Connect MCP Omie to your AI assistant

MCP Omie is a remote MCP server (Model Context Protocol): it works with AI assistants that accept MCP connectors. The steps are the same in any compatible assistant — only the menu names change; below is where each thing is in the most used ones.

What the assistant must support

A remote MCP connector (server), reached at an https:// address — not only local servers;
sign-in with OAuth, with fields for the OAuth Client ID and Client Secret.

For security, sign-in only hands access back to assistants your firm has enabled. Whoever administers the client picks them in the client area, under AI assistants, among the most used — Claude, ChatGPT, VS Code / GitHub Copilot, Cursor, Claude Code, Gemini CLI — and may enable another one by entering the return address (redirect URI) it shows. New firms start with Claude enabled.

1. Get the connector's values

Open the client area and sign in with the Google account of the e-mail your firm invited. Connect to your AI assistant shows three values, each with a copy button:

Connector URL — usually https://mcp-omie.damasiormoura.org/mcp;
OAuth Client ID;
OAuth Client Secret — treat it like a password: do not publish it or send it over an open chat.

2. Add the connector in the assistant

Open your assistant's connectors (or MCP servers) settings.
Choose to add a custom connector / remote MCP server.
Give it a name (for example, Omie) and paste the Connector URL.
In the authentication (OAuth) options, paste the OAuth Client ID and Client Secret.
Save and connect.

In each assistant

Claude: On claude.ai → Settings → Connectors → Add custom connector: give it a name and paste the URL; the ID and secret are under Advanced settings. The connector also shows up in Claude Desktop and the apps.
ChatGPT: In ChatGPT → Settings → Apps, turn on developer mode and create an app: paste the URL and choose OAuth authentication; under Advanced settings, pick User-defined OAuth client and paste the ID and secret.
VS Code / GitHub Copilot: In the command palette, MCP: Add Server → HTTP, paste the URL and give it a name. When VS Code asks, enter the client ID and then the secret.
Cursor: In Settings → MCP, open mcp.json and add the server below, pasting the secret where indicated.
Claude Code: In a terminal, run the command below; it then asks for the secret without showing it. Then, in a session, use /mcp to sign in.
Gemini CLI: In Gemini CLI's settings.json, add the server below, pasting the secret where indicated. Then, in a session, use /mcp auth omie to sign in.

For Cursor, Claude Code and Gemini CLI, the client area shows the command or configuration already filled in with your URL and ID, ready to copy. On Claude Team and Enterprise plans, an administrator of your organization may need to add the connector first. Menu names may vary between versions.

3. Sign in and authorize

The assistant opens MCP Omie's sign-in page: choose Google and use the account of the invited e-mail.
Approve the access the connector asks for (name and e-mail only).
Back in the assistant, the connector shows as connected.

4. Use it in a chat

In a new chat, turn the connector on in the assistant's tools and ask, for example: "List the Omie companies I can access" or "What is due this week across all companies?". Operations that move money or issue a tax document show a preview and only happen after you confirm.

If something goes wrong

"Authorization failed" when connecting: remove the connector and add it again, checking the ID and secret. In Claude, Reconnect reuses the old values and does not fix it.
A return-address error (redirect_uri) on the sign-in page: your assistant has not been enabled yet — ask whoever administers your firm to enable it under AI assistants.
"Este conector não foi configurado com o ID do cliente OAuth de…" (this connector was not set up with your firm's client ID): the connector uses another firm's ID and secret. Each firm has its own — remove the connector and add it again with the values from the right firm's client area.
"Not registered in any client": the e-mail you signed in with was not invited. Ask whoever administers your firm to invite exactly that e-mail.
Other questions: [email protected].