AsyncAPI channel · StepFun
· StepFun Realtime Voice & Streaming TTS WebSocket API
/v1/realtime/audio
Streaming text-to-speech channel (model selected via ?model=, e.g. step-tts-mini).
Channel address
/v1/realtime/audio
Operations
send
streamingTts
Streaming text-to-speech synthesis.
Messages
tts.create
Client creates a TTS synthesis session.
Content-Type:
tts.connection.done
Server confirms the TTS connection.
Content-Type:
tts.text.delta
Client streams text to synthesize.
Content-Type:
tts.text.done
Client signals end of text input.
Content-Type:
tts.text.flush
Client forces synthesis of buffered text.
Content-Type:
tts.text.flushed
Server acknowledges the flush.
Content-Type:
tts.response.created
Server starts a synthesis response.
Content-Type:
tts.response.audio.delta
Incremental synthesized audio.
Content-Type:
tts.response.audio.done
Synthesized audio complete.
Content-Type:
tts.response.sentence.start
Sentence boundary start marker.
Content-Type:
tts.response.sentence.end
Sentence boundary end marker.
Content-Type:
tts.response.subtitle
Subtitle/timestamp payload for synthesized audio.
Content-Type:
tts.response.error
Synthesis error event.
Content-Type:
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.
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