Quick answer
Choose Alpaca for US stocks, ETFs and crypto when you want plain REST with API keys and free paper trading. Choose Interactive Brokers when you need global stocks, futures, FX or bonds and can run TWS or IB Gateway with paced historical requests and paid data subscriptions.
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 |
Which one should you pick?
Alpaca if speed of setup, serverless deployment and US markets matter most.
Build with AlpacaInteractive Brokers if market breadth, futures and international access matter most.
Build with Interactive Brokers
Key differences
| Alpaca | Interactive Brokers | |
|---|---|---|
| Connection | HTTPS REST + WebSocket | Socket to TWS / IB Gateway |
| Auth | Two API key headers | Logged-in gateway session |
| Paper | Separate paper keys and host | Paper login, port 7497 / 4002 |
| Markets | US stocks, ETFs, options, crypto | 150+ markets, futures, FX, bonds |
| Data | Free IEX; $99/mo all exchanges | Per-exchange subscriptions |
| Python | alpaca-py | ib_async, ibapi |
Frequently asked questions
Can I start on Alpaca and move to IBKR later?
Yes. Keep the strategy separate from the broker adapter (AlgoGP exports do this) and swap the adapter.
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.