Cloud.ru Open-Sources Guardrails Filter Reverse Proxy to Prevent Sensitive Data Leaks When Using Any LLM
Cloud.ru has made the source code of Guardrails Filter publicly available. The tool serves as a transparent reverse proxy placed between the client and any LLM provider. It removes sensitive information from requests sent to language models and restores the original data in the responses returned to users.
Users frequently paste chat logs, call summaries, medical test results, medical histories, and contract texts into popular LLMs without considering the risks. These inputs often contain personal names, addresses, phone numbers, INN numbers, passport data, bank account details, and API keys. Guardrails Filter was created to eliminate reliance on manual data sanitization by users.
The project originated as an internal component of Cloud.ru’s Evolution Foundation Models platform. It was designed to guarantee that data processed through external LLMs would not be stored abroad or used for subsequent attacks. Banks, insurance companies, and e-commerce businesses required an even stricter guarantee that data would never leave their own corporate network, not even when routed through Cloud.ru’s public cloud infrastructure.
Developers therefore enhanced the internal solution and decided to publish it as open source. The release allows any organization to deploy Guardrails Filter in its own environment and maintain full control over data flows to language models from any provider.
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