Setup guideAbout 2 minutesLast checked 12 October 2026

Connect CaptableAI to ChatGPT

Custom connectors through developer mode. Once it's connected, ask about your equity in plain language, upload documents, model a round and export the result, all from the same chat.

Short answer

Turn on developer mode in ChatGPT's settings, create a connector with https://mcp.captable.ai/mcp and OAuth, then sign in to CaptableAI. A saved connector is off by default, so select it in each new chat.

What you need

✓A ChatGPT plan with developer mode. Availability depends on your plan, and on Business or Enterprise, on your workspace admin.
✓A CaptableAI company where you are an owner or admin.

Set it up

Turn on developer mode

Open Settings, go to Apps & Connectors (Connectors on some versions), open Advanced settings and switch on Developer mode. Until it's on, there is no option to add a custom server.

Create the CaptableAI connector

In Apps & Connectors, click Create. Name it CaptableAI, paste the server URL, keep authentication on OAuth, tick the box confirming you trust the app, and click Create.

Server URL

https://mcp.captable.ai/mcp

Sign in

ChatGPT sends you to CaptableAI. Sign in and approve access to the companies you own or administer.

Select it in each chat

In a new chat, click + → More → Developer mode and select CaptableAI. ChatGPT asks you to confirm before any action that changes data.

Check it worked

Ask “Which CaptableAI tools do you have?” If ChatGPT answers from general knowledge, the connector isn't selected for this conversation.

First things to ask

“What happens to my ownership if we raise $4M at a $20M pre-money with a 10% pool top-up?”

“Who are my ten largest holders, fully diluted?”

“Draft a shareholder update covering this quarter's equity changes.”

Troubleshooting

I can't find developer mode.

Its location has moved between ChatGPT releases, so search Settings for “Developer mode”. On a Business or Enterprise workspace, an admin may need to allow it first.

Why does ChatGPT ignore CaptableAI?

Saved connectors aren't active by default. Select CaptableAI from + → More → Developer mode at the start of each conversation.

ChatGPT warns that custom connectors aren't verified. Is that a problem?

OpenAI shows that notice for every custom connector. CaptableAI is operated by Fairmint, and the sign-in screen shows exactly what access is requested before you approve.

Then: upload your documents

CaptableAI builds your cap table by reading your legal documents. These seven habits keep it fast and accurate. Share them with ChatGPT.

01 Upload everything first +

Add all of your cap table documents up front, in one batch where possible: incorporation documents, SAFEs, stock and option agreements, board consents. PDF, DOCX, XLSX, DOC and images are supported.

02 Wait for classification +

Each document is read and classified, so the system knows its type and effective date. Don't trigger extraction until every document shows CLASSIFIED.

03 Check the classification dates +

The effective date decides processing order. If one looks wrong, fix it before extraction so the cap table is built in the right sequence.

04 Trigger extraction once +

Extraction doesn't start automatically for agent uploads. Trigger it a single time after everything is classified; the whole queue is picked up.

05 Let the queue run +

Documents are extracted one at a time, earliest first, so later events build on earlier ones. Expect a few minutes per document and don't re-trigger.

06 Validation runs on its own +

When the last document finishes, a company-wide validator checks every extracted object and repairs cross-document issues. There's nothing to trigger.

07 Review, then commit +

When every document reaches PROCESSED, review the drafts and commit. The first commit activates your cap table.