Guardrails
A PII-redaction guardrail service: prompts pass through a browser extension and a FastAPI/Presidio NER pipeline before reaching Claude or OpenAI, with an org-level admin panel.
About
A PII-redaction guardrail as a polyglot microservice: a Chrome MV3 extension intercepts prompts, a FastAPI service running Microsoft Presidio and Flair NER scans for PII and redacts before the prompt reaches Claude, OpenAI or Gemini, and an Express API with a React admin panel handles auth and org management. I worked across the full stack: file scanning end-to-end (PDF, DOCX, XLSX and plain-text extractors, auto-scan trigger, sidebar review UI); a full role hierarchy (deactivate, reactivate, promote, demote) with soft-delete and session revocation; anonymised usage analytics from extension through server to an admin dashboard; login and signup pathway improvements including dual-mint auth for panel-role extension sign-ins; smarter PII detection for UK postcodes, name initials and location spans; and the extension popup auth flow including self-healing after sign-in.
Highlights
- Smarter PII detection: UK postcode pattern matching and name-initial detection.
- Added Google Gemini as a third AI provider, extending the architecture beyond Claude and OpenAI.
- File-attachment warning in the Chrome extension sidebar.
- Genuine polyglot microservice architecture: Chrome MV3 extension, React admin panel, Express API, FastAPI/Presidio NER service.
- 10 PII entity types: PERSON, EMAIL, PHONE, LOCATION, ORG, CREDIT_CARD, SSN, postcode, and more.
By the numbers
- Commits
- 100
- Lines added
- +14,607
- Lines removed
- −10,186
- Source files
- 21,751
of 200 total