Show HN: Local Privacy Firewall-blocks PII and secrets before ChatGPT sees them

Summary

PrivacyFirewall (Local AI Privacy Shield / Local LLM DLP) 👋 If you're trying PrivacyFirewall, please star the repo! It helps others discover the project and motivates development. Takes 2 seconds → ⭐ (top right) PrivacyFirewall is a local-first PII and secrets firewall for AI tools like ChatGPT, Claude, and Gemini.It blocks risky paste events, warns as you type, and (optionally) uses a lightweight on-device Transformer model for deeper PII detection. 🔒 **No data ever leaves your machine.**Everything runs locally in your browser or through an optional local API.You can verify this by inspecting the network panel and reading the open-source code. 🚨 Why This Project Exists Modern AI tools make it extremely easy to leak sensitive information: Emails & phone numbers API keys & credentials Customer or employee data IP & MAC address Internal logs & stack traces Regulated personal information (PII/PHI) Traditional enterprise DLP tools don’t cover AI chat prompts. PrivacyFirewall adds a zero-trust privacy shield BEFORE your text ever reaches a third-party AI system. What PrivacyFirewall gives you: ✋ Human-in-the-loop protection for accidental leaks 🔒 100% local processing (browser + localhost only) ⚡ Practical protection (regex + optional transformer NER) 🧩 Friendly UX (warnings, paste-block modals, override options) 🛠 OSS and auditable (MV3 + FastAPI + Hugging Face stack) 🧠 How It Works Two Layers of Protection **Lite Mode (regex-only)**Runs instantly in the extension — no setup needed. **AI Mode (optional, local LLM)**Uses a local FastAPI agent + transformer model for deeper detection(People, organizations, locations, contextual entities). High-level architecture graph TD A[User Pastes/Types Text]:::blueNode -->|Intercept| B(Chrome Extension):::blueNode B -->|Regex Check| C{Contains Secrets/PII?} C -->|Yes & Paste| D[BLOCK & WARN]:::redNode C -->|Yes & Typing| E[SHOW WARNING BANNER]:::redNode C -->|No| F{Local Engine Online?} F -->|No| G[Allow]:::blueNode F -->|Yes| H[Pyth...