Multi-language calls

A caller who opens in Spanish gets the whole call in Spanish. Every assistant picks up the caller's language within the first few sentences and carries the conversation in it — nothing to configure.

What it is#

Every OnCore assistant listens for the caller's language from their first few utterances. When a caller speaks Spanish, French, Japanese — any of the supported languages — the assistant switches the whole conversation to match: it understands the caller, replies in their language, and speaks it in the assistant's voice. Once the language is settled, the call stays in it, so the conversation feels consistent from start to finish. There is nothing to turn on — this is how every assistant behaves out of the box.

What you can do with it#

• Serve a multilingual customer base on one number — no separate lines, no "for Spanish, press 2" menu: each caller simply starts talking and is answered in kind.
• Write your instructions once — your assistant's rules and tasks apply in whichever language the caller speaks; you don't maintain a copy per language.
• Welcome international callers — a tourist or overseas customer gets the same service as a local one, in their own language.
• Hand off without losing the language — transfer announcements and warm-transfer briefings are spoken in the language of the call, so a Spanish caller hears the hand-off in Spanish.

How to set it up#

There is nothing to enable. Language detection is on for every assistant created through OnCore's REST API and works from the first call — no field to set, no per-language configuration. The one choice that matters is the assistant's voice: each entry in the voice catalogue lists the languages it can speak, so pick a voice whose list covers your callers — see Voices, Models & Transcribers and the Assistants guide.

Limits & FAQ#

• Automatic detection covers English, French, German, Spanish, Italian, Portuguese, Arabic, Dutch, Hindi, Russian, and Japanese.
• The assistant's opening line is spoken exactly as you wrote it — detection starts from the caller's speech, so the first exchange happens in your greeting's language before the call settles into the caller's.
• Some voices in the catalogue are English-only while others are multilingual; a voice speaks only the languages listed on its catalogue entry — so the one prerequisite for multilingual service is picking a voice whose language list covers your callers.
• A caller speaking a language outside the supported set is not switched: the assistant simply continues in its current language.

Is this an interpreter service? No. OnCore doesn't translate between two people on a call — it holds its own conversation in the caller's language. When a call is handed to your team, the caller keeps speaking their language; the assistant does not interpret for the person who picks up.

What if a caller changes language mid-call? The assistant settles on the caller's language over the first few exchanges and then keeps the whole call there. It isn't designed for switching back and forth within one conversation.

Do we need to pick or restrict languages? No — there is no language setting to manage. Detection is automatic, and a caller who speaks English is simply answered in English; other languages only come into play when a caller uses them.