# TIL: Adding a custom MCP server to Claude and ChatGPT
Source: [https://simonwillison.net/2026/Jul/29/mcp-in-claude-and-chatgpt/](https://simonwillison.net/2026/Jul/29/mcp-in-claude-and-chatgpt/)
29th July 2026
[](https://til.simonwillison.net/llms/mcp-in-claude-and-chatgpt)
[TIL](https://simonwillison.net/elsewhere/til/)[Adding a custom MCP server to Claude and ChatGPT](https://til.simonwillison.net/llms/mcp-in-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\.
Connecting a custom MCP server to Claude and ChatGPT's standard chat interfaces is possible, but can take quite a few steps\.
Posted[29th July 2026](https://simonwillison.net/2026/Jul/29/)at 12:13 am
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This is a**beat**by Simon Willison, posted on[29th July 2026](https://simonwillison.net/2026/Jul/29/)\.
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Anthropic introduces Desktop Extensions for Claude Desktop, a new .mcpb packaging format that simplifies the installation of MCP servers with a one-click process, removing the need for manual configuration and dependency management.
An open-source MCP tool that allows Claude.ai to run and manage Claude Code sessions, enabling a loop where Claude.ai triggers Claude Code and receives responses back in the browser, eliminating copy-pasting.
Dan Kornas highlights a curated directory of Model Context Protocol (MCP) servers, grouping implementations by job and linking to supported hosts like Claude Desktop, Cursor, VS Code, and Zed. The open-source directory includes security guidance and official markers.
The author presents a novel approach to multi-agent orchestration using a project plan as a shared control plane via MCP, enabling AI agents like ChatGPT and Claude to work as team members with task assignments and human approval gates.