Connect Penlog to ChatGPT

Penlog is listed in the ChatGPT plugin directory. You add it from the listing and approve the connection by signing in with Apple. There is no token to copy and no URL to paste.

Open Penlog in ChatGPT →

Before you start

  • Penlog Pro is required. Without it the connection succeeds, but every tool call returns a text notice (isError: true) instead of data.
  • You sign in with the same Apple ID you use in the Penlog app on your iPad. A different Apple ID creates a separate, empty Penlog account.

Add Penlog from the directory

  1. Open Penlog's listing, or search for Penlog under Plugins in ChatGPT.
  2. Add the plugin. ChatGPT shows a Sign in with Penlog card.
  3. Sign in with Apple, review the scopes on our consent screen, and choose Allow.

Alternative: Developer mode

You can also register our server by hand in Developer mode, which lets you add any remote MCP server. Use this if your workspace restricts directory plugins. It is a web feature, so set it up at chatgpt.com rather than in the mobile app, and it works on a Free ChatGPT account.

Penlog MCP server URL

https://mcp.penlog.app

That is the whole credential. There is no token, client ID, or secret to paste — Penlog registers your client automatically and then asks you to sign in.

  1. Open Settings → Plugins in ChatGPT on the web, and turn on Developer mode if it is not already on. OpenAI renamed these menus in July 2026 — on an older build the same screens are called Connectors, with Developer mode under Advanced.
  2. Choose + Create app.
  3. Paste https://mcp.penlog.app as the MCP server URL.
  4. Choose OAuth for authentication. ChatGPT reads our server's metadata and selects Dynamic Client Registration on its own; the read, seed, and write scopes are discovered and pre-checked. Leave them as they are unless you want a read-only connection.
  5. Create the app, then sign in with Apple and choose Allow on the card ChatGPT shows.

There is no place for an API token

ChatGPT's New Plugin dialog offers OAuth, No Auth, or Mixed. It has no API-key or custom-header field, so a plg_live_ bearer token minted in the Penlog app cannot be used to connect ChatGPT — there is nowhere to put it. OAuth is the only path here. Tokens remain useful for CLI tools and self-hosted agents; see Remote MCP clients.

Check that it worked

Ask for something only your journal can answer:

What are my open tasks in Penlog?

A good negative test is asking about a date you know you never wrote on. A working connection says it has no page for that date. An answer that invents content means ChatGPT is not actually calling the connector.

Deep research and search

Alongside the six core tools, Penlog exposes search and fetch aliases that return OpenAI's deep-research shape ({id, title, text, url, metadata}), so your handwriting is citable in deep-research runs. They are the same underlying data as search_pages and get_page.

If it doesn't connect

What you seeWhat it means
Penlog doesn't appear in the plugin directory Your workspace admin may restrict plugins. Ask them to allow Penlog, or use Developer mode if it is permitted.
No + Create app option (Developer mode) Developer mode is off, or you are in the mobile app rather than the web app.
Registration fails before any sign-in (Developer mode) The URL has a path or a typo. It is exactly https://mcp.penlog.app.
Every tool returns a "not included in your plan" notice The Penlog account you signed in as is not Pro. If you do have Pro, you most likely signed in with a different Apple ID from the one on your iPad. Disconnect and sign in again with the right one.
One tool returns 403 You unchecked a scope during setup. Reconnect and approve it.

More cases are in Troubleshooting.

Disconnecting

Delete the plugin in ChatGPT, or revoke it from Penlog under Settings → Connected Apps. Revocation is immediate.