Connect your AI

Connect to ChatGPT

Ask about any US public company and get the real numbers back — revenue, margins, segments, a decade of history. Your assistant stops hallucinating figures and answers from live, verified data, grounded in what each company actually reported. So you can dig into a business, size it up against peers, and move fast on what you find — with every number traceable to where it came from.

ChatGPT by OpenAI supports the Model Context Protocol (MCP), which lets it connect directly to OpenCapital 's stock research index. Here's how to set it up in under 5 minutes.

How to connect

01

Add the OpenCapital connector

Follow the steps below to add OpenCapital in ChatGPT. It works the same on ChatGPT web and desktop.

Step 1a

Open Advanced Settings

Go to chatgpt.com, open Settings, then navigate to "Apps" in the sidebar. Click "Advanced settings" at the bottom.

Open settings
Step 1b

Enable Developer Mode

Toggle on "Developer mode". This allows you to add custom MCP server connections. You only need to do this once.

Step 1c

Create a new App

Go back to the Apps page. You'll now see a "Create app" button. Click it to set up the OpenCapital connection.

Step 1d

Configure the MCP connection and authorize

Name the app "OpenCapital", paste the MCP Server URL below, select "OAuth" for authentication, then click "Create". When prompted, sign in to OpenCapital and authorize read-only access.

https://api.opencapital.sh/mcp
02

Start asking about stocks

You're all set. To route a question through OpenCapital , type @OpenCapital at the start of your message — ChatGPT will call the MCP server for that question. The prompts below are pre-formatted; copy and paste straight in.

Start a new ChatGPT chat

Ask about fundamentals, segments, peer comparisons — anything an analyst would dig into.

Try these prompts

“@OpenCapital What's Uber's Mobility take rate over the last 8 quarters?”
“@OpenCapital How does Airbnb's ADR compare across regions?”
“@OpenCapital Show me DoorDash Marketplace GOV every quarter since IPO.”
“@OpenCapital Compare cloud revenue across AWS, Azure, GCP, and Oracle.”
“@OpenCapital Find me 10 large-caps growing revenue over 20% with positive free cash flow and a P/E under 30.”
“@OpenCapital Before Nvidia reports, summarize what their suppliers, hyperscaler customers, and competitors said in their last filings.”

Works with ChatGPT Plus and Team

The OpenCapital MCP server works with ChatGPT Plus, Team, and Enterprise plans that have MCP support enabled. Data is read live from the OpenCapital index — ChatGPT always sees the latest fundamentals and price data.

Read-only by design

The OpenCapital MCP server only exposes read-only stock research data — fundamentals, price performance, and earnings dates derived from public SEC filings. ChatGPT cannot place trades or modify any account state.

Troubleshooting

My AI doesn't see OpenCapital 's tools
Make sure the connector is added andenabled, and that you finished the OAuth sign-in. If it still won't use them, ask it directly to “use the OpenCapital MCP server.” In ChatGPT, start the message with @OpenCapital .
The sign-in window didn't open
Authorization happens in your browser. If it didn't open automatically, allow pop-ups and try again, or copy the URL your client shows and open it manually. In Claude Code, run /mcp and choose Authenticate; in the Codex CLI, run codex mcp login opencapital.
It says “needs login” or stopped working
Sign-in tokens can expire. Re-authorize from your client's connector settings, or remove and re-add the OpenCapital server and sign in again — that resolves most connection issues.
Connection failed or the server is unreachable
Confirm the URL is exactly https://api.opencapital.sh/mcp and that you chose the Streamable HTTP transport (not stdio). Make sure your client is up to date — the older SSE transport is deprecated in favor of HTTP.
Still stuck?
Email support@opencapital.sh and we'll help you get connected.

Disclosures

Informational only — not investment advice

OpenCapital provides financial data and research tools, not recommendations. Nothing surfaced through the MCP server is an offer, solicitation, or recommendation to buy or sell any security, and it is not personalized investment, legal, or tax advice. Do your own research and consider consulting a licensed professional before making decisions.

Data sources and accuracy

Fundamentals are derived from public SEC filings and other third-party sources and processed automatically. Data may contain errors, omissions, or delays and is provided “as is” without warranty of accuracy or completeness. Verify against primary sources before relying on it. See our methodology for how the numbers are built.

Read-only access

The OpenCapital MCP server is read-only. It exposes research data only and cannot place trades, move money, or modify any account — yours or anyone else's.

Third-party AI clients

When you connect an AI client (such as Anthropic Claude, OpenAI ChatGPT or Codex, or Cursor), your prompts and the data returned are processed by that third party under its own terms and privacy policy. OpenCapital does not control and is not responsible for third-party AI behavior, output, or data handling. AI can be inaccurate or incomplete — verify before acting on anything it tells you.

Authorization

Connecting grants your client read access to OpenCapital research data via OAuth. You can revoke that access at any time from your client's connector settings. Use is governed by our Terms and Privacy Policy.