Underanchor

Pesquise sua própria biblioteca de PDFs e escreva LaTeX com cada afirmação ancorada ao parágrafo exato do PDF de origem. Cita com um link para o parágrafo destacado, sinaliza frases sem suporte e permite que seu supervisor revise texto e fontes lado a lado. Login via OAuth, somente leitura ou leitura e escrita.

Ver em underanchor.com

Servidor MCP hospedado

npx add-mcp 'https://underanchor.com/mcp'

Instala no Claude Code, Codex, Cursor e outros

Documentação

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.

Three steps (Claude or ChatGPT)

The dialog shows a short animation of these steps.

  1. Copy this link (Copia este enlace): the address ending in /mcp, with Copy (Copiar).
  2. Paste it into your AI as a custom connector (Pégalo en tu IA como conector personalizado), in the browser:
    • Claude (claude.ai): Customize → Connectors → Add custom connector.
      • ChatGPT (chatgpt.com): Settings → Connectors → Advanced → turn on Developer mode, then Create.
  3. Click “Allow” (Pulsa «Permitir»): your AI sends you to Underanchor to sign in and choose the permission. No key to copy.

It shows up under Connected (Conectadas); Revoke (Revocar) removes it at once.

Advanced: private URL (AIs without sign-in)

Only for an AI that cannot sign in with the link above. Open Advanced: private URL, for AIs without sign-in (Avanzado: URL privada, para IAs sin inicio de sesión):

  1. 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, as in step 2 above.

You can have up to 10. Revoke one under Your private URLs (Tus URL privadas); it stops working immediately.

How many custom connectors you can add depends on your Claude or ChatGPT account (in ChatGPT, custom connectors need Developer mode). 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). With no connector yet, the window asks you to connect first, with a Connect (Conectar) button that opens the three steps above; once connected it shows Connector ready (Conector listo).

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).