f09b917f1a
Framework-agnostic PII anonymization extracted from Mobiletic's chatbot. Pluggable LLM detection + configurable regex fallback, deterministic coreference, and streaming-safe de-anonymization. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
147 lines
4.9 KiB
Markdown
147 lines
4.9 KiB
Markdown
# @mobiletic/anonymizer
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Framework-agnostic **PII anonymization & pseudonymization** for TypeScript/JavaScript.
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It replaces personal data in text with stable placeholders before the text leaves your trust boundary
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(e.g. before sending it to a third-party LLM, log sink, or analytics pipeline), and restores the real
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values afterwards — including across **streamed** tokens.
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- 🔌 **Pluggable LLM detection** — catch free-form PII (names, addresses) via any OpenAI-compatible
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endpoint, or your own provider. No LLM? It degrades gracefully to regex.
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- 🧩 **Deterministic regex fallback** — structured identifiers (email, phone, IBAN, …) via configurable
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pattern presets (`swiss`, `generic`) or your own.
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- 🔁 **Deterministic coreference** — the same person keeps the same id (`[PER_1]`) across a question and
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every retrieved chunk, with automatic de-collision.
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- 🌊 **Streaming-safe** — a placeholder split across two stream chunks (`[PER_` + `1.NOM:M]`) is never
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leaked partially.
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- 🪶 **Zero runtime dependencies**, ESM + CJS, fully typed.
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> Built by [Mobiletic](https://mobiletic.com) and extracted from a production Swiss-nLPD chatbot.
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## Install
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```bash
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npm install @mobiletic/anonymizer
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```
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Requires Node ≥ 18 (uses native `fetch`).
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## Quick start
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### Regex-only (no LLM, fully deterministic)
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```ts
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import { Anonymizer, presets } from '@mobiletic/anonymizer';
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const anonymizer = new Anonymizer({ patterns: presets.swiss });
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const { anon, mapping } = await anonymizer.anonymize('Écris à jean@exemple.ch');
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// anon -> "Écris à [EMAIL_1]"
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// mapping -> { "[EMAIL_1]": "jean@exemple.ch" }
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anonymizer.deanonymize(anon, mapping); // -> "Écris à jean@exemple.ch"
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```
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### With an LLM (also catches names, addresses…)
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```ts
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import { Anonymizer, openAICompatibleProvider, presets } from '@mobiletic/anonymizer';
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const anonymizer = new Anonymizer({
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llm: openAICompatibleProvider({
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baseUrl: process.env.LLM_BASE_URL!, // OpenAI, Infomaniak, vLLM, Ollama, …
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apiKey: process.env.LLM_API_KEY!,
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model: process.env.LLM_MODEL!,
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timeoutMs: 3000,
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}),
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patterns: presets.swiss, // regex fallback if the LLM is down/misbehaves
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});
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const { anon, mapping } = await anonymizer.anonymize('Le dossier de Alain Jaccard est complet.');
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// anon -> "Le dossier de [PER_1.NOM:M] est complet."
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```
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If the LLM call fails, times out, or returns an invalid shape, the anonymizer automatically falls back to
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the regex engine — it never throws on a provider failure.
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### Streaming de-anonymization
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When you stream an LLM answer back to a user, restore real values without ever emitting a half-written
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placeholder:
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```ts
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const stream = anonymizer.makeStreamDeanonymizer(mapping);
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for await (const token of llmTokens) process.stdout.write(stream.push(token));
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process.stdout.write(stream.flush());
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```
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### Anonymizing retrieved chunks consistently (RAG)
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`anonymizeChunks(chunks, seed)` reuses the question's mapping (`seed`) so the same person gets the same id
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across the question and every chunk, batches the LLM call, and de-collides genuinely new entities:
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```ts
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const q = await anonymizer.anonymize(question);
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const { anon, mapping } = await anonymizer.anonymizeChunks(retrievedChunks, q.mapping);
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// `mapping` is the full question ∪ chunks table; pass it to deanonymize()/makeStreamDeanonymizer().
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```
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## Configuration
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```ts
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new Anonymizer({
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llm?, // LlmProvider — omit for regex-only mode
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patterns?, // PatternDef[] — defaults to presets.swiss
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nameHint?, // RegExp flagging likely names so the LLM is consulted (has a default)
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logger?, // { warn(msg) } — receives fallback warnings; defaults to no-op
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});
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```
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### Presets & custom patterns
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```ts
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import { presets } from '@mobiletic/anonymizer';
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presets.swiss; // AVS, IBAN CH, EMAIL, Swiss phone, DATE
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presets.generic; // EMAIL, IBAN, credit card, IPv4, phone, DATE
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// Compose / extend:
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const patterns = [
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...presets.generic,
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{ tag: 'TICKET', re: /\bJIRA-\d+\b/g }, // patterns must use the global flag
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];
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```
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### Custom LLM provider
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Implement `LlmProvider` to use any backend (Anthropic, a local model, a rules engine…):
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```ts
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import type { LlmProvider } from '@mobiletic/anonymizer';
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const myProvider: LlmProvider = {
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isConfigured: () => true,
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async anonymize(text) { /* return { anon, mapping } */ },
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async anonymizeBatch(texts, usedIds) { /* return { segments, mapping } */ },
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};
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```
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## Placeholder format
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```
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[PER_1.NOM:M] entity PER #1, attribute NOM, context M (rich, from the LLM)
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[EMAIL_1] structured id from the regex fallback
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```
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`PLACEHOLDER_RE` is exported if you need to scan text for placeholders.
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## Compliance note
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This library is a **best-effort** pseudonymization aid, not a guarantee of legal compliance. LLM and regex
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detection can miss or mis-classify data. Validate against your own requirements (nLPD, GDPR, HIPAA, …)
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before relying on it for regulated data.
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## License
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[MIT](./LICENSE) © Mobiletic
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