A pelican for GPT-5.5 via the semi-official Codex backdoor API

Simon Willison Blog
Generative AI

GPT-5.5 is out. It's available in OpenAI Codex and is rolling out to paid ChatGPT rs. I've had some preview access and found it to be a fast, effective and highly capable model. As is usually the case these days, it's hard to put into words what's good about it - I ask it to build things and it builds exactly what I ask for! There's one notable omission from today's release - the API: API deployments require different safeguards and we are working closely with partners and customers on the safety and security requirements for serving it at scale.