Posted by keepamovin 12/14/2025
I basically don't use notifications for anything. The noise is too much. Slack is too loud. Email is too slow. But sometimes you do need a note in your face.
I found myself missing 1990s pagers. I wanted a digital equivalent - something that does one thing: beep until I ack it.
So I built UDP-7777.
Concept:
- 0% Cloud: It listens on UDP Port 7777. No accounts, no central servers. You don't need Tailscale/ZeroTier/WG/etc, it's just easy for device sets.
- CAPCODES: It maps your IP address (LAN or Tailscale) to a retro 10-digit "CAPCODE" that looks like a phone number (e.g., (213) 070-6433 for loopback).
- Minimalism: Bare-bones interface. Just a box, a few buttons, and a big red blinker.
The Tech:
It's a single binary written in Go (using Fyne). It implements "burst fire" UDP (sending packets 3x) to ensure delivery without the handshake overhead of TCP.
New in v2.2.7:
- Frequency Tuning: Bind specifically to your Tailscale/ZeroTier interface.
- Squelch: Optional shared-secret keys to ignore unauthorized packets.
- Heartbeat: Visual/Audio alerts that persist until you physically click ACK.
I built this for anyone looking to cut through the noise—DevOps teams handing off the "on-call IP", or deep-work focus where you only want interruptions from a high-trust circle.
I'd love to hear your thoughts on the IP-to-Phone-Number mapping logic (it's purely visual, but I'm really into it).
Site & Binaries (Signed for Mac/Win): https://udp7777.com
PS: The "SHA256 CHECKSUMS VERIFIED." is static. No hash check is performed, and as far as I can see the website doesn't have a list of hashes to check.
Your radar was okay: site is machine-generated by build workflow which pushes the binaries. The "Verified" label reflects internal CI attestation, but without public hashes? Might cause concern. Did not consider, tho based on your comment I've now replaced with "Digitally Signed and Notarized".
So reflects more accurately how the binaries are always digitally signed and notarized (Apple Developer ID + Microsoft Authenticode) with our company certs. SOP for my releases. The verification is the cryptographic signature checked by your OS kernel, not just a text file.
I actually like this presentation better now!
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Public WhoIS registrant:
Chris [redacted]
The Dosyago Corporation
Beaverton, Oregon
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OP has ~2 year old /hn/ account, with ~11k karma
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I have made no further investigations, but obviously haven't installed this myself (as I have an IRL pager that solves similar issues to OP's).
> The system is intentionally raw. No headers, no JSON, no XML.
> Transport: UDP Port 7777
> Encoding: UTF-8 Plain Text
> Format: [SECRET::]MESSAGE
you dont get it, the protocol is flawless
> Only messages matching your Secret Key will ring.
I assume that's the "Secret Key" is placed in this prefix tag, '[SECRET::]' ?
Since plain-text over UDP is not very secret, I'm now motivated to look into how Wireguard is able to use PKI to only accept packets from a trusted clients. And, how that protocol could be used to generate the Secrey Key.