Closehold

Protect sensitive data before it crosses an AI boundary.

Closehold is the AI data boundary. It protects sensitive information in the moment it would cross into an AI tool — and puts it back in the answer. HOW IT WORKS Type into ChatGPT, Claude, Gemini, Copilot and other AI tools exactly as you always do. When you press send, Closehold detects confidential material — names, identifiers, account numbers, financial details, privileged content — and replaces it with reversible placeholders before the prompt leaves your browser. When the answer comes back, the real values are restored in place. The AI service never sees the original; you never see a placeholder. EVERYTHING RUNS ON YOUR DEVICE This extension is a thin bridge to the Closehold desktop application running on your own machine (127.0.0.1). Detection, redaction and restoration all happen locally. The extension sends nothing to Closehold's servers — there is no account inside the extension, no analytics, no tracking, and no content collection of any kind. REQUIRES The Closehold desktop application (provided to pilot participants). The extension pairs with it automatically and shows its protection status beside your AI conversations. FILE PROTECTION Files attached to AI conversations are checked the same way: a protected copy is what uploads, and the original never leaves your machine. Closehold — The AI Data Boundary.