Order book and fill cost
pm_bookRead-onlyIdempotent
Use this when the user asks how liquid a Polymarket market is, how much a trade of a given size would really cost, how far it would move the price, or what the order book looks like. Returns the live book for one outcome: best levels, spread, dollar depth near the mid and which side is heavier. With amount it walks the book level by level for a market order (dollars to spend when buying, shares when selling) and returns shares filled, average and worst price, slippage against the mid, Polymarket's taker fee and the breakeven probability.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| side | No | buy (default) or sell. | buy |
| amount | No | For buy: dollars to spend. For sell: number of shares to sell. Omit to see the book only. | |
| market | Yes | A polymarket.com link, or a market or event slug from pm_search. | |
| outcome | No | Which outcome: "Yes"/"No", a team name, or for a multi-outcome event the outcome label ("25 bps decrease"). Default: the first outcome (usually Yes). |