Configure

Voice languages

Your voice agent speaks and understands 30+ languages natively — no cascading speech-to-text, translation, and text-to-speech pipeline, no extra latency. One language directive goes into the realtime model’s system prompt and the model handles the rest: transcribes in the target language, understands in the target language, responds in the target language.

Configure per widget

In Widget → Customize → AI agent, enable voice chat. A Languages panel appears below the toggle with three controls.

Setting	What it does
Supported languages	Multi-select. Empty = every language the realtime model supports is allowed. Pick a subset to restrict (e.g. only en-US + es-ES). Non-matching utterances are politely redirected to the default language.
Default language	Dropdown. Used as the session lock when Supported languages has exactly one entry, and as the fallback when auto-detect confidence is low or when the visitor speaks something outside your supported list.
Auto-detect	Checkbox. When on, the model runs a `detect_language` tool on the first utterance, locks the session to the detected BCP-47 code, and responds in that language for the rest of the call. Off = no tool call; session runs in the default (or visitor’s picked) language from the start.

Behavior matrix

Configuration	What the visitor experiences
Supported = 1, default set	Session is always in that language. If the visitor speaks another, the agent acknowledges in the locked language and continues.
Supported = many, auto-detect on	First utterance triggers `detect_language`. Session locks to the detected code (if it’s in the supported list). Otherwise switches to the default language.
Supported = many, auto-detect off, default set	Session runs in the default language. Visitor can ask to switch mid-call (“can we do this in Spanish?”) — the model calls `detect_language` again and the session re-locks.
Supported = empty, auto-detect on	No restriction. Any language the realtime model handles is accepted; the agent follows whatever the visitor speaks.
Supported = empty, auto-detect off, no default	Falls back to English (US) as the universal default so voice never hangs on a missing language.

During the call

The widget shows a small language badge in the voice control bar (🌐 ES for a locked session, 🌐 auto while auto-detect is pending).
The session record’s detectedLanguage column is set to the BCP-47 code and languageSource is set to configured, picker, or autodetect — visible on the conversation review page.
Mid-session switches work: the visitor just asks to change language and the agent complies. The language badge updates on the next turn.

Supported languages

All BCP-47 codes our curated picker offers. The upstream realtime models (xAI Grok, OpenAI gpt-realtime, Google Gemini Live) all handle these natively.

Code	Native name	English name
`en-US`	English	English (US)
`en-GB`	English	English (UK)
`es-ES`	Español	Spanish (Spain)
`es-MX`	Español	Spanish (Mexico)
`fr-FR`	Français	French
`de-DE`	Deutsch	German
`it-IT`	Italiano	Italian
`pt-PT`	Português	Portuguese
`pt-BR`	Português	Portuguese (Brazil)
`nl-NL`	Nederlands	Dutch
`sv-SE`	Svenska	Swedish
`no-NO`	Norsk	Norwegian
`da-DK`	Dansk	Danish
`fi-FI`	Suomi	Finnish
`pl-PL`	Polski	Polish
`cs-CZ`	Čeština	Czech
`tr-TR`	Türkçe	Turkish
`ru-RU`	Русский	Russian
`uk-UA`	Українська	Ukrainian
`ar-SA`	العربية	Arabic
`he-IL`	עברית	Hebrew
`hi-IN`	हिन्दी	Hindi
`bn-IN`	বাংলা	Bengali
`ja-JP`	日本語	Japanese
`ko-KR`	한국어	Korean
`zh-CN`	中文	Chinese (Simplified)
`zh-TW`	中文	Chinese (Traditional)
`th-TH`	ไทย	Thai
`vi-VN`	Tiếng Việt	Vietnamese
`id-ID`	Indonesia	Indonesian
`ms-MY`	Melayu	Malay
`fil-PH`	Filipino	Filipino
`ro-RO`	Română	Romanian
`hu-HU`	Magyar	Hungarian
`el-GR`	Ελληνικά	Greek

Troubleshooting

Agent keeps answering in English even though I selected Spanish. Check that Supported languages actually contains es-ES (or es-MX), that the Default is set to the same code, and that the widget has been re-published since you saved. Hard-refresh the page the widget lives on to invalidate the CDN cache.
Auto-detect picks the wrong language. The detect_language tool is called on the first utterance only; a two-word greeting like “hola” may resolve to a low-confidence code. Have the visitor say a full sentence, or disable auto-detect and set a default for your primary market.
Visitor speaks an unsupported language. The agent switches to your default language and politely explains. If this happens often, add that language to Supported languages.