Connect Claude or ChatGPT

Underanchor does not include an AI: you connect your own Claude or ChatGPT through an MCP connector. The AI can then search your library, read paragraphs and (if you allow it) write in your documents with every sentence anchored.

Open it from the account menu → Connect an AI (Conectar una IA).

Permissions

• Read only (research) (Solo leer (investigar)) — the AI searches and reads your library but never touches your documents.
• Read and write (draft) (Leer y escribir (redactar)) — the AI can also read and write your projects: replace text anchored to a paragraph, comment and propose changes.

Option 1 — With sign-in (recommended, Claude)

1. Under With sign-in (recommended) (Con inicio de sesión (recomendado)), copy the URL.
2. In claude.ai (in the browser): Customize → Connectors → Add custom connector, paste the URL and save.
3. Claude sends you to Underanchor to sign in and choose the permission. No secret to copy.

Revoke it any time under Authorized applications (Aplicaciones autorizadas) → Revoke.

Option 2 — With a private URL (Claude or ChatGPT)

1. Under With a private URL (Con una URL privada): Connector name (Nombre del conector), Permission (Permiso), then Create URL (Crear URL).
2. Copy it now: it will not be shown again. Anyone with the URL has that permission.
3. Paste it as a custom connector:
   • Claude (claude.ai): Customize → Connectors → Add custom connector.
   • ChatGPT (chatgpt.com): Settings → Connectors → Advanced → turn on Developer mode, then create a connector with the URL.

You can have up to 10. Revoke one under Your connectors (Tus conectores); it stops working immediately.

Claude’s Free plan allows one custom connector; paid plans allow more. In ChatGPT, custom connectors (Developer mode) depend on your plan. Once added in the browser, the connector also works in the mobile apps of the same account.

Ask your AI

In a project, Ask the AI (Pedir a la IA) lets you type a task (“Write the motivation paragraph with sources from my library”) and pick Claude or ChatGPT. It opens with the full task copied to your clipboard: paste it in the chat (your text never travels in the web address).

If the AI does not see Underanchor

• Check the connector is enabled in that chat.
• If you revoked it, add it again (sign in again, or create a new URL).
• A read-only connector cannot write: choose Read and write for drafting.
• If the web app is open when the AI writes, it asks you to Reload (Recargar).