UnderSelf editorial desk · October 10, 2026 · 5 min read · Source: underself.io
What is an MCP connector, in one sentence?
An MCP connector is a link built on the Model Context Protocol, an open standard that lets an AI assistant like ChatGPT read and write to an outside app, such as a dream journal, only with your permission. One address, one approval in your browser, and the assistant can reach an app it never had a way into before.
That idea stopped being a developer curiosity in September, when companies with nothing to do with dreams, Potloc and FinTech Studios, shipped connectors that reach Claude and ChatGPT together. We walked through that week in how to keep a dream journal inside Claude. UnderSelf runs its own MCP server, and on September 25, 2026 we connected it to ChatGPT ourselves.
What is a connection key, and how is it different from signing in?
A connection key is a code you generate on your own UnderSelf account page and paste into an assistant instead of signing in through a browser. It is shown once, lasts ninety days, and stops working within five minutes of a revoke. The standard connector flow, the one ChatGPT and Claude both use, skips the key: you approve the assistant on UnderSelf's consent page and it signs in on its own behind the scenes. A pasted connection key exists for assistants and scripts that cannot open a browser to sign in on their own.
How do you connect ChatGPT to UnderSelf?
In ChatGPT, turn on developer mode, then add UnderSelf as a remote MCP app: paste `https://api.underself.io/mcp` as the server address and save it. ChatGPT opens UnderSelf's consent page in your browser; sign in with Google or Apple and read what ChatGPT will be able to do. It is two things: read your dreams, readings and patterns, and record new dreams and request readings. Nothing else. Then approve it. Back in ChatGPT, ask about your dreams the way you would ask anything else. Full walkthrough: connect ChatGPT.
To undo it, tap Disconnect next to ChatGPT under Connected apps on your account page, and access stops within fifteen minutes. Removing the app inside ChatGPT works too, but Disconnect is the sure way.
Does this work with any AI assistant, or only Claude, ChatGPT, Grok and Muse?
Any MCP client that supports OAuth sign in, or a pasted connection key, can connect at the same address. Claude, ChatGPT and Grok are verified: we connected each one ourselves through the standard sign in. Meta Muse connects by a pasted key, and we have not completed a Muse run ourselves yet. Gemini follows the same open standard and should work the same way, though it is untested too. Building something else, or using a client not on that list? The technical flow for any MCP client covers OAuth, the key, and what each error means.
Once it is connected, the point stops being the plumbing. It is being able to say "log this dream" the moment you are awake enough to remember it, in whatever chat window is already open, and later ask what keeps showing up.
If you have ever woken up certain you would remember a dream and lost it by the time you found a notebook, this is the same few seconds, in a different window. What would you ask, if the assistant you already talk to every day could answer from your own dreams?
and see what a reading looks like before deciding whether to connect anything at all.
Questions
What is an MCP connector, in one sentence? A link built on the Model Context Protocol, an open standard, that lets an AI assistant read and write to an outside app, such as a dream journal, with your permission.
What is a connection key? A code generated on your UnderSelf account page and pasted into an assistant instead of a browser sign in. It is shown once, lasts ninety days, and stops within five minutes of a revoke.
How do I connect ChatGPT to UnderSelf? Turn on developer mode in ChatGPT, add UnderSelf as a remote MCP app, paste the server address, sign in with Google or Apple, and approve what it can do.
Does this only work with Claude, ChatGPT, Grok and Meta Muse? No. Any MCP client that supports OAuth sign in or a connection key can connect at the same address. Claude, ChatGPT and Grok are verified; Muse and Gemini are untested so far.
Albert Manukyan, October 10, 2026
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