Show HN: Sinkzone DNS forwarder that blocks everything except your allowlist

What is Sinkzone? Sinkzone is a local DNS resolver that helps you eliminate distractions and get deep work done. It blocks all domains by default — only the ones you explicitly allow can get through. This means notifications, social media, news, and other time-sinks are unreachable at the network level — not just in your browser. It features a modern HTTP API, wildcard pattern support, and a beautiful terminal UI for real-time monitoring and control. It's lightweight, cross-platform, and built for hackers, makers, and anyone serious about focus. Motivation Most tools make you list what you want to block. But the internet is infinite — that list never ends. It's much easier to list the few things you actually want to allow. Sinkzone was born from that insight. I was tired of coding sessions interrupted by Slack pings and email alerts. I needed something stronger than a browser plugin — a system-level kill switch for distractions. Now I can code for hours uninterrupted. Even my son uses Sinkzone during chess practice to stay focused. Sinkzone exists because I needed it. Maybe you do too. Why use Sinkzone? Avoid distraction without browser extensions or hacks Run locally on macOS, Linux and Windows — no cloud, no telemetry Perfect for deep work sessions, writing, coding, or child safety Terminal UI included — toggle modes, view logs, edit allowlist Key Features DNS-level blocking : Stops distractions before they reach your apps : Stops distractions before they reach your apps Focus Mode : Block all but allowlisted domains for a set duration : Block all but allowlisted domains for a set duration Wildcard Support : Use patterns like *github* or *.google.com for flexible domain matching : Use patterns like or for flexible domain matching HTTP API : RESTful API for monitoring and control : RESTful API for monitoring and control Terminal UI : Real-time DNS traffic viewer with tabbed interface : Real-time DNS traffic viewer with tabbed interface Memory-backed rules : Focus mode expires automatically : Focus mode expires automatically Cross-platform: Works on macOS and Linux Demos Terminal User Interface (TUI) The TUI provides real-time DNS monitoring and allowlist management: Real-time DNS traffic monitoring, allowlist management, and focus mode control Command Line Interface (CLI) The CLI offers powerful command-line tools for system management: Command-line allowlist management, focus mode control, and system status monitoring Quick Start Installation by Platform 👉 macOS Installation Homebrew (Recommended): brew tap berbyte/ber brew install sinkzone Manual Setup: # 1. Start the DNS Resolver (default port 53, requires admin privileges) sudo sinkzone resolver # 2. Launch the UI (in another terminal) sinkzone tui # 3. Enable Focus Mode sinkzone focus start Configure System DNS (Required): sudo networksetup -setdnsservers " Wi-Fi " 127.0.0.1 Direct Download: # Apple Silicon (M1/M2) curl -L -o sinkzone https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-darwin-arm64 chmod +x sinkzone sudo mv sinkzone /usr/local/bin/ # Intel Mac curl -L -o sinkzone https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-darwin-amd64 chmod +x sinkzone sudo mv sinkzone /usr/local/bin/ 👉 Linux Installation Package Managers (Recommended): Debian/Ubuntu: # Download and install the .deb package curl -L -O https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-amd64.deb sudo dpkg -i sinkzone-linux-amd64.deb Red Hat/Fedora/CentOS: # Download and install the .rpm package curl -L -O https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-amd64.rpm sudo rpm -i sinkzone-linux-amd64.rpm Alpine Linux: # Download and install the .apk package curl -L -O https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-amd64.apk sudo apk add --allow-untrusted sinkzone-linux-amd64.apk Arch Linux: # Download and install the .pkg.tar.zst package curl -L -O https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-amd64.pkg.tar.zst sudo pacman -U sinkzone-linux-amd64.pkg.tar.zst Manual Installation: # AMD64 curl -L -o sinkzone https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-amd64 chmod +x sinkzone sudo mv sinkzone /usr/local/bin/ # ARM64 curl -L -o sinkzone https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-linux-arm64 chmod +x sinkzone sudo mv sinkzone /usr/local/bin/ Manual Setup: # 1. Start the DNS Resolver (default port 53, requires admin privileges) sudo sinkzone resolver # 2. Launch the UI (in another terminal) sinkzone tui # 3. Enable Focus Mode sinkzone focus start Configure System DNS (Required): echo " nameserver 127.0.0.1 " | sudo tee /etc/resolv.conf Note: Package installations include the manual page. Run man sinkzone for detailed documentation. 👉 Windows Installation Direct Download: # AMD64 Invoke-WebRequest - Uri " https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-windows-amd64.exe " - OutFile " sinkzone.exe " # Move to a directory in your PATH (e.g., C:\Windows\System32 or create a custom directory) Move-Item sinkzone.exe C:\Windows\System32\ sinkzone.exe # ARM64 Invoke-WebRequest - Uri " https://github.com/berbyte/sinkzone/releases/latest/download/sinkzone-windows-arm64.exe " - OutFile " sinkzone.exe " # Move to a directory in your PATH (e.g., C:\Windows\System32 or create a custom directory) Move-Item sinkzone.exe C:\Windows\System32\ sinkzone.exe Manual Setup: # 1. Start the DNS Resolver (run as Administrator for port 53) sinkzone resolver # 2. Launch the UI (in another terminal) sinkzone tui # 3. Enable Focus Mode sinkzone focus start Configure System DNS (Required): Open Network & Internet settings Change adapter options Right-click your network adapter → Properties Select "Internet Protocol Version 4 (TCP/IPv4)" → Properties Select "Use the following DNS server addresses" Enter 127.0.0.1 as the preferred DNS server Note: On Windows, you may need to run the resolver as Administrator for port 53, or use an unprivileged port like 5353. 👉 Build from Source # Clone and build git clone https://github.com/berbyte/sinkzone.git cd sinkzone go build -o sinkzone . # Follow the manual setup steps above for your platform Documentation Manual Page For detailed documentation, run: sinkzone man Usage Common Commands Command Description sinkzone monitor Show last 20 DNS requests sinkzone tui Launch the terminal UI sinkzone resolver Start DNS resolver on port 53 sinkzone focus start Enable focus mode for 1 hour sinkzone focus --disable Disable focus mode immediately sinkzone status View current focus mode state sinkzone allowlist add Add domain to allowlist sinkzone allowlist add "*github*" Add wildcard pattern sinkzone allowlist remove Remove domain from allowlist sinkzone allowlist list List all allowed domains sinkzone config set resolver Set resolver IP sinkzone man Show manual page Note: On Unix-like systems (macOS/Linux), you may need to run sudo sinkzone resolver for port 53. On Windows, run as Administrator or use an unprivileged port like 5353. Wildcard Patterns Sinkzone supports wildcard patterns for flexible domain matching: Pattern Matches Examples *github* Any domain containing "github" github.com , api.github.com , githubusercontent.com *.google.com All subdomains of google.com maps.google.com , drive.google.com , docs.google.com api.*.com Any api subdomain of .com domains api.github.com , api.example.com , api.stackoverflow.com exact.com Exact domain match only exact.com (not sub.exact.com ) Examples: # Allow all GitHub-related domains sinkzone allowlist add " *github* " # Allow all Google subdomains sinkzone allowlist add " *.google.com " # Allow all API subdomains sinkzone allowlist add " api.*.com " # Allow exact domain sinkzone allowlist add " stackoverflow.com " TUI Navigation ← / → : Switch tabs f : Enable focus mode (1 hour) ESC : Quit Tabs include: Monitor : Real-time DNS traffic Allowlist : Add or remove allowed domains Settings : DNS resolver config How It Works Architecture Sinkzone is composed of three parts: Resolver : A local DNS server that intercepts queries and maintains real-time data via HTTP API. : A local DNS server that intercepts queries and maintains real-time data via HTTP API. HTTP API Server : Provides REST endpoints for monitoring DNS queries and controlling focus mode. : Provides REST endpoints for monitoring DNS queries and controlling focus mode. TUI/CLI : User interfaces that communicate with the resolver via HTTP API. : User interfaces that communicate with the resolver via HTTP API. TUI: A terminal UI for interacting with and monitoring the system via HTTP API. API Endpoints The resolver exposes the following HTTP endpoints: GET /api/queries - Get the last 100 DNS queries - Get the last 100 DNS queries GET /api/focus - Get current focus mode state - Get current focus mode state POST /api/focus - Set focus mode (enabled/disabled, duration) - Set focus mode (enabled/disabled, duration) GET /api/state - Get complete resolver state - Get complete resolver state GET /health - Health check endpoint API Usage Examples: # Start resolver with custom API port sinkzone resolver --port 53 --api-port 8080 # Use CLI with custom API URL sinkzone monitor --api-url http://127.0.0.1:8080 sinkzone focus --enable --api-url http://127.0.0.1:8080 sinkzone tui --api-url http://127.0.0.1:8080 # Direct API calls curl http://127.0.0.1:8080/api/queries curl http://127.0.0.1:8080/api/focus curl -X POST http://127.0.0.1:8080/api/focus \ -H " Content-Type: application/json " \ -d ' {"enabled": true, "duration": "1h"} ' Normal Mode All DNS queries are forwarded to upstream resolvers You can view and manage DNS traffic and allowlist Focus Mode Only allowlisted domains resolve Everything else returns NXDOMAIN Automatically expires after specified duration Allowlist is reloaded when focus mode is enabled (changes take effect on new focus sessions) Configuration Files are stored in ~/.sinkzone/ : sinkzone.yaml : Main config : Main config allowlist.txt : Simple text file containing allowed domains (supports wildcard patterns) : Simple text file containing allowed domains (supports wildcard patterns) resolver.pid : Process ID file for the DNS resolver Allowlist Format: # Comments start with # github.com stackoverflow.com *github* *.google.com api.*.com Development # Build binary go build -o sinkzone . # Run tests go test ./... # Run resolver with custom ports sinkzone resolver --port 5353 --api-port 8080 # Test API endpoints curl http://127.0.0.1:8080/health curl http://127.0.0.1:8080/api/queries # Run TUI with custom API URL sinkzone tui --api-url http://127.0.0.1:8080 Architecture: DNS Server: Handles DNS resolution and blocking HTTP API Server: Provides REST endpoints for monitoring and control CLI/TUI: User interfaces that communicate via HTTP API PRs and issues welcome. We love contributors. License MIT License. See the LICENSE file for full details. Contact (back to top)