Every Holm app now speaks MCP
Since v0.255.0, apps on a Holm node can be used from inside ChatGPT and Claude. Holm speaks the Model Context Protocol (MCP), the open standard both use for plugins and connectors, and builds the tools from what your app already does. Nothing extra to write or set up.
If you run Holm through Claude or another agent, it looks like this. You ask for an app, say a feedback form or a waitlist. The agent builds it and deploys it to your node. That app now also has an address ChatGPT or Claude can connect to, and anyone who adds it can use the app in plain words: "what's on the waitlist?", "send this feedback".
Why it matters: OpenAI reported 800 million weekly ChatGPT users in October 2025, and both ChatGPT and Claude let people add tools to their chats. Nobody knows yet how much a small plugin gets used, and you can't sell digital goods inside ChatGPT, so think of it as a new front door to your app rather than a store. With Holm, that door comes with every app.
What an assistant can do
Only what your app already offers the public. Anything that needs a signed-in user stays out, and every request from an assistant goes through the same checks as one from a browser. Holm tells the assistant which actions only look things up and which change something. Actions that change things can be made safe to retry: if a connection drops and the assistant sends the same request again, Holm returns the first result instead of doing it twice.
Our own feedback app works this way. In a chat it can look up a widget's public settings and send feedback; the owner's inbox stays private.
Apps built before v0.255.0 have this switched off. Ask your agent to switch it on, or to keep any app out of AI chats.
What's tested, and what's next
Before building this in, we connected a hand-written version of the feedback app to Claude. Claude picked the right actions from plain questions, read and wrote data, and showed an interactive card. The built-in version passes our tests for the current versions of the protocol, but we haven't yet run it through real ChatGPT and Claude conversations end to end. That's next.
Still to come:
- Sign-in, so an assistant can reach a person's own data in your app, with their consent. It is designed and under review.
- Cards in the chat, which the prototype showed and the built-in version doesn't yet.
- Help getting listed in the ChatGPT and Claude directories.
Try it
Ask your agent for your app's MCP address, then add it as a custom connector: in Claude, or in ChatGPT's developer mode (paid plans). The guide has the details. If something behaves oddly, the Feedback link at the bottom of this page reaches us.