dsh-privacy-guard

A send-time privacy reminder for DeepSeek Harness: before you hand a phone number, an ID number, a card number or an API key to a model, a strip appears under the composer and offers to mask it.

Built for people who are not security professionals. It does not lecture, it does not block the send, and it stays completely silent until the text actually matches something.

What it catches

rule	severity	note
private-key	high	a PEM private-key header
api-key	high	sk-, ghp_/gho_/ghu_/ghs_/ghr_, github_pat_, AKIA, AIza, xox?
id-card	high	18-digit ID number, checksum verified
bank-card	high	13-19 digits with optional spaces or dashes, Luhn verified
phone-cn	medium	mainland mobile number
email	low	email address
ipv4	low	dotted-quad IP address

The two checksum-verified rules exist because their shapes are common in innocent data. A 16-digit order number that looks like a card, or a long numeric id that looks like an ID number, does not fire.

Install

Requires Node.js 20 or newer and a DeepSeek Harness web profile.

dsh plugin --profile web add github:ciceroyang/dsh-privacy-guard#v0.1.1

One command installs the package and mounts it: the manifest declares dsh.bundle, so the profile adds the package to its loader tree, and the browser half is served from exports["./client"].

From a local checkout instead, mount it by hand:

ln -sfn "$PWD/dsh-privacy-guard" ~/.dsh/profiles/web/node_modules/dsh-privacy-guard
# then in ~/.dsh/profiles/web/cordis.patch.yml
- insert:
    - id: privacy-guard
      name: dsh-privacy-guard

The web profile reloads the patch live; refresh the page afterwards.

No build step: the browser bundle is committed and served as-is.

What it does not do

• It does not send anything anywhere. The scan runs in your browser, on the draft text, with no network call and no storage write. Uninstalling the plugin removes every trace of it.
• It does not block the send. You stay in charge: mask it, or press send anyway.
• It is not a guarantee. Pattern matching finds the shapes it knows. A secret it has never seen the shape of will pass. Treat it as a second pair of eyes, not as a data-loss-prevention system.

Notes

• Masked samples only ever show a two-character prefix and a two-character suffix. The middle never reaches the screen, the logs or the DOM.
• "Ignore" silences the strip for the current draft only; editing the draft brings it back.
• Rules live in lib/patterns.js as plain data. Adding one is a data change plus a test.

Test

node build.mjs && node --test

CI also rebuilds the bundle and fails if the committed lib/client.js differs from its sources.

Licence

MIT. Maintained by @ciceroyang.