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

18 dominis 11 8/6/2025, 4:08:23 PM github.com ↗
Most site blockers work by blacklisting distractions. That never worked for me, the internet is too big, and there’s always something new to waste time on.

I wanted the opposite: allowlist‑only browsing. Block everything by default, and explicitly allow only what I need.

So I built Sinkzone: a local DNS forwarder with two modes:

Monitor mode: lets all traffic through, but logs every domain so you can decide what to allow.

Focus mode: only allowlisted domains resolve; everything else is blocked (NXDOMAIN).

It’s open source, written in Go, and runs locally on macOS, Linux, and Windows. Works a bit like Pi‑hole, but instead of blocking ads, it blocks everything unless you say otherwise.

I’m curious if this would be useful in your workflow. If you try it, please let me know what breaks, what works well, and what you’d improve.

Comments (11)

eszpee · 40m ago
Sounds interesting! The Pomodoro app I'm using for focus times has this feature built in (I wrote about it here: https://peterszasz.com/finding-focus-through-intention-and-a... ), but before finding that, I would've definitely tried this.

Improvement idea: Integrate with Apple Shortcuts, so the user could automate switching focus mode on and off, tied to changing Apple Focus mode.

dominis · 34m ago
Hey Eszpee, Thanks for checking Sinkzone out. I'm thinking about building custom schedules in the next iteration, that would support some basic pomodoro style scheduling for sure.
pozsi · 15m ago
Will this work when I'm connected to the company vpn? We have a private DNS zone set up for our private network, and this would probably mess up my DNS config. It would be awesome if it worked though!
dominis · 7m ago
You can configure your upstream resolvers in the config, so I think Sinkzone can be placed in front of your VPN's resolver. I never tested this to be honest.
buzicsotto · 29m ago
This sounds awesome - I wish I could run it on my iphone, because otherwise it's not even gonna put a dent in my infinite capacity for slacking off....
dominis · 26m ago
It's on my list :)
artooro · 47m ago
How is this better than using Pi-hole to do the same? It can also run in an allow only mode as I understand.
daft_pink · 37m ago
I think the idea is that it blocks everything on your machine instead of causing the whole network to go offline as piholes are generally applied to the entire home network.

Your mileage might vary, but in my home, causing my smarthome plus my wife and children’s internet to go offline might cause a bigger distraction to my focus. Also you couldn’t use a pi-hole at work for instance.

dominis · 36m ago
I wanted to build my tool because eventually I want to support multi-tenancy. Custom allowlists and schedules for all family members.
mikehotel · 29m ago
- single binary file deployment

- TUI based configuration

- API endpoints