live_translate
Start live translation of the call. The translation will be sent to the specified webhook URL.
Properties
live_translate
An object that accepts the following properties.
live_translate.action
The action to perform. See actions below.
Actions
The action property controls the translation session. Use start to begin translating with configuration options, stop to end an active session, summarize to request an on-demand AI summary mid-session, or inject to insert a translated message into the conversation.
start
stop
summarize
inject
action.start
Start a live translation session.
start.webhook
The URL to receive translation events via HTTP POST.
When live_events is enabled, partial results are sent as they occur.
When ai_summary is enabled, summaries in both languages are sent when the session ends.
Authentication can also be set in the URL in the format of username:password@url.
start.from_lang
The language to translate from. See supported voices & languages.
start.to_lang
The language to translate to. See supported voices & languages.
start.from_voice
The TTS voice to use for the source language. See supported voices & languages.
start.to_voice
The TTS voice to use for the target language. See supported voices & languages.
start.filter_from
Translation filter to apply to the source language direction. Adjusts the tone or style of translated speech.
Preset values: polite (removes insults, maintains sentiment), rude (adds insults, maintains sentiment),
professional (removes slang), shakespeare (iambic pentameter), gen-z (Gen-Z slang and expressions).
For custom filters, use the prompt: prefix (e.g., prompt:Use formal business language).
start.filter_to
Translation filter to apply to the target language direction. Adjusts the tone or style of translated speech.
Preset values: polite, rude, professional, shakespeare, gen-z.
For custom filters, use the prompt: prefix.
start.live_events
Whether to enable live events.
start.ai_summary
Whether to enable automatic AI summarization. When enabled, AI-generated summaries in both languages will be sent to your webhook when the translation session ends.
start.speech_timeout
The timeout for speech recognition in milliseconds. Minimum value: 1500.
start.vad_silence_ms
Voice activity detection silence time in milliseconds.
Default depends on the speech engine: 300 for Deepgram, 500 for Google. Minimum value: 1.
start.vad_thresh
Voice activity detection threshold. Range: 0 to 1800.
start.debug_level
Debug level for logging.
start.direction
The direction of the call that should be translated. Possible values: remote-caller, local-caller.
start.speech_engine
The speech recognition engine to use. Possible values: deepgram, google.
start.ai_summary_prompt
The AI prompt that instructs how to summarize the conversation when ai_summary is enabled.
This prompt is sent to an AI model to guide how it generates the summary.
Action usage context
Call start: The initial SWML document returned when a call first arrives.
Live call: Actions sent to active calls via the Call Commands REST API or SWML sections executed via transfer or execute during a call.
ai_summary vs summarize action
ai_summary: true(instart): Automatically generates summary when session endssummarizeaction: On-demand summary during an active session