> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bravadotrade.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Live order books on Polymarket and Predict.fun

> Subscribe to live Polymarket and Predict.fun order books with a shared WebSocket message format.

Connect to the public endpoint for your venue. No API key is required on these routes.

| Venue       | WebSocket URL                                                 |
| ----------- | ------------------------------------------------------------- |
| Polymarket  | `wss://partner-api.bravadotrade.com/stream/polymarket/market` |
| Predict.fun | `wss://partner-api.bravadotrade.com/stream/predictfun/market` |

## Subscribe

Use the venue's outcome token ID, not its event or market ID. On Predict.fun this is the outcome's `onChainId`.

```javascript theme={null}
const venue = "predictfun"; // or "polymarket"
const asset = "<OUTCOME_TOKEN_ID>";
const ws = new WebSocket(
  `wss://partner-api.bravadotrade.com/stream/${venue}/market`
);
ws.onopen = () => ws.send(JSON.stringify({
  op: "sub",
  streams: [`book:${asset}`]
}));
ws.onmessage = ({ data }) => {
  const frame = JSON.parse(data);
  if (frame.type === "error") {
    console.error(frame.code, frame.message);
    return;
  }
  if (frame.channel !== "book") return;
  if (frame.type === "snapshot" || frame.type === "delta") {
    // Both frame types carry complete sides: replace your local book.
    console.log(frame.asset, frame.seq, frame.bids, frame.asks);
  } else if (frame.type === "status") {
    console.log(frame.state, frame.reason);
  }
};
```

Alternatively, pass `?streams=book:<OUTCOME_TOKEN_ID>` on the connection URL. Subscribe to multiple tokens with a `streams` array. Unsubscribe with `{"op":"unsub","streams":["book:<OUTCOME_TOKEN_ID>"]}`. The public route accepts up to 120 streams per connection.

## Read the messages

Book frames include `channel: "book"`, `venue`, `asset`, `type`, `seq`, `ts` and, for snapshots and deltas, `bids` and `asks`.

* Each price level is `[price, size]`, with both values encoded as decimal strings.
* **Both snapshots and deltas contain complete sides**, not level patches. Replace the previous sides on each frame.
* Bids are descending; asks are ascending. A transient crossed book is possible during venue updates.
* Sequence numbers are per venue and asset. A snapshot resets local book state; do not infer ordering across venues.
* `ts` is Bravado's timestamp in milliseconds. `upstreamTs` is the venue timestamp when available, otherwise `null`.
* Status frames distinguish `live` and `degraded`. Check `reason`; a connection or status frame alone does not mean a fresh book has arrived.

Reconnect and resubscribe after a disconnection. Do not display a buffered book as fresh while the stream is degraded.

## Coverage

These routes serve live order books. Predict.fun subscriptions require an indexed binary market and its outcome token IDs. The [enriched trade feed](/api/market-data/trade-feed) is a separate Polymarket feed; book changes are not executions.

For historical L2 or bulk extracts, see [historical data and custom delivery](/api/market-data/historical-data).