set_language_mode()

Configures the voice agent to understand and respond in additional languages beyond English. The agent starts in the primary language and switches to a secondary language when the caller requests it or speaks in that language.

call.set_language_mode(
    primary: Language = "english",
    secondary: list[Language] | None = None,
)

The Language type is defined as:

Literal["english", "spanish", "french", "german", "italian"]

Return value: None / Promise<void>

Example: single secondary language

@agent.on_call_start
def on_call_start(call: guava.Call):
    call.set_persona(organization_name="Harper Valley Property Insurance")
    call.set_language_mode(primary="english", secondary=["spanish"])
    call.set_task(
        task_id="intro",
        objective="Answer questions regarding property insurance policy.",
    )

Example: multiple secondary languages

call.set_language_mode(
    primary="english",
    secondary=["spanish", "french", "german"],
)

Transcript behavior

• There is no auto-translation on the transcript. Each turn appears in the language it was spoken in — if the caller speaks Spanish, that turn is in Spanish; if they speak English, that turn is in English.
• There is currently no per-turn language marker in the transcript.

Edge cases

• If secondary is None or empty, the agent operates in primary only (the current default behavior).
• When a non-English language is detected during a call, the system automatically switches to a language-specific TTS voice.
• The grace voice has clones for Spanish, French, German, and Italian. If no dedicated clone exists for a voice + language combination, the base voice is used.