Interactive Brokers API guide

What Interactive Brokers offers developers

IBKR is a global broker regulated through local entities (SEC/FINRA and CFTC in the US, FCA in the UK and others). One account can trade stocks, ETFs, options, futures, FX, bonds and more on well over a hundred venues. Developers choose it for breadth, low costs and mature order types, not for ease of setup.

• Good fit: multi-asset or international strategies, options and futures, anyone who needs one account for everything.
• Harder fit: a small script that should run unattended with no desktop software, or a serverless function.

TWS API vs Client Portal (Web) API vs FIX

IB Gateway is a lighter, GUI-less sibling of TWS meant for API use. Either must be logged in for the TWS API to work, and both restart daily, so a production bot needs reconnect logic and a process supervisor.

Market data and historical pacing

Real-time and historical data require market data subscriptions on the account, billed per exchange. Without them you get delayed data or errors. Historical requests are paced: no more than 50 simultaneous requests, and repeated identical or very small-bar requests within short windows trigger pacing violations (error 162).

Python libraries

IBKR ships an official Python client (ibapi) with the TWS API download. Most Python developers use the community ib_async package (the maintained successor of ib_insync), which wraps the callback API in a simpler synchronous/asyncio interface.

from ib_async import IB, Stock, util

ib = IB()
ib.connect("127.0.0.1", 7497, clientId=1)   # paper TWS
contract = Stock("AAPL", "SMART", "USD")
bars = ib.reqHistoricalData(contract, endDateTime="", durationStr="1 Y",
                            barSizeSetting="1 day", whatToShow="TRADES", useRTH=True)
print(util.df(bars).tail())
ib.disconnect()

Common errors and fixes

502 Couldn’t connect to TWS

TWS/Gateway not running, API not enabled, or the wrong port (7497 paper vs 7496 live).

326 client id already in use

Two programs used the same clientId; give each a unique integer.

162 Historical Market Data Service error

Pacing violation or missing data permission; slow down and check subscriptions.

354 Requested market data is not subscribed

Subscribe to the exchange’s data in Client Portal, or request delayed data.

Daily disconnect

TWS and Gateway restart once a day; schedule the restart and reconnect automatically.

Build an Interactive Brokers strategy with AlgoGP

AlgoGP does not connect to Interactive Brokers natively yet. Interactive Brokers connects through a local gateway, socket, FIX or Protobuf stack rather than plain HTTPS, so it runs as a separate process next to your strategy.

1. 1

   Design and backtest in AlgoGP

   Describe the strategy to the copilot and backtest it on years of normalized history. The result does not depend on any vendor.

2. 2

   Export the Python project

   Every project exports strategy.py, market_data.py, brokers.py and live.py. The strategy only sees bars, cash, positions and orders, never a vendor’s wire format.

3. 3

   Plug in Interactive Brokers

   Implement the four adapter methods (account, positions, submit_market_order and a candle fetcher) with Interactive Brokers’s SDK, or keep a built-in platform for paper trading and add Interactive Brokers when you go live.

Built-in brokers for the same markets: Alpaca, Binance, Kraken, Bybit.