Rules & Automation

Automation rules let you define how FIXSIM responds to certain messages or patterns, ideal for regression and stress testing.

Example: reject orders > 1000 shares

IF 38 > 1000 THEN
  ExecType = 8        # Reject
  OrdStatus = 8       # Rejected
  Text = "Order exceeds maximum size"
END

Combine multiple rules to simulate venue behavior, risk checks, partial fills, and latency scenarios.