What is true today (October 2026)
- ChatGPT can connect to custom MCP servers, but only remote ones: a server with an HTTPS URL. It has no way to launch a local process over stdio, which is how Health Access MCP, and every other local MCP server, talks to its client.
- Which plans may add a custom MCP server has changed more than once since the feature appeared in 2025. At the time of writing, OpenAI's help center lists it for Business and Enterprise/Edu workspaces, with a read-only form for Pro. to confirm Check OpenAI's article on developer mode and MCP in ChatGPT before you plan around it.
- Nothing about Health Access MCP changes for ChatGPT. The server speaks standard MCP. If OpenAI adds local servers, the Claude Desktop snippet is the one you would use.
Path 1: the files. Works now.
The folder is the API. Everything the MCP serves is a plain file in the folder your phone writes, so ChatGPT can read it as an upload.
- The briefing.
briefing.mdis a one-page summary the app writes after every sync: last four weeks, recent sessions, vitals, the next planned session, open items. Upload it to a conversation, or add it to a ChatGPT project so every chat there starts with it. The command line gives you the same thing:healthaccess summary --weeks 4andhealthaccess show <id>; paste the output. - One session. Upload
workouts/2026-05-14_0712_PoolSwim_7A1C3E90.json(or whichever) and ask. The file carries every interval, every length, the heart-rate series and your effort rating. What the fields mean. - A plan back. Ask ChatGPT to write the session in the plan format, save the JSON it gives you into
plans/, and the app offers "Put on Watch" within a minute. No MCP needed for that either; the file is the interface.
Then say to it:
This is my training briefing from Health Access. Read it, then ask me how I slept and how motivated I feel. After my answers, tell me whether the numbers suggest I am overdoing it, as a hypothesis with your confidence, not a verdict.
Path 2: a bridge to an HTTPS URL. Possible, not recommended.
A stdio-to-HTTP proxy plus a public tunnel turns the local server into a URL that ChatGPT can connect to. It works in principle. We do not recommend it: your training data then travels through a tunnel and sits behind a URL, and the server has no authentication of its own. If you do it anyway, put real authentication in front of it and take it down when you are done.
Why not just run a cloud server for you
Because then there would be a server, an account and a copy of your health data we hold. The other products made that choice; this one did not. The folder you own is the whole design.