Telnyx Voice Gather Go

Telnyx Voice Gather - Go

Installation

go get github.com/team-telnyx/telnyx-go

Setup

import (
  "context"
  "fmt"
  "os"

  "github.com/team-telnyx/telnyx-go"
  "github.com/team-telnyx/telnyx-go/option"
)

client := telnyx.NewClient(
  option.WithAPIKey(os.Getenv("TELNYX_API_KEY")),
)

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:

import "errors"

result, err := client.Messages.Send(ctx, params)
if err != nil {
  var apiErr *telnyx.Error
  if errors.As(err, &apiErr) {
    switch apiErr.StatusCode {
    case 422:
      fmt.Println("Validation error — check required fields and formats")
    case 429:
      // Rate limited — wait and retry with exponential backoff
      fmt.Println("Rate limited, retrying...")
    default:
      fmt.Printf("API error %d: %s\n", apiErr.StatusCode, apiErr.Error())
    }
  } else {
    fmt.Println("Network error — check connectivity and retry")
  }
}

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).

Add messages to AI Assistant

Add messages to the conversation started by an AI assistant on the call.

POST /calls/{call_control_id}/actions/ai_assistant_add_messages

Optional: client_state (string), command_id (string), messages (array[object])

	response, err := client.Calls.Actions.AddAIAssistantMessages(
		context.Background(),
		"call_control_id",
		telnyx.CallActionAddAIAssistantMessagesParams{},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: result (string)

Start AI Assistant

Start an AI assistant on the call. Expected Webhooks:

• call.conversation.ended
• call.conversation_insights.generated

POST /calls/{call_control_id}/actions/ai_assistant_start

Optional: assistant (object), client_state (string), command_id (string), greeting (string), interruption_settings (object), message_history (array[object]), participants (array[object]), send_message_history_updates (boolean), transcription (object), voice (string), voice_settings (object)

	response, err := client.Calls.Actions.StartAIAssistant(
		context.Background(),
		"call_control_id",
		telnyx.CallActionStartAIAssistantParams{},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: conversation_id (uuid), result (string)

Stop AI Assistant

Stop an AI assistant on the call.

POST /calls/{call_control_id}/actions/ai_assistant_stop

Optional: client_state (string), command_id (string)

	response, err := client.Calls.Actions.StopAIAssistant(
		context.Background(),
		"call_control_id",
		telnyx.CallActionStopAIAssistantParams{},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: result (string)

Gather

Gather DTMF signals to build interactive menus. You can pass a list of valid digits. The Answer command must be issued before the gather command.

POST /calls/{call_control_id}/actions/gather

Optional: client_state (string), command_id (string), gather_id (string), initial_timeout_millis (int32), inter_digit_timeout_millis (int32), maximum_digits (int32), minimum_digits (int32), terminating_digit (string), timeout_millis (int32), valid_digits (string)

	response, err := client.Calls.Actions.Gather(
		context.Background(),
		"call_control_id",
		telnyx.CallActionGatherParams{
		MinimumDigits: 1,
		MaximumDigits: 4,
	},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: result (string)

Gather stop

Stop current gather. Expected Webhooks:

• call.gather.ended

POST /calls/{call_control_id}/actions/gather_stop

Optional: client_state (string), command_id (string)

	response, err := client.Calls.Actions.StopGather(
		context.Background(),
		"call_control_id",
		telnyx.CallActionStopGatherParams{},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: result (string)

Gather using AI

Gather parameters defined in the request payload using a voice assistant. You can pass parameters described as a JSON Schema object and the voice assistant will attempt to gather these informations.

POST /calls/{call_control_id}/actions/gather_using_ai — Required: parameters

Optional: assistant (object), client_state (string), command_id (string), gather_ended_speech (string), greeting (string), interruption_settings (object), language (object), message_history (array[object]), send_message_history_updates (boolean), send_partial_results (boolean), transcription (object), user_response_timeout_ms (integer), voice (string), voice_settings (object)

	response, err := client.Calls.Actions.GatherUsingAI(
		context.Background(),
		"call_control_id",
		telnyx.CallActionGatherUsingAIParams{
			Parameters: map[string]any{
				"properties": "bar",
				"required":   "bar",
				"type":       "bar",
			},
		},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: conversation_id (uuid), result (string)

Gather using audio

Play an audio file on the call until the required DTMF signals are gathered to build interactive menus. You can pass a list of valid digits along with an 'invalid_audio_url', which will be played back at the beginning of each prompt. Playback will be interrupted when a DTMF signal is received.

POST /calls/{call_control_id}/actions/gather_using_audio

Optional: audio_url (string), client_state (string), command_id (string), inter_digit_timeout_millis (int32), invalid_audio_url (string), invalid_media_name (string), maximum_digits (int32), maximum_tries (int32), media_name (string), minimum_digits (int32), terminating_digit (string), timeout_millis (int32), valid_digits (string)

	response, err := client.Calls.Actions.GatherUsingAudio(
		context.Background(),
		"call_control_id",
		telnyx.CallActionGatherUsingAudioParams{},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

Returns: result (string)

Gather using speak

Convert text to speech and play it on the call until the required DTMF signals are gathered to build interactive menus. You can pass a list of valid digits along with an 'invalid_payload', which will be played back at the beginning of each prompt. Speech will be interrupted when a DTMF signal is received.

POST /calls/{call_control_id}/actions/gather_using_speak — Required: voice, payload

Optional: client_state (string), command_id (string), inter_digit_timeout_millis (int32), invalid_payload (string), language (enum: arb, cmn-CN, cy-GB, da-DK, de-DE, en-AU, en-GB, en-GB-WLS, en-IN, en-US, es-ES, es-MX, es-US, fr-CA, fr-FR, hi-IN, is-IS, it-IT, ja-JP, ko-KR, nb-NO, nl-NL, pl-PL, pt-BR, pt-PT, ro-RO, ru-RU, sv-SE, tr-TR), maximum_digits (int32), maximum_tries (int32), minimum_digits (int32), payload_type (enum: text, ssml), service_level (enum: basic, premium), terminating_digit (string), timeout_millis (int32), valid_digits (string), voice_settings (object)

	response, err := client.Calls.Actions.GatherUsingSpeak(
		context.Background(),
		"call_control_id",
		telnyx.CallActionGatherUsingSpeakParams{
			Payload: "say this on call",
			Voice:   "male",
		},
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%+v\n", response.Data)

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:

// In your webhook handler:
func handleWebhook(w http.ResponseWriter, r *http.Request) {
  body, _ := io.ReadAll(r.Body)
  event, err := client.Webhooks.Unwrap(body, r.Header)
  if err != nil {
    http.Error(w, "Invalid signature", http.StatusBadRequest)
    return
  }
  // Signature valid — event is the parsed webhook payload
  fmt.Println("Received event:", event.Data.EventType)
  w.WriteHeader(http.StatusOK)
}

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.

Webhook payload fields

CallAIGatherEnded

CallAIGatherMessageHistoryUpdated

CallAIGatherPartialResults

callGatherEnded