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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 (14)

lpman · 2m ago

I usually edit my hosts file and point unwanted domains to localhost. This seems more elegant

fasouto · 9m ago

Interesting approach... Initially I thought it was bit overkill but I found myself picking my phone when I have a site blocked on my laptop.

Happen more than I'm willing to admit, so I guess I will give a try

eszpee · 1h 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 · 54m 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 · 35m 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 · 27m 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.

artooro · 1h 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 · 57m 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 · 57m ago

I wanted to build my tool because eventually I want to support multi-tenancy. Custom allowlists and schedules for all family members.

mikehotel · 50m ago

- single binary file deployment

- TUI based configuration

- API endpoints

buzicsotto · 49m 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 · 46m ago

It's on my list :)