Connect your AI

Connect any MCP client

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 chase any question as far as the filings go — with every number traceable to where it came from.

OpenCapital works with any AI that speaks the Model Context Protocol (MCP) — Claude, ChatGPT, Codex, Cursor, and a growing list of others. The setup is always the same: one URL, one sign-in.

How to connect

Add it as a remote MCP server

Two interchangeable ways — use whichever your client supports.

In your client's connector or MCP settings, add a new server using the Streamable HTTPtransport (some clients call it a “custom connector” or “remote MCP server”), name it OpenCapital, and paste the URL below.

https://api.opencapital.sh/mcp

Authorize with OpenCapital

The first time your client calls OpenCapital, it opens your browser to sign in (Google) and approve read-only access. After that the connection stays active.

Now just ask.

You're all set. Ask your assistant about fundamentals, segments, or peer comparisons and it'll pull live numbers from OpenCapital.

Your assistant calls OpenCapital automatically — no special prefix needed.

Try asking

Step-by-step guides

Using one of these? We have a tailored walkthrough.

Claude Claude Code ChatGPT Codex Codex CLI Cursor

One endpoint, every client

A standard remote MCP server over Streamable HTTP with OAuth — any spec-compliant client connects. Data is read live.

Read-only by design

Exposes read-only research data from public SEC filings. It cannot place trades or change any account.

Troubleshooting

My AI doesn't see OpenCapital's tools

Make sure the connector is added, enabled, and signed in. Still nothing? Ask it to “use the OpenCapitalMCP server” — in ChatGPT, start the message with @OpenCapital.

The sign-in window didn't open

Authorization opens in your browser — allow pop-ups and retry. In Claude Code run /mcp → Authenticate; in the Codex CLI, run codex mcp login opencapital.

It says “needs login” or stopped working

Tokens can expire — re-authorize from your client's connector settings, or remove and re-add the OpenCapital server.

Connection failed or the server is unreachable

Confirm the URL is exactly https://api.opencapital.sh/mcp, the transport is Streamable HTTP (not stdio), and your client is up to date.

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, not recommendations. Nothing here is an offer or personalized investment, legal, or tax advice — do your own research.

Data sources and accuracy

Derived automatically from public SEC filings and other sources; it may contain errors or delays and is provided “as is.” Verify against primary sources — see our methodology.

Read-only access

The OpenCapital MCP server is read-only — it cannot place trades, move money, or modify any account.

Third-party AI clients

Your prompts and the data returned are processed by your AI client (Claude, ChatGPT, Codex, Cursor) under its own terms. AI can be wrong — verify before acting.

Authorization

Connecting grants read access via OAuth; revoke it anytime from your client's settings. Use is governed by our Terms and Privacy Policy.