Polymarket Odds Snapshot

A Polymarket odds API you can call in one line: structured, analysis-ready odds for exactly the markets you care about — filter by category tag, 24h-volume floor, or an explicit list of market slugs. History mode adds recent price history per market (a time series straight from the public CLOB), so you get both the current snapshot and how the odds moved.

The cheapest way to put live prediction-market probabilities and price history into a spreadsheet, dashboard, model, or AI agent — no blockchain knowledge, no API keys.

Three ways to select markets

1. By slug list — pass market_slugs and get exactly those markets (great for monitoring a fixed watchlist).
2. By category — category: "crypto" (or politics, sports, economy, tech, world, any Polymarket tag slug) returns the highest-volume open markets in that vertical.
3. Top of the whole exchange — leave both empty and get all open markets ordered by 24h volume, optionally with a min_volume_24h floor.

Output

One flat row per market:

{
  "question": "Will Bitcoin go Up or Down on August 4?",
  "market_slug": "bitcoin-up-or-down-on-august-4-2026",
  "condition_id": "0x80942ae6...",
  "outcomes": ["Up", "Down"],
  "outcome_prices": [0.9995, 0.0005],
  "price_by_outcome": {"Up": 0.9995, "Down": 0.0005},
  "yes_price": null,
  "best_bid": 0.999,
  "best_ask": 1.0,
  "spread": 0.001,
  "last_trade_price": 0.999,
  "volume_24h_usd": 1581410.95,
  "volume_total_usd": 74636359.98,
  "liquidity_usd": 23679.26,
  "end_date": "2026-08-05T00:00:00Z",
  "url": "https://polymarket.com/market/bitcoin-up-or-down-on-august-4-2026",
  "snapshot_utc": "2026-08-04T06:10:00+00:00"
}

In history mode each row additionally carries:

{
  "history_interval": "1d",
  "history_fidelity_minutes": 10,
  "price_history": {"Up": [{"t": 1785772808, "p": 0.505}, {"t": 1785773410, "p": 0.515}]},
  "price_history_points": 145
}

(Series covers the market's first outcome token; for binary markets the other side is simply 1 − p.)

Input

Field	Default	Description
mode	current	current or history (history caps markets at 25)
market_slugs	—	Explicit watchlist; overrides other filters
category	—	Polymarket tag slug (crypto, politics, …)
min_volume_24h	0	Volume floor in USD
limit	100	Max markets (by 24h volume, descending)
history_interval	1d	1h, 6h, 1d, 1w, 1m, max
history_fidelity_minutes	10	Series resolution

Use cases

Dashboards and spreadsheets

Schedule hourly, pipe the dataset to Google Sheets/BI, chart real-money probabilities over time.

Forecast benchmarking

Compare your model's probabilities (elections, sports, crypto, Fed decisions) against market consensus — and use history mode to score how the market converged.

Trading research

Spread + liquidity + 24h volume in one flat row makes screening for tradeable markets trivial.

Using from Claude / AI agents (MCP)

Add Apify's MCP server (https://mcp.apify.com) to Claude, Cursor, or any MCP-capable client and your agent can pull live odds and price history mid-conversation:

{
  "tool": "polymarket-odds-snapshot",
  "input": { "category": "politics", "mode": "history", "history_interval": "1w", "limit": 10 }
}

"What does Polymarket say about the next Fed cut, and how did it move this week?" — one call answers both halves.

Data source and fair use

Only Polymarket's public, unauthenticated endpoints (Gamma market data + CLOB price history). No login, no keys. Snapshots are timestamped (snapshot_utc) so downstream consumers always know data freshness.

Pricing

Pay per event: a tiny per-run fee plus a tenth of a cent per market row (and half a cent per market when price history is requested). A 100-market snapshot costs about $0.12.