Decision Log
Append-only dated records of decisions and their one-line rationale: what was chosen, why, and what it superseded. The agent-era descendant of architecture decision records.
When to use
Preventing re-litigation: agents (and humans) re-encounter settled questions constantly, and the log answers them without re-deciding.
Specification
| Memory type | episodic |
|---|---|
| Storage | append-only flat file or one file per decision |
| Retrieval | keyword or index lookup on encounter with a settled question |
| Update method | agent- or human-written at decision time; entries never edited, only superseded |
| Decay / staleness handling | Supersession, not deletion: a new dated entry marks the old one overturned, preserving the history that explains the present. |
| Risk level / maturity | low / established |
Privacy and safety
Low; rationale text can leak context, standard write rules apply.
Failure modes
- Decisions recorded without the why, which is the valuable half
- Log unsearched because retrieval was never wired up
- Supersession forgotten, leaving two live answers
Assessment
The cheapest memory pattern per unit of prevented waste. Its failure mode is social, not technical: the discipline of writing the entry at decision time.
Evaluation method: Re-litigation count: how often settled questions get re-argued in sessions.