Skip to content
WithSoft
← All projects
Automation2026

Brokerage API Automated Trading and Market Data Tools

Multiple individual investors

Delivered automated trading programs to individual investors that receive real-time quotes through multiple brokerage and exchange APIs and place orders when conditions are met.

Deliverables
Desktop programTrading engineNotification integration
Tech
C++ / MFCPythonPySide6Brokerage Open API

Problem

Each investor used a different brokerage and different trading rules. Watching screens during market hours to check conditions and place orders by hand had its limits.

Constraints

  • Many brokerage APIs are 32-bit only, which makes them hard to use alongside modern 64-bit environments.
  • Requests are rejected once per-second or per-hour query limits are exceeded, so call rates had to be controlled.
  • Holdings and order status must stay consistent even if the program shuts down unexpectedly.

Solution

  1. 1

    The 32-bit APIs run in a separate process that communicates with the main program.

  2. 2

    Query requests are paced by a timer, and when a limit is exceeded the program waits and retries.

  3. 3

    Trading state is saved with checksums and backups, and on restart quantities are reconciled against the actual account balance.

  4. 4

    One grid trading engine was reused for US stocks, Korean stocks and cryptocurrency.

Other projects