Key Features

SPX is built for building testable simulation models and validating them with deterministic, code-driven workflows.

Deterministic simulation control

• Run SPX as a server process (typically in Docker).

• Drive simulation time explicitly from a client (MiL tests) instead of relying on wall-clock time.

• Inspect and mutate runtime state through the API and UI.

Start here:

• Model-in-the-Loop (MiL) with SPX

• Using spx-python for Simulation

Model authoring (YAML + Python)

• Author models as YAML definitions (attributes, actions, timer, communication).

• Extend behavior with custom Python classes via the SDK registry.

Start here:

• SPX SDK

• Extending Simulations

Protocol adapters and integrations

SPX ships with built-in communication adapters (e.g., Modbus, MQTT, HTTP, ASCII/SCPI, BLE) so your Software Under Test can talk to the simulation over the same interfaces as real hardware.

Start here: Communication Adapters.

Scenarios, snapshots, and testing

• Use Scenarios to script repeatable events (fault injection, step changes, sequencing).

• Use Snapshots to capture/restore state for fast iteration and stable tests.

• Wire everything into pytest/CI using docker compose + MiL test helpers.

Start here:

• Scenarios

• Snapshots (Core)

• Use in Unit Tests (MiL)

• Snapshots — Getting Started