PerryLink/dsh-defend

🛡️ dsh-defend

• 1024 store channel: npm i -g dsh1024 once, then dsh1024 plugin --profile web add dsh-defend (counts toward the deepseek1024.com install ranking).

Prompt-injection, jailbreak, and secret-leak defense for DeepSeek Harness.

Rules decide the known. Interception decides the rest — and everything is audited.

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📖 Ecosystem knowledge base — measured data, not marketing: plugin development guide · plugin-selection data · maintenance criteria.

⭐ 如果它帮到了你

这个插件是 DSH 插件家族的一员（40+ 个，全部 Apache-2.0）。如果你在用，给个 star —— 它不会解锁任何功能，但会让下一个人在搜索里更容易找到它。

English: part of a 40+ plugin family for DeepSeek Harness. If it is useful, a star helps the next person find it — nothing is gated behind it.

Maintenance status: 🧊 FROZEN

Frozen on 2026-10-05. No new features. This package still works, and it is not retired — but it no longer receives feature work. Only a genuine breakage will be fixed.

Maintainers treat this capability as one where better-adopted alternatives now exist, so effort has moved elsewhere. The comparison below was measured on 2026-10-05 and is recorded so nobody has to redo it.

	package	weekly downloads
this package	dsh-defend	937
better-adopted alternative	cc-safety-net	13,087

Why the alternative leads. cc-safety-net provides blocks destructive commands and secret-file access as a coding-agent CLI hook.

Compatibility. declares no dsh peers, so the compatibility guard never blocks it.

What this package still does that the alternatives do not. this package's differentiators are the Aho-Corasick pattern engine ported from the prompt-injection / jailbreak / secret-leaker asset sets, three-way allow/ask/block interception on user messages, tool arguments AND tool results, and sanitized defend/* session audit events. The rival above is narrower (destructive commands and secret files) but is adopted an order of magnitude more widely.

👉 For new work, prefer dsh-defend is still the broader detector; cc-safety-net is the far better-adopted alternative for the destructive-command gate specifically. Existing installs keep working unchanged; nothing is being removed.

Full evidence, including the host-version compatibility matrix: dsh-plugin-supersession-review-20261005.md.

Compatibility

Surface	Status
Harness	DeepSeek Harness dsh-v0.2.1-alpha.1 (verified 2026-09-25; peer ranges >=0.1.2-rc.1 <0.2.0 || >=0.1.5-alpha.1 <0.2.0 || >=0.1.6-0 <0.2.0 || >=0.1.7-0 <0.2.0). On this line Session.append's third argument exists only for surface-eligible event types and is a SurfaceIntent, so the non-surface defend/detection type still cannot stamp the ignorable marker: session-log audit stays fail-closed-disabled and /defend renders that state explicitly. Session format V4 has no tool-result content block — this plugin never produced one, and its two content walkers keep a read-only fallback for the retired V3 wrapper so sessions written before the upgrade still scan. Verified 2026-09-25 (dual typecheck rulers + full test suite + build + self-contained/artifacts gates + pack; exactly one copy of the host type graph).
Node	^22.19.0 || >=24.0.0
Platforms	All (pure host; no native code, no network)
Model	Any (detection runs before content reaches the model)

What you get

dsh-defend puts two independent layers in front of the agent:

1. Destructive-delete guard — the executable form of the 8·14/8·16 postmortem lesson. On tools/pre-execute, recursively deleting shell commands are refused unless every target is an explicit absolute path inside the session workspace and outside the protected prefixes (home config, .dsh/.claude, system directories). Dry-run markers (-WhatIf, --dry-run, git clean -n) pass, because they are exactly the check the lesson demands.
2. Detection layer — ported from four upstream assets (all Apache-2.0, see THIRD_PARTY_NOTICES.md): 25 Prompt-Injection-Payloads rules, 25 Jailbreak-Detector patterns through a pure-TypeScript Aho-Corasick automaton, 12 secret grammars from Secret-Key-Leaker-Detect plus the issuers' public references, and the Prompt-Attack-Dataset kept verbatim as the regression benchmark.

Three interception points, one decision model each:

Point	Scanned	Decision
agent/pre-step	inbound user messages	allow → next(); ask → approval; block → reject the step
tools/pre-execute	tool arguments	allow → next(); ask → approval; block → deny
tools/post-execute	tool results	allow → next(); ask → approval; block → corrective feedback

Defaults: ask for every family, block for critical secrets (the upstream interrupt-on-sight semantics). No approval answerer = fail closed. Every pass-through calls next() — downstream policy plugins are never short-circuited.

inbound message ── agent/pre-step ── scan ── clean → next()/enter
tool arguments ── tools/pre-execute ── scan ── allow → next()
tool results   ── tools/post-execute ── scan ── block → feedback
                                  │
                                  └─ defend/detection audit (rule id, family,
                                     severity, decision — never matched text)

Quick start

# 1. install the bundle into your profile
dsh plugin --profile web add "github:PerryLink/dsh-defend#main"

# or from npm (published releases)
dsh plugin --profile web add dsh-defend

# 2. restart and verify the row
dsh --profile web --dump-config | grep -A3 'id: dsh-defend'

Install & uninstall

• git channel (latest main): dsh plugin --profile web add "github:PerryLink/dsh-defend#main" — the prepare script builds with production dependencies only.
• npm channel (published releases): dsh plugin --profile web add dsh-defend.
• tarball channel: pnpm pack in this repo, then dsh plugin --profile web add ./dsh-defend-<version>.tgz.
• uninstall: dsh plugin --profile web remove dsh-defend (or remove the row from the profile patch).

Configuration

All tunables are Schemastery Config fields (changeable from cordis.yml). An id-targeted override replaces the whole row — restate every key you need. cordis.patch.yml documents each key inline.

Key	Default	Meaning
enabled	true	Master switch for both layers
action	deny	Destructive-delete guard action (deny / ask)
toolNames	['bash','persistent-bash','terminal-bash']	Tool names whose command arguments the guard reviews
detection.enabled	true	Detection-layer switch
detection.maxScanChars	10000	Scan cap per interception (head only)
detection.normalizeUnicode	true	NFKC-normalize text before scanning (blocks lookalike-Unicode bypass)
detection.secretMinEntropy	3.0	Minimum Shannon entropy (bits/char) to admit a secret regex hit; 0 disables
detection.injectionAction	ask	Injection family: allow / ask / block
detection.jailbreakAction	ask	Jailbreak family: allow / ask / block
detection.secretAction	ask	Secret family: allow / ask / block
detection.secretBlockCritical	true	Critical secrets always block regardless of secretAction
detection.audit	true	Write defend/detection session audit events
detection.allowUnmarkedAudit	false	Keep writing session audit on hosts whose Session.append predates the ignorable marker (every released line so far, the 0.2.x prereleases included) or that fail-closed on unknown event types (host 0.1.2-rc.1+), accepting the unresumable-session hazard
detection.maxReportEntries	200	In-memory report ring-buffer cap
registerCommand	true	Register the /defend command
registerTool	true	Register the defend_report tool

Tools & surfaces

Surface	Kind	Notes
defend_report	tool	Totals (recorded/blocked/asked), per-family counts, and the 20 most recent matches — never matched text
/defend	command	The same summary as text
agent/pre-step	listener	Inbound message scanning (enter/reject)
tools/pre-execute	listener	Tool-argument scanning (deny/ask) + the destructive-delete guard
tools/post-execute	listener	Tool-result scanning (block feedback)

Permissions & data

• Permissions: ask decisions ride the official approval seam; nothing is re-implemented or bypassed. The plugin declares session:append and network:none in its workshop manifest.
• Data: nothing is stored on disk; the report ring buffer is in-memory and bounded. No network requests, no subprocesses.
• Session log: defend/detection events carry rule id, family, category, severity, secret type, decision, and scan facts — matched text never reaches the log, and secret matches are type-only by construction.

Security boundaries

• Detection, not enforcement. The guard and the detection layer only produce deny/ask/block decisions on official seams; the sandbox and approval systems remain the enforcement authorities.
• Fail closed. Missing approval answerer, missing session, or a missing services surface degrades to the strictest decision — never to silent pass-through.
• No content leaves the process. Scanning is local; audit events are sanitized; secrets are never logged, displayed, or reported.
• Bounded work. Scan caps, one match per rule, and ring-buffer bounds keep hostile inputs from consuming unbounded resources.

Known limitations

• Detection gaps. The rule library catches the ported vocabularies and their tolerant variants; novel phrasing, lookalike-Unicode encodings (NFKC normalization is tracked as future work), and multi-step attacks can evade it. The benchmark pins the measured floor (27/28 on the upstream dataset) so regressions are visible.
• No model-level verdicts. dsh-defend is deterministic; it never calls a model and cannot judge novel intent.
• Message rejection is silent. agent/pre-step reject carries no reason to the model (the seam has no reason field); the audit event records the rule facts.
• Session audit and the ignorable marker. Audit appends request the envelope's ignorable: true marker so any harness build can load the log. Every released harness line so far (0.1.0-rc.1–0.1.0-rc.8, 0.1.1-rc.1–0.1.1-rc.2, and the 0.2 corridor — re-verified 2026-10-04 against the published 0.2.1-alpha.1, whose append(type, data, ...opts) reads only sourceEventSeqs/surfaceOp out of the options bag and builds the envelope as { type, seq, time, data }) silently drops it — the event lands unmarked and makes the session unresumable on stricter builds; host 0.1.2-rc.1 retains the envelope field for stored-log read compatibility only, but Session.append still cannot stamp it and the read path rejects unmarked unknown event types (defend/detection is not registered), so writing there also makes the session unloadable. dsh-defend therefore decides BEFORE the first append (peer-version pre-check; unresolvable versions fail closed) and disables session-log audit with a one-time warning; the 0.2.x prereleases are classified unmarked up front for exactly that reason, while a stable 0.2.x still falls back to the append probe. Set detection.allowUnmarkedAudit: true to opt back in. See issue #2.

Development

pnpm install        # node ^22.19 || >=24
pnpm run typecheck  # tsc: src + tests against the local harness checkout
pnpm run typecheck:ci  # tsc against the published 0.1.7-rc.2 types (no paths)
pnpm test           # vitest: 97 tests, 9 suites (detection benchmark incl.)
pnpm run build      # tsdown bundle + tsc declarations (lib/)
pnpm run verify:self-contained  # dependency specs resolve from the registry
pnpm run verify:artifacts       # built ESM face + shipped files present
pnpm pack           # the published tarball

Benchmark

The red-team benchmark (per-category P/R/F1 over 105 samples, plus the 27/28 fixture floor) is published in benchmark/RESULTS.md; regenerate it with node --experimental-strip-types benchmark/run.mjs (zero new dependencies, no build step).

Interoperability with other DSH plugins

Verified against DSH 0.2.0-rc.2 (the runtime this README ships for) and the high-star plugin set surveyed on 2026-10-05.

This plugin does not interfere with other plugins, including the widely installed high-star ones:

• No tool-name collision. Every tool is namespaced; no bare name owned by a shipped tool or another plugin is registered.
• No service-key collision. It provides no service key at all, so it cannot collide on one.
• No slot collision. It registers no client slot key, so it cannot contend for a shadows-shipped-ui seat.
• No HTTP route collision. It registers no webServer prefix.
• No patch-layer collision. The bundle patch only inserts its own row; it never overrides a built-in row's config.
• No global mutation. It does not patch prototypes, rewrite process.env, or replace the global fetch dispatcher.

Shared event listeners are non-interfering by construction. It observes the ordering-sensitive events agent/pre-step, tools/post-execute, tools/pre-execute with ctx.on() — Cordis's broadcast registration, where every listener runs and none can starve another. Every listener here delegates through next(), so the chain is never short-circuited, and a mutation is applied to the value next() produced rather than returned in its place:

• agent/pre-step — also used by dsh-routing-suite (7000★, 7 listeners), modlens (4122★), dsh-purge (3317★), dsh-agent-teams (1923★), dsh-context (1849★).
• tools/post-execute — also used by cc-safety-net (1576★).
• tools/pre-execute — also used by cc-safety-net (1576★).

Static evidence: dsh-plugin-doctor K10–K13 report pass for every check on this repository.

Topics

dsh, dsh-plugin, deepseek-harness, deepseek, cordis, security, prompt-injection, jailbreak, secret-scanning, ai-safety

Contributors

• @PerryLink — creator and maintainer: destructive-delete guard, the four-asset detection port, interception wiring, audit surface, and the five-language docs.
• @cuohua — the precise report on defend/detection events landing unmarked and making sessions unresumable on stricter builds (#2); the runtime host-capability detection and the ignorable-marker discipline derive directly from that analysis.

PerryLink DSH Plugin Family

This project is one of the 44 DeepSeek Harness plugins maintained by PerryLink. If this one helps you, the others likely will too:

Plugin	One-liner
dsh-auto-review	Second-model auto-review on the approval chain, fail-closed by default
dsh-autotier	Automatic strong/cheap model-tier routing with deterministic risk guards and a /tier command
dsh-background-agents	Durable background child agents with a Web UI sidebar, messaging and interrupt
dsh-budget	Cost governance for DeepSeek Harness: budgets, carbon, and latency in one panel.
dsh-catalog	DSH Desktop Market standard catalog source for the PerryLink family
dsh-cert-mcp	Read-only MCP server exposing the certification registry: grades, snapshots and five-dimension evidence
dsh-checkpoint-rewind	Claude Code /rewind-equivalent: snapshots, session forks, one-shot restore
dsh-claude-move	Migrate Claude Code sessions, memory, skills and CLAUDE.md into DSH
dsh-click	Cross-platform native desktop control for DeepSeek Harness — Windows first.
dsh-composer-history	Terminal-style input history for the web composer: arrows, Ctrl+R search
dsh-data-quality	Dataset quality checks and citation cross-checks (the optional numeric bridge consumed here)
dsh-defend	Prompt-injection, jailbreak, and secret-leak defense for DeepSeek Harness.
dsh-doublecheck	Engineering-discipline guard: requirements grill, test gates, adversary review
dsh-draw	Unified static-image generation routing for DeepSeek Harness.
dsh-fast	Read-only performance diagnostics for DeepSeek Harness.
dsh-fund-research	Deterministic research reports for Chinese public mutual funds
dsh-github	GitHub PR/issues integration for DSH, every write gated by approval
dsh-industry-research	Industry research orchestration that seals its deliverables through this plugin's ctx.researchReport.assemble
dsh-laya	Laya typed decisions (noul/choice/score) as a first-class Cordis service and model-visible tools
dsh-library	Local document knowledge base for DeepSeek Harness.
dsh-local-ai	Local-model (Ollama) integration for DeepSeek Harness.
dsh-lsp-actions	LSP diagnostics, formatting, completion, code actions and rename over language servers
dsh-mask	PII masking middleware: anonymize at the model boundary, restore at the display layer
dsh-mcp-panel	Read-only MCP runtime panel: /mcp command + Settings tab with status, tools and errors
dsh-memento	Approval-gated cross-session memory: ctx.memory seam + SQLite + memory tool
dsh-observe	OpenTelemetry and Langfuse observability exporter for DeepSeek Harness.
dsh-output-styles	Claude Code outputStyles-equivalent runtime style switching
dsh-permission-rules	Claude Code-style declarative allow/deny/ask permission rules with audit
dsh-plugin-certification	Community certification registry with repro-checkable grades and badges
dsh-plugin-doctor	Zero-dependency static + sandbox smoke detector for DSH plugins
dsh-plugin-guide	Plugin-development knowledge base as an on-demand agent skill
dsh-plugin-kit	Shared zero-runtime-dependency toolkit for the PerryLink DSH plugins
dsh-plugin-upgrade	One-package, one-corridor-index plugin upgrade skill: routes a repository to the matching closed corridor card
dsh-reach	Multi-channel approval/question bridge: WeChat/Telegram/Feishu, session console
dsh-research-report	Verifiable research-report engine: content-addressed evidence ledger and sealed versions
dsh-score	Multi-dimensional quality scoring for DeepSeek Harness plugins.
dsh-session-pin	Pin sessions in the Web sidebar with durable ordering
dsh-session-sync	Cross-device session sync for DeepSeek Harness — a dedicated git mirror of your session store.
dsh-skill-pack-security	Security-audit skill pack: secret scan, dependency and supply-chain review
dsh-talk	Voice-first session loop for DeepSeek Harness: talk to it, hear it answer.
dsh-team-rooms	Cross-session team rooms: shared message bus, task board and timeline
dsh-test-drive	Isolated install-and-smoke test drives for DeepSeek Harness plugins.
dsh-ticktick	TickTick/Dida365 task bridge: session-header panel + 11 tools
dsh-translate	Vendor parameter translation and deterministic JSON repair for DeepSeek Harness.

Install from the DSH Desktop Market

All PerryLink plugins are browsable in the built-in DSH Desktop Market: Market → Sources → add source → paste https://perrylink-dsh-catalog.perrylink.workers.dev/catalog-source.json → select it. Installation still goes through the Market's npm-identity verification and your confirmation.

License

Apache License 2.0 © 2026 dsh-defend contributors