Client-VAD speech segments

Use [Segment Transcription](/docs/api-reference/segment-transcription) when your application already knows where speech starts and ends.

When to use Segment

| Use Segment | Use something else | |---|---| | You run VAD locally and upload one clip per utterance | Continuous mic stream → [Realtime WS](/docs/realtime) | | You need a synchronous transcript in ~1s | Long file at a URL → [Batch jobs](/docs/recorded/transcribe-audio) | | OpenAI Whisper file upload pattern | Server should detect silence → Realtime WS |

Contract

1. You segment — only POST clips that contain speech you want transcribed. 2. We do not filter — silence, near-empty WAVs, and noise are transcribed as-is. 3. You pay for what you send — wasting quota on silence is the caller's responsibility. 4. No server HTTP retry — up to 2 worker attempts (800ms each) per request; on 502 the client may resend the same clip.

Typical flow

Client VAD detects utterance end
  → encode clip (e.g. WAV)
  → POST /v1/audio/transcriptions (multipart)
  → 200 + text (or 502 → client decides to retry)

Integrators like Flow follow this pattern: WebSocket voice session → local VAD → HTTP segment per utterance.

Example

curl -X POST https://audio.lansonai.com/v1/audio/transcriptions \
  -H "Authorization: Bearer sk-..." \
  -F "file=@utterance.wav" \
  -F "language=zh"

Anti-patterns

Uploading a full meeting recording to Segment — use batch audio_url instead.

Streaming continuous PCM to Segment — use Realtime WS.

Expecting the API to skip silence — it will not.

[Segment API reference](/docs/api-reference/segment-transcription)

[Choose an API](/docs/start/choose-an-api)