createAnonymizer

Creates and configures an anonymizer instance for PII detection and replacement.

Signature

function createAnonymizer(config?: AnonymizerConfig): Anonymizer

Parameters

config (optional)

string

default:"'pseudonymize'"

Anonymization mode:

'pseudonymize' — Reversible. Returns an encrypted piiMap for later rehydration.
'anonymize' — Irreversible. No piiMap is returned; PII is permanently removed.

NERConfig

NER model configuration

Show NERConfig properties

string

required

Model mode: 'disabled' | 'quantized' | 'standard' | 'custom'

string

Custom model path (required when mode is 'custom')

string

Custom vocab path (required when mode is 'custom')

boolean

default:"true"

Auto-download model if not present

Record<PIIType, number>

Confidence thresholds per PII type (0.0-1.0)

(status: string) => void

Status message callback

DownloadProgressCallback

Download progress callback

boolean

default:"false"

Enable case-insensitive fallback for detecting lowercase names. Runs a second NER pass on title-cased text and merges new detections. Doubles NER inference time but catches names like "tom" that the case-sensitive model would otherwise miss.

number

default:"0.85"

Confidence penalty multiplier for case-fallback detections (0.0–1.0). Applied as confidence * caseFallbackPenalty. Lower values are stricter.

string

default:"'local'"

Inference backend: 'local' (ONNX on device) or 'inference-server' (remote GPU server)

string

URL of the inference server (required when backend is 'inference-server')

number

default:"30000"

Inference server request timeout in milliseconds

SemanticConfig

Semantic enrichment configuration

Show SemanticConfig properties

boolean

default:"false"

Enable semantic enrichment (gender/scope attributes)

boolean

default:"true"

Auto-download semantic data if not present

(status: string) => void

Status message callback

DownloadProgressCallback

Download progress callback

KeyProvider

Encryption key provider. If not provided, generates a random key.

PIIStorageProvider

Storage provider for session-based PII map persistence

AnonymizationPolicy

Default anonymization policy

SecretsConfig

Secrets/credentials detection configuration

Show SecretsConfig properties

boolean

default:"false"

Enable secrets detection (API keys, tokens, connection strings, etc.)

string[]

Paths to .env files for literal value redaction

boolean

Redact secret values found in .env files

RegExp[]

Additional patterns to match secret key names

number

default:"4"

Minimum value length to consider a secret

TagFormat

Tag format for PII placeholder tags. Controls the delimiters and keyword.

Show TagFormat properties

string

default:"'<'"

Opening delimiter (e.g., "<" for XML, "[[" for bracket style)

string

default:"'/>'"

Closing delimiter (e.g., "/>" for XML self-closing, "]]" for bracket style)

string

default:"'PII'"

Tag keyword. Allows using e.g., "REDACTED" instead of "PII"

(warnings: Array<{ code: string; message: string }>) => void

Callback for validation warnings. When not provided, warnings are silently ignored — check stats.leakScanPassed in the result instead.

RecognizerRegistry

Custom recognizer registry (uses default if not provided)

Returns

An Anonymizer instance with these methods:

Method	Description
`initialize()`	Initialize the anonymizer (loads models)
`anonymize(text, locale?, policy?)`	Anonymize text
`session(sessionId)`	Create a session for persistent storage
`dispose()`	Release resources
`getRegistry()`	Get the recognizer registry
`getNERModel()`	Get the NER model instance
`isInitialized`	Check if initialized

Examples

Basic (Regex Only)

import { createAnonymizer } from 'rehydra';

const anonymizer = createAnonymizer();
await anonymizer.initialize();

const result = await anonymizer.anonymize('Contact: test@example.com');
console.log(result.anonymizedText);
// "Contact: <PII type="EMAIL" id="1"/>"

await anonymizer.dispose();

With NER

const anonymizer = createAnonymizer({
  ner: { 
    mode: 'quantized',
    onStatus: (status) => console.log(status)
  }
});

await anonymizer.initialize();

const result = await anonymizer.anonymize('Hello John Smith!');
// "Hello <PII type="PERSON" id="1"/>!"

With Semantic Enrichment

const anonymizer = createAnonymizer({
  ner: { mode: 'quantized' },
  semantic: { enabled: true }
});

await anonymizer.initialize();

const result = await anonymizer.anonymize('Contact Maria in Berlin');
// "Contact <PII type="PERSON" gender="female" id="1"/> in <PII type="LOCATION" scope="city" id="2"/>"

With Storage

import { 
  createAnonymizer,
  InMemoryKeyProvider,
  SQLitePIIStorageProvider 
} from 'rehydra';

const storage = new SQLitePIIStorageProvider('./pii.db');
await storage.initialize();

const anonymizer = createAnonymizer({
  ner: { mode: 'quantized' },
  keyProvider: new InMemoryKeyProvider(),
  piiStorageProvider: storage,
});

await anonymizer.initialize();

// Use sessions for automatic persistence
const session = anonymizer.session('chat-123');
await session.anonymize('Hello John!');

Irreversible Anonymization

const anonymizer = createAnonymizer({
  mode: 'anonymize',  // No piiMap returned, PII permanently removed
  ner: { mode: 'quantized' },
});

await anonymizer.initialize();

const result = await anonymizer.anonymize('Contact John Smith at john@acme.com');
console.log(result.anonymizedText);
// "Contact <PII type="PERSON" id="1"/> at <PII type="EMAIL" id="1"/>"
console.log(result.piiMap);  // undefined

With Inference Server

const anonymizer = createAnonymizer({
  ner: {
    mode: 'quantized',
    backend: 'inference-server',
    inferenceServerUrl: 'http://gpu-server:8000/predict',
  }
});

With Custom Tag Format

const anonymizer = createAnonymizer({
  tagFormat: { open: '[[', close: ']]' }
});

await anonymizer.initialize();

const result = await anonymizer.anonymize('Contact: test@example.com');
console.log(result.anonymizedText);
// "Contact: [[PII type="EMAIL" id="1"]]"

With Custom Thresholds

import { createAnonymizer, PIIType } from 'rehydra';

const anonymizer = createAnonymizer({
  ner: { 
    mode: 'quantized',
    thresholds: {
      [PIIType.PERSON]: 0.8,
      [PIIType.ORG]: 0.7,
    }
  }
});

With Custom Policy

import { createAnonymizer, PIIType, createDefaultPolicy } from 'rehydra';

const policy = createDefaultPolicy();
policy.enabledTypes = new Set([PIIType.EMAIL, PIIType.PHONE, PIIType.PERSON]);
policy.allowlistTerms = new Set(['Support Team', 'Help Desk']);
policy.enableLeakScan = true;

const anonymizer = createAnonymizer({
  ner: { mode: 'quantized' },
  defaultPolicy: policy,
});

Excluding Countries and Regions

const anonymizer = createAnonymizer({
  ner: { mode: 'quantized' },
  semantic: { enabled: true },
  defaultPolicy: {
    excludeLocationScopes: new Set(['country', 'region']),
  },
});

await anonymizer.initialize();

const result = await anonymizer.anonymize('Meeting in Berlin, Germany.');
// "Meeting in <PII type="LOCATION" scope="city" id="1"/>, Germany."

anonymize - The anonymize method
Sessions - Session-based persistence
Storage Providers - Available storage options

Overview

Core

Storage

Streaming & Proxy

Utilities

Signature

Parameters

config (optional)

Returns

Examples

Basic (Regex Only)

With NER

With Semantic Enrichment

With Storage

Irreversible Anonymization

With Inference Server

With Custom Tag Format

With Custom Thresholds

With Custom Policy

Excluding Countries and Regions

​Signature

​Parameters

​config (optional)

​Returns

​Examples

​Basic (Regex Only)

​With NER

​With Semantic Enrichment

​With Storage

​Irreversible Anonymization

​With Inference Server

​With Custom Tag Format

​With Custom Thresholds

​With Custom Policy

​Excluding Countries and Regions

​Related

Signature

Parameters

config (optional)

Returns

Examples

Basic (Regex Only)

With NER

With Semantic Enrichment

With Storage

Irreversible Anonymization

With Inference Server

With Custom Tag Format

With Custom Thresholds

With Custom Policy

Excluding Countries and Regions

Related