set_language_mode()

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

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

await call.setLanguageMode({
  primary?: Language,   // default: "english"
  secondary?: Language[],
})

type Language = "english" | "spanish" | "french" | "german" | "italian";

​

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.",
    )

agent.onCallStart(async (call: guava.Call) => {
  await call.setPersona({ organizationName: "Harper Valley Property Insurance" });
  await call.setLanguageMode({ primary: "english", secondary: ["spanish"] });
  await call.setTask({
    taskId: "intro",
    objective: "Answer questions regarding property insurance policy.",
  });
});

​

Example: multiple secondary languages

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

await call.setLanguageMode({
  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 empty or not provided, 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.