Telnyx Voice Media - Java

Installation

<!-- 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

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

TelnyxClient client = TelnyxOkHttpClient.fromEnv();

All examples below assume

client

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:

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

403

404

422

429

Play audio URL

Play an audio file on the call. If multiple play audio commands are issued consecutively, the audio files will be placed in a queue awaiting playback. Notes:

• When

  overlay

  is enabled,

  target_legs

  is limited to

  self

  .

POST /calls/{call_control_id}/actions/playback_start

Optional:

audio_type

audio_url

cache_audio

client_state

command_id

loop

media_name

overlay

playback_content

stop

target_legs

import com.telnyx.sdk.models.calls.actions.ActionStartPlaybackParams;
import com.telnyx.sdk.models.calls.actions.ActionStartPlaybackResponse;

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

Returns:

result

Stop audio playback

Stop audio being played on the call. Expected Webhooks:

• call.playback.ended

  or

  call.speak.ended

POST /calls/{call_control_id}/actions/playback_stop

Optional:

client_state

command_id

overlay

stop

import com.telnyx.sdk.models.calls.actions.ActionStopPlaybackParams;
import com.telnyx.sdk.models.calls.actions.ActionStopPlaybackResponse;

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

Returns:

result

Record pause

Pause recording the call. Recording can be resumed via Resume recording command. Expected Webhooks:

There are no webhooks associated with this command.

POST /calls/{call_control_id}/actions/record_pause

Optional:

client_state

command_id

recording_id

import com.telnyx.sdk.models.calls.actions.ActionPauseRecordingParams;
import com.telnyx.sdk.models.calls.actions.ActionPauseRecordingResponse;

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

Returns:

result

Record resume

Resume recording the call. Expected Webhooks:

There are no webhooks associated with this command.

POST /calls/{call_control_id}/actions/record_resume

Optional:

client_state

command_id

recording_id

import com.telnyx.sdk.models.calls.actions.ActionResumeRecordingParams;
import com.telnyx.sdk.models.calls.actions.ActionResumeRecordingResponse;

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

Returns:

result

Recording start

Start recording the call. Recording will stop on call hang-up, or can be initiated via the Stop Recording command. Expected Webhooks:

• call.recording.saved

• call.recording.transcription.saved

• call.recording.error

POST /calls/{call_control_id}/actions/record_start

format

channels

Optional:

client_state

command_id

custom_file_name

max_length

play_beep

recording_track

timeout_secs

transcription

transcription_engine

transcription_language

transcription_max_speaker_count

transcription_min_speaker_count

transcription_profanity_filter

transcription_speaker_diarization

trim

import com.telnyx.sdk.models.calls.actions.ActionStartRecordingParams;
import com.telnyx.sdk.models.calls.actions.ActionStartRecordingResponse;

ActionStartRecordingParams params = ActionStartRecordingParams.builder()
    .callControlId("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ")
    .channels(ActionStartRecordingParams.Channels.SINGLE)
    .format(ActionStartRecordingParams.Format.WAV)
    .build();
ActionStartRecordingResponse response = client.calls().actions().startRecording(params);

Returns:

result

Recording stop

Stop recording the call. Expected Webhooks:

• call.recording.saved

POST /calls/{call_control_id}/actions/record_stop

Optional:

client_state

command_id

recording_id

import com.telnyx.sdk.models.calls.actions.ActionStopRecordingParams;
import com.telnyx.sdk.models.calls.actions.ActionStopRecordingResponse;
import com.telnyx.sdk.models.calls.actions.StopRecordingRequest;

ActionStopRecordingParams params = ActionStopRecordingParams.builder()
    .callControlId("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ")
    .stopRecordingRequest(StopRecordingRequest.builder().build())
    .build();
ActionStopRecordingResponse response = client.calls().actions().stopRecording(params);

Returns:

result

Speak text

Convert text to speech and play it back on the call. If multiple speak text commands are issued consecutively, the audio files will be placed in a queue awaiting playback. Expected Webhooks:

• call.speak.started

• call.speak.ended

POST /calls/{call_control_id}/actions/speak

payload

voice

Optional:

client_state

command_id

language

loop

payload_type

service_level

stop

target_legs

voice_settings

import com.telnyx.sdk.models.calls.actions.ActionSpeakParams;
import com.telnyx.sdk.models.calls.actions.ActionSpeakResponse;

ActionSpeakParams params = ActionSpeakParams.builder()
    .callControlId("v3:550e8400-e29b-41d4-a716-446655440000_gRU1OGRkYQ")
    .payload("Say this on the call")
    .voice("female")
    .language("en-US")
    .build();
ActionSpeakResponse response = client.calls().actions().speak(params);

Returns:

result

Webhooks

Webhook Verification

Telnyx signs webhooks with Ed25519. Each request includes

telnyx-signature-ed25519

telnyx-timestamp

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

telnyx-signature-ed25519

client.webhooks.unwrap()

callPlaybackEnded

callPlaybackStarted

callRecordingError

callRecordingSaved

callRecordingTranscriptionSaved

callSpeakEnded

callSpeakStarted

Webhook payload fields

callPlaybackEnded

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state

data.payload.media_url

data.payload.media_name

data.payload.overlay

data.payload.status

data.payload.status_detail

callPlaybackStarted

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state

data.payload.media_url

data.payload.media_name

data.payload.overlay

callRecordingError

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state

data.payload.reason

callRecordingSaved

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_leg_id

data.payload.call_session_id

data.payload.connection_id

data.payload.client_state

data.payload.recording_started_at

data.payload.recording_ended_at

data.payload.channels

single

dual

callRecordingTranscriptionSaved

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state

data.payload.calling_party_type

data.payload.recording_id

data.payload.recording_transcription_id

data.payload.status

data.payload.transcription_text

callSpeakEnded

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state

data.payload.status

callSpeakStarted

data.record_type

data.event_type

data.id

data.occurred_at

data.payload.call_control_id

data.payload.connection_id

data.payload.call_leg_id

data.payload.call_session_id

data.payload.client_state