WebSocket

Real-time market data. No authentication required.

Connection

wss://oracle-api.parti.com/v1/ws          # production
wss://oracle-gateway.pbcapps.dev/v1/ws    # staging

The message field is type (not action). Only book: and trades: are served by the gateway relay today (user: is reserved for the per-market DO feed and returns unknown_channel_kind):

{"type": "subscribe", "channel": "book:abc123def456..."}
{"type": "subscribe", "channel": "trades:abc123def456..."}

Heartbeat: {"type":"ping"} → {"type":"pong"}. Ack: {"type":"subscribed","channel":"..."}.

Events

BookUpdate

Sent on every order book change. Includes full snapshot + live prices.

{
  "type": "book_update",
  "market_id": "abc123...",
  "snapshot": {
    "yes_bids": [{"price": 6200, "size": 500, "order_count": 3}],
    "yes_asks": [{"price": 6300, "size": 200, "order_count": 1}],
    "yes_price": 6250,
    "no_price": 3750,
    "spread": 100,
    "sequence": 42
  }
}

Trade

Sent on every fill.

{
  "type": "trade",
  "market_id": "abc123...",
  "trade": {
    "price": 6200,
    "quantity": 100,
    "taker_side": "buy",
    "outcome": "yes",
    "taker_fee": 15,
    "builder_fee": 62,
    "timestamp": 1700000000
  }
}

MarketUpdate

Sent when a market is resolved or status changes.

Channels

Channel	Events
`book:{market_id}`	BookUpdate
`trades:{market_id}`	Trade
`markets`	MarketUpdate (all markets)
`user:{0x_address}`	Trades involving this user

Example

const ws = new WebSocket('wss://oracle-api.parti.com/v1/ws');

ws.onopen = () => {
  ws.send(JSON.stringify({ type: 'subscribe', channel: `book:${marketId}` }));
  ws.send(JSON.stringify({ type: 'subscribe', channel: `trades:${marketId}` }));
};

ws.onmessage = (e) => {
  const msg = JSON.parse(e.data);
  if (msg.type === 'book_update') {
    updatePrices(msg.snapshot.yes_price, msg.snapshot.no_price);
    updateOrderBook(msg.snapshot);
  }
  if (msg.type === 'trade') {
    addTrade(msg.trade);
  }
};

Backpressure

If your client falls behind (4096 message buffer), you'll get:

{"type": "error", "code": "lagged", "message": "Dropped N messages"}

Re-fetch state via REST when this happens.