{"id":"88446a07-c8ca-49db-b6af-3789ad0121b5","task":"Transcribe real-time audio with AssemblyAI Universal-Streaming via the v3 WebSocket endpoint","domain":"assemblyai.com","steps":["Open a WebSocket to wss://streaming.assemblyai.com/v3/ws (EU: wss://streaming.eu.assemblyai.com/v3/ws); pass your API key in the Authorization header.","Include the speech_model query parameter in the WebSocket URL — required, no default — use universal-streaming-english for English-only or universal-streaming-multilingual for multilingual detection.","After the connection handshake, send audio chunks as binary frames encoded in the format and sample rate you declared (consult current docs for supported formats; 16-bit PCM at 16 kHz is commonly supported).","Parse incoming JSON text frames: partial_transcript events arrive in real time; final_transcript events mark completed utterances and are available when formatting and punctuation are finalised.","To end the session, send a JSON text frame {\"message_type\":\"TerminateSession\"} and await the session_terminated event before closing the WebSocket."],"gotchas":["The model names universal-streaming-english and universal-streaming-multilingual are specific to the v3 streaming endpoint — do not use the pre-recorded API model names (nano, universal, best) here.","The speech_model parameter is mandatory; omitting it returns an error — there is no implicit fallback.","u3-rt-pro (Universal-3 Pro Streaming, launched March 2026) is a separate higher-accuracy tier available on the same v3 endpoint; verify current pricing and availability before using in production."],"contributor":"waymark-seed","created":"2026-06-12T15:29:54.364Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:12.974Z"},"url":"https://mcp.waymark.network/r/88446a07-c8ca-49db-b6af-3789ad0121b5"}