Call media streaming lets Wavix customers send live call audio to another application using a WebSocket connection. You can stream inbound and outbound audio in real time for seamless integration with AI voice assistants, large language models (LLMs), and other applications. Wavix supports unidirectional and bidirectional call media streaming.

Wavix call media streaming is exclusively available for the Flex Pro account level.

Streaming types

Unidirectional streaming

Your application receives call audio but can’t send audio back to Wavix. You can stream:

Inbound audio (to Wavix)
Outbound audio (from Wavix)
Both channels

Bidirectional streaming

Your application can both receive and send audio over the same WebSocket connection. Wavix plays the audio you send directly into the call, which is useful for real-time AI conversations.

With bidirectional media streaming, your application can only receive the inbound audio stream.

Prerequisites

Create a Wavix account

Sign up for a Wavix account using your business email address.
Confirm your email address and phone number during the sign-up process.
Wait for your account to be approved by the Wavix team.
After approval, choose either the Wavix Flex or Flex Pro account level.

Once your account is approved, you can access the Wavix app and APIs.

Get your API key

Wavix uses API keys to authenticate requests. To find API keys associated with your account:

Sign in to your Wavix account.
Go to Administration → API Keys.
Copy the API key you want to use, or create a new one by clicking Create new.

Call media streaming flow

To stream raw call audio, follow these steps:

Subscribe to call events.
Initiate or answer a call programmatically.
Start the call media streaming.
Stop the call media streaming.

To receive all call-related events, Wavix recommends subscribing to both inbound and outbound call events. To subscribe to outbound call events, include your webhook URL in the status_callback parameter of the Initiate outbound call request. To receive inbound call events, assign a call status callback URL to your phone number using the Wavix Phone numbers API or GUI.

2. Initiate or answer a call programmatically

To start an outbound call, use the following method

Initiate an outbound call

    curl -L -X POST https://api.wavix.com/v1/call?appid=your_api_key 
      -H 'Content-Type: application/json' 
      -d '{
            "from": "Caller ID",
            "to": "Destination number",
            "status_callback": "Call status endpoint URL"
          }'

your_api_key: Your Wavix API key.
from: Caller ID the will be used. Must be an active or verified number in your Wavix account.
to: Destination phone number. The number must be present in international E.164 format.
status_callback: A webhook URL to post call events to.

If successful, the method returns HTTP 200 OK and a unique call identifier. To answer an inbound call, use the following method

Answer an inbound call

    curl -L -X POST https://api.wavix.com/v1/call/{{call_id}}/answer?appid=your_api_key  

your_api_key: Your Wavix API key.
call_id: Unique identifier of the call which you received on your webhook assigned to a phone number.

Optionally, paste the following JSON into the request body to start streaming immediately.

{
  "stream_channel": "The channel you want to stream",
  "stream_type": "oneway or twoway streaming",
  "stream_url": "WebSocket URL"
}

stream_channel: Indicates what call channel should be streamed. Can beinbound, outbound, or both
stream_type: Can be ‘oneway’ for unidirectional or ‘twoway’ for bidirectional call media streaming.
stream_url: WebSocket URL to which the inbound call media will be streamed (must start with ws or wss).

If successful, the method returns HTTP 200 OK and a success indicator. Streaming starts right away.

3. Start call media streaming

Wait until the call is answered before starting media streaming. To start the streaming, use the following method

Start call streaming

    curl -L -X POST https://api.wavix.com/v1/call/{{id}}/streams?appid=your_api_key
      -H 'Content-Type: application/json' 
      -d '{
            "stream_channel": "The channel you want to stream",
            "stream_type": "oneway or twoway streaming",
            "stream_url": "WebSocket URL"
            }'

your_api_key: Your Wavix API key.
stream_channel: Indicates what call channel should be streamed. Can beinbound, outbound, or both
stream_type: Can be ‘oneway’ for unidirectional or ‘twoway’ for bidirectional call media streaming.
stream_url: WebSocket URL to which the inbound call media will be streamed (must start with ws or wss).

All parameters are mandatory.

With bidirectional media streaming, your application can only receive the inbound audio stream.

If successful, the method returns HTTP 200 OK. The response will contain a unique stream identifier.

You can only have a single bidirectional and up to 5 unidirectional streams for a single call.

4. Stop call media streaming

Call media streaming is automatically stopped when the call is completed. To stop it programmatically use the following method

Stop call streaming

    curl -L -g -X DELETE 'https://api.wavix.com/v1/call/answer/{{call_id}}/streams/{{stream_id}}?appid=your_api_key'

your_api_key: Your Wavix API key.
call_id: Unique identifier of the call.
stream_id: Unique identifier of the stream.

If successful, the method returns HTTP 200 OK and a success indicator.

Call media streaming events

While streaming a call, Wavix sends messages to your WebSocket server. For bidirectional streaming, your server can also send messages back to Wavix.

WebSocket messages from Wavix

Wavix sends the following message to your WebSocket server while streaming a call.

`connected`

Sent once the connection is established.

{
  "event": "connected",
  "event_time": "Date and time of the event"
}

`start`

Sent before media streaming begins. Contains stream metadata.

{
  "event": "start",
  "event_time": "Date and time of the event",
  "call_id": "Unique identifier of the call",
  "stream_id": "Unique identifier of the stream",
  "stream_type": "oneway/twoway",
  "channel": "inbound/outbound",
  "sequence_number": "Message order number"
}

`media`

Contains audio chunks streamed to your WebSocket server.

{
  "event": "media",
  "event_time": "Date and time of the event",
  "call_id": "Unique identifier of the call",
  "stream_id": "Unique identifier of the stream",
  "sequence_number": "Message order number",
  "media": {
    "payload": "base64 encoded audio payload",
    "track": "inbound/outbound",
    "timestamp": "Milliseconds from stream start",
    "chunk": "Chunk number"
  }
}

`stop`

Sent when streaming is stopped or the call ends.

{
  "event": "stop",
  "event_time": "Date and time of the event",
  "call_id": "Unique identifier of the call",
  "stream_id": "Unique identifier of the stream",
  "sequence_number": "Message order number"
}

`mark`

Acknowledges that the previous media message finished playing. Only used in bidirectional call streaming.

{
  "event": "mark",
  "event_time": "Date and time of the event",
  "call_id": "Unique identifier of the call",
  "stream_id": "Unique identifier of the stream",
  "sequence_number": "Message order number",
  "mark": {
    "name": "Name of the mark message"
  }
}

WebSocket messages to Wavix

When using bidirectional streaming, your server can send these messages to Wavix to play audio back into the call and control the stream flow.

`media`

Send audio chunks from your server to Wavix.

{
  "event": "media",
  "stream_id": "Unique identifier of the stream",
  "media": {
    "payload": "base64 encoded audio payload"
  }
}

`mark`

You can send the mark message after sending media to request notification when the audio chunk has been played. Wavix responds with the mark message with a matching name when the audio ends (or if there is no audio buffered).

{
  "event": "mark",
  "stream_id": "Unique identifier of the stream",
  "mark": {
    "name": "Name of the mark message"
  }
}

`clear`

You can send the clear message to interrupt previously sent audio and empty all buffered audio. This causes any queued mark message to be sent back to your WebSocket server.

{
  "event": "clear",
  "stream_id": "Unique identifier of the stream"
}

Getting started

Messaging

Voice

Numbers

Stream calls with WebSocket

Streaming types

Unidirectional streaming

Bidirectional streaming

Prerequisites

Create a Wavix account

Get your API key

Call media streaming flow

2. Initiate or answer a call programmatically

3. Start call media streaming

4. Stop call media streaming

Call media streaming events

WebSocket messages from Wavix

`connected`

`start`

`media`

`stop`

`mark`

WebSocket messages to Wavix

`media`

`mark`

`clear`

Getting started

Messaging

Voice

Numbers

​Streaming types

​Unidirectional streaming

​Bidirectional streaming

​Prerequisites

​Create a Wavix account

​Get your API key

​Call media streaming flow

​1. Subscribe to call events

​2. Initiate or answer a call programmatically

​3. Start call media streaming

​4. Stop call media streaming

​Call media streaming events

​WebSocket messages from Wavix

​connected

​start

​media

​stop

​mark

​WebSocket messages to Wavix

​media

​mark

​clear

Streaming types

Unidirectional streaming

Bidirectional streaming

Prerequisites

Create a Wavix account

Get your API key

Call media streaming flow

1. Subscribe to call events

2. Initiate or answer a call programmatically

3. Start call media streaming

4. Stop call media streaming

Call media streaming events

WebSocket messages from Wavix

`connected`

`start`

`media`

`stop`

`mark`

WebSocket messages to Wavix

`media`

`mark`

`clear`