feat(pii-audit): Autocapture PII Audit Chrome extension

[djih]

Summary

Adds a standalone Chrome MV3 extension at pii-audit-extension/ that audits what Amplitude Autocapture would collect — entirely locally, with zero egress.

• Channel A (network): MAIN-world interceptor patches fetch/XHR/sendBeacon at document_start to capture ingest payloads, drop real sends, and force-enable autocapture via remote-config rewrite
• Channel B (DOM): Content script scans the full document + watches mutations, relays items to a docked side panel
• Detection: Two-pass pipeline — deterministic regex/checksum (email, SSN, credit card, etc.) → local Piiranha ONNX classifier in a Web Worker
• Panel: 3-tab React UI (Everything / PII only / Masking rules) with hover-highlight and exportable masking rules JSON
• Demo page: Fake login → billing SPA with PII fields for end-to-end rehearsal

33 unit tests passing. Extension builds with Vite + @crxjs/vite-plugin.

Test plan

• cd pii-audit-extension && npm test — 33/33 pass
• npm run build — produces loadable dist/
• Load unpacked extension in Chrome from dist/
• Serve demo: cd demo && python3 -m http.server 8080
• Open demo, click Start PII audit — page reloads, panel docks right
• Tab 1 shows DOM + network + autocapture items; PII rows highlighted
• Hover a row — red highlight box on matching DOM element
• Tab 2 shows PII-only with reasons
• Tab 3 lists masking rules; Export to file downloads JSON
• Network tab: no successful Amplitude ingest POSTs; no Hugging Face/CDN model fetches

Notes

• Standalone project outside the Lerna/Nx packages/ workspace (intentional per plan)
• ONNX weights (.onnx) are gitignored — fetch via instructions in models/README.md
• Piiranha model license is CC-BY-NC-ND-4.0 (non-commercial); GLiNER-PII (Apache-2.0) noted as commercial alternative
• tokenizer.json is large (~1M lines) — consider git-lfs or fetch-on-build before merge

Made with Cursor

[github-actions]

size-limit report 📦

Path	Size
packages/analytics-browser/lib/scripts/amplitude-min.js.gz	61.51 KB (0%)
packages/session-replay-browser/lib/scripts/session-replay-browser-min.js.gz	134.97 KB (0%)
packages/unified/lib/scripts/amplitude-min.umd.js.gz	215.59 KB (0%)
@amplitude/element-selector (gzipped esm)	2.67 KB (0%)