LaMetric Clock Backend

A Cloudflare Workers backend service for LaMetric Time clocks. Fetches data from external APIs on a schedule, caches it in KV storage, and serves it to LaMetric devices.

Live URL: https://lametric-backend.austin-david-schaefer.workers.dev

Setup

1. Install dependencies:

   npm install

2. Login to Cloudflare (first time only):

   npx wrangler login

3. Register a workers.dev subdomain:

   • Visit the Cloudflare dashboard
   • Go to Workers & Pages
   • Register your workers.dev subdomain (e.g., yourname.workers.dev)

4. Create a KV namespace:

   npx wrangler kv:namespace create CLOCK_DATA

5. Update wrangler.toml with the KV namespace ID from step 4

6. Deploy:

   npm run deploy

7. (Optional) Seed initial data if scheduled worker hasn't run yet:

   npx wrangler kv:key put --binding CLOCK_DATA "app:counter" "0"

Development

Run locally with hot reload and scheduled event support:

npx wrangler dev --local --test-scheduled

In another terminal, trigger the scheduled worker:

curl http://localhost:8787/__scheduled

Test endpoints:

curl http://localhost:8787/health
curl http://localhost:8787/apps/counter

LaMetric Device Configuration

1. Go to https://developer.lametric.com/applications
2. Create a new "Indicator App" or "Metric App"
3. Choose "Poll" as the data source
4. Configure:
   • URL: https://your-worker.workers.dev/apps/counter
   • Poll frequency: 1 minute (or your preference)
   • Data format: Predefined (LaMetric Format)
5. Define a fallback frame:
   • Icon: Select any icon you like
   • Text: #0 or Loading...
   • This frame only displays if your API is unreachable
6. Publish and install the app on your LaMetric device

How It Works

• Scheduled worker runs every 5 minutes (configured in wrangler.toml)
• Fetches/updates data and stores in KV
• LaMetric device polls the /apps/counter endpoint
• Returns cached data formatted as LaMetric frames
• Counter increments automatically: #1, #2, #3, etc.
• Random icon from LaMetric's gallery on each request

Monitoring

View live logs from your deployed worker:

npx wrangler tail --format pretty

Apps

Counter

Increments a counter every 5 minutes and displays on LaMetric devices. README-counter.md

OSRS

Displays Old School RuneScape XP gains from Wise Old Man API. README-OSRS.md

Scryfall

Displays random Magic: The Gathering cards from Scryfall API. README-scryfall.md

Stoxx

Displays top S&P 500 gainer and loser from Financial Modeling Prep API. README-stoxx.md

Weather

Displays multi-city weather (Portland, LA, NYC, Kona, Vrsac) from Open-Meteo API. README-weather.md

Adding New Apps

See CLAUDE.md for the app module pattern and instructions.