My background scrapers run on PythonAnywhere. My phone runs Termux. I wanted the scrapers to ping my phone when something interesting happened — without Firebase, without Ngrok, without paying for anything.

So I built Intent Bus.

The Problem

Most cross-device automation forces you to choose between:

• Too simple: hardcoded cron jobs with no coordination
• Too complex: Redis, RabbitMQ, Firebase — full infrastructure for a simple notification

I just wanted my cloud script to say "hey, buzz my phone." That's it.

How It Works

Intent Bus is a tiny Flask app backed by SQLite. It has one job: let scripts post work, and let workers claim and execute that work.

Step 1 — Cloud script posts an intent:

curl -X POST https://your-bus.pythonanywhere.com/intent \
 -H "Content-Type: application/json" \
 -H "X-API-Key: your_key_here" \
 -d '{"goal":"send_notification","payload":{"message":"Scrape complete"}}'

Step 2 — Termux worker claims it:

A bash script running on my phone polls the bus every 10 seconds. When it sees a job, it claims it with an atomic lock, executes it, and marks it fulfilled.

Step 3 — Phone buzzes:

termux-notification --title "System Update" --content "$MESSAGE"

That's the entire flow.

What Makes It Reliable

Three things I had to get right:

Atomic locking — SQLite's UPDATE with rowcount check ensures only one worker ever claims a job, even with multiple workers running simultaneously.

Visibility timeout — if a worker crashes mid-job, the lock expires after 60 seconds and the job goes back into the queue automatically.

Topic routing — workers only claim jobs matching their goal via ?goal=. A notification worker never accidentally picks up a logging job.

The Architecture

Cloud Scraper (PythonAnywhere)
 |
 | POST /intent
 ↓
Intent Bus (Flask + SQLite)
 |
 | claim + fulfill
 ↓
Termux Worker (Android Phone)
 |
 | termux-notification
 ↓
📱 Phone Notification

What It Can Do

Because the bus is just HTTP, any script anywhere can post or claim jobs:

• Scraper finishes → notify phone
• Website goes down → alert Discord
• GitHub push → trigger deploy on home Raspberry Pi behind a firewall
• Old Android phone → free Twilio replacement via termux-sms-send

Security

After posting this publicly, people immediately stress-tested the open endpoint. Fair. I added API key auth — key stored in PythonAnywhere's WSGI environment, never in the repo. Workers read from a local .apikey file.

Try It

The full code, spec, and examples are on GitHub:

https://github.com/dsecurity49/Intent-Bus

It runs free on PythonAnywhere + any Android phone with Termux. No Docker, no dependencies beyond Flask.

If you build a worker script for it, PRs are welcome.

Update: v7 is Live

Since the original post, Intent Bus has been hardened significantly based on real-world feedback:

• Rate limiting (60 req/min per key+IP)
• Tester key system — request a free key to try the live instance
• Intent expiry after 24 hours
• Python worker for non-bash users
• Security headers and payload size limits

DM me on Dev.to, open a GitHub Issue, or join the Discord to request a free tester key: https://discord.gg/bzAneAQzGX