AssemblyAI launches Sync API: full transcript in a single HTTP call, ~134ms latency
AssemblyAI introduced the Sync API, a new transport for transcribing short audio clips: one HTTP POST request returns a finished Universal-3.5 Pro transcript in the same response, at roughly 134ms median latency. It fills the gap between the Async API (submit-and-poll, 5-6 seconds of added latency) and the Realtime API (WebSocket, built for ongoing sessions), targeting workloads like dictation, voice-agent turn transcription, IVR, and push-to-talk. Clips from 80ms to 2 minutes and up to 40MB are supported, with word error rate of 1.59% on short-form audio. Pricing is $0.45/hr, the same rate as Universal-3.5 Pro Realtime.