Connect ChatGPT

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Connect Signit to ChatGPT

ChatGPT passes an authorized attachment reference to Signit for creation and sending. Live client verification of attachment transfer and private PDF review is pending.

1. In ChatGPT Settings → Security and login, enable Developer mode where your account and workspace permit it.
2. Open Plugins, select the plus button, and add Signit with https://app.sign-it.ro/mcp and OAuth. Sign in to Signit and approve creation and sending access.
3. Enable Signit in a new chat, attach a PDF up to 25 MiB, and ask for signatures from named recipients with their email addresses.
4. Refresh tools after updates and reconnect existing grants for the added sending permission. Hosted review has a separate 3 MiB limit; sign only after reading the complete authorized PDF.

OpenAI: Developer mode and full MCP connectors in ChatGPT

Connect once

1. In ChatGPT, open Settings → Security and login and enable Developer mode.
2. Open Plugins, select the plus button, and create a connection named Signit with https://app.sign-it.ro/mcp and OAuth authentication.
3. Use dynamic client registration (DCR), or Client ID Metadata Documents (CIMD) where offered. You do not need a Signit API key.
4. Sign in to Signit and approve its access, including creation and sending.
5. Add Signit to a new conversation. After a server update, refresh the connection's tools; reconnect older grants to approve the added sending permission.

Account eligibility and workspace administrators can control developer mode. See OpenAI's connection instructions.

Attach and request signatures

Attach one PDF to the conversation and ask:

Use Signit to send the attached PDF to Alice (alice@example.com), Bob (bob@example.com), and Carol (carol@example.com) for signature in parallel.

ChatGPT passes an authorized file reference to Signit, which downloads and validates the original PDF before creating the Envelope. PDFs are limited to 25 MiB and 200 pages. Creation accepts autoDetectSignatureFields (default true): Signit reads the whole PDF in the background and places each Signer's fields at their signature blocks; false skips the analysis and puts every Signer on an added signature page. The agent then sends the created draft when your instruction authorizes sending; while the PDF is still being read, sending waits briefly and then returns a placement-pending result with retryAfterSeconds, and the agent retries the same request. Review any write-action approval ChatGPT shows. A local path or a pasted file identifier alone does not transfer the PDF.

If the file reference expires before transfer, reattach the original and retry with the same operation key. Do not recreate the PDF from extracted text.

Review and verification limits

The connector also offers pending-signature inspection and explicit signing. Inspection lists every field prepared for you and its fieldSetDigest; signing must pass that digest and applies the adopted name to every field in the set. Hosted PDF review has a separate 3 MiB limit. Signing requires reading the complete authorized private PDF resource; if ChatGPT cannot read that resource, complete signing in Signit. The larger creation limit does not expand review.

The chat-attachment journey and private PDF review still require live ChatGPT verification. This guide describes the implemented custom connection; it does not mean Signit has been published in a public connector directory.

See OpenAI's file-input contract and OAuth documentation.