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
Compatibility
- DSH: verified against the 0.2.x line (source snapshot 0.2.1-alpha.2); installs on any profile via
dsh plugin add (prebuilt lib/, no build approval).
- Node: >= 20 (CI matrix: Node 20/22/24 on Ubuntu and Windows).
- Disposable-profile evidence (2026-10-19):
dsh plugin --profile <fresh> add github:zhengqiuyang/dsh-compaction-guard → installed in 30s; boot shows [dsh-compaction-guard] active: …; dsh plugin --profile <fresh> remove dsh-compaction-guard → dependencies cleared, bundles restored.
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.
