Decision Ledger · Layer 03
Replay & Calibration
Two mechanisms ensure the system improves over time without silent drift: replay (deterministic re-execution) and calibration (weight tuning from ground truth).
Replay
Any completed task can be replayed from its stored ECO snapshot. Replay re-runs the pipeline logic against the same inputs — it does not re-query the codebase.
nirnex replay --task <id>
# Re-runs classification, strategy selection, and decomposition
# against the stored eco_snapshot. Reports any divergence.
nirnex replay --all --since 30d
# Replays all tasks from the last 30 days.
# Used to verify a system change didn't alter historic behaviour.
What Replay Validates
- Lane classification would produce the same result
- Strategy selection would produce the same result
- TEE scope declarations are unchanged
- Confidence score is identical (deterministic)
Any divergence is flagged as a replay delta and stored in the ledger.
Calibration
Monthly calibration uses accumulated ground truth labels to tune penalty weights in the confidence scoring matrix.
nirnex calibrate --since 30d
# Reads ground_truth_label records from the last 30 days
# Computes penalty weight adjustments
# Outputs proposed changes — does NOT apply automatically
Calibration Rules
- Calibration proposes changes — a human must approve before they are applied
- Any new penalty rule requires a 30-day observation period before being added
- No single calibration cycle may change more than 3 penalty weights
- All weight changes are recorded in the Decision Ledger with the ground truth batch that produced them
Design intent
Calibration is a slow, deliberate process. The system must not chase noise. The 30-day window and 3-weight limit exist to prevent overfitting to recent data.