Protocol

Voice nodes accept control and media packets over UDP.

Control packets (JSON)

• Auth:
  • {"type":"auth","channelId":"...","userId":"...","secret":"..."}
• Ping:
  • {"type":"ping"}

Media packets (binary, recommended)

UVN packet format v1:

• Header (24 bytes):
  • magic (3 bytes): UVN
  • version (1 byte): 1
  • packetType (1 byte): 1 for audio
  • flags (1 byte, reserved)
  • channelIdLen (u16 BE)
  • userIdLen (u16 BE)
  • payloadLen (u16 BE)
  • sequence (u32 BE)
  • timestampMs (u64 BE)
• Body:
  • channelId (utf8)
  • userId (uuid string)
  • payload (Opus frame bytes)

Hardening behavior

• Rate limit per sender socket (VOICE_NODE_MAX_PACKETS_PER_SECOND)
• Payload size hard cap (VOICE_NODE_MAX_AUDIO_PAYLOAD_BYTES)
• Sequence replay guard (sequence must be newer)
• Session ownership check (socket + user + channel)

Legacy

Legacy JSON audio packets are accepted for migration:

• {"type":"audio","channelId":"...","userId":"...","payload":"<base64>"}.