Signals
Probabilities
Probabilities are normalized from venue prices into 0 to 1 values so applications can compare outcomes consistently.
How to use probabilities
Use probability for current implied odds, probability_change_24h for movement, best_bid/best_ask/spread for quote quality, and quote_age_seconds to avoid stale signals.
Get Polymarket prices
Fetch current Polymarket outcome probabilities, bid/ask, spread, volume, and quote freshness from TPM outcome rows.
Live GET Request
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Live Response
Click Try It to run this GET request against the API.Request
curl 'https://api.thepredictionmarkets.com/api/v2/polymarket/prices?market_slug=2026-nba-champion&limit=5' \
-H 'X-API-Key: YOUR_TPM_API_KEY'Response
{
"prices": [
{
"market_slug": "2026-nba-champion",
"event_slug": "2026-nba-champion",
"event_title": "2026 NBA Champion",
"title": "Oklahoma City Thunder",
"probability": 0.495,
"best_bid": 0.49,
"best_ask": 0.5,
"spread": 0.01,
"volume": 8208874.22,
"platform_url": "https://polymarket.com/event/2026-nba-champion"
}
],
"count": 1
}Query Parameters
| Name | Type | Required | Default | Example | Description |
|---|---|---|---|---|---|
| market_slug | string | No | - | 2026-nba-champion | Filter prices to one Polymarket market slug. |
| event_slug | string | No | - | 2026-nba-champion | Filter prices to a TPM event slug. |
| condition_id | string | No | - | 0xabc123 | Filter by Polymarket condition ID or stored outcome identifier. |
| outcome | string | No | - | Oklahoma City Thunder | Filter by outcome title substring. |
| limit | integer | No | 25 | 5 | Maximum number of outcome prices to return. |
Response Fields
| Field | Type | Example | Description |
|---|---|---|---|
| market_slug | string | - | Polymarket market slug. |
| title | string | Oklahoma City Thunder | Outcome title. |
| probability | number | null | 0.495 | Current probability (0 to 1). |
| best_bid | number | null | 0.49 | Best bid. |
| best_ask | number | null | 0.50 | Best ask. |
| spread | number | null | 0.01 | Spread. |
| volume | number | 8208874.22 | Outcome volume. |
| quote_age_seconds | number | null | - | Age of the quote in seconds. |
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