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Connect Agent Nexus to OpenAI Codex CLI

Add Agent Nexus to Codex as a streamable HTTP MCP server.

  1. 1. Edit ~/.codex/config.toml

    Add the server block, then restart Codex.

    [mcp_servers.agent-nexus]
url = "https://agentnexus.app/mcp"

  2. 2. Check it loaded

    Inside Codex, run /mcp to list connected servers.

    /mcp

Test it

Ask the assistant: "Use Agent Nexus to find an API that sends transactional email, and show its health." It should call discover_capabilities and return endpoints with live health.

Reads need no key. For 1,000 calls/day, get a free key. Official docs: https://github.com/openai/codex