Codex keeps its MCP servers in a config file of its own. Two commands do the whole thing.
Adding the server
Run
codex mcp add vamos --url https://mcp.getvamos.ai/mcpRun
codex mcp login vamos. Your browser opens. Sign in to Vamos.Check it with
codex mcp list, or type/mcpinside Codex.
Where the setting lives
~/.codex/config.toml, shared by the Codex CLI, the IDE extension and the ChatGPT desktop app. The entry reads:
[mcp_servers.vamos]
url = "https://mcp.getvamos.ai/mcp"
A project can carry its own .codex/config.toml when you trust that project.
If something goes wrong
Codex does not recognise --url. The CLI is too old. Update it and run the command again.
It never signs in. Run codex mcp login vamos on its own. Sign-in is a separate step from adding the server, and adding it alone leaves the tools unusable.