# Polymarket API
> Live prediction-market data from Polymarket, the largest real-money prediction market, via its public Gamma API. On Polymarket people trade shares in the outcome of real-world events, so each market's price is a live, money-backed probability. Get the most active markets, each with its outcomes and their implied probabilities, the best bid and ask, the traded volume and the liquidity. Read one market in full, including its description and resolution date. Pull the biggest events — an event groups related markets, like a championship with one market per team — with their total volume and market count. Get one event with every sub-market and its current probability, the whole field at a glance. Live, no key, nothing stored. Distinct from sports-betting-odds and price-feed APIs — this is Polymarket's money-backed event probabilities and its markets. Perfect for forecasting, trading-signal, news and analytics apps.

## Authentication
All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys.

```bash
curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/polymarket-api/..."
```

## Pricing
- **Free** (Free) — 9,000 calls/Mo, 3 req/s
- **Starter** ($10/Mo) — 158,000 calls/Mo, 6 req/s
- **Pro** ($28/Mo) — 890,000 calls/Mo, 15 req/s
- **Business** ($67/Mo) — 4,850,000 calls/Mo, 40 req/s

## Endpoints

### Markets

#### `GET /v1/market` — One market in full

**Parameters:**
- `id` (query, required, string) — Polymarket market id Example: `703258`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/polymarket-api/v1/market?id=703258"
```

**Response:**
```json
{
    "data": {
        "id": "703258",
        "slug": "will-jesus-christ-return-before-2027",
        "active": true,
        "closed": false,
        "source": "Polymarket",
        "best_ask": 0.022,
        "best_bid": 0.021,
        "category": null,
        "end_date": "2026-12-31T00:00:00Z",
        "outcomes": [
            {
                "outcome": "Yes",
                "probability_pct": 2.15
            },
            {
                "outcome": "No",
                "probability_pct": 97.85
            }
        ],
        "question": "Will Jesus Christ return before 2027?",
        "start_date": "2025-11-25T18:08:21.296Z",
        "volume_usd": 63651490.63,
        "description": "This market will resolve to \"Yes\" if The Second Coming of Jesus Christ occurs by December 31, 2026, 11:59 PM ET. Otherwise, this market will resolve to \"No\".\n\nThe resolution source for this market will be a consensus of credible sources.",
        "liquidity_usd": 787286.16,
        "last_trade_price": 0.022
    },
    "meta": {
        "timestamp": "2026-06-10T14:02:18.211Z",
        "request_id": "81e4d832-89ca-40c0-a9aa-ffa2ab7b624b"
    },
    "status": "ok",
    "message": "Market retrieved successfully",
    "success": true
}
```

#### `GET /v1/markets` — Most active markets with probabilities

**Parameters:**
- `sort` (query, optional, string) — volume or liquidity Example: `volume`
- `limit` (query, optional, string) — Max 1-100 Example: `25`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/polymarket-api/v1/markets?sort=volume&limit=25"
```

**Response:**
```json
{
    "data": {
        "sort": "volume",
        "count": 25,
        "source": "Polymarket",
        "markets": [
            {
                "id": "703258",
                "slug": "will-jesus-christ-return-before-2027",
                "active": true,
                "closed": false,
                "best_ask": 0.022,
                "best_bid": 0.021,
                "end_date": "2026-12-31T00:00:00Z",
                "outcomes": [
                    {
                        "outcome": "Yes",
                        "probability_pct": 2.15
                    },
                    {
                        "outcome": "No",
                        "probability_pct": 97.85
                    }
                ],
                "question": "Will Jesus Christ return before 2027?",
                "volume_usd": 63651490.63,
                "liquidity_usd": 787286.16,
                "last_trade_price": 0.022
            },
            {
                "id": "558960",
                "slug": "will-uzbekistan-win-the-2026-fifa-world-cup-773",
                "active": true,
                "closed": false,
                "best_ask": 0.001,
                "best_bid": null,
                "end_date": "2026-07-20T00:00:00Z",
                "outcomes": [
                    {
                        "outcome": "Yes",
                        "probability_pct": 0.05
                    },
                    {
                        "outcome": "No",
                     
…(truncated, see openapi.json for full schema)
```

### Events

#### `GET /v1/event` — One event + every sub-market probability

**Parameters:**
- `id` (query, required, string) — Polymarket event id Example: `30615`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/polymarket-api/v1/event?id=30615"
```

**Response:**
```json
{
    "data": {
        "id": "30615",
        "slug": "world-cup-winner",
        "title": "World Cup Winner ",
        "source": "Polymarket",
        "markets": [
            {
                "id": "558934",
                "question": "Will Spain win the 2026 FIFA World Cup?",
                "volume_usd": 35686861.16,
                "probability_pct": 16.35
            },
            {
                "id": "558936",
                "question": "Will France win the 2026 FIFA World Cup?",
                "volume_usd": 42729871.37,
                "probability_pct": 16.05
            },
            {
                "id": "558940",
                "question": "Will Portugal win the 2026 FIFA World Cup?",
                "volume_usd": 37042929.43,
                "probability_pct": 10.95
            },
            {
                "id": "558935",
                "question": "Will England win the 2026 FIFA World Cup?",
                "volume_usd": 30906456.24,
                "probability_pct": 10.85
            },
            {
                "id": "558938",
                "question": "Will Argentina win the 2026 FIFA World Cup?",
                "volume_usd": 32421221.42,
                "probability_pct": 8.55
            },
            {
                "id": "558937",
                "question": "Will Brazil win the 2026 FIFA World Cup?",
                "volume_usd": 32309036.87,
                "probability_pct": 8.45
            },
            {
               
…(truncated, see openapi.json for full schema)
```

#### `GET /v1/events` — Biggest events with volume

**Parameters:**
- `limit` (query, optional, string) — Max 1-100 Example: `25`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/polymarket-api/v1/events?limit=25"
```

**Response:**
```json
{
    "data": {
        "count": 25,
        "events": [
            {
                "id": "30615",
                "slug": "world-cup-winner",
                "title": "World Cup Winner ",
                "end_date": "2026-07-20T00:00:00Z",
                "volume_usd": 1877501548.55,
                "market_count": 60,
                "liquidity_usd": 368432174.42
            },
            {
                "id": "30829",
                "slug": "democratic-presidential-nominee-2028",
                "title": "Democratic Presidential Nominee 2028",
                "end_date": "2028-11-07T00:00:00Z",
                "volume_usd": 1191662480.1,
                "market_count": 128,
                "liquidity_usd": 66260142.01
            },
            {
                "id": "31875",
                "slug": "republican-presidential-nominee-2028",
                "title": "Republican Presidential Nominee 2028",
                "end_date": "2028-11-07T00:00:00Z",
                "volume_usd": 654912804.85,
                "market_count": 128,
                "liquidity_usd": 46034429.63
            },
            {
                "id": "31552",
                "slug": "presidential-election-winner-2028",
                "title": "Presidential Election Winner 2028",
                "end_date": "2028-11-07T00:00:00Z",
                "volume_usd": 623650873.28,
                "market_count": 128,
                "liquidity_usd": 35787468.22
            },
            {
     
…(truncated, see openapi.json for full schema)
```


---
Marketplace page: https://www.oanor.com/api/polymarket-api
OpenAPI spec: https://www.oanor.com/api/polymarket-api/openapi.json