A local AI model inside a new browser tool detects personal information such as names and account numbers and replaces them with realistic substitutes before a prompt is sent to an LLM. The software swaps these sensitive values back into the response locally to preserve context, supporting ChatGPT, Claude, Gemini, Grok and DeepSeek.

The AgentCloak extension is free to use and does not require a user account for its primary functions. It is designed for use cases such as summarizing support tickets or debugging logs where maintaining the reasoning capability of the AI is required without disclosing specific identities to the model provider.

The browser-based system operates by removing identity details without altering the semantics of the underlying task, which prevents the model from receiving private data. Users can employ the tool to rewrite emails or process sensitive documents while keeping the resulting AI output useful and tailored to their original input.