---
type: Note
id: ec1b12f02288
title: The MCP spec grows up
description: 'OAuth 2.1 authorization, streamable HTTP, batching and tool annotations:
  the March 2025 update that made enterprise MCP plausible.'
tags:
- governed-ai
generated:
  by: seed-import/1.0
  at: '2026-10-17T19:25:45+00:00'
  body_hash: sha256:1d55787e9056818306c557782d6d04feb20678fe9953e30c61f1f61d74ad58df
sources:
- id: s1
  resource: /raw/20261017-192545-the-mcp-spec-grows-up.md
  title: The MCP spec grows up
kind: Essay
status: stable
stale_after: '2027-10-17T00:00:00Z'
classification: public
owner: human:muthu
canonical_essay: https://muthub.org/writing/the-mcp-spec-grows-up
verified:
  by: human:muthu
  at: '2026-10-18T02:01:22Z'
---

# Overview

OAuth 2.1 authorization, streamable HTTP, batching and tool annotations: the March 2025 update that made enterprise MCP plausible.[^s1]

# Read the original

The full note is on muthub.org: [The MCP spec grows up](https://muthub.org/writing/the-mcp-spec-grows-up).

[^s1]: The MCP spec grows up, muthub.org, 2025-04-01.