dsh-compaction-guard

Compaction integrity for DeepSeek Harness (dsh).

Long sessions compact; the compacted range takes constraints with it — "never commit to main", "必须先跑测试" — and the agent silently forgets rules it was told to keep. This plugin watches compaction/summary session events: it extracts directive lines from the user-authored events being shadowed, verifies each against the summary (verbatim, whitespace-normalized, or in substance — a coverage threshold on content words), and reports every constraint the agent just forgot — console plus a durable JSONL ledger. Pinned constraints from config are verified on every compaction. Zero LLM calls in the trust path.

Family channel #9: read / write / do / call / leave-behind / egress / told / running / remembered — what the agent forgets.

Why now (checked 2026-10-17)

The awesome list has 209 memory plugins and an entire compaction package family in dsh itself — and not one verifies that constraints survive compaction. Memory plugins add recall; this audits loss. The compaction/summary event even ships shadowedSeqs (exactly what was compact away) — the integrity check is deterministic by construction.

How it works

compaction/summary event
  ├── shadowedSeqs → session.eventAt(seq) → user/message directive lines
  ├── pinned constraints from config (always verified)
  ├── verify against the summary text:
  │     verbatim (whitespace-normalized substring)  → kept
  │     content-word coverage ≥ threshold (default 0.6) → kept
  │     otherwise                                     → LOST (reported + ledgered)
  └── ledger: .dsh-compaction-guard/ledger.jsonl (CI-consumable)

Honest limitation, on purpose: word coverage tracks words, not meaning — a summary that rewords "run the tests" as "execute the checks" with no shared vocabulary counts as lost (conservative direction: false alarm, not silent loss). Synonym-aware matching would need embeddings or an LLM, which is exactly what this family refuses to put in the trust path.

Install

dsh plugin --profile default add github:zhengqiuyang/dsh-compaction-guard

Prebuilt lib/ ships in the repo — no build step, no allowBuilds.

Configure

- id: dsh-compaction-guard
  name: dsh-compaction-guard
  config:
    pinned: ["Never force-push to main"]   # always verified, verbatim
    coverage: 0.6
    ledgerPath: .dsh-compaction-guard/ledger.jsonl

Develop

npm install && npm test

Roadmap

• reinject mode: steer the lost constraints back into the session after compaction (default stays observe — auto-injection deserves live testing first)
• Post-compaction reassertion listener (a constraint restated after the summary also counts as survived)
• Turn-boundary constraints (task briefs in the first turn pinned per-turn)

Kill criteria

If dsh ships first-party compaction-integrity verification, this freezes at its last working version with a postmortem here.