# Connect ChatGPT

> Connect ChatGPT and Codex to your FactorIn library as a custom MCP app, and the plan limits that apply to workspaces and personal accounts.

Source: https://factor.in/docs/connect-chatgpt/
Updated: September 30, 2026


ChatGPT reaches your library as a custom MCP app. Add it once in the browser and it is there in ChatGPT on the web and in the desktop app. Codex, OpenAI's coding agent, connects from a terminal.

Connecting an AI app needs an active plan or a library inside its first 7 days. On a ChatGPT Business or Enterprise workspace, only an owner can add a custom MCP app, so the person who sets up the tools should be the one to do this. Personal ChatGPT plans carry some restrictions that may limit what you can write through a custom MCP connection.

## What you need

- A FactorIn login. Sign in, open **Connected apps** in your settings, and pick the **ChatGPT** tab. The URL to paste is shown there.
- The connector URL: `https://connect.factorin.com/mcp`.

## ChatGPT on the web and desktop

ChatGPT reads no name or URL out of a link, so both are typed.

1. Use your browser, not the desktop app.
2. Turn on **Developer mode** in Settings, if it isn't on already. A custom MCP app cannot be added without it, and the toggle sticks once it is on.
3. Click **Add to ChatGPT**, or open ChatGPT's Plugins page yourself. Choose **Add**, then **Create MCP app**.
4. Name it `FactorIn`, paste the connector URL as the server URL, then click **Create** or **Connect**.
5. Approve the connection when FactorIn asks. The consent screen names the libraries the connection will reach.
6. In the desktop app, sign out and back in to see FactorIn.

## Codex CLI

Codex is OpenAI's, so it folds in here. Adding the server and signing in are two separate steps in Codex.

```
codex mcp add FactorIn --url https://connect.factorin.com/mcp && codex mcp login FactorIn
```

Codex opens your browser to sign in. Approve the connection when FactorIn asks.

## Confirm it worked

Ask ChatGPT to list your libraries. It should name each one you can reach and whether it can write to it. Then paste the setup prompt from the Connected apps page, which is the first thing to do with a new connection. See [Set up your library](https://factor.in/docs/set-up-your-library/index.md).

## What ChatGPT can do once connected

Read anything in your library by name, path or link. Search it by content and by name. List and follow your skills. Create notes, prompts, folders and skills. Save new versions of existing files. Upload attachments. Rename, move and archive. Nothing it does destroys content, and every write is a version you can roll back. The full list is in [The MCP tools](https://factor.in/docs/mcp-tools/index.md).

## Disconnect

Open **Connected apps** in your settings and revoke the connection. That ends every session ChatGPT holds. Removing the app in ChatGPT alone leaves the grant in place until you revoke it here.

## If it does not connect

- **There is no "Create MCP app" option.** Developer mode is off. Turn it on in Settings. Where the toggle sits differs between a personal account and a workspace.
- **ChatGPT says the connection failed with no detail.** The URL has to match byte for byte: `https`, the host `connect.factorin.com`, the path `/mcp`, no trailing slash.
- **ChatGPT connects but sees no libraries.** Your plan has lapsed or the library is past its first 7 days without one. The library is still readable in the web app and still exports whole. Choose a plan and the connection comes back.