addLanguage | SignalWire

Add a language configuration with voice settings. The agent uses these configurations to support multilingual conversations with appropriate TTS voices.

Language configurations map to the SWML ai.languages array. See the SWML languages reference for the full specification.

The voice parameter supports three formats: a simple voice name, an explicit engine/model via separate parameters, or a combined "engine.voice:model" string.

Parameters

config

LanguageConfigRequired

A language configuration object with the following fields:

config.name

stringRequired

Human-readable language name (e.g., "English", "French", "Spanish").

config.code

stringRequired

Language code (e.g., "en-US", "fr-FR", "es-MX").

config.voice

string

TTS voice identifier. Accepts one of three formats:

Simple name: "en-US-Neural2-F"
Combined format: "elevenlabs.josh:eleven_turbo_v2_5"
Short name with explicit engine: "josh"

config.engine

string

Explicit TTS engine name (e.g., "elevenlabs", "rime").

config.fillers

Record<string, string[]>

Filler phrases keyed by category for this language.

config.speechModel

string

Speech recognition model identifier.

config.functionFillers

Record<string, Record<string, string[]>>

Per-function filler phrases, keyed by function name then language code.

config.params

Record<string, unknown>

Optional per-language params dictionary for engine-specific tuning (e.g. voice settings). Only emitted into the SWML document when non-empty, so existing entries stay byte-identical when omitted. Can also be set or updated later via setLanguageParams().

Returns

AgentBase — Returns this for method chaining.

Examples

Simple voice

1 import { AgentBase } from '@signalwire/sdk';
2 
3 const agent = new AgentBase({ name: 'support', route: '/support' });
4 agent.setPromptText('You are a helpful assistant.');
5 agent.addLanguage({ name: 'English', code: 'en-US', voice: 'rime.spore' });
6 await agent.serve();

Explicit engine

1 import { AgentBase } from '@signalwire/sdk';
2 
3 const agent = new AgentBase({ name: 'support', route: '/support' });
4 agent.setPromptText('You are a helpful assistant.');
5 agent.addLanguage({
6   name: 'English',
7   code: 'en-US',
8   voice: 'josh',
9   engine: 'elevenlabs',
10 });
11 await agent.serve();

With fillers

1 import { AgentBase } from '@signalwire/sdk';
2 
3 const agent = new AgentBase({ name: 'support', route: '/support' });
4 agent.setPromptText('You are a helpful assistant.');
5 agent.addLanguage({
6   name: 'English',
7   code: 'en-US',
8   voice: 'rime.spore',
9   fillers: {
10     speech: ['Um...', 'Let me think...'],
11   },
12   functionFillers: {
13     get_weather: { 'en-US': ['Checking the weather...', 'One moment please...'] },
14   },
15 });
16 await agent.serve();