---
title: "Open the call audio WebSocket"
method: GET
path: "/v1/instance/{instance}/calls/{callID}/audio"
tags: ["Calls"]
---

# Open the call audio WebSocket

`GET /v1/instance/{instance}/calls/{callID}/audio`

## Request

- Base URL: `http://localhost:8080`
- URL: `http://localhost:8080/v1/instance/{instance}/calls/{callID}/audio`
- Auth: API key in header `apikey`

Upgrades to WebSocket. Each client-to-call and call-to-client binary message must be exactly 3,840 bytes: 960 little-endian float32 PCM samples, mono, 16 kHz (60 ms). No SDP, relay data, encrypted media, or call keys cross this boundary.

## Path parameters

- `instance` string, required
- `callID` string, required

## Other responses

- `101`: WebSocket Switching Protocols
- `401`: Unauthorized
- `404`: Not Found
- `503`: Service Unavailable

## Changes

- **2026-10-05** `a23d742d180b`: 1 info
  - added the non-success response with the status `503`
- **2026-07-18** `f812473c5a89`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/verbeux-ai/apis/whatsmiau-api/changes/v1/instance/:instance/calls/:callID/audio/get.md)

---

[API](https://skmtc.dev/verbeux-ai/apis/whatsmiau-api.md) - [All operations](https://skmtc.dev/verbeux-ai/apis/whatsmiau-api/llms.txt) - [OpenAPI document](https://skmtc.dev/verbeux-ai/apis/whatsmiau-api/revisions/b425ec589eb0?raw)