Prediction markets API

A prediction event's volume, liquidity and open interest over time

How trading on a whole prediction event moved bucket by bucket — volume, trades, traders, and liquidity and open interest as OHLC — across all of its markets.

GET/api/external/prediction/prediction-event-bars/{id}

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What it returns

Per-bucket trading across all the markets of one event (e.g. every candidate of an election): volume bought and sold, trades, unique traders, the lifetime volume as of each bucket, and the open, high, low and close of its liquidity and open interest. Bounded by from and to (Unix seconds, both inclusive), at most 1000 buckets per request. The id is an event id from prediction-events. Per-market prices are prediction-market-bars. An unknown id is 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-event-bars/<id>?resolution=min1&from=<from>&to=<to>"

Parameters
Parameter	Description
`resolution` query · string · required	The bucket width.`min1min5min15min30hour1hour4hour12day1week1`
`from` query · integer · required	Window start, Unix seconds (inclusive).
`to` query · integer · required	Window end, Unix seconds (inclusive). A window of ≤ 80 bars keeps the answer under 32 KB.
`id` path · string · required	A prediction-market event id (groups one or more markets, e.g. a multi-candidate election) — 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 A prediction event's volume, liquidity and open interest over time
Field	Type	Description
`eventId`	string	The event id, as passed.
`bars`	object[]	One bucket per period of the window, oldest first.
`bars[].t`	number	Bucket open time, Unix seconds.
`bars[].volumeUsd`	number \| null	Bought plus sold across the event in this bucket, USD.
`bars[].buyVolumeUsd`	number \| null
`bars[].sellVolumeUsd`	number \| null
`bars[].allTimeVolumeUsd`	number \| null	The event's lifetime volume as of this bucket, USD.
`bars[].trades`	number \| null
`bars[].uniqueTraders`	number \| null
`bars[].lastActivityTimestamp`	number \| null	Unix seconds of the last activity inside the bucket. Null when there is none.
`bars[].liquidityUsd`	object \| null	Liquidity across the event over the bucket, USD: open, high, low, close.
`bars[].liquidityUsd.o`	number \| null
`bars[].liquidityUsd.h`	number \| null
`bars[].liquidityUsd.l`	number \| null
`bars[].liquidityUsd.c`	number \| null
`bars[].openInterestUsd`	object \| null	Open interest across the event over the bucket, USD: open, high, low, close.
`bars[].openInterestUsd.o`	number \| null
`bars[].openInterestUsd.h`	number \| null
`bars[].openInterestUsd.l`	number \| null
`bars[].openInterestUsd.c`	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.

One prediction-market trader's results bucketed over a window
Same inputs: from, id, resolution, to.
One prediction-market event's identity, lifecycle and windowed stats
The event's state right now, against how its trading moved over a window.
One prediction market's OHLC-style bars over a bounded window
One market of the event, priced, against the whole event.
Many prediction markets' OHLC-style bars over a bounded window
The priced series of up to 25 prediction markets in one request, at one resolution over one bounded window, in OHLC-style bars.
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.
Many prediction markets' state and live outcome prices
Up to 25 prediction markets in one request: each one's lifecycle, windowed stats and the live price of each outcome.

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