# ProbSights

> Prediction market data across Kalshi and Polymarket.

## Docs

- [Cross-venue arbitrage](https://docs.probsights.com/api-reference/arbitrage-current.md): Find fee-adjusted Kalshi ↔ Polymarket arbitrage opportunities.
- [Price spreads](https://docs.probsights.com/api-reference/arbitrage-difference.md): Cross-venue price disagreement for the same outcome.
- [Arbitrage overview](https://docs.probsights.com/api-reference/arbitrage-overview.md): Cross-venue arbitrage opportunities and price spreads.
- [Kalshi historical orderbook](https://docs.probsights.com/api-reference/kalshi-orderbook.md): Full orderbook snapshots for Kalshi markets.
- [Polymarket historical orderbook](https://docs.probsights.com/api-reference/polymarket-orderbook.md): Orderbook snapshots per Polymarket token.
- [Search events](https://docs.probsights.com/api-reference/search-events.md): Find events by text query or series.
- [Search markets](https://docs.probsights.com/api-reference/search-markets.md): Find markets by text query or series.
- [Search overview](https://docs.probsights.com/api-reference/search-overview.md): Discover and filter prediction markets across Kalshi and Polymarket.
- [Related search endpoints](https://docs.probsights.com/api-reference/search-related.md): Combined search, recent listings, and event markets.
- [Search series](https://docs.probsights.com/api-reference/search-series.md): List Kalshi and Polymarket series by text query.
- [Unified historical orderbook](https://docs.probsights.com/api-reference/unified-orderbook.md): Kalshi and Polymarket orderbooks in one response shape.
- [Whale tracking](https://docs.probsights.com/api-reference/whales-overview.md): Monitor large trades across prediction markets.
- [Authentication](https://docs.probsights.com/authentication.md): Authenticate API requests with your API key.
- [Error handling](https://docs.probsights.com/errors.md): HTTP status codes and error response format.
- [ProbSights API](https://docs.probsights.com/index.md): Prediction market data across Kalshi and Polymarket.
- [Rate limits](https://docs.probsights.com/rate-limits.md): Per-tier rate limits and quotas.