Introducing the Realtime API

OpenAI launched a public beta of the Realtime API on Oct. 1, 2024 for all paid developers, using a persistent WebSocket to stream low-latency speech-to-speech interactions with GPT-4o. It supports function calling and interruption handling, priced at $5/1M text input tokens and $100/1M audio input tokens; the post also says audio I/O for Chat Completions would arrive in the following weeks.

Why it matters: OpenAI moved voice apps from stitched ASR+TTS calls to a persistent GPT-4o session, with function calling, interruption handling, and published audio/token pricing. HKR-H/K/R all pass, so this is a same-day must-write developer platform update and clears p1.