If you're writing your own bot (in Python, JavaScript or anything else), the broker API is the foundation. The things that matter most: which assets you can trade, what the API and commissions cost, whether there's a paper/sandbox environment, and any account minimums. Here are six broker APIs worth knowing, checked against each broker's own pages.
| Broker | Assets via API | API cost | Stock commissions | Notes |
|---|---|---|---|---|
| Alpaca | Stocks, ETFs, options, crypto | Free | $0 via Trading API | Paper trading API; REST/FIX; SDKs; MCP server |
| Interactive Brokers | Global multi-asset | Free with account | $0 on IBKR Lite; Pro Fixed $0.005/share | TWS API (C++, C#, Java, Python), Client Portal API, FIX |
| Tradier | Stocks, options (futures, crypto listed) | Included | Lite $0.35/trade; Pro $0 | Plans: Lite $0, Pro $10, Pro Plus $35/mo |
| Public | Stocks, ETFs, options, index options, bonds, crypto | Free, no fees for calls | Commission-free | Rebates on stock & ETF options |
| TradeStation | Stocks, options, futures | No subscription cost | $0 stocks & ETFs | API key after funding $10,000 minimum |
| tastytrade | Equities, options, futures, futures options, crypto | Open API | $0 stocks | Options $1/contract to open ($10 max/leg), $0 to close |
Prices in USD as listed on October 27, 2026. Prices and promos change; confirm on the tool’s site before buying.
Alpaca: easiest start for developers
Alpaca is built API-first. Its site describes commission-free stock and options trading through the Trading API, a separate Paper Trading API that doesn't use real money, REST and FIX integration, 24/5 trading, and SDKs for Python, .NET/C#, Go and Node. It also offers crypto and an MCP server for AI-driven trading. Best for: first-time bot builders and US stocks/options/crypto.
Interactive Brokers: the most markets
Interactive Brokers offers the TWS API, now open source under the GPL, for C++, C#, Java, Python, ActiveX, RTD and DDE, plus a Client Portal (web) API and FIX for higher-volume setups. US stocks and ETFs are $0 with IBKR Lite; IBKR Pro Fixed is USD 0.005 per share and Tiered starts at USD 0.0035. Best for: global, multi-asset bots. Trade-off: steeper learning curve, and the TWS API needs TWS or IB Gateway running.
Tradier: the options-bot favorite
Tradier prices by plan: Lite $0/mo ($0.35 per stock trade and per equity option contract), Pro $10/mo ($0 stocks and equity options; index options $0.35) and Pro Plus $35/mo (index options $0.10). The API is included, and it now lists an MCP server. Many options platforms, including Option Alpha, connect to it. Best for: options strategies with frequent trades.
Public: free API with options rebates
Public says its trading API is free to use with no fees for access or calls (standard trading fees may still apply to some trades). It covers stocks, ETFs, options, index options, bonds and crypto, supports multi-leg strategies, and pays rebates on stock and ETF options contracts. Best for: budget-conscious options traders who want a simple API.
TradeStation: strong for futures, with a minimum
TradeStation gives API access with no subscription cost, but its API page says you get your API key after opening an account and funding it with a minimum balance of $10,000. Stock and ETF commissions are $0 on its standard pricing. It also supports EasyLanguage strategies inside its own platform. Best for: traders who want stocks, options and futures under one account and already meet the minimum.
tastytrade: options and futures with a modern REST API
tastytrade publishes an Open API, a REST/JSON API for equities, options, futures, futures options and crypto, with real-time and historical quotes, option chains with Greeks, and an open-source MCP server where order submission is gated by a dry-run-first confirmation. Pricing: $0 stock commissions; stock and ETF options are $1 per contract to open (capped at $10 per leg) and $0 to close. Best for: options and futures traders who code.
No-code alternative
Not writing code? Bridges like TradersPost and SignalStack connect TradingView alerts to several of these brokers. TradersPost lists Alpaca, Interactive Brokers (beta), Tradier, TradeStation and tastytrade among its connections.
How we checked
Every price, plan limit and feature on this page was read from the tool’s own pricing, help or product pages on October 27, 2026 (links under Sources). We don’t copy numbers from other review sites. Where a vendor didn’t publish a figure clearly, we say so instead of guessing. Vendors change prices and run promotions often, so treat the table as a snapshot and confirm on the vendor’s site before you pay. Spot something out of date? Email us and we’ll re-check it.
FAQ
Which broker API is best for beginners?
Alpaca is the usual starting point: it's API-first, has a separate paper trading API, SDKs in Python, .NET, Go and Node, and commission-free stock and options trading through its Trading API.
Is the Interactive Brokers API free?
IBKR's APIs (TWS API, Client Portal API, FIX) come with an account; normal commissions apply. US stocks and ETFs are $0 on IBKR Lite.
Does TradeStation charge for API access?
TradeStation says there's no subscription cost for its API, but its API page says your key is issued after you fund an account with a minimum balance of $10,000.
Which broker API is best for options bots?
Tradier (Pro plan: $0 equity options commissions for $10/mo), tastytrade ($1/contract to open, capped at $10 per leg, $0 to close) and Public (commission-free with options rebates) are all popular options choices.
Sources
- https://alpaca.markets/
- https://www.interactivebrokers.com/en/trading/ib-api.php
- https://www.interactivebrokers.com/en/pricing/commissions-stocks.php
- https://tradier.com/individuals/pricing
- https://public.com/api
- https://www.tradestation.com/platforms-and-tools/trading-api/
- https://www.tradestation.com/pricing/
- https://developer.tastytrade.com/
- https://tastytrade.com/pricing/
- https://traderspost.io/connections