Using Hydracept for ChatGPT and Codex

The ChatGPT Apps/Connectors and Codex remote MCP endpoint is https://api.hydracept.com/mcp/openai. When ChatGPT or Codex asks you to sign in, use your Hydracept account and choose Allow. That connection is OAuth. Do not paste a Hydracept API key. This URL rejects API keys.

This connection includes text, reasoning, structured execution, jobs, quoting, and receipts. It does not generate images, video, audio, or 3D.

ChatGPT custom MCP (before directory listing)

1. Open ChatGPT Plugins and choose Add custom MCP server.
2. Enter MCP server URL https://api.hydracept.com/mcp/openai.
3. Choose OAuth authentication and complete the browser sign-in.
4. Create as a plugin, then install it and type @Hydracept in a new chat.

Codex CLI remote MCP

codex mcp add hydracept --url https://api.hydracept.com/mcp/openai
codex mcp login hydracept

Codex discovers OAuth (DCR + PKCE S256). Do not pass --bearer-token-env-var for this endpoint. Loopback callback URLs such as http://127.0.0.1/callback are accepted when Codex registers them during login.

Plugin package

Portable Agent Plugins packaging for the shared ChatGPT/Codex directory lives in zencodeinc/hydracept-public under public/agents/openai. Public directory submission is separate and is not complete until OpenAI reviews and publishes the plugin.

The full hosted catalog is a separate install at https://api.hydracept.com/mcp. That install uses a Hydracept API key as a bearer token, and it is not the ChatGPT/Codex directory listing. Add it only when you need image, video, audio, 3D, or the rest of the public catalog.