Relmio

Using OpenAI models in self-hosted n8n normally requires a separate API key with pay-as-you-go billing. Relmio lets you use the ChatGPT and Codex access already available on your account instead.

Relmio is an open-source browser wizard that connects to your ChatGPT account through OAuth, safely checks your VPS and n8n setup, then installs a private bridge. It does not edit or restart your existing n8n container, and it does not expose the bridge publicly.

Once connected, n8n nodes such as OpenAI Chat Model, AI Agent, Basic LLM Chain, and HTTP Request can use account-supported Codex models, including gpt-5.6-sol, gpt-5.6-terra, and gpt-5.6-luna.

Relmio can also work with free ChatGPT accounts. For free accounts, the highest available tier is gpt-5.6-terra, but the usage quota is very limited. Available models and limits depend on your account and may change.

Relmio and the upstream openai-oauth project are unofficial community projects. They do not create an OpenAI Platform API key and are intended for personal and experimental workflows.