Durable Facts Store

Goal: Keep a small, high-trust set of project facts agents may rely on without re-deriving every session.

When to use

• Architecture invariants (“we use Postgres, not MySQL”)
• Owners, SLAs, non-goals
• Safety rules that must survive session resets

Tiers

Tier	Role
Durable	Primary
Episodic	Provenance / history of the decision
Scratch	Never

Scheduling

• Write only on explicit decision events (ADR, PR merge, human approve)
• Review quarterly or when audit flags stale facts
• Revoke by marking status: revoked — do not silent-delete without note

Required skills

• memory-write — propose durable entry (draft only)
• memory-verifier — required gate
• memory-recall — always include durable candidates first under budget

State shape

## Durable facts
- id: stack.db
  fact: Primary database is PostgreSQL 16
  confidence: decided
  owner: @platform
  evidence: ADR-0004
  status: active
  as_of: 2026-06-01

How it runs

1. Something becomes “true for the project.”
2. Agent or human drafts durable entry in a promote queue.
3. Verifier checks: evidence present, not secret, not hypothesis, no conflict.
4. Human or policy merges into Durable.
5. Recall always loads active durable facts (subject to budget priority).

Verification strategy

• No durable write without evidence + owner
• hypothesis confidence rejected
• Conflicts: new fact must supersedes: <id>
• Optional CI: memory-audit fails if durable section lacks owners

Human handoff

• Default: human merge for first 30 days
• Later: allow verifier auto-merge only for low-risk namespaces (style.*, tooling.*)

Tool-specific notes

Claude Code / Cursor: durable facts in MEMORY-STATE.md + mirror one-liners in AGENTS.md if short.

Pair with outerloop: durable facts can be evidence-backed verdicts.

Failure modes

Failure	Mitigation
Fact rot	as_of + quarterly hygiene
Over-durable noise	Hard cap (e.g. 50 facts)
Secret leakage	constraints deny-list
Agent overwrites	file ownership + verifier

Cost profile

Scenario	Tokens
Load all durable	~1–4k if kept small
Promote review	~5–10k

Cap: prefer 25–50 active facts. If more, namespace and retrieve.

Scaffold

node tools/memory-init/cli.js . --pattern durable-facts-store --tool grok