polymarket.markets

stable Advanced

Top active prediction markets by 24h volume (Gamma).

GET /v1/polymarket/markets

What you get#

A list of Polymarket results in Onekey's unified shape, in data (an array). An empty array is a normal, successful answer and is charged like any other; a source that reports "nothing found" as an error returns a free 404 not_found instead.

What it costs#

Advanced · 5 credits for a fresh fetch, charged only when it succeeds.
Free when served from cache (0.2 credit for a cached response over 100 KB).
Free if the request is invalid (never charged) or the source fails or reports not found (refunded).

Parameters#

Name	Type	Required	Default	What it is	Constraints
`limit`	string	no	`20`	Rows (1-100)	max 3 chars; must match `[1-9]\d?\|100`; trimmed

Request#

curl "https://api.onekey.dev/v1/polymarket/markets?limit=5" \
  -H "x-api-key: YOUR_API_KEY"

Try it

Add your key to run this call right here. No key? Get one free. The key stays in this tab.

Recorded response#

A real Polymarket response, recorded and returned in Onekey's shape. Fields the platform does not provide are null.

json

{
  "success": true,
  "data": [
    {
      "entity": {
        "id": "4581768",
        "name": "Will France win on 2026-09-28?",
        "slug": "unl-bel-fra-2026-09-28-fra",
        "description": "In the upcoming game, scheduled for September 28, 2026\nIf France wins, this market will resolve to \"Yes\".\nOtherwise, this market will resolve to \"No\".\nIf the game is postponed, this market will remain open until the game has been completed.\nIf the game is canceled entirely, with no make-up game, this market will resolve \"No\".\nThis market refers only to the outcome within the first 90 minutes of re",
        "date": "2026-09-28T18:45:00Z"
      },
      "media": {
        "thumbnailUrl": "https://polymarket-upload.s3.us-east-2.amazonaws.com/soccer-leagues/unl.png"
      },
      "market": {
        "volume": 3781854.5237449966,
        "liquidity": 85157.6582,
        "volume24h": 3582687.5046109967,
        "price": 0.45,
        "bid": 0.45,
        "ask": 0.48,
        "change24h": -0.05
      },
      "ext": {
        "outcomes": "[\"Yes\", \"No\"]",
        "outcomePrices": "[\"0.465\", \"0.535\"]",
        "tokenIds": "[\"110842582318648062017260301759054663836028300201858808991939499354773358824458\", \"6570736768586531778305906800330243503420851954788128056678194310642051325190\"]",
        "conditionId": "0xe40546397445aa9bfcc7017184a52197e74af1539e71a1afa2b443e21dd2db64",
        "active": true,
        "closed": false
      }
    },
    {
      "entity": {
        "id": "4581765",
        "name": "Will Belgium win on 2026-09-28?",
        "slug": "unl-bel-fra-2026-09-28-bel",
        "description": "In the upcoming game, scheduled for September 28, 2026\nIf Belgium wins, this market will resolve to \"Yes\".\nOtherwise, this market will resolve to \"No\".\nIf the game is postponed, this market will remain open until the game has been completed.\nIf the game is canceled entirely, with no make-up game, this market will resolve \"No\".\nThis market refers only to the outcome within the first 90 minutes of r",
        "date": "2026-09-28T18:45:00Z"
      },
      "media": {
        "thumbnailUrl": "https://polymarket-upload.s3.us-east-2.amazonaws.com/soccer-leagues/unl.png"
      },
      "market": {
        "volume": 1397412.7940300002,
        "liquidity": 56687.7329,
        "volume24h": 1371144.8430900003,
        "price": 0.2,
        "bid": 0.17,
        "ask": 0.19,
        "change24h": -0.075
      },
      "ext": {
        "outcomes": "[\"Yes\", \"No\"]",
        "outcomePrices": "[\"0.18\", \"0.82\"]",
        "tokenIds": "[\"67144485481037824353658978599351365276404964132594238946384478254500444104495\", \"25618814946951455596920857136845723066153921784361858128141971994013676014089\"]",
        "conditionId": "0x3d0e110a6fb9ae0caebe8808b40b7e27de398af0d373e69ea6abb9bdbae61b3e",
        "active": true,
        "closed": false
      }
    }
  ],
  "metadata": {
    "platform": "polymarket",
    "endpoint": "markets",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 5,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}

Field mapping#

How this endpoint's source fields become Onekey's unified schema. Fields the source lacks come back as null.

Source path	Onekey field	Transform
`id`	`entity.id`	`toString`
`question`	`entity.name`	-
`slug`	`entity.slug`	-
`description`	`entity.description`	-
`image`	`media.thumbnailUrl`	`safeUrl`
`endDate`	`entity.date`	`toIsoDate`
`volume`	`market.volume`	`toNumber`
`liquidity`	`market.liquidity`	`toNumber`
`volume24hr`	`market.volume24h`	`toNumber`
`lastTradePrice`	`market.price`	`toNumber`
`bestBid`	`market.bid`	`toNumber`
`bestAsk`	`market.ask`	`toNumber`
`oneDayPriceChange`	`market.change24h`	`toNumber`
`outcomes`	`ext.outcomes`	-
`outcomePrices`	`ext.outcomePrices`	-
`clobTokenIds`	`ext.tokenIds`	-
`conditionId`	`ext.conditionId`	-
`active`	`ext.active`	`toBoolean`
`closed`	`ext.closed`	`toBoolean`

Caching and freshness#

Fresh for about 2 minutes. Repeat calls in that window are served from cache and are free.
Between 2 minutes and 15 minutes the cached copy is still served instantly and marked stale: true while Onekey refreshes it in the background.
If the source is down when a refresh is needed, the last copy can be served for up to 1 hour more (marked stale).
A "not found" is remembered for 1 minute and is free.
The cache is shared across all customers, which is what keeps repeat calls cheap.

What can go wrong#

Status	Code	What to do
401	`unauthorized`	Check the `x-api-key` header.
402	`insufficient_credits`	Add credits; your balance must cover the price.
404	`not_found`	Unknown endpoint path.
422	`invalid_params`	Fix the parameters using the table above. Free.
429	`rate_limited`	Wait `Retry-After` seconds, then retry.
502	`upstream_error`	The source failed. Refunded; retry with backoff.

See Errors for the full list and retry guidance.

Status: stable (verified against the live source).