health-checks.md

Health Checks

Spanda provides unified health monitoring for robots, devices, sensors, actuators, agents, fleets, and swarms.

Health statuses

Healthy, Degraded, Warning, Critical, Failed, Unknown, Offline, Unsafe

Robot health check

health_check RoverHealth for robot Rover {
    check battery.level > 20%;
    check gps.status == Healthy;
    check wheels.status == Healthy;
    check emergency_stop.available == true;
}

Sensor / actuator health

health_check GPSHealth for sensor gps {
    check gps.fix_available == true;
    check gps.accuracy <= 3 m;
}

health_check WheelsHealth for actuator wheels {
    check wheels.temperature < 70 C;
    check wheels.emergency_stop_supported == true;
}

Fleet / swarm health

health_check FleetHealth for fleet WarehouseFleet {
    require at_least 80% robots Healthy;
    require no robot Unsafe;
    check rover.status == Healthy;
}

Fleet require clauses are parsed and evaluated at runtime against fleet membership and monitor faults.

Health policies

health_policy SafetyPolicy {
    on Critical { enter degraded_mode; notify_operator; }
    on Failed { stop_all_actuators; audit.record("health_failed"); }
    on Unsafe { trigger kill_switch EmergencyStop; }
}

At runtime, matching reactions execute when health status transitions (wired to HardwareMonitor polling). Fleet-target checks are refined against fleet membership and member faults via apply_fleet_health_checks. Swarm programs log coordination events when fleet health is critical. Policies latch per (policy, status) until health returns to Healthy.

Example: examples/hardware/capability_verification.sd · Fleet requires: examples/features/fleet_health_require.sd

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Typed handler returns

Return type annotations on behaviors, tasks, triggers, and events are documented in typed-handler-io.md.

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Health triggers

on health Rover becomes Degraded {
    reduce_speed(0.5 m/s);
}

CLI

spanda health robot rover.sd
spanda health robot rover.sd --json
spanda trace health rover.sd
spanda verify rover.sd --health
spanda sim rover.sd --inject-health-faults

See also Fleet Health and Swarm Health.