Connect Codex

← Agents

Connect Codex to Monomer with your Google sign-in. You can use the desktop app without installing the CLI. On the same host, Codex’s desktop app, CLI, and IDE extension share MCP configuration. See the official Codex MCP guide for configuration options.

Desktop app

Open Codex settings and find MCPs under Plugins, or MCP servers, depending on your version.
Add a server named monomer, choose Streamable HTTP if a server type is requested, and enter:
```
https://api.monomer.cc/mcp
```
Leave the bearer-token and custom-header fields empty. Monomer uses browser sign-in.
Save and enable the server. Restart when offered, then use Authenticate if sign-in is requested. Complete the Monomer sign-in flow with the Google account you intend to use.
Open a new conversation and perform the Workspace check below.

CLI or IDE extension

In the IDE extension, open the MCP server settings and add the same name and URL, then authenticate. If you use the CLI, run:

codex mcp add monomer --url https://api.monomer.cc/mcp
codex mcp login monomer --oauth-client-registration cimd

Complete browser authorization. If the server was already added on this host, skip the add command. In the CLI, /mcp shows configured servers; verify actual access with the prompt below.

Verify Workspace access

Paste this into a new Codex conversation:

Use Monomer to list the workspaces I can access. Make a real authenticated
request, not just a check that tools are available. Show each workspace's
name and ID, and wait for me to choose one. Do not change anything.

Choose a returned Workspace, then ask:

Use the workspace I selected. List its connectors and metrics without
changing anything. If a list is empty, say so.

A successful Workspace response followed by these resource listings verifies access. Empty lists are normal in a new Workspace. Seeing tools alone does not verify sign-in or data access.

Continue with Quick start to connect a warehouse and create an analysis and dashboard with Codex.

If connection fails

Tools appear but calls require authentication: use the server’s authenticate action, finish the browser flow, and repeat the Workspace check in a new conversation.
The wrong account or Workspace appears: check the Google account used during Monomer authorization. For a CLI-managed connection, codex mcp logout monomer clears its saved login; run the login command again with the intended account. This also affects clients using that same saved connection on the host.
No Authenticate action, or a registration error: follow the connection troubleshooting guide. If you already use the CLI, the explicit CIMD login command above is another way to start authorization. Installing the CLI is not required for the desktop setup.

If you remain blocked, contact Monomer with your Codex version and the failed step. Do not include tokens, cookies, or warehouse credentials.

After connecting, follow Direct your agent to read resources, follow availableOperations, and fetch input schemas with monomer_describe.