issues like modelcontextprotocol/python-sdk #756, where stateless Streamable HTTP leaked tasks across requests, a form of runtime gluttony even when the payload itself was not large.

https://github.com/modelcontextprotocol/python-sdk/commits?a...

Many contributors to the python sdk continued to iterate on the mcp server implementation using the name fastmcp ( since it had been donated to the project ) resulting in growing interest:

The official Python SDK documentation is at modelcontextprotocol.io/docs/develop/build-server. The source code is at github.com/modelcontextprotocol/python-sdk.

Python with FastMCP (the official MCP Python SDK)

There is a pending proposal (#287) to add namespace prefixes server-side, dated around early 2026, but as of writing it has not landed and the client implementations have not picked it up. So this is an "until further notice" problem.

The news. On May 17, 2026, MCP SEP-2468 was merged into the Model Context Protocol specification — proposed March 25, accepted May 5. The change recommends that authorization servers advertise iss support in their metadata and include the parameter in their authorization responses, and requires clients to validate it against the recorded issuer using simple string comparison per RFC 3986 §6.2.1. The motivation, taken directly from RFC 9207, is to close the long-standing OAuth mix-up attack in clients that trust multiple identity providers.

Semrush data fills in the picture. Claude.ai hit 220 million monthly visits in January 2026, then jumped 30.9% to 288 million in February. Meanwhile, the Model Context Protocol SDK hit 97 million monthly downloads in March, up from 2 million at launch in November 2025. That's 4,750% growth in 16 months. The developer ecosystem is building momentum that feeds back into consumer adoption.

The Solution: User-specific authorization flows. The MCP server obtains tokens scoped to individual users, inheriting their permissions from the downstream systems. This is what our PR #475 addresses—enabling secure token exchange without exposing credentials to clients or LLMs.

If you've been following the rise of MCP (Model Context Protocol), this week was significant: Azure Functions now has first-class support for building MCP servers.

Azure Functions Documentation Model Context Protocol Specification Sample Repository TypeScript Sample Repository Python Sample Repository DotNet Sample Repository Java Azure Functions TypeScript Guide

No. Any file that runs MCP Server is fine anywhere. I am intending a workspace separate from the rails app. The MCP server should be run in a separate process from the rails app. At least until the streamable http transport is ready.

https://github.com/modelcontextprotocol/specification/pull/2...

Another aspect worth noting is that, to date, the protocol requires a persistent connection between client and server, so this can be a drawback for auto-scalable architectures that adapt to demand, as well as moving in the opposite direction in a world that is striving to become stateless.

The MCP protocol is evolving with proposals like the new Streamable HTTP transport that supports fully stateless servers without requiring long-lived connections. We're following these developments closely and evaluating how they might benefit the Supabase MCP experience.