Adding a custom MCP server to Claude and ChatGPT
Custom MCP servers now work natively in Claude and ChatGPT — here's how to build and deploy one.
Why it matters
Developer tooling has matured: MCP (Model Context Protocol) integration across Claude and ChatGPT means practitioners can now extend both platforms with custom backends without wrappers or workarounds. This lowers the barrier to building AI-powered workflows on top of either service.
The key facts
10 to knowMCP server integration now available in both Claude and ChatGPT
Custom server capability removes friction for developers building integrations
Reduces need for third-party wrapper tools and API abstraction layers
Published by Simon Willison (credible technical source on AI tooling)
How-to/tutorial format indicates feature is in active use
MCP (Model Context Protocol) now supported across Claude and ChatGPT
Custom server integration available for both platforms
Enables connection of proprietary data sources and tools to assistants
Published Jul 29, 2026 (very recent how-to content)
Author: Simon Willison (credible AI/developer voice)
Go to the source
Simon Willisonsimonwillison.net