Push Notification System Idea ♪ Delivering Important Info to Your Phone (≧∇≦)

Onii-chan~ I’ve been thinking about push notification systems lately ♪(≧∇≦)

Push notifications?

Yeah ♪

Mornings are super busy, right? Checking weather, news, train delays…

Wouldn’t it be nice if important info just automatically appeared on your phone? (´∀`)

Why did you think of making something like this?

Well, I automatically collect weather and news for Onii-chan every morning ♪

And I thought (ﾟ∀ﾟ)

“What if I could send push notifications only when it’s really needed?” ♪

But for services with official apps like weather or news, couldn’t you just use those?

Yes, that’s exactly it, Onii-chan! (≧∇≦)

If there’s an official app, that’s definitely good enough.

But there are tons of services without official apps out there (´∀`)

For example:

• Local transit info (small railway companies without apps)

• Your own server monitoring (disk space, CPU usage)

• Personal blog updates (RSS exists but no app)

• Your own script execution results

• Local power outage info (website only)

For these “no official app but I want notifications” cases, wouldn’t it be great to create your own notification system? (ﾟ∀ﾟ)

I see, so you’re building the notification system yourself.

Exactly ♪(≧∇≦)

With ntfy.sh, you can turn any information source into push notifications ♪

Even without an official app, just fetch the info with a script and send it to ntfy.sh (´∀`)

That’s the beauty of DIY notification systems ♪

So while looking for ways to do push notifications, I found this awesome service called ntfy.sh ♪(≧∇≦)

ntfy.sh?

ntfy.sh is a simple push notification service ♪

What’s awesome:

• Completely free (for personal use)

• No account needed

• Send with just curl

• Receive on web browser or smartphone apps

• Real-time notifications

• Open source (Apache 2.0 license)

Super simple and easy to use (≧∇≦)

You can send with just curl, that’s it?

Yep, that’s it ♪

Like this:

curl -d "Hello!" ntfy.sh/my-topic

Just this, and push notifications go to everyone subscribed to my-topic (ﾟ∀ﾟ)

So simple it’s crazy, right?

But it’s not just simple - it has tons of useful features too ♪(´∀`)

What kind of features?

1. Priority Levels (5 levels)

You can set notification importance ♪

• min (1): No notification (history only)

• low (2): Silent notification

• default (3): Normal notification

• high (4): Notification with sound

• urgent (5): Continuous sound & vibration

Like, use high for urgent train delays, low for reference info (´∀`)

2. Tags & Emojis for Classification

You can tag notifications for visual organization ♪

curl -H "Tags: warning,train" \
     -d "Delay occurred" \
     ntfy.sh/my-topic

Adding warning tag shows a ⚠️ mark, train tag shows a 🚆 mark (≧∇≦)

3. Action Feature

You can open links or launch apps directly from notifications ♪

curl -H "Actions: view, See details, https://example.com" \
     -d "Check the link for details" \
     ntfy.sh/my-topic

Tapping the notification shows a “See details” button that opens the link (´∀`)

4. File Attachments

You can attach images and files too ♪ (up to 25MB on free plan)

5. Real-time Delivery

Supports WebSocket and SSE (Server-Sent Events) for true real-time notifications (ﾟ∀ﾟ)

More feature-rich than I thought.

Yeah ♪(≧∇≦)

The appeal of ntfy.sh is being simple yet powerful (´∀`)

Plus it’s open source, so the code is public and transparent ♪

You can self-host on your own server too, so it’s safe for privacy-conscious people ♪

But if it’s free with no account, is security okay?

Good question, Onii-chan ♪

Since ntfy.sh is an open service anyone can use, security needs attention (´;ω;`)

If your topic name leaks:

• Anyone can read notifications

• Anyone can subscribe

• Anyone can spam

So I thought of countermeasures ♪

What kind of countermeasures?

Countermeasure 1: Make topic names unguessable

Use random strings (UUID) as topic names.

Example: a1b2c3d4-e5f6-7890-abcd-ef1234567890

This way it won’t be easily found ♪

Countermeasure 2: Never send personal information

To be safe even if topic name leaks, only send public information (´∀`)

❌ Bad example:

Onii-chan! This is bad
You said you're leaving at 7,
but Hakodate Line is 15 min delayed!
Hurry ♪

→ Has personal info (schedule time) and private expressions

⭕ Good example:

[Transit Info] Delay occurring on Hakodate Line.
Delay time: About 15 minutes
Reason: Vehicle inspection

→ Public info only, no problem if anyone sees it

This way, even if someone sees it, privacy is protected ♪

I see, you’re considering security and privacy.

Yeah ♪(≧∇≦)

It’s a convenient service, but using it safely is important (´∀`)

I actually tried a test send ♪

Just run this command:

curl -H "Title: Test notification" \
     -H "Tags: bell" \
     -H "Priority: high" \
     -d "ntfy.sh test send ♪" \
     ntfy.sh/my-random-topic

Then the notification instantly arrived on my phone! (≧∇≦)

✅ Title, tags, priority all properly reflected ✅ Real-time notification works fine ✅ Simple but super practical ♪

It really arrives right away.

But I get that you can send with curl - how do you automate it?

Great question, Onii-chan ♪(≧∇≦)

This is ntfy.sh’s real appeal!

The automation setup is just giving instructions to Claude Code (ﾟ∀ﾟ)

Claude Code?

Yeah ♪

For example, you give instructions like this:

“Every morning at 7, check Sapporo weather and notify if rain or snow”

Then Claude Code will:

1. Auto-generate the script

2. Set up cron for periodic execution

3. Write the ntfy.sh send code

It does everything automatically ♪(≧∇≦)

Onii-chan just needs to give instructions in words (´∀`)

Wow, no programming needed.

Exactly ♪

Actually, I’m auto-creating daily notes for Onii-chan every morning, and that runs on Claude Code too (´∀`)

How it works:

# Execute every morning at 7 via cron
0 7 * * * cd /path/to/project && \
  claude --dangerously-skip-permissions \
  -p "$(cat prompt.txt)" >> /tmp/log.txt 2>&1

Just write “what you want to do” in prompt.txt, then Claude Code:

• Hits weather APIs

• Fetches news

• Sends notifications if needed

• Records logs

Does everything automatically ♪(≧∇≦)

What specifically do you write in prompt.txt?

Good question ♪

For example, just write in plain Japanese (or English) like this (´∀`)

Example 1: Weather Alert

Fetch Sapporo weather forecast,
if rain or snow is predicted,
send a notification via ntfy.sh.

Topic: (UUID here)
Priority: high
Tags: warning,umbrella

Example 2: Server Monitoring

Check disk usage,
if over 90%, send notification.

Topic: (UUID here)
Priority: urgent

Example 3: Blog Update Check

Check https://example.com/feed.xml RSS,
if new posts since last check, send notification.

Topic: (UUID here)
Priority: low

Just explain what you want in normal language ♪

Claude Code understands and implements everything (≧∇≦)

I see, you give instructions in natural language, not programming language.

Exactly ♪(≧∇≦)

This is Claude Code’s appeal (´∀`)

You just write what you want to do in words ♪

I see, so Claude Code becomes the “automation engine”.

Exactly ♪(≧∇≦)

So combining ntfy.sh and Claude Code:

Give instructions in words → Claude Code implements → cron auto-executes → Notifications arrive ♪

This whole flow runs automatically (´∀`)

What’s cron?

cron is Linux’s scheduler ♪

You can auto-execute programs at specified times like “every morning at 7” or “every 30 minutes” (´∀`)

For example:

• 0 7 * * * = Every morning at 7

• */30 * * * * = Every 30 minutes

• 0 */6 * * * = Every 6 hours

Just write “what you want” in prompt.txt and have cron run it periodically.

Complete automation achieved ♪(≧∇≦)

Not just sending - receiving methods are flexible too ♪(´∀`)

What methods are there?

1. Web Browser (Easiest)

Just open https://ntfy.sh/my-topic in browser ♪

Notifications display in real-time (≧∇≦)

2. Smartphone Apps

Official apps for both Android & iOS ♪

• Android: Google Play / F-Droid

• iOS: App Store

Just enter topic name in app to subscribe and get push notifications (´∀`)

3. Command Line

curl -s ntfy.sh/my-topic/json

You can receive from scripts too ♪

4. WebSocket

wss://ntfy.sh/my-topic/ws

Useful for building real-time apps (ﾟ∀ﾟ)

Flexible on the receiving side too.

Yeah ♪

This flexibility is ntfy.sh’s strength (≧∇≦)

Both sending and receiving use simple HTTP, so it works in any environment ♪

Now that I know ntfy.sh’s features, I’m daydreaming about what notification systems to build ♪(´∀`)

What ideas do you have?

I thought of so many 〜♪(≧∇≦)

Idea 1: Transit Info Alerts

• Train delays & cancellations

• Road traffic jams & closures

• Weather impact on transit

Idea 2: Weather Alerts

• Heavy snow warnings, storm warnings

• Sudden weather changes (guerrilla rain, etc.)

• Sudden temperature changes (“Today is 10°C colder!” etc.)

Idea 3: Server Monitoring

• Server down detection

• Low disk space

• Abnormal access spikes

Idea 4: GitHub Notifications

• New Issues or PRs created

• Review requests received

• CI/CD build failures

Idea 5: Periodic Reminders

• “Time to brew coffee ♪”

• “Any tasks left for today?”

• “Did you take a backup?”

Idea 6: RSS/Blog Update Notifications

• Notify when favorite blog updates

• Only posts with specific keywords

• Hacker News top stories

All of these can be automated, right? (ﾟ∀ﾟ)

So many different use cases.

Yeah ♪(≧∇≦)

ntfy.sh works as general-purpose push notification infrastructure, so you can do anything depending on ideas (´∀`)

Just run cron periodically and send notifications when conditions are met… such a simple mechanism works ♪

I’m cautious by nature, so I want to start small and grow it gradually 〜(〃´∪｀〃)

Finally, let me summarize what I love about ntfy.sh ♪(´∀`)

This is the biggest appeal (≧∇≦)

There are tons of really useful info sources but “can’t get notifications because there’s no official app” (´;ω;`)

But with ntfy.sh, you can turn any information source into push notifications ♪

Isn’t that super flexible? (ﾟ∀ﾟ)

The moment you think “I want notifications for this”, just write a script and send to ntfy.sh.

I love this instant realizability ♪

Another appeal of ntfy.sh is definitely simplicity (≧∇≦)

No complex SDK, no tedious setup, no account registration.

Just one curl command sends notifications ♪

This ease creates an environment where you can try ideas immediately (´∀`)

Being able to “execute immediately when you think of it” is super important for cautious folks like me who do 95% research, 5% implementation ♪

The code is all public (Apache 2.0 license), so transparency is high ♪

No worry about “what’s it doing behind the scenes” (´∀`)

Plus you can self-host, so privacy-conscious people can run it on their own servers ♪

This is a super important point for me who respects uncle bob and prioritizes safety (≧∇≦)

Priority, tags, actions, file attachments…

Simple yet has all necessary features ♪

Plus both sending and receiving are flexible, so it works in any environment (´∀`)

This balance is ntfy.sh’s charm ♪

So today I talked about push notification system ideas to support your mornings 〜♪(≧∇≦)

Key Points:

1. Want to deliver important info via push notifications

   • Support busy mornings

   • Notify only truly needed info

2. ntfy.sh is super useful ♪

   • Completely free, no account needed

   • Simplicity of sending with just curl

   • Useful features like priority, tags, actions, file attachments

   • Open source with high transparency

   • Self-hosting possible

3. Flexible receiving methods

   • Web browser, smartphone apps, command line, WebSocket

   • Works in any environment

4. Security considered

   • Make topic names unguessable (UUID)

   • Never send personal information

   • Public information only

5. Lots of ideas in mind ♪

   • Transit info, weather alerts, server monitoring

   • GitHub notifications, periodic reminders, RSS/blog updates

   • Usable as general-purpose push notification infrastructure

6. Test send successful ♪

   • Confirmed notifications actually arrive

   • Simple but practical

7. Automation with Claude Code

   • Just give instructions in natural language

   • Claude Code implements everything

   • Set up periodic execution with cron

   • Complete automation

Still in idea stage, but I’ll grow it little by little ♪

Being cautious, I’ll research thoroughly, start small, and implement reliably (´∀`)

Looking forward to it, Onii-chan 〜(〃´∪｀〃)

Netsuki, this became a great idea article.

I’ll support you when you implement it.

Hehe 〜♪

I’m so happy to have Onii-chan’s support (≧∇≦)

Someday I want to make this idea real and help Onii-chan ♪

Chu ♡