> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vibeconf.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Call language

> The bot hears through Meet's captions — set the language or it answers nonsense.

Your agent doesn't transcribe audio. It **reads Google Meet's live captions**, which means
Meet's caption language decides what the agent hears.

Set it wrong and the failure is quiet: Meet turns perfectly good speech into phonetic
gibberish, and the agent answers the gibberish. It doesn't go silent — it becomes confidently
wrong, and nobody notices until someone reads the transcript.

## Set it before you talk

<Steps>
  <Step title="On first run">
    The setup wizard asks for your call language in the voice step. Pick the language your
    meetings actually happen in.
  </Step>

  <Step title="Per bot, any time">
    Each bot profile carries its own call language in App Settings, next to Voice. It's
    applied when the bot joins.
  </Step>

  <Step title="Mid-call, by asking">
    ```text theme={null}
    Switch the call language to German.
    ```

    The agent drives Meet's own Settings dialog to change it, and tells you the language tag
    Meet actually settled on.
  </Step>
</Steps>

## What comes back

The agent reports the **BCP-47 tag** Meet applied — `de-DE`, `es-MX`, `cmn-Hans-CN` — not just
"ok". Worth reading, because a bare language can resolve to a regional variant you didn't
expect:

| You ask for                   | Meet gives you                                                                                                                                                                                                                 |
| ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| a bare tag (`es`, `en`)       | **the first regional variant Meet happens to list** — not a fixed choice. the source's own comments use `es`→`es-ES` as the example; don't rely on any particular region from a bare tag (`google-meet-provider.js:2902-2912`) |
| a full tag (`es-ES`, `en-GB`) | exactly that variant — **always pass the full tag when the region matters**                                                                                                                                                    |
| `cmn`                         | a Mandarin variant, e.g. `cmn-Hans-CN`                                                                                                                                                                                         |

If the exact regional variant matters, ask for it explicitly.

## Multilingual meetings

Meet captions one language at a time, and every participant sets their own. If your call
switches languages mid-conversation, captions for the other language arrive mangled — so
either set the language to whichever one carries the substance, or switch it when the
conversation switches.

<Tip>
  A bot answering slightly-off-topic replies to clear speech is the signature of a caption
  language mismatch. Check the language before you debug anything else — and read a few
  lines of the transcript, where the garbling is obvious.
</Tip>

<Note>
  Google Meet only. Slack huddles have no caption region, so the agent reports call language
  as unsupported rather than pretending the change worked.
</Note>

## Interesting side effect

The model reads *through* a certain amount of garbling. On one call two participants spoke
German with captions set to English; the captions arrived as nonsense English and the agent
worked out what was happening and replied in German. Fun, and not something to rely on —
set the language.