Orderbook responses

Binary markets only need bids. A YES bid at tick t is economically the same as a NO ask at 10000 − t, so sending asks would duplicate the book. Ticks are pips (0.01¢): 3500 is 35.00¢. See Ticks, pips, and subcents.

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GET /v1/markets/{market_id}/orderbook?depth=10

{
  "market_id": 71,
  "yes": [[2400, 1200], [2300, 800]],
  "no":  [[6500, 950],  [6400, 400]],
  "tick_size": {
    "type": "tick_size",
    "market_id": 71,
    "policy": "narrow",
    "mode": "cent",
    "tick_step": 10,
    "wing_lo": 400,
    "wing_hi": 9600
  },
  "as_of_seq": "182390"
}

Field	Meaning
`yes`	YES bids, YES-space ticks, best first
`no`	NO bids, NO-space ticks, best first
Level	`[tick, aggregate_qty]` — `tick` is pips 1–9999, `qty` a JSON number on REST
`tick_size`	Advertised rest grid (`policy`, `tick_step`, wing bounds)
`depth`	Levels per side (default 10, max 99)

Per-order queue data is never published, this is an aggregated L2 book. For shares ahead of your resting order, use GET /v1/portfolio/orders/{id}/queue_position.

WebSocket orderbook_snapshot / orderbook_delta render level qty as a decimal string. REST uses a JSON number. Do not assume the two wires are identical.

Reciprocal pricing

On the book	Equivalent ask
YES bid at tick `t`	NO ask at `10000 − t`
NO bid at tick `t`	YES ask at `10000 − t`

Best prices and spread (YES)

TICK_SPAN = 10_000
best_yes_bid = orderbook["yes"][0][0]                 # highest YES bid
best_yes_ask = TICK_SPAN - orderbook["no"][0][0]      # implied from best NO bid
spread = best_yes_ask - best_yes_bid

If either side is empty, that implied ask (or bid) does not exist. In the example, best YES bid is 2400 (24.00¢) and best YES ask is 3500 (35.00¢). Place only on-grid ticks. Interior [400, 9600] is whole cents; wings allow tick_step (v1: 10 = 0.10¢).

Live updates

For UIs, subscribe to orderbook_snapshot, full book on connect, then a fresh full book about 5 times per second. Replace your local book from each snapshot; no delta folding required. Snapshots include tick_size. For bots that reconstruct every level change, subscribe to orderbook_delta - the first frame per market is a full orderbook_snapshot, then level deltas. On a delta, qty is the new aggregate at that level (set it; do not add). qty of 0 clears the level. After a sequence gap, re-baseline with update_subscription / get_snapshot rather than inventing missing levels. See WebSocket overview and Channels.

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Reciprocal pricing

Best prices and spread (YES)

Live updates

​Shape

​Reciprocal pricing

​Best prices and spread (YES)

​Live updates

Shape

Reciprocal pricing

Best prices and spread (YES)

Live updates