README.md

metadata

title: Rampart
emoji: 🛡️
colorFrom: gray
colorTo: gray
sdk: static
app_file: index.html
short_description: On-device PII redaction by National Design Studio

Rampart — Client-Side PII Redaction Demo

A live demo of the Rampart model — a 14.7 MB ONNX token-classification model that detects and redacts personally identifiable information (PII) before it leaves your device.

What this demo does

• Live redaction — type or paste text and watch PII get replaced with stable placeholders in real time
• 17 entity types — color-coded legend showing all detected PII classes
• 7 languages — English, Spanish, French, German, Italian, Portuguese, Dutch
• Chat simulation — see how Rampart protects you before sending text to an AI assistant
• Placeholder mapping — view the reversible placeholder ↔ real value table
• 100% client-side — the model runs in your browser via transformers.js / ONNX Runtime Web (WASM). No data is sent to any server.

How it works

The demo loads the @nationaldesignstudio/rampart npm package from jsdelivr CDN, which bundles transformers.js and the ONNX Runtime Web. The model weights are fetched from the Hugging Face Hub and cached in IndexedDB. All inference happens in the browser — no server compute required.

Model details

Property	Value
Model	nationaldesignstudio/rampart
Architecture	MiniLM-L6-H384 with 35-label BIO head (17 entity types)
Size	14.7 MB (4-bit quantized ONNX)
Runtime	ONNX Runtime Web (WASM)
Languages	English, Spanish, French, German, Italian, Portuguese, Dutch
Recall	98.42% private-term recall across all 7 languages
Latency	~4ms p50 (WebGPU), ~12ms p50 (WASM)

Known limitations

• Phone numbers must not start with 555. The 555-01XX exchange is reserved for fiction and is effectively absent from the model's real-world training data, so Rampart does not recognize 555-… numbers as phones. Use a realistic exchange (e.g. 212-867-5309) to see PHONE detection fire. Non-US / international formats (+44 …, 0151 …) are also well supported.
• Credit cards that fail the Luhn checksum pass through unredacted. CREDIT_CARD is handled by the deterministic layer, which validates the Luhn check digit. A made-up number that does not satisfy Luhn is treated as ordinary digits and is not redacted — there is no leak warning. Use a Luhn-valid test number (e.g. 4532 1234 5678 9014) to see it caught.

License

CC BY 4.0 — National Design Studio