Hexlock – Replace PII in text with fake data that has the same format

What it does

hexlock transforms sensitive data before it reaches your LLM. Phone numbers, emails, and card numbers become realistic tokens that your prompt still understands, and can be restored after. hexlock is a tool for preventing sensitive data from being used with LLMs. It replaces sensitive data but preserves the format so the LLM understands it still. Then it rehydrates the response with the original data. The sensitive data never gets sent to the LLM. Data types protected include email, phone, SSNs, driver's license identifiers, passport IDs, credit card, GitHub tokens, Anthropic tokens, AWS keys, and more. See CONFIG for more types. pip install hexlock Usage import hexlock # ephemeral — no key…from github.com

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  Hi HN, I’m one of the maintainers of Bridge Anonymization. We built this because the existing solutions for translating sensitive user content are insufficient for many of our privacy-concious clients (Governments, Banks, Healthcare, etc.). We couldn't send PII to third-party APIs, but standard redaction destroyed the translation quality. If you scrub "John" to "[PERSON]", the translation engine loses gender context (often defaulting to masculine), which breaks grammatical agreement in languages like French or German. So we built a reversible, local-first pipeline for Node.js/Bun. Here…

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