Simon Willison’s Weblog

29th July 2026

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TIL Adding a custom MCP server to Claude and ChatGPT — I've started exploring [MCP](https://modelcontextprotocol.io/) in more detail. The web chat UIs for both Claude and ChatGPT can access MCP servers but it's not obvious how to set them up. Here's what I figured out.

Posted 29th July 2026 at 12:13 am

Recent articles

OpenAI’s accidental cyberattack against Hugging Face is science fiction that happened - 22nd July 2026
A Fireside Chat with Cat and Thariq from the Claude Code team - 21st July 2026
Kimi K3, and what we can still learn from the pelican benchmark - 16th July 2026

This is a beat by Simon Willison, posted on 29th July 2026.

ai 2,148 generative-ai 1,900 chatgpt 198 llms 1,867 claude 296 model-context-protocol 29

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