WebSocket Protocol

Senticore WebSocket channels use a multiplexed JSON protocol over a single TLS connection.

Connection

Environment	Endpoint
Public beta streams	wss://stream.beta.sentico-labs.xyz/public
Private beta streams	wss://stream.beta.sentico-labs.xyz/private
Mainnet streams	wss://stream.sentico-labs.xyz after public launch

Private streams require an authenticated handshake. See Authentication.

Message envelope

Every data message follows a stable envelope:

{
  "channel": "l2Book",
  "market": "BTC-USDC",
  "seq": 184273,
  "prevSeq": 184272,
  "schemaId": "l2Book.v1",
  "schemaVersion": 1,
  "schemaEncoding": "json",
  "ts": 1730000000000,
  "data": {}
}

Field	Purpose
channel	Channel name
market	Market identifier when channel-specific
seq	Monotonic sequence within the channel scope
prevSeq	Previous sequence used for gap detection
schemaId / schemaVersion	Schema identity for compatibility checks
schemaEncoding	json for current public streams
ts	Server timestamp in unix milliseconds
data	Channel-specific payload

Subscribe and unsubscribe

{
  "op": "subscribe",
  "channels": [
    {"channel": "l2Book", "market": "BTC-USDC"},
    {"channel": "trades", "market": "BTC-USDC"}
  ]
}

Server acknowledgement:

{
  "op": "subscribed",
  "channels": [
    {"channel": "l2Book", "market": "BTC-USDC"},
    {"channel": "trades", "market": "BTC-USDC"}
  ]
}

Unsubscribe uses the same channel selector:

{
  "op": "unsubscribe",
  "channels": [
    {"channel": "trades", "market": "BTC-USDC"}
  ]
}

Heartbeat

The server sends a heartbeat every 30 seconds:

{"op": "ping", "ts": 1730000000000}

The client must respond within 10 seconds:

{"op": "pong", "ts": 1730000000123}

Missed pongs close the connection.

Sequence handling

Consumers must:

• verify seq == prevSeq + 1 for every scoped stream
• trigger resync on a gap, checksum mismatch, or resync_required
• fetch a fresh REST snapshot before applying new deltas
• resume private streams from the last acknowledged account sequence where available

Error model

Errors arrive as control messages:

{
  "op": "error",
  "code": "resync_required",
  "channel": "l2Book",
  "market": "BTC-USDC",
  "message": "client lag exceeded retention window"
}

Code	Client action
resync_required	Fetch a snapshot, resubscribe, and replay from fresh state
auth_failed	Reconnect with valid credentials
rate_limited	Back off per retry guidance
unknown_channel	Correct the subscription request
permission_denied	Request the required account or institutional permission

Resilience

See Reconnect Strategy for production-grade client behavior.