Quick answer
For US stocks with the least setup, Alpaca is the best broker API: plain API-key REST, free paper trading and free IEX data. Interactive Brokers has the widest market access but needs TWS or IB Gateway running. TradeStation and Schwab cover stocks and options (TradeStation adds futures) behind OAuth logins. Tradier is the developer pick for options; Saxo for multi-asset outside the US.
Side-by-side comparison
| API | Markets | Auth | Paper / sandbox | Pricing | In AlgoGP |
|---|---|---|---|---|---|
| Alpaca | Stocks, ETFs, Crypto | REST + API key | Paper trading account with simulated fills | Free account; free IEX market data plan | Built into AlgoGP |
| Interactive Brokers | Stocks, ETFs, Options, Futures, Forex, Bonds, Crypto | Local gateway | Paper trading account (TWS port 7497, Gateway 4002) | API free with account; market data subscriptions extra | Guide |
| TradeStation | Stocks, ETFs, Options, Futures | OAuth login | Simulated (SIM) trading account | API free; funded account needed for a key | Guide |
| Charles Schwab Trader API | Stocks, ETFs, Options | OAuth login | — | API free with a Schwab account | Guide |
| Tradier | Stocks, ETFs, Options | REST + API key | Sandbox paper account (15-minute delayed data) | Free API with a brokerage account | Built into AlgoGPPro |
| Saxo OpenAPI | Stocks, ETFs, Options, Futures, Forex, CFDs, Bonds | OAuth login | Simulation environment; 24-hour developer token | API free; non-FX market data needs entitlements | Guide |
Which one should you pick?
Alpaca if you trade US stocks, ETFs or crypto and want the fastest path from code to paper trading.
Build with AlpacaInteractive Brokers if you need global markets, futures, FX or bonds in one account and can run a gateway.
Build with Interactive BrokersTradeStation if you want stocks, options and futures through one REST API with a SIM account.
Build with TradeStationTradier if options strategies are the focus and you want a simple bearer-token API.
Build with TradierCharles Schwab Trader API if your account is at Schwab (formerly TD Ameritrade).
Build with Charles Schwab Trader APISaxo OpenAPI if you are outside the US and need equities, FX and derivatives together.
Build with Saxo OpenAPI
How to choose
- Authentication friction: API keys (Alpaca, Tradier) take minutes; OAuth (Schwab, TradeStation, Saxo) needs a browser login and token refresh; IBKR needs a running gateway.
- Paper trading: all six offer a paper, SIM or demo environment except Schwab, where you test with small live orders.
- Markets: futures narrow the field to IBKR, TradeStation and Saxo (plus futures-only platforms such as Tradovate).
- Data costs: real-time consolidated US data is usually a paid add-on; budget for it separately from the API.
Frequently asked questions
Which broker has the best API for beginners?
Alpaca: API keys, free paper trading and good docs make it the quickest to get working.
Is the Interactive Brokers API worth the complexity?
Yes if you need its markets; no if you only trade US stocks, where Alpaca or Tradier are simpler.
Which broker APIs support futures?
Interactive Brokers, TradeStation and Saxo among these; Tradovate and Rithmic are futures specialists.
Test the strategy before you pick the API
Describe your idea to AlgoGP’s copilot, backtest it on years of stock, crypto or forex data with realistic costs, then export Python wired to Alpaca or any built-in broker. Swap the broker later without touching the strategy.
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AlgoGP is not affiliated with any provider listed. Details change; check each provider’s documentation. Nothing here is investment advice.