One command checks your build for leaked source and secrets, and tells you what to move or harden. Free and open source.
$npx cloak-audit audit
No sign-upNo backendThe audit runs offline
Chapter IThe map left open
A source map turns a minified bundle back into the original files, comments included.
Claude Code’s npm package, March 2026, reported by heise online
Chapter IIThe thieves
A source map hands an agent your original files, comments included. Without one, it reads the minified bundle and rebuilds your logic as code you can follow.
Cloak reads your build the way the agent will, and tells you what to take back first.
Interlude · the reckoning
Chapter IIIThe watch
One command checks your build for source maps, secrets, debug builds and exposed endpoints. In an AI app it also finds model keys, browser-side model calls and shipped prompts. It runs offline in seconds and writes a report that opens in any browser.
Chapter IVThe trial
Cloak rates each of your own modules from 1 to 5 by how much a copy would cost you, then says what to do with it: move it server-side, harden it, or leave it.
src/pricing/quote.tsmove server-sidesrc/api.tshardensrc/config.tsleavesrc/App.tsxleaveExample on the demo app. Classification uses your own Anthropic key and asks before it sends anything. A small app costs under one US cent.
Chapter VThe keep
Every finding names its fix. Apply them, build again and run the audit again.
Still open3critical2high
Chapter VIThe seal
Run cloak lock once and commit the file. It records what your build exposes: hosts, API routes, inlined environment names, browser-side model providers and sensitive modules. After that, every audit and pull request flags anything new. It never records a secret.
$ npx cloak-audit lock Wrote cloak.lock.json: 3 hosts, 6 API routes, 2 environment variables, 0 model providers, 4 kinds of shipped file. # a week later, on a pull request HIGH F1.14 New host: billing.internal (not in cloak.lock.json)
Chapter VIIThe scribe’s hand
An agent writes much of your code now. Inside Claude Code, the edit guard checks each edit before the file changes, and blocks one that turns on production source maps or puts a secret where the browser can read it. Elsewhere, run cloak check-edit.
› Edit src/lib/checkout.ts blocked This edit writes a Stripe live secret key into src/lib/checkout.ts, which is code that ships to browsers. fix Keep the key on the server: read it from an environment variable in a server endpoint, and have the client call that endpoint.
Interlude · the audit, again
Example run on the demo app after the fixes: npx cloak-audit audit. Critical 0, high 0, medium 0, low 0, info 1. Since the last run: 0 new, 5 resolved. Passed: no findings at critical or worse.
Chapter VIIIThree ways in
The audit needs no key and no network, wherever you run it.
Nothing to install. Point it at your build folder and read the findings.
audit makes no network calls and needs no key.init --prepublish makes npm publish fail on a critical finding.$ npx cloak-audit audit # leaks in your build, offline $ npx cloak-audit estimate # what classification would send $ npx cloak-audit init --prepublish # npm publish now fails on a critical finding
Ask from the chat. Before Claude runs a publish command, the plugin audits your build and blocks the publish while critical findings remain.
/cloak:audit runs the audit and explains each finding./cloak:fix works through the findings one at a time.› /cloak:fix 1 vite.config.ts sourcemap true → 'hidden' 2 src/pricing/quote.ts move to POST /api/quote › npm publish blocked Cloak found 1 critical finding F1.4 dist/assets/index-9f8e.js:1
The Action audits each pull request and fails the job on a critical finding. Its comment gives the counts and what changed since the last run.
# .github/workflows/cloak.yml - uses: PeterTCraig/cloak/action@v1 with: build-command: npm run build fail-on: critical # the comment on the pull request Cloak audit: Passed Since the last run: 0 new, 2 resolved.
Chapter IXThe oath
No account and no backend. Reports stay in .cloak/ in your repo.
Classification uses your own Anthropic key. The audit needs no key at all.
Cloak scans build output inside the current project. It refuses URLs.
Before the first model call, Cloak shows what it will send and what it will cost, then asks.
Cloak redacts secrets before any model call. Reports show only their first four characters.
Cloak collects nothing about you, your code or your runs.
Chapter XAt the gate
Anything else, open an issue on GitHub.
Yes. Cloak is open source under the MIT licence, and the audit costs nothing. Classification uses your own Anthropic key. A small app costs under one US cent, and cloak estimate shows the cost first.
Not for the audit, which makes no network calls. Classification sends each module’s path, exported names, imports and up to 6,000 characters of source, with secrets redacted, and only once you agree.
The build output of web apps and Electron apps, and the files in your npm package. It looks for source maps, secrets, inlined environment variables, debug builds and exposed endpoints. In AI apps it also finds model API keys, calls to model providers straight from the browser, and system prompts shipped in client code. If Gitleaks or TruffleHog is installed, it runs them too, offline.
No. Cloak only scans build output inside the current project, and it refuses URLs.
It can. For logic that has to stay in the browser, the cloak-audit/vite plugin obfuscates the modules worth protecting. Then it runs your own check and fails the build if that breaks. Obfuscation slows a reader down; moving the logic server-side stops one. Hardening works with Vite.
Run npx cloak-audit init --prepublish. From then on npm publish fails while critical findings remain. In CI, the GitHub Action fails the pull request instead.
EpilogueHold fast
The audit takes seconds, needs no account and makes no network calls.
$npx cloak-audit audit
No sign-upNo backendMIT licence