Prediction markets API

One prediction market's state and live outcome prices

One market: its lifecycle, windowed stats and the live price of each outcome. How that price MOVED over a window is a separate read.

GET/api/external/prediction/prediction-market/{id}

Get a free API key Try it in the API reference

What it returns

One market's full detail, addressed by the id from GET /prediction/prediction-markets. This is a DIFFERENT universe from the rest of this API: the id here is never a token mint or contract address. A well-formed but unrecognised id returns every field null rather than a 404.

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-market/<id>"

Parameters
Parameter	Description
`id` path · string · required	A prediction-market id, e.g. "<marketAddress>:Polymarket:<exchangeAddress>:<networkId>" or "<slug>:Kalshi" — 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's state and live outcome prices
Field	Type	Description
`id`	string \| null
`protocol`	string \| null	The venue this market trades on, e.g. "POLYMARKET" or "KALSHI".
`eventId`	string \| null	The event this market belongs to, or null for a standalone market.
`question`	string \| null
`label`	string \| null	A short label for this market within its event, when it has a parent event.
`outcomeIds`	string[] \| null	The two outcome ids — pass one to `GET /prediction/prediction-outcome-order-book`.
`outcomeLabels`	string[] \| null
`categories`	object[] \| null
`categories[].name`	string \| null
`categories[].slug`	string \| null
`categories[].subcategories`	unknown[] \| null
`resolution`	object \| null	Null until the market resolves.
`resolution.result`	string \| null
`resolution.source`	string \| null
`createdAt`	number \| null	Unix seconds this market was created.
`opensAt`	number \| null	Unix seconds the market opened for trading.
`closesAt`	number \| null	Unix seconds trading closes.
`resolvesAt`	number \| null	Expected resolution time, Unix seconds.
`resolvedAt`	number \| null	Actual resolution time, Unix seconds — null while unresolved.
`networkId`	number \| null	The on-chain settlement network id (e.g. 137 for Polygon/Polymarket) — null for a Kalshi market, which has none.
`exchangeAddress`	string \| null	The on-chain exchange contract, when this market settles on-chain.
`winningOutcomeId`	string \| null	Null until the market resolves.
`lifecycle`	object
`lifecycle.ageSeconds`	number \| null
`lifecycle.expectedLifespanSeconds`	number \| null
`lifecycle.timeToResolutionSeconds`	number \| null
`lifecycle.isResolved`	boolean \| null
`lifecycle.winningOutcomeId`	string \| null
`allTimeVolumeUsd`	number \| null	Lifetime trading volume, USD.
`statsHour1`	object
`statsHour1.volumeUsd`	number \| null	Trading volume over the window, USD.
`statsHour1.trades`	number \| null	Number of trades over the window.
`statsHour1.uniqueTraders`	number \| null	Distinct trading accounts over the window — null on venues that do not report it (measured: Kalshi).
`statsDay1`	object
`statsDay1.volumeUsd`	number \| null	Trading volume over the window, USD.
`statsDay1.trades`	number \| null	Number of trades over the window.
`statsDay1.uniqueTraders`	number \| null	Distinct trading accounts over the window — null on venues that do not report it (measured: Kalshi).
`priceObservedAt`	number \| null	Unix seconds the outcome prices below were observed at.
`outcomePrices`	object[]	One entry per outcome. Empty for an unrecognised market id.
`outcomePrices[].outcomeId`	string \| null
`outcomePrices[].lastTradePriceUsd`	number \| null	Last traded price, USD (0-1 for a binary market).
`outcomePrices[].bestBidUsd`	number \| null	Best resting bid, USD — null when there is none (a literal `"0"` in the source data is read as absent, never a real zero price).
`outcomePrices[].bestAskUsd`	number \| null	Best resting ask, USD — null when there is none, same reasoning as `bestBidUsd`.
`outcomePrices[].bookLiquidityUsd`	number \| null	Liquidity currently backing the order book for this outcome, USD.

Price per call

Every call: 422 credits

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

One prediction market's OHLC-style bars over a bounded window
The state right now, against how the price moved over a window.
The markets of one prediction event, and the part each plays
Pick one market of the event, then read its state and live outcome prices.
What is a prediction market's open interest, and how many holders and trades?
The market's question, prices and USD volume, alongside its open interest and holder count.
Prediction markets, ranked by volume, liquidity or open interest
The ranked list, against one market's own state and live outcome prices.
Many prediction markets' state and live outcome prices
The same answer for one market.
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.

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