Prediction markets API

One prediction-market outcome's live order book

What is resting on one outcome's book right now, bid and ask. A different question from who already holds the outcome token.

GET/api/external/prediction/prediction-outcome-order-book/{id}

Get a free API key Try it in the API reference

What it returns

Bid and ask price levels for one outcome, addressed by the id from a market's own outcomeIds (GET /prediction/prediction-market). A timestamp of null means no book is indexed for this outcome, not a real book with zero depth.

Chains

This endpoint is not tied to a chain: it takes no chain in its request.

Request

Send your key in the x-dex-data-key header. Replace each <placeholder> with a real value.

curl -H "x-dex-data-key: $DEXDATA_API_KEY" \
  "https://api.dexdata.io/api/external/prediction/prediction-outcome-order-book/<id>"

Parameters
Parameter	Description
`id` path · string · required	A prediction-market outcome id (one of a market's two outcomes) — not a token mint or contract address, and not scoped to any chain this API otherwise supports.

Response fields

A JSON response. Every field is always present; null means the value could not be established, never zero.

Response fields of One prediction-market outcome's live order book
Field	Type	Description
`outcomeId`	string \| null
`protocol`	string \| null	The venue this outcome trades on, e.g. "POLYMARKET" or "KALSHI".
`timestamp`	number \| null	Unix seconds this book was observed at. Null when no book is indexed for this outcome.
`bookLiquidityUsd`	number \| null	Total liquidity currently in this book, USD.
`bids`	object[]
`bids[].price`	number \| null
`bids[].size`	number \| null
`asks`	object[]
`asks[].price`	number \| null
`asks[].size`	number \| null

Price per call

Every call: 141 credits

Charged only when the call succeeds. Prices as of 2026-10-30; the current ones are always in the API reference.

Holder balances for one outcome token of one prediction market
Orders waiting to be filled, against position already taken.
Latest trades and redemptions on one prediction market
The tape of one market: who traded which outcome, at what price and size, newest first, with redemptions once it resolves.
Who traded one prediction market, and how each trader did on it
The traders of one market ranked by volume, realized PnL or activity, with each one's position, entry price and PnL per outcome.
Prediction-market traders ranked by profit or volume
Who is winning on prediction markets right now: the leading traders by realized profit or volume over a day, week or month, with their win rate, lifetime record and bot labels.
Every market one prediction-market trader traded, and how they did on each
One trader's track record market by market, ranked by volume, realized PnL or activity, with the position, entry price, PnL and win or loss per outcome.
Prediction trader markets brief: a trader's results per market
At most 20 markets with volume, PnL and per-outcome position and result.

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