Access OpenAI models via an existing Codex subscription

Apparently this is OK! There's more background on my blog.

Install this plugin in the same environment as LLM.

llm install llm-openai-via-codex

First, make sure you have installed and authenticated OpenAI Codex CLI.

To see the models available via your Codex subscription run:

llm models -q openai-codex

To run a prompt against one of those models:

llm -m openai-codex/gpt-5.5 'Generate an SVG of a pelican riding a bicycle'

To set up this plugin locally, first checkout the code. Run the tests using uv:

cd llm-openai-via-codex
uv run pytest

To run LLM with the dev plugin installed:

uv run llm -m models
uv run llm -m openai-codex/gpt-5.5 'Talk to me in Swedish'