--- name: al-625-keep-client-names-and-account-numbers-off-ai-servers-mask description: "On Nov 3, 2026 Solo Tested published how accountant Noa Lin built WP Guard with Claude Code: a local Windows tool that swaps client names, people, bank accounts and IDs for stable codes, keeps the code map encrypted with a project password (scrypt + AES-256-GCM), and only sends masked copies into an ai_workspace. Claude Code is fenced with CLAUDE.md rules, deny permissions on the private folder, and a PreToolUse hook that blocks web tools and path escapes. After the AI writes papers, WP Guard restores codes locally. The first version took about two hours to build; a later version added on-device OCR for JPEGs. The post stresses this is a safety layer, not legal advice, and that amounts/dates still leave the machine. Use when the user wants help with local client pii mask before ai (security) for a small business." --- # Keep client names and account numbers off AI servers: mask every identifier into codes like CLIENT_0001 on your own computer, let the AI work on the masked files, then restore the real details locally On Nov 3, 2026 Solo Tested published how accountant Noa Lin built WP Guard with Claude Code: a local Windows tool that swaps client names, people, bank accounts and IDs for stable codes, keeps the code map encrypted with a project password (scrypt + AES-256-GCM), and only sends masked copies into an ai_workspace. Claude Code is fenced with CLAUDE.md rules, deny permissions on the private folder, and a PreToolUse hook that blocks web tools and path escapes. After the AI writes papers, WP Guard restores codes locally. The first version took about two hours to build; a later version added on-device OCR for JPEGs. The post stresses this is a safety layer, not legal advice, and that amounts/dates still leave the machine. ## Inputs to collect first Ask the user for anything below that they haven't already given you. Don't guess missing facts. - The material the task is about (pasted text, notes or data) ## Instructions Do the task below with the user's inputs in place of each [bracket]. 1. Before any client file goes to ChatGPT/Claude/etc., decide which fields must never leave: names, IDs, account numbers, phones, emails, addresses. 2. Ask Claude Code (on your machine) to build a local masker: replace each sensitive value with a stable code (CLIENT_0001), store the map in an encrypted file with a project password using a standard crypto library, and write only masked copies to an ai_workspace folder. 3. Start Claude Code only inside ai_workspace. Add CLAUDE.md rules to keep codes unchanged and never guess who they are, plus permission denies and a PreToolUse hook that blocks WebFetch/WebSearch and any path into the private folder. 4. Run the AI on the masked files, then restore codes locally into the AI's output and read the restore report for any code that failed. 5. Test with made-up client data first. If your firm or client agreement bans AI on client material even when masked, do not use this—use templates with fake figures instead. ## Safety checks (share these with the user) - Anything legal, tax or compliance-related is a first draft for a qualified person to check. It is not professional advice, and clause references and deadlines must be checked against the source. - Remove names, contact details, account numbers and other personal data the task doesn't need before you paste, and check your AI tool's data and training settings. - Read and edit the draft before it reaches a customer or goes public. If you later automate this prompt, start with "draft and notify me", not "send automatically". - Check names, dates, numbers and any claim against your own source material before you use the answer. AI can misread or invent details. - Say clearly which parts need a person to review or approve before anything is sent, paid, posted or filed. ## About this skill - Works with: Claude Code, local Python, spreadsheet term list, optional on-device OCR - Based on this real-world example: https://solotested.com/posts/client-info-remover-with-claude/ - Free prompt from AgentPlaybook Real Estate: https://agentic-library.netlify.app/prompt/al-625-keep-client-names-and-account-numbers-off-ai-servers-mask-ev/ - To install in an agent that supports Agent Skills, save this file as SKILL.md in a folder with the same name as `name` above (for example in your skills directory). Install steps for Claude.ai, Claude Code, Cursor and Codex: https://agentic-library.netlify.app/skills/