# polymarket.market

**stable** **Standard**

One prediction market by slug (Gamma).

`GET /v1/polymarket/market`

## What you get

One Polymarket record in Onekey's unified shape, in `data`. If the record does not exist you get a `404 not_found` and are not charged.

## What it costs

- **Standard · 1 credit** 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 |
| --- | --- | --- | --- | --- | --- |
| `slug` | string | yes | (required) | Market slug | max 151 chars; must match `[a-z0-9][a-z0-9-]{0,150}`; trimmed, lowercased |

## Request

```bash
curl "https://api.onekey.dev/v1/polymarket/market?slug=will-lebron-james-win-the-2028-us-presidential-election" \
  -H "x-api-key: YOUR_API_KEY"
```

```python
import requests

res = requests.get(
    "https://api.onekey.dev/v1/polymarket/market",
    params={"slug": "will-lebron-james-win-the-2028-us-presidential-election"},
    headers={"x-api-key": "YOUR_API_KEY"},
)
body = res.json()

if body["success"]:
    print(body["data"])
else:
    print(body["error"]["code"], body["error"]["message"])
```

```javascript
const params = new URLSearchParams({ slug: "will-lebron-james-win-the-2028-us-presidential-election" });
const res = await fetch(`https://api.onekey.dev/v1/polymarket/market?${params}`, {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const body = await res.json();

if (body.success) console.log(body.data);
else console.error(body.error.code, body.error.message);
```

## 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": "561251",
      "name": "Will LeBron James win the 2028 US Presidential Election?",
      "slug": "will-lebron-james-win-the-2028-us-presidential-election",
      "description": "The 2028 US Presidential Election is scheduled to take place on November 7, 2028.\n\nThis market will resolve to the person who wins the 2028 US Presidential Election.\n\nThe resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race for the same candida",
      "date": "2028-11-07T00:00:00Z"
    },
    "media": {
      "thumbnailUrl": "https://polymarket-upload.s3.us-east-2.amazonaws.com/Lebron_James.png"
    },
    "market": {
      "volume": 54782190.51410801,
      "liquidity": 2532017.60257,
      "volume24h": 148.3,
      "price": 0.001,
      "bid": null,
      "ask": 0.001,
      "change24h": null
    },
    "ext": {
      "outcomes": "[\"Yes\", \"No\"]",
      "outcomePrices": "[\"0.0005\", \"0.9995\"]",
      "tokenIds": "[\"39223330966352513418907732239455948906399882924787587183466504819170775983376\", \"50862799703982327636174441241062907649998751737045006653560124656563256528691\"]",
      "conditionId": "0x836b850fc838195374862551a36f1c8691d96ff01e58b0a071f0fc1a0e357fb1",
      "active": true,
      "closed": false
    }
  },
  "metadata": {
    "platform": "polymarket",
    "endpoint": "market",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 1,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}
```

## Field mapping

How this endpoint's source fields become Onekey's [unified schema](https://onekey.dev/docs/schema.md). 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 30 minutes. Repeat calls in that window are served from cache and are free.
- Between 30 minutes and 6 hours 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 day more (marked stale).
- A "not found" is remembered for 5 minutes 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](https://onekey.dev/pricing); your balance must cover the price. |
| 404 | `not_found` | That record does not exist. Free; do not retry. |
| 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](https://onekey.dev/docs/errors.md) for the full list and retry guidance.

Status: stable (verified against the live source).