Audit log signing (ADR-0008)

Every interesting event lands in the audit log. The log is structured for SOC 2, HIPAA, and GDPR review without per-event signing overhead.

Shape

• Events stream through the os-core bus.
• @agentskit/os-audit batches them into Merkle trees.
• Each batch's root references the previous batch's root, forming a chain.
• The chain head can be signed via HSM / KMS in production deployments.

What this gives you

• Tamper-evident by design — flipping one event invalidates the chain.
• Per-event verifiability without per-event signature cost.
• Forwards-compatible with SIEM ingestion.
• Air-gap-friendly — chain export is a single file, importable into any external auditor's verifier.

Source: ADR-0008.