livekit-plugins-gandr

Gandr text to speech for LiveKit Agents.

pip install livekit-plugins-gandr

from livekit.agents import AgentSession
from livekit.plugins import gandr

session = AgentSession(
    stt=...,
    llm=...,
    tts=gandr.TTS(voice="gandr-mia"),   # key from GANDR_API_KEY
)

Get a key at gandr.ai. The free tier is 100,000 characters, no card.

Voices

gandr-mia, gandr-ava, gandr-jenny, gandr-dane, gandr-leo, gandr-lewis, or a gnd: clone id. One cloned voice speaks 23 languages. Swap mid-session with session.tts.update_options(voice=...).

Behaviour worth knowing

• Audio streams back in chunks as it is generated, so playback starts while the rest is still rendering.
• A truncated stream is never played as if complete. The API flags an early end and the plugin raises instead of handing back half a sentence, so a FallbackAdapter can take the turn.
• One retry through a busy moment, rather than letting the first caller in that window hear silence. await tts.prewarm() opens the path early if you would rather do it on the SIP invite than on first speech.

Accuracy

Word error rate 1.982% against a 2.171% human reference, scored by one whisper-large-v3 configuration across everything including the human baseline, n=1,088. Numbers, dates and order IDs are read correctly rather than approximated, which is the failure that actually breaks phone agents.

Every render carries an inaudible watermark.

MIT.