FIXSIM
Simulate a FIX Counterparty
A FIX counterparty simulator acts like the other side of your FIX session—accepting connections, validating messages, and generating responses based on deterministic rules. This lets you test faster and with far fewer dependencies.
If you are trying to validate your FIX integration before a broker is available, start with test FIX without a counterparty.
What a Counterparty Simulator Should Cover
- Session behavior: logon rules, heartbeats, disconnects
- Recovery: resend requests, duplicates, gap handling
- Validation: required tags, supported message types, business rejects
- Order flows: acks, partial fills, fills, cancels, cancel rejects
- Failure cases: timeouts, delayed responses, reject scenarios
Common Simulation Use Cases
- Developing a new integration without waiting on a broker environment
- QA regression testing after releases
- Certification rehearsal before formal onboarding
- Reproducing production issues with replayable scenarios
If you are trying to validate your FIX integration before a broker is available, start with test FIX without a counterparty.
How FIXSIM Helps
FIXSIM can emulate counterparty behavior in a controlled way so your team can iterate quickly, validate edge cases, and keep scenarios as regression tests.
Run These Test Cases in a FIX Simulator
To run these scenarios in a controlled environment, use a FIX protocol simulator that can emulate counterparties, replay message flows, and validate session behavior before certification.
