---
name: telnyx-voice-streaming-java
description: >-
  Stream call audio in real-time, fork media to external destinations, and
  transcribe speech live. Use for real-time analytics and AI integrations. This
  skill provides Java SDK examples.
metadata:
  author: telnyx
  product: voice-streaming
  language: java
  generated_by: telnyx-ext-skills-generator
---

<!-- Auto-generated from Telnyx OpenAPI specs. Do not edit. -->

# Telnyx Voice Streaming - Java

## Installation

```text
<!-- Maven -->
<dependency>
    <groupId>com.telnyx.sdk</groupId>
    <artifactId>telnyx</artifactId>
    <version>6.36.0</version>
</dependency>

// Gradle
implementation("com.telnyx.sdk:telnyx:6.36.0")
```

## Setup

```java
import com.telnyx.sdk.client.TelnyxClient;
import com.telnyx.sdk.client.okhttp.TelnyxOkHttpClient;

TelnyxClient client = TelnyxOkHttpClient.fromEnv();
```

All examples below assume `client` is already initialized as shown above.

## Error Handling

All API calls can fail with network errors, rate limits (429), validation errors (422),
or authentication errors (401). Always handle errors in production code:

```java
import com.telnyx.sdk.errors.TelnyxServiceException;

try {
    var result = client.messages().send(params);
} catch (TelnyxServiceException e) {
    System.err.println("API error " + e.statusCode() + ": " + e.getMessage());
    if (e.statusCode() == 422) {
        System.err.println("Validation error — check required fields and formats");
    } else if (e.statusCode() == 429) {
        // Rate limited — wait and retry with exponential backoff
        Thread.sleep(1000);
    }
}
```

Common error codes: `401` invalid API key, `403` insufficient permissions,
`404` resource not found, `422` validation error (check field formats),
`429` rate limited (retry with exponential backoff).

## Forking start

Call forking allows you to stream the media from a call to a specific target in realtime. This stream can be used to enable realtime audio analysis to support a 
variety of use cases, including fraud detection, or the creation of AI-generated audio responses. Requests must specify either the `target` attribute or the `rx` and `tx` attributes.

`POST /calls/{call_control_id}/actions/fork_start`

Optional: `client_state` (string), `command_id` (string), `rx` (string), `stream_type` (enum: decrypted), `tx` (string)

```java
import com.telnyx.sdk.models.calls.actions.ActionStartForkingParams;
import com.telnyx.sdk.models.calls.actions.ActionStartForkingResponse;

ActionStartForkingResponse response = client.calls().actions().startForking("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ");
```

Returns: `result` (string)

## Forking stop

Stop forking a call. **Expected Webhooks:**

- `call.fork.stopped`

`POST /calls/{call_control_id}/actions/fork_stop`

Optional: `client_state` (string), `command_id` (string), `stream_type` (enum: raw, decrypted)

```java
import com.telnyx.sdk.models.calls.actions.ActionStopForkingParams;
import com.telnyx.sdk.models.calls.actions.ActionStopForkingResponse;

ActionStopForkingResponse response = client.calls().actions().stopForking("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ");
```

Returns: `result` (string)

## Streaming start

Start streaming the media from a call to a specific WebSocket address or Dialogflow connection in near-realtime. Audio will be delivered as base64-encoded RTP payload (raw audio), wrapped in JSON payloads. Please find more details about media streaming messages specification under the [link](https://developers.telnyx.com/docs/voice/programmable-voice/media-streaming).

`POST /calls/{call_control_id}/actions/streaming_start`

Optional: `client_state` (string), `command_id` (string), `custom_parameters` (array[object]), `dialogflow_config` (object), `enable_dialogflow` (boolean), `stream_auth_token` (string), `stream_bidirectional_codec` (enum: PCMU, PCMA, G722, OPUS, AMR-WB, L16), `stream_bidirectional_mode` (enum: mp3, rtp), `stream_bidirectional_sampling_rate` (enum: 8000, 16000, 22050, 24000, 48000), `stream_bidirectional_target_legs` (enum: both, self, opposite), `stream_codec` (enum: PCMU, PCMA, G722, OPUS, AMR-WB, L16, default), `stream_track` (enum: inbound_track, outbound_track, both_tracks), `stream_url` (string)

```java
import com.telnyx.sdk.models.calls.actions.ActionStartStreamingParams;
import com.telnyx.sdk.models.calls.actions.ActionStartStreamingResponse;

ActionStartStreamingResponse response = client.calls().actions().startStreaming("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ");
```

Returns: `result` (string)

## Streaming stop

Stop streaming a call to a WebSocket. **Expected Webhooks:**

- `streaming.stopped`

`POST /calls/{call_control_id}/actions/streaming_stop`

Optional: `client_state` (string), `command_id` (string), `stream_id` (uuid)

```java
import com.telnyx.sdk.models.calls.actions.ActionStopStreamingParams;
import com.telnyx.sdk.models.calls.actions.ActionStopStreamingResponse;

ActionStopStreamingResponse response = client.calls().actions().stopStreaming("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ");
```

Returns: `result` (string)

## Transcription start

Start real-time transcription. Transcription will stop on call hang-up, or can be initiated via the Transcription stop command. **Expected Webhooks:**

- `call.transcription`

`POST /calls/{call_control_id}/actions/transcription_start`

Optional: `client_state` (string), `command_id` (string), `transcription_engine` (enum: Google, Telnyx, Deepgram, Azure, A, B), `transcription_engine_config` (object), `transcription_tracks` (string)

```java
import com.telnyx.sdk.models.calls.actions.ActionStartTranscriptionParams;
import com.telnyx.sdk.models.calls.actions.ActionStartTranscriptionResponse;
import com.telnyx.sdk.models.calls.actions.TranscriptionStartRequest;

ActionStartTranscriptionParams params = ActionStartTranscriptionParams.builder()
    .callControlId("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ")
    .transcriptionStartRequest(TranscriptionStartRequest.builder().build())
    .build();
ActionStartTranscriptionResponse response = client.calls().actions().startTranscription(params);
```

Returns: `result` (string)

## Transcription stop

Stop real-time transcription.

`POST /calls/{call_control_id}/actions/transcription_stop`

Optional: `client_state` (string), `command_id` (string)

```java
import com.telnyx.sdk.models.calls.actions.ActionStopTranscriptionParams;
import com.telnyx.sdk.models.calls.actions.ActionStopTranscriptionResponse;

ActionStopTranscriptionResponse response = client.calls().actions().stopTranscription("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ");
```

Returns: `result` (string)

---

## Webhooks

### Webhook Verification

Telnyx signs webhooks with Ed25519. Each request includes `telnyx-signature-ed25519`
and `telnyx-timestamp` headers. Always verify signatures in production:

```java
import com.telnyx.sdk.core.UnwrapWebhookParams;
import com.telnyx.sdk.core.http.Headers;

// In your webhook handler (e.g., Spring — use raw body):
@PostMapping("/webhooks")
public ResponseEntity<String> handleWebhook(
    @RequestBody String payload,
    HttpServletRequest request) {
  try {
    Headers headers = Headers.builder()
        .put("telnyx-signature-ed25519", request.getHeader("telnyx-signature-ed25519"))
        .put("telnyx-timestamp", request.getHeader("telnyx-timestamp"))
        .build();
    var event = client.webhooks().unwrap(
        UnwrapWebhookParams.builder()
            .body(payload)
            .headers(headers)
            .build());
    // Signature valid — process the event
    System.out.println("Received webhook event");
    return ResponseEntity.ok("OK");
  } catch (Exception e) {
    System.err.println("Webhook verification failed: " + e.getMessage());
    return ResponseEntity.badRequest().body("Invalid signature");
  }
}
```

The following webhook events are sent to your configured webhook URL.
All webhooks include `telnyx-timestamp` and `telnyx-signature-ed25519` headers for Ed25519 signature verification. Use `client.webhooks.unwrap()` to verify.

| Event | Description |
|-------|-------------|
| `callForkStarted` | Call Fork Started |
| `callForkStopped` | Call Fork Stopped |
| `callStreamingFailed` | Call Streaming Failed |
| `callStreamingStarted` | Call Streaming Started |
| `callStreamingStopped` | Call Streaming Stopped |
| `transcription` | Transcription |

### Webhook payload fields

**`callForkStarted`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the type of the resource. |
| `data.event_type` | enum: call.fork.started | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |
| `data.payload.call_control_id` | string | Unique ID for controlling the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | State received from a command. |
| `data.payload.stream_type` | enum: decrypted | Type of media streamed. |

**`callForkStopped`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the type of the resource. |
| `data.event_type` | enum: call.fork.stopped | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |
| `data.payload.call_control_id` | string | Unique ID for controlling the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | State received from a command. |
| `data.payload.stream_type` | enum: decrypted | Type of media streamed. |

**`callStreamingFailed`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the resource. |
| `data.event_type` | enum: streaming.failed | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.call_control_id` | string | Call ID used to issue commands via Call Control API. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | State received from a command. |
| `data.payload.failure_reason` | string | A short description explaning why the media streaming failed. |
| `data.payload.stream_id` | uuid | Identifies the streaming. |
| `data.payload.stream_type` | enum: websocket, dialogflow | The type of stream connection the stream is performing. |

**`callStreamingStarted`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the type of the resource. |
| `data.event_type` | enum: streaming.started | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.call_control_id` | string | Call ID used to issue commands via Call Control API. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | State received from a command. |
| `data.payload.stream_url` | string | Destination WebSocket address where the stream is going to be delivered. |

**`callStreamingStopped`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the type of the resource. |
| `data.event_type` | enum: streaming.stopped | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.call_control_id` | string | Call ID used to issue commands via Call Control API. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | State received from a command. |
| `data.payload.stream_url` | string | Destination WebSocket address where the stream is going to be delivered. |

**`transcription`**

| Field | Type | Description |
|-------|------|-------------|
| `data.record_type` | enum: event | Identifies the type of the resource. |
| `data.event_type` | enum: call.transcription | The type of event being delivered. |
| `data.id` | uuid | Identifies the type of resource. |
| `data.occurred_at` | date-time | ISO 8601 datetime of when the event occurred. |
| `data.payload.call_control_id` | string | Unique identifier and token for controlling the call. |
| `data.payload.call_leg_id` | string | ID that is unique to the call and can be used to correlate webhook events. |
| `data.payload.call_session_id` | string | ID that is unique to the call session and can be used to correlate webhook events. |
| `data.payload.client_state` | string | Use this field to add state to every subsequent webhook. |
| `data.payload.connection_id` | string | Call Control App ID (formerly Telnyx connection ID) used in the call. |