# Predexon

> Predexon is the data layer for prediction markets: tick-level historical orderbook data, the fastest real-time WebSocket, and blockchain-indexed analytics for Polymarket, Kalshi, and other major venues — through one API.

Predexon is a data-only company. It does not operate a trading venue, match orders, or execute trades. It sells market data and analytics to trading firms, developers, and researchers.

Key facts:
- Orderbook tick history: every placement, update, cancel, and fill on Polymarket, Kalshi, and Opinion (captured since January 2026), at raw, 100ms, 1s, 1m, and 1h granularities, downloadable as zstd-compressed Parquet, finalized daily (T-1, ~06:00 UTC). Slices can be quoted for free before purchase; pricing is $40/GiB (Polymarket) or $80/GiB (Kalshi, Opinion) with a $5 minimum and $50 free credits for new accounts.
- Real-time WebSocket (wss.predexon.com): mempool-aware Polymarket streams delivering updates 3–5 seconds ahead of Polymarket's own RTDS. Seven channels: trades, activity, orderbook, lifecycle, oracle, collateral, and Chainlink crypto prices. Available on Dev plan and above.
- REST API (api.predexon.com): markets, trades, prices, candlesticks, wallet positions and PnL, smart-money leaderboards — Polymarket trade and price history complete since 2020, indexed directly from the blockchain. Venues: Polymarket, Kalshi, Opinion, Limitless, Predict.fun, plus Binance reference data.
- Pricing tiers: Free ($0, 1 req/s), Dev ($49/mo, 20 req/s, WebSocket), Pro ($249/mo, 100 req/s), Enterprise ($499+/mo, custom).
- Used by 1,000+ developers; over 1B API calls served.

## Products

- [Orderbook tick history](https://predexon.com/products/orderbook-tick-history): Historical orderbook data for prediction markets, tick-level, Parquet downloads
- [Real-time WebSocket](https://predexon.com/products/websocket): The fastest prediction market data feed
- [Polymarket data](https://predexon.com/data/polymarket): Real-time and historical Polymarket API
- [Kalshi data](https://predexon.com/data/kalshi): Real-time and historical Kalshi API
- [Polymarket orderbook history](https://predexon.com/data/polymarket/orderbook-history): Tick-level Polymarket book replay, captured since January 2026
- [Kalshi orderbook history](https://predexon.com/data/kalshi/orderbook-history): Tick-level Kalshi book replay
- [Pricing](https://predexon.com/pricing): Free tier available, no credit card required

## Docs

- [API documentation](https://docs.predexon.com): Full REST + WebSocket reference
- [Agent skill](https://docs.predexon.com/skill.md): One-prompt setup for AI coding agents (Claude Code, Cursor, Codex)
- [Dashboard](https://dashboard.predexon.com): Sign up and get an API key

## Blog

- [Blog](https://predexon.com/blog): Guides on prediction market data, Polymarket indexing, and orderbook history