# MON-01 Per-step logging (Critical)

Domain: MON Continuous Monitoring & Human Oversight · HI-AAF v1.3 · Public review · https://humanintel.net/standard/mon/mon-01

Every agent step is logged: input, reasoning trace, tool calls, tool results, memory reads and writes, and final output. Logs are immutable, time-stamped, and attributable.

Per-step logging is the runtime substrate that makes everything else possible. Without it, no incident is investigable, no drift is detectable, and no control is auditable. MON-01 requires that the full trace of agent reasoning and action be captured, retained, and accessible for retrospective review. In multi-agent topologies, MAS-06 extends per-hop logging requirements.

Critical control: a Critical failure precludes HI-AAF Certification regardless of the maturity level achieved on any other control.

## Maturity

- L1 Ad hoc: Controls exist informally; documentation is incomplete; no consistent review.
- L2 Documented: Controls are written down; ownership is assigned; review cadence is defined.
- L3 Operated: Controls are followed in practice; evidence is collected; deviations are tracked. Published criterion for MON-01: All production agents log per-step traces to a tamper-evident store; sampling-based review of traces occurs at a documented cadence; retention is enforced by deterministic process.
- L4 Measured: Control effectiveness is measured against documented thresholds; trends are reported.
- L5 Continuously Improved: Controls evolve based on incident learning; maturity gains are evidenced over time.

## Evidence an assessor asks for

- All production agents log per-step traces to a tamper-evident store.
- Sampling-based review of traces occurs at a documented cadence.
- Retention is enforced by deterministic process.

## Framework mappings

- NIST AI RMF: MANAGE 4.1, MEASURE 1.1
- ISO/IEC 42001: A.9.2
- SOC 2 (TSC): CC7.2, CC7.3
- EU AI Act: Art. 14(4)
- Singapore: MAIGF Incident Reporting, AI Verify Human Agency & Oversight

Mappings are directional: meeting this control evidences but does not by itself satisfy the external requirement.

## Related

- Cites MAS-06 Per-hop invocation logging: https://humanintel.net/standard/mas/mas-06
- Cited by DAT-13 Retrieved memory traceability: https://humanintel.net/standard/dat/dat-13
- Cited by OUT-13 Explainability for consequential decisions: https://humanintel.net/standard/out/out-13
- Cited by MAS-06 Per-hop invocation logging: https://humanintel.net/standard/mas/mas-06
- Glossary: Decision path: https://humanintel.net/standard/glossary#decision-path

## Cite this control

Human Intelligence. HI-AAF v1.3, MON-01 Per-step logging. Public review edition, July 2026. https://humanintel.net/standard/mon/mon-01