Spanda

Explainability

Status: Stable (static v1) · Phase: Build, Operate, Recover · Priority: P0.3

Help engineers understand code, missions, verification results, and autonomous decisions.

CLI

# Static analysis (Phase A)
spanda explain rover.sd
spanda explain rover.sd --config spanda.toml --baseline approved/
spanda explain readiness --file rover.sd
spanda explain verify --file rover.sd
spanda explain safety --file rover.sd

# Trace decisions (Phase D)
spanda explain decision <mission.trace> [--json]
spanda explain <mission.trace> [--json]

With --config, reports add configuration validation, deployment gates preview (including composite_trust and secure_boot when trust contracts are imported), and package trust sections. All program explains include a composite_trust category breakdown when source is available; programs importing trust.jetson or trust.pi also include a secure_boot section. With --baseline, adds a drift section comparing approved vs live configuration.

Capabilities by phase

Phase Explains
A (static) Source structure, readiness failures, verify failures, safety rule violations, composite trust, secure boot (when trust.jetson / trust.pi imported), config validation, deployment gates, package trust, drift (with --baseline)
B Policy violations, drift deltas
D (trace) Decision, reason, evidence, safety checks, chosen action, rejected actions

AI-assisted development (Area 1)

Experimental — see ai-assisted-development.md.

spanda generate mission [--out patrol.sd]
spanda generate robot
spanda generate health-policy
spanda suggest rover.sd

Crate

spanda-explain — composes spanda-assurance, spanda-readiness, spanda-hardware, and spanda-trust diagnostics.

See diagnostics.md · platform-maturity-roadmap.md.