Codex

The Agent Plugin does not install in Codex or ChatGPT yet. Point Codex at the hosted MCP server with the same entry you would give Cursor:

{
  "mcpServers": {
    "cosmic": {
      "url": "https://mcp.cosmicjs.com/v1/buckets/your-bucket-slug",
      "headers": {
        "Authorization": "Bearer your-read-key:your-write-key"
      }
    }
  }
}

Drop :your-write-key for read-only tools. The key rules are in MCP Server. Install the coding skill with:

npx skills add cosmicjs/skills

Put that JSON in the MCP config Codex reads for the project. If the client cannot attach an HTTP MCP server, it can still write code from the REST and SDK guides. Start it at AI onboarding and REST.