Markets

Alpaca

Commission-free US stocks, options, and crypto brokerage API with a free paper-trading environment

• brokerage
• stocks
• options
• +4 more
• +3 more

Kalshi

CFTC-regulated event contract exchange with a documented REST and WebSocket API for algorithmic trading

• prediction-market
• event-contracts
• regulated
• +2 more
• +1 more

Manifold

Play-money prediction market with a fully open API that explicitly invites trading bots

• prediction-market
• play-money
• bots
• +2 more
• +1 more

Polygon.io

Stocks, options, forex, and crypto market data over REST and WebSocket, with a free self-serve API key

• market-data
• stocks
• options
• +3 more
• +2 more

The Odds API

Live and historical sports odds from global bookmakers over a REST API with a free self-serve tier

• odds
• sports
• market-data
• +2 more
• +1 more

Betfair Exchange

Betting exchange with a documented JSON-RPC API for automated market data and bet placement

• betting-exchange
• odds
• automated-betting
• +2 more
• +1 more

Kraken

Spot and futures crypto exchange with documented REST and WebSocket endpoints for order entry

• crypto
• exchange
• spot
• +2 more
• +1 more