Voice
Give your agent a voice. Bookbag transcribes the caller, answers with the same brain, prompt, and knowledge as the text chat, and speaks the reply back — with multi-provider speech-to-text (OpenAI, Deepgram, Cartesia, Soniox, ElevenLabs), a searchable voice picker, realtime in-widget voice mode, and per-call limits.
View as MarkdownVoice gives your agent a spoken interface. Every voice turn flows through the same pipeline as a text message — the caller's speech is transcribed, the transcript runs through this agent's prompt, knowledge, and actions, and the reply is spoken back. Same brain, same answers, just spoken.
Open an agent at app.bookbag.ai and pick the Voice tab. Speech-provider API keys are added once, workspace-wide, under Settings → Models & providers.
Speech providers
Speech-to-text (transcription) and text-to-speech (the agent's voice) are powered by provider engines you bring keys for. Add each provider's key under Settings → Models & providers → Provider keys, then pick it on the Voice tab.
| Capability | Providers |
|---|---|
| Speech-to-text (transcriber) | OpenAI Whisper, Deepgram, Cartesia, Soniox, ElevenLabs Scribe |
| Text-to-speech (agent voice) | OpenAI, ElevenLabs, Cartesia |
| Realtime (speech-to-speech) | OpenAI Realtime |
The provider and model dropdowns on the Voice tab are driven by your model catalog — the speech models listed under Settings → Models & providers. Add a new STT/TTS model there and it shows up in the Voice tab automatically. Nothing is hardcoded.
Credit usage
Voice replies are billed exactly like text chat: a flat 1 credit per response, no per-minute metering. Transcription and speech synthesis are included in that.
Model
Voice can use its own LLM (separate from the text-chat model) and temperature — pick them in the Model card, or leave it on the agent's default model. Lower temperature keeps spoken answers reserved and grounded.
Transcriber (speech-to-text)
Choose the provider and model that turn the caller's audio into text, plus the language and two tuning sliders:
Agent voice (text-to-speech)
Pick the provider, model, and the voice itself. The voice picker has two tabs:
Voice mode (talk to the agent)
Turn on Voice mode in an agent's Chat Interface settings to add a voice button to the chat widget. Visitors tap it to open a real-time spoken conversation — they talk, the agent talks back — powered by OpenAI Realtime using the realtime model and voice you selected. Requires an OpenAI key. The same realtime engine powers the dashboard's "Start live call" tester.
Messages & session
Set the initial message the agent speaks when a session begins (leave it empty to wait for the caller) and the error message played on failure. Session settings control whether callers can interrupt the agent, end-after-silence, and type during a call.
Limits
Max call duration and end-after-silence are enforced on live calls — a session that hits either limit ends automatically, so abandoned calls don't run up cost. Per-agent concurrent and daily call caps are coming as voice gets per-session metering.
Recordings
Call recording isn't available yet. When it ships, recordings will be stored in your workspace object storage and billed for the storage they use — you'll set a retention period (or keep forever), and HIPAA / Zero-Data-Retention workspaces will have it permanently off. We're building the storage + retention pipeline first so audio you pay for never silently accumulates.
On HIPAA / Zero-Data-Retention workspaces, transcription is limited to HIPAA-eligible providers (Deepgram, Cartesia), recordings stay off, and no voice audio is retained. See HIPAA & ZDR.