langchain-ai/voice-demo

Python

10 environment variables found in .env.example

Set these on your host before deploying. Each platform has an “Environment Variables” section in the deploy flow.

LANGSMITH_API_KEY secret Shared
LANGSMITH_PROJECT_PREFIX
OPENAI_API_KEY secret Used by: both OpenAI Realtime backends (raw + Agents SDK), the LLM stage of the LiveKit and Pipecat cascades and their OpenAI Realtime…
DEEPGRAM_API_KEY secret Used by: the Pipecat cascade backend — Deepgram STT (Nova) + TTS (Aura).
ASSEMBLYAI_API_KEY secret Used by: the LiveKit cascade backend — AssemblyAI STT + Cartesia TTS.
CARTESIA_API_KEY secret
GOOGLE_API_KEY secret Used by: the Google ADK Live backend and the livekit-with-gemini-live variant.
LIVEKIT_API_KEY secret LiveKit — console mode doesn't need a real server, but the SDK still validates these at startup. Dummy values are fine.
LIVEKIT_API_SECRET secret
LIVEKIT_URL

Best match Fly.io Anything Dockerized — requires the Fly CLI.

macOS

brew install flyctl && fly launch --from https://github.com/langchain-ai/voice-demo

Linux

curl -L https://fly.io/install.sh | sh && fly launch --from https://github.com/langchain-ai/voice-demo

Windows (PowerShell)

iwr https://fly.io/install.ps1 -useb | iex; fly launch --from https://github.com/langchain-ai/voice-demo

Or deploy to a different host