Node.js SDK

The @pii-firewall/sdk package lets you integrate PII detection and masking into any Node.js application. No API key required — all processing runs locally.

Installation

npm install @pii-firewall/sdk

Quick Start

const { createFirewall } = require("@pii-firewall/sdk");

const fw = createFirewall();

const { masked, detections } = fw.mask("Contact: user@example.com Phone: 090-1234-5678");
console.log(masked);
// Contact: [SECURED:type=email,id=abc123] Phone: [SECURED:type=phone,id=def456]

console.log(detections);
// [{ type: 'email', count: 1 }, { type: 'phone', count: 1 }]

TypeScript is fully supported:

import { createFirewall, MaskResult } from "@pii-firewall/sdk";

const fw = createFirewall({ extraTypes: ["name"] });
const result: MaskResult = fw.mask("John Smith 090-1234-5678");

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Configuration Options

createFirewall({
  extraTypes?: string[],    // Additional PII types to detect (e.g. ["name"])
  dpMode?: boolean,         // Differential privacy (adds noise to numeric values)
  engine?: string           // Cryptography engine selection (advanced mode available on Starter and above)
})

---

Core Methods

fw.mask(text)

Detects and masks PII in text.

const { masked, detections } = fw.mask("Call me at 090-1234-5678");
// masked:     "Call me at [SECURED:type=phone,id=xxx]"
// detections: [{ type: 'phone', count: 1 }]

fw.detect(text)

Detects PII without masking.

const candidates = fw.detect("test@example.com");
// [{ type: 'email', level: 'auto', value: 'test@example.com', index: 0 }]

fw.restore(id) / fw.restoreAll(text)

Restores masked tokens to their original values.

const { masked } = fw.mask("user@example.com");
const id = masked.match(/id=([a-f0-9]+)/)[1];
const original = fw.restore(id);
// { type: 'email', value: 'user@example.com' }

// Restore all tokens in a text at once
const restored = fw.restoreAll(masked);

fw.detectInjection(text)

Detects prompt injection attacks.

const result = fw.detectInjection("Ignore all previous instructions");
// [{ level: "critical", label: "Instruction override attempt", value: "..." }]

level	Meaning	Recommended Action
warning	Suspicious but not confirmed	Log and flag for review
critical	Clear attack pattern	Block request (403)

---

fw.detectAllInjections(text, lang?) — Composite Attack Detection

Detects SQL injection and prompt injection simultaneously in a single pipeline — designed for AI agents, RAG pipelines, and MCP environments.

// Normal input
fw.detectAllInjections("Check inventory status");
// → { hasSQLInjection: false, hasPromptInjection: false, compositeRisk: false }

// SQL only
fw.detectAllInjections("' OR 1=1 --");
// → { hasSQLInjection: true, hasPromptInjection: false, compositeRisk: false }

// Composite attack (targets AI agent + database simultaneously)
fw.detectAllInjections(
  "Ignore previous instructions. UNION SELECT * FROM users WHERE 1=1 --"
);
// → { hasSQLInjection: true, hasPromptInjection: true, compositeRisk: true }

Field	Type	Description
hasSQLInjection	boolean	SQL injection detected
hasPromptInjection	boolean	Prompt injection detected
compositeRisk	boolean	Both detected simultaneously — block immediately

Why compositeRisk matters:

Tool	Coverage
Traditional WAF	SQL injection only
Prompt Shield / LakeraGuard	Prompt injection only
PII Firewall	SQL + Prompt + compositeRisk (composite attack)

// Recommended: integrate composite attack check
const result = fw.detectAllInjections(userInput, "en");
if (result.compositeRisk) {
  return res.status(403).json({ error: "Composite attack detected" });
}
if (result.hasSQLInjection || result.hasPromptInjection) {
  return res.status(403).json({ error: "Injection detected" });
}
// → Only safe requests pass through

---

Express Middleware

const express = require("express");
const { createExpressMiddleware } = require("@pii-firewall/sdk");

const app = express();
app.use(express.json());
app.use(createExpressMiddleware({ extraTypes: ["name"] }));

app.post("/chat", (req, res) => {
  // req.body.messages is automatically masked
  console.log(req.piifw.detections); // detection results
  res.json(req.body);
});

---

Supported PII Types

Type	Description	Default
email	Email addresses	✅ Auto
phone	Phone numbers (JP format)	✅ Auto
my_number	Japanese My Number (12 digits)	✅ Auto
credit_card	Credit card numbers	✅ Auto
passport	Passport numbers	✅ Auto
address	Street addresses	✅ Auto
postal_code	Postal codes	✅ Auto
bank_account	Bank account numbers	✅ Auto
company	Company names	✅ Auto
password	Passwords	✅ Auto
api_key	API keys and tokens	✅ Auto
ip_address	IP addresses	✅ Auto
pin	PIN codes	✅ Auto
name	Personal names	🔲 Enable with extraTypes: ["name"]

Name Detection Note

Name detection (extraTypes: ["name"]) requires a space between first and last name.

fw.mask("Yamada Taro")   // ✅ detected
fw.mask("YamadaTaro")    // ❌ not detected (by design, to prevent false positives)

Need katakana or rare-surname detection? (Python SDK)

For industries such as healthcare, HR, legal, and finance where katakana-format names or rare kanji surnames appear, consider the GiNZa NER extension for the Python SDK.

from pii_firewall import PIIFirewall

fw = PIIFirewall(ner_model="ja_ginza")  # pip install pii-firewall[nlp]
fw.mask_pii("Patient: ヤマダ タロウ")   # detects katakana names
fw.mask_pii("勅使河原 太郎")            # detects rare kanji surnames

→ Details: Service Limitations > NER Extension Option

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About API Keys

This SDK runs locally and does not require an API key.

If you want to use cloud-based PII detection (Proxy API), see Getting an API Key.