ai.languages

Use ai.languages to configure the spoken language of your AI Agent, as well as the TTS engine, voice, and fillers.

Name	Type	Default	Description
languagesOptional	object	-	An object that accepts the languages parameters.

Use ai.languages to configure the spoken language of your AI Agent, as well as the TTS engine, voice, and fillers.

Parameters for the languages object

Name	Type	Default	Description
nameRequired	string	English	Name of the language ("French", "English", etc). This value is used in the system prompt to instruct the LLM what language is being spoken.
codeRequired	string	en-US	Set the language code for ASR Automatic Speech Recognition (STT Speech-to-text ) purposes. By default, SignalWire uses Deepgram's Nova-3 STT engine, so this value should match a code from Deepgram's Nova-3 language codes table. If a different STT model was selected using the openai_asr_engine parameter, you must select a code supported by that engine.
voiceRequired	string	Standard-tier voice picked by SignalWire	String format: <engine id>.<voice id>. Select engine from gcloud, polly, elevenlabs, or deepgram. Select voice from TTS provider reference. For example, "gcloud.fr-FR-Neural2-B".
emotionOptional	string	None	Enables emotion for the set TTS engine. This allows the AI to express emotions when speaking. A global emotion or specific emotions for certain topics can be set within the prompt of the AI. Valid values:* auto IMPORTANT: Only works with Cartesia TTS engine.
function_fillersOptional	string[]	None	An array of strings to be used as fillers in the conversation when the agent is calling a SWAIG function. The filler is played asynchronously during the function call.
modelOptional	string	None	The model to use for the specified TTS engine (e.g. arcana). Check the TTS provider reference for the available models.
speech_fillersOptional	string[]	None	An array of strings to be used as fillers in the conversation. This helps the AI break silence between responses. Note that speech_fillers are used between every 'turn' taken by the LLM, including at the beginning of the call. For more targed fillers, consider using function_fillers.
speedOptional	string	None	The speed to use for the specified TTS engine. This allows the AI to speak at a different speed at different points in the conversation. The speed behavior can be defined in the prompt of the AI. Valid values:* auto IMPORTANT: Only works with Cartesia TTS engine.
fillersOptional	string[]	None	An array of strings to be used as fillers in the conversation and when the agent is calling a SWAIG function.Deprecated: Use speech_fillers and function_fillers instead.
engineOptional	string	gcloud	The engine to use for the language. For example, "elevenlabs".Deprecated. Set the engine with the voice parameter.

Use voice strings

Compose the voice string using the <engine id>.<voice id> syntax.

First, select your engine using the gcloud, polly, elevenlabs, or deepgram identifier. Append a period (.), and then the specific voice ID (for example, en-US-Casual-K) from the TTS provider. Refer to SignalWire's Supported Voices and Languages for guides on configuring voice IDs strings for each provider.

Supported voices and languages

SignalWire's cloud platform integrates with leading text-to-speech providers. For a comprehensive list of supported engines, languages, and voices, refer to our documentation on Supported Voices and Languages.

Examples

Set a single language

SWML will automatically assign the language (and other required parameters) to the defaults in the above table if left unset. This example uses ai.language to configure a specific English-speaking voice from ElevenLabs.

YAML

languages:
  - name: English
    code: en-US
    voice: elevenlabs.rachel
    speech_fillers:
      - one moment please,
      - hmm...
      - let's see,

JSON

{
  "languages": [
    {
      "name": "English",
      "code": "en-US",
      "voice": "elevenlabs.rachel",
      "speech_fillers": [
        "one moment please,",
        "hmm...",
        "let's see,"
      ]
    }
  ]
}

Set multiple languages

SWML will automatically assign the language (and other required parameters) to the defaults in the above table if left unset. This example uses ai.language to configure multiple languages using different TTS engines.

YAML

languages:
  - name: Mandarin
    code: cmn-TW
    voice: gcloud.cmn-TW-Standard-A
  - name: English
    code: en-US
    voice: elevenlabs.rachel

JSON

{
  "languages": [
    {
      "name": "Mandarin",
      "code": "cmn-TW",
      "voice": "gcloud.cmn-TW-Standard-A"
    },
    {
      "name": "English",
      "code": "en-US",
      "voice": "elevenlabs.rachel"
    }
  ]
}