# Twilio
TWILIO_ACCOUNT_SID=AC...
TWILIO_AUTH_TOKEN=
# Groq (Whisper STT)
GROQ_API_KEY=gsk_...
# ElevenLabs (TTS)
ELEVENLABS_API_KEY=
# API bearer token for /api/* endpoints
# Generate with: openssl rand -hex 32
ECHO_API_TOKEN=
# Public URL where Twilio can reach this server
SERVER_EXTERNAL_URL=https://your-server.example.com