Geohash Notification Service

Get browser push notifications whenever an XKCD geohash lands near your chosen location.

I host an instance of this at geohash.kaiserapps.com, feel free to go and subscribe for notifications there.

However if you are the super-privacy kind or would just like to run it yourself, follow the below developer instructions.

How It Works

1. Visit the app and select a location on the Leaflet/OpenStreetMap map
2. Set a radius (in km) for how close a geohash needs to be
3. Click "Enable Notifications" to subscribe to browser push notifications
4. When a geohash lands within your radius, you'll get a push notification
5. Click the notification to open OpenStreetMap at the geohash coordinates

Developer Instructions

This application is built with deployment to Dokku / Heroku in mind.

Environment Variables

VAPID_PUBLIC_KEY=<your VAPID public key>
VAPID_PRIVATE_KEY=<your VAPID private key>
VAPID_SUBJECT=mailto:your@email.com
MONGO_URL=mongodb://localhost:27017/geohash-notifier

Generating VAPID Keys

npx web-push generate-vapid-keys

This will output a public and private key pair. Set them as environment variables.

Note: HTTPS is required for service workers and push notifications (except on localhost for development).

Running in Docker + Docker Compose

bin/go

And you're done! Good to go! Try it out on http://localhost:3000

Without Docker

You'll need:

• Node.js >= 18
• MongoDB running

Then execute:

npm install
MONGO_URL=mongodb://localhost:27017/geohash-notifier npm start

Checking for Geohashes

Run the check job manually or set up a cron to run it periodically:

node jobs/check_stocks.js

Deploying to Dokku

git push dokku@benkaiser.dev:geohash-notifier master

The buildpack auto-detects Node.js from package.json.