Simon Willison first-party · 6h ago · 2/5
A pelican for GPT-5.5 via the semi-official Codex backdoor API ↗
Simon Willison has released llm-openai-via-codex, a new plugin for the LLM command-line tool that allows users to access GPT-5.5 through their existing OpenAI Codex subscription. The plugin leverages OpenAI's official support for third-party integrations with the Codex API, as confirmed by OpenAI's Romain Huet in March. Willison demonstrated the tool by generating SVG pelican images, showing GPT-5.5's capability with extended reasoning tokens.
We want people to be able to use Codex, and their ChatGPT subscription, wherever they like! That means in the app, in the terminal, but also in JetBrains, Xcode, OpenCode, Pi, and now Claude Code.
I ask it to build things and it builds exactly what I ask for!