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Posted by u/keepamovin 10 days ago
Show HN: A pagerudp7777.com/...
Hello HN,

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

ProllyInfamous · 10 days ago
>I found myself missing 1990s pagers.

I still use one which gets one-way service from <https://pagersdirect.net/> (~$14/mo, with phone number and pager included). Most US cities, large and small, still have active infrastructure. I live in a city with a few hundred thousand people, great coverage.

This has replaced my mobile phone, which I no longer carry. It also prevents spammers from messaging... because the systems don't understand this antiquated technology [1].

For those interested, Pagers Direct has an email-to-pager option (I don't use it, phone digits only please caller, after the beep). It also has two-way pagers, which I have no experience with.

One caution: for one-way pagers, if you're out of range[0] when somebody sends you text, you will never get the message (no handshake/confirmation).

[0] does not use traditional cellular infrastructure

[1] TBH: most humans don't either, unless you explain how to page somebody: key in your callback#/code after the beep [no audio/text]

[•] I don't work for the above-linked paging service, I'm just a very happy customer.

calvinmorrison · 9 days ago
Also had a pager up until 2023 (when I was on call). If you're in range is an awesome tool to use. Great for alerts, ironically I had it hooked up to SMS with PagerDuty.
keepamovin · 10 days ago
That is so cool. I really want to get one (or make a hardware company that builds simple, DIY kits for them).
ProllyInfamous · 10 days ago
With a prepaid annual subscription, they sent me a pager for FREE.

>builds simple, DIY kits for them

So I highly doubt this would be profitable for you.

----

As far as the paging infrastructure is concerned, all the messages are mass-sent, in an un-encrypted analogue broadcast. EVERY device receives EVERY page, as long as within range. It is the pager itself which chooses to only display "your" message(s).

Your DIY hardware could lead you into some interesting discoveries of your local area's messaging/users.

ProllyInfamous · 10 days ago
Really neat project, see my sister comment (on analogue pagers still in service).

>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).

Personally, this seems like a really bad idea. The similarity to actual phone numbers might lead to confusion by non-technical high-trust contactors. Worse (e.g.) if the IP were 91.1x.x.x then this could lead to further confusion &/or erroneous 9-1-1 misdials (by inept contactors).

It's a UDP packet, ought it not be in IP-format?

>where you only want interruptions from a high-trust circle

I don't even have a phone contact number anymore. After you page me, I'll VoIP you back from an outbound-only.

But overall I LOVE that you have attempted this; only real problem for your average installer/recipient is that most home ISPs are firewalled (so a UDP7777 inbound isn't possible), but this obviously isn't for even your average technical installer.

----

Just leave me alone, world/SPAMmers!

How do you prevent malicious actors from invading your 7777UDPs?

keepamovin · 10 days ago
For anti-spam, the general use case is use of Tailscale/Zerotier where you are in control of your network. If you are on public internet and have 7777 open then you can use the Squelch filter under the CFG page. It drops every message that doesn't start with your secret::
robertlagrant · 9 days ago
> It drops every message that doesn't start with your secret::

Depending on how internet-proof you want to make this, I wonder if it might be better to sign with a secret and attach the signature to the message instead of directly sending the secret.

blargwill · 10 days ago
Woah! The world really works in mysterious ways. I've found myself thinking in this space a lot recently. I've been working on a pager that takes the notifications from my phone and relays only the ones I want to see. I use LTE-M/NB-IOT to get connectivity anywhere and the device works and I'm looking to find a way to get a pcd/case made..

Landing page (doesn't link to anything): https://fob.launchbowl.com/

A little word dump of thoughts at the start of the journey: https://launchbowl.com/e_ink_pager

Your project seems really cool and allows you to bring your own hardware. Out of curiosity, have you blocked all notifications on your phone? Would this be run on your computer? Would you ever move in the direction of a physical device?

wkat4242 · 10 days ago
I'd love to get a real pager again too. But not LTE-M based because that's still a two way system so I can be traced.

I just have a pretty strong desire to get my anonymity back when I want it. Not because I need it but just to feel free again.

ProllyInfamous · 10 days ago
US: <http://www.pagersdirect.net>

I have and use one, partially for the reasons you list above.

[•] Not a representative of the company, just a very happy customer.

keepamovin · 9 days ago
Heh, that is exactly why I kept UDP-7777 passive. It listens on 0.0.0.0 but sends zero telemetry and requires no "online" status packet. Unless you hit ACK (which sends a packet back), you are a ghost.
keepamovin · 9 days ago
Just took another look at your work, and your LTE-M project looks incredible. The e-ink aesthetic is exactly right for this. I've fantasized about building some apps for e-ink displays (wanted to drop BrowserBox in a remarkable tablet, etc), but haven't yet. Here I stuck to desktop/software for v1 to solve the immediate 'screen fatigue' issue, but I'd love to see a world where physical tokens like yours replace the smartphone notification center.

Yes, I block all the notifications on the phone. I leave badges for some apps and check when I want, or just periodically check when it's in my rhythm. (A few people have exceptions). It runs on computer now, but the next step is I want to test if mobile could be achieved without a server (I'm okay with a Tailscale/ZT requirement or such, for now). Aside from that I would love physical infra. If it could work such that it piggy-backed off existing infra, at first, might be good approach. Someone should do this. I don't know if it's us, but it should be created.

If anyone would like to discuss these possibilities, please reach out at pager@dosaygo.com

keepamovin · 10 days ago
Yes! I really want a physical device for things like this. It's cool we are both thinking about it: independent invention. That is a sick website. Love the design!
kotaKat · 9 days ago
I am also here for an LTE-M pager… I have no POCSAG coverage anywhere near me… that would be a very nice little design.

Deleted Comment

nineteen999 · 9 days ago
As someone who builds and operating a very large simulcast paging network for emergency services I can assure you POCSAG is not completely legacy ;-) very much alive and well in 2025.

Definitely old but highly reliable.

bflesch · 9 days ago
Inhowfar were you able to harden such a legacy protocol against state-actor attacks on critical infrastructure? Is it a legacy protocol in the sense of simple & robust or spoofable & floodable?

Edit: To clarify, if the frequency is known couldn't they simply disable/jam all devices?

nineteen999 · 9 days ago
The area covered in question is over 200km2. Might be hard to imagine how much RF transmission/reception equipment we have in that space.

An attacker would need a lot of fairly powerful jamming equipment just to disrupt a small area of it. And our customer would advise us pretty quickly if their personnel were having reception issues and our field engineers would diagnose the source of the interference pretty quickly. So no.

antihoney · 9 days ago
This arrived at the perfect time! I was discussing pagers with my friend a few days back, after he expressed annoyance at me always being offline :. unavailable, unless I made the active choice to check my notifications (something I do not enjoy at all).
keepamovin · 9 days ago
Timing is everything!
andai · 10 days ago
Do you have this running on some kind of pager shaped device? What do you use it for?
Western0 · 9 days ago
finger is better (and best is reticulum)

or https://shop.exploitee.rs/shop/p/the-hacker-pager

aiiotnoodle · 10 days ago
Really cool. I like the flashing red.
keepamovin · 10 days ago
Thanks. I thought I should not just use a sound in case people are deaf or don't have volume on.