Simon Willison’s Weblog

OpenAI WebRTC Audio Session, now with document context. I built the first version of this tool in December 2024 to try out the then-new OpenAI WebRTC API for interacting with their realtime audio models.

Last month OpenAI introduced a brand new model to that API called GPT‑Realtime‑2, which they promoted as "our first voice model with GPT‑5‑class reasoning" - with a Sep 30, 2024 knowledge cut-off.

I've been waiting for that model to show up in the ChatGPT iPhone app but it still hasn't, so I revisited my old playground.

You can now pick the better model, and you can also paste in a big chunk of document context so you can have as audio conversation in your browser about whatever information you think would be useful to explore in a conversational way.