dsh-mask
- 1024 store channel:
npm i -g dsh1024 once, then dsh1024 plugin --profile web add dsh-mask (counts toward the deepseek1024.com install ranking).
PII masking middleware for DeepSeek Harness — anonymize personal data before it reaches the model, keep it reversible host-side.
Phones, emails, ID cards, bank cards, keys, and more become placeholders at the model boundary; the plaintext never enters your session log.
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Compatibility
| Surface | Status |
|---|
| Harness | DeepSeek Harness dsh-v0.1.6-alpha.2 (adapted 2026-09-18): the session envelope keeps its ignorable field for stored-log read compatibility only - Session.append still cannot stamp it, so audit-gate behavior is unchanged. Verified 2026-09-18 against the dsh-v0.1.6-alpha.2 master checkout (full gate chain + profile install smoke). |
| Node | ^22.19.0 || >=24.0.0 |
| Platforms | Anywhere DSH runs (pure host, zero-dependency regex; no browser half) |
| Model | Text models fully supported; no extra model capability required |
What you get
dsh-mask anonymizes personal data at the model boundary — before a message reaches the model — and keeps a restore table host-side so placeholders stay reversible:
- Request-time masking —
agent/pre-step messages are rewritten so phones, emails, ID cards, bank cards, and keys (on by default) and IPs (opt-in) become <PHONE_1>-style placeholders. The masked text is what gets logged and sent to the model.
- Restore table — the
placeholder → original map lives only in memory and a controlled storage domain (dsh_mask); the plaintext never enters the session log.
- Audit, not plaintext — the
mask/applied session event records only "replaced N values + type distribution", never the original text or the mapping.
/mask command — status (counts + distribution), on/off (runtime toggle), restore <text> (unmap placeholders), help.mask_test tool — run a snippet through the detector and see the placeholder result; it never reveals the original values.
user message ──agent/pre-step──▶ placeholders ──model──▶ placeholders ──restore──▶ display
▲ │
└──────── restore table (memory + dsh_mask) ────────┘
Quick start
# 1. install the bundle into your profile
dsh plugin --profile web add "github:PerryLink/dsh-mask#main"
# or from npm (published releases)
dsh plugin --profile web add dsh-mask
# 2. verify the row mounts
dsh --profile web --dump-config | grep -A2 'id: mask'
Then tailor the entity list in your profile patch:
- insert:
- id: mask
name: dsh-mask
config:
entities: [phone, email, id-card, bank-card, key]
> /mask status
> /mask restore <PHONE_1>
Install & uninstall
- git channel (latest
main): dsh plugin --profile web add "github:PerryLink/dsh-mask#main" (equivalent to installing from git+https://github.com/PerryLink/dsh-mask.git). No build step — index.mjs and lib/ are the shipped artifacts.
- npm channel (published releases):
dsh plugin --profile web add dsh-mask.
- tarball channel:
pnpm pack in this repo, then dsh plugin --profile web add ./dsh-mask-<version>.tgz.
- uninstall:
dsh plugin --profile web remove dsh-mask (or remove the row from the profile patch).
dsh-mask no longer bundles the storage stack. Profiles that already compose it (the web profile does, via @deepseek-ai/dsh-web-app) provide storageDomain, so persistence works out of the box. On a bare profile without storage the plugin still mounts and masks, but the restore table is memory-only (lost on restart) — compose the storage stack in your profile patch, or set persistRestoreTable: false.
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; false unregisters the listener, the /mask command, and the mask_test tool |
mode | regex | Detection mode; only regex is implemented (regex+ner for name/address recognition is reserved and fails loud) |
entities | [phone, email, id-card, bank-card, key] | Which PII types to mask; ip is also regex-capable (opt-in), person/address require NER |
scope | [messages] | Masking surface(s); messages masks agent/pre-step messages, tools masks tool-result text on tools/post-execute. Accepts a string or an array, e.g. [messages, tools] |
registerCommand | true | Register the /mask command |
registerTools | true | Register the mask_test tool when the tools service is present |
persistRestoreTable | true | Persist the restore table to the controlled dsh_mask storage domain (false = memory only) |
maxRestoreEntriesPerSession | 500 | Per-session restore entry cap (oldest evicted first) |
maxSessions | 1000 | In-memory session cap (least-recently-used evicted, mapping reloaded on demand) |
maskClientEnabled | false | Feature flag for the browser half "reveal" bubble (defensive; off by default until the live slot catalog verifies the target slot). The key is schema-declared and validated, but no runtime code reads it yet, so it changes nothing until the browser half ships |
Example override in your profile patch:
- insert:
- id: mask
name: dsh-mask
config:
entities: [phone, email, id-card, bank-card, key, ip]
persistRestoreTable: false
registerCommand: true
Tools & surfaces
| Surface | Reveals plaintext | Notes |
|---|
agent/pre-step masking | never | Rewrites messages to placeholders before they are logged or sent to the model |
tools/post-execute masking | never | Rewrites tool-result text blocks to placeholders before they are logged or fed back to the model (scope: tools) |
/mask status | never | Enabled state, total replaced, type distribution |
/mask on / /mask off | never | Runtime toggle (resets to config.enabled on restart) |
/mask restore <text> | yes (explicit) | Unmaps placeholders back to the values stored for this session |
mask_test | never | Masks a snippet and reports the placeholder result + counts |
Permissions & data
- Permissions:
dsh-mask performs no network requests and stores no credentials; it only reads the session at the agent/pre-step boundary and writes its own dsh_mask storage domain. The dshWorkshop manifest declares network:none and credentials:none.
- Data: the
placeholder → original restore table lives in memory and, when persistRestoreTable: true, in the controlled dsh_mask storage domain — this is the only place plaintext PII is stored, and it is never written to the session log.
- Session log:
mask/applied is declared in types.d.ts and appended only when the host records the type (see Known limitations). Its payload is counts + type distribution only.
Security boundaries
- Plaintext never enters the session log. The masked (placeholder) form is what gets logged and sent to the model, so model-visible content is reconstructable from the log in placeholder form; the originals stay in the restore table.
- Sanitize before display/log.
lib/sanitize.mjs redacts PII, secrets, and URL credentials before any text reaches the model or the log; mask_test and /mask status never echo originals.
- Controlled restore.
/mask restore is the single explicit reveal surface, and it only reads the mapping for the active session.
- Fail closed. Unimplemented
mode (regex+ner), unknown scope values, NER-only entities, and out-of-bounds numbers all fail loudly at load.
- Registrations are effects. The listener, command, tool, and storage-domain close are all Cordis effects — stop/hot-reload removes them.
Known limitations
- Regex only. Name (
person) and address (address) recognition needs an external NER recognizer, which the pure-host zero-dependency form does not bundle; mode: regex+ner and those entities fail loudly at load. The PII types covered out of the box are phone, email, ID card, bank card, key, and (opt-in) IP.
- Region-specific patterns. The
phone and id-card detectors match mainland-China formats only: phone is 1[3-9] followed by nine digits, and id-card is an 18-character Chinese resident ID (17 digits plus a digit or X). Phone numbers and national identifiers from other countries are not detected. email, ip, and key are region-agnostic; bank-card accepts any 16-19 digit run at a lower confidence score.
- Display-layer restore needs a client half. Masking is fully host-side, but transparently un-masking the assistant bubbles in the client UI is a browser-half feature this pure-host form does not ship. The host side keeps the restore table and the exported
RestoreStore seam (its methods take a session id), so a future client half would reach them through a host remote rather than directly; today the unmasking surface is the /mask restore <text> command, and the maskClientEnabled key is validated but read by no runtime code yet.
- Session events on
0.1.6-alpha.2. The harness records 58 session event types and none of them is mask/*; its Session.append also cannot stamp the ignorable envelope, so the session-log audit appends are skipped and sessions keep loading. The gate is not silent about it: the first refusal per session logs one visible warning naming the skipped type and this documented limitation. The plugin enables the append automatically once a host records the type or supports the ignorable envelope.
Development
pnpm install # node ^22.19 || >=24
pnpm run typecheck && pnpm run typecheck:ci # two rulers: checkout face (guarded; unverifiable without the checkout) + published-line face
pnpm test # node --test
pnpm run verify:self-contained # dependency specs resolve from the registry
pnpm run verify:artifacts # shipped files present + index.mjs importable
pnpm run check:readmes # five-language README consistency
pnpm pack # the published tarball
There is no build step: pure ESM, index.mjs and lib/ are the shipped artifacts.
Benchmark
The PII benchmark (per-type P/R/F1 over 108 synthetic samples) is published in benchmark/RESULTS.md; regenerate it with node benchmark/run.mjs (no build step, zero new dependencies).
Topics
dsh, dsh-plugin, deepseek-harness, deepseek, cordis, pii, mask, privacy, anonymization, security
Contributors
- @PerryLink — creator and maintainer: the regex PII detector ported from Pii-Stripper-Middleware, the
agent/pre-step masking seam, the restore table, the /mask command and mask_test tool, and the five-language docs.
PerryLink DSH Plugin Family
This project is one of the 40 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-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-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. |
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
LICENSE (Apache License 2.0) © 2026 dsh-mask contributors
