Orderbook Updates

A prediction-orderbook message carries a full snapshot of a market’s order book. It is not a delta — each message replaces your view entirely.

{"type":"subscribe","data":{"targets":[{"target":"event-market","data":{"ticker":"ANTHROPIC-VALUATION-26Q3-2.1T"}}]}}

Public. No credential required.

Fields

Field	Type	Description
`type`	string	Always `"prediction-orderbook"`
`eventMarketId`	string	UUID of the market
`yesBids`	array	Buy-YES orders, one entry per price level
`noBids`	array	Buy-NO orders, one entry per price level
`ts`	number	Unix timestamp in nanoseconds

Each entry in yesBids and noBids is a price level:

Field	Type	Description
`price`	number	Price in cents, 1–99
`size`	number	Total shares resting at this price

Example

{
  "type": "market-update",
  "data": {
    "type": "prediction-orderbook",
    "eventMarketId": "9f1c2d3e-4a5b-6c7d-8e9f-0a1b2c3d4e5f",
    "yesBids": [
      { "price": 61, "size": 250 },
      { "price": 60, "size": 1200 },
      { "price": 58, "size": 400 }
    ],
    "noBids": [
      { "price": 37, "size": 800 },
      { "price": 36, "size": 150 }
    ],
    "ts": 1789238400123456789
  }
}

Both sides are bids

There is no ask ladder. The book is expressed as two bid ladders, because a buy-NO order is an offer to sell YES. noBids is derived from the internal book as 100 − ask_price. To reconstruct a conventional YES book:

Conventional view	Source
YES bid	`yesBids[i].price`
YES ask	`100 − noBids[i].price`

So a NO bid at 37¢ is equivalent to a YES ask at 63¢.

This is why the two ladders do not overlap. If the best yesBids price were 62 and the best noBids price were 39, that would imply a YES bid of 62 and a YES ask of 61 — a crossed book, which the engine would have matched.

Notes

Replace, don’t merge. Every message is a complete snapshot. Discard your previous book and apply the new one wholesale.
Do not rely on level ordering. The ladders are passed through in the order the engine emits them. Sort by price yourself — descending for yesBids, descending for noBids — rather than assuming [0] is the best level.
A price level absent from the snapshot has no resting size. There are no explicit zero-size entries to process.
Snapshots are published on change, not on a fixed interval. A quiet market may go a long time between messages — that is not a stall.

Getting started

Market data

Private stream

Reference

Fields

Example

Both sides are bids

Notes

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​Example

​Both sides are bids

​Notes

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Fields

Example

Both sides are bids

Notes