Sinch Agentic Tools
Sinch SDKs
Sinch CLI & Functions
Sinch Voice API: Choosing between v1 and v2
For all new projects, please use Voice API v2. This is especially important for projects involving:
- AI capabilities like Streams and Voice Relay
- Voice campaigns like Batch calling
You should only use the older Voice API v1 if one of the following is a strict requirement:
- The project must be in General Availability (GA).
- The project requires In-App voice or Conferencing (until these features are available in v2).
Raw PCM (Pulse Code Modulation) audio bytes transmitted as a binary WebSocket frame.
Format: 16-bit signed linear PCM, mono (single channel), little-endian byte order.
Frame size: Audio should be sent in 20ms chunks. At 8 kHz this is 320 bytes per frame (160 samples × 2 bytes); at 16 kHz it is 640 bytes per frame. Larger chunks are accepted but increase latency.
The sample rate is determined by the value specified in the SVAML connectStream command. Raw PCM audio bytes sent as a WebSocket binary message