A daily AI currency-insight site on Cloudflare for $0.30 a month: Workers, Workflows, D1 and KV
Summary
Currency Insight is a daily AI currency-insight site that runs on Cloudflare for about $0.30 a month: Workers, Workflows, D1 and KV cover the infrastructure at $0, and usage of Xiaomi’s MiMo model is the only real line item.
Problem
Turning a daily data pull into a written insight and a page worth visiting usually means a server running around the clock, a database bill, and a subscription AI API — infrastructure priced for constant availability, not for one scheduled job a day. The brief here was the opposite: run one cron-triggered job daily, keep it running close to $0, and still get a real, readable site out of it rather than a private spreadsheet.
Architecture
A Cloudflare Workflow, triggered on a cron schedule, pulls daily rates for 15 currencies against the rupiah from the Frankfurter API, stores the historical series in D1, and writes the latest computed values into KV so the site’s normal read path never has to touch D1. The same Workflow calls Xiaomi’s MiMo model to turn that day’s numbers into a written insight, which also lands in KV. Astro renders the site itself, built for SEO rather than as a bare data dump, with Hono handling the API side and TypeScript throughout. Visitors who sign up get the day’s insight by email.
The Hard Parts
Keeping the whole pipeline — pull, store, generate, publish, notify — inside a single cron-triggered Workflow on Cloudflare’s free tier, while still producing something worth reading every day, is the actual constraint here. Splitting storage two ways exists specifically to serve that: D1 holds the historical series a trend chart needs, KV holds the single latest generated insight a visitor’s request needs, so the common read path never touches the database.
Results
The whole thing runs for about $0.30 a month — $0 for Cloudflare Workers, Workflows, D1 and KV, and roughly $0.30 a month in Xiaomi MiMo usage generating the daily insight. It draws about 150 visitors a month.
Stack
Cloudflare Workers and Workflows run the daily job on a cron trigger, with D1 and KV for storage. Xiaomi’s MiMo model generates the written insight. Astro renders the site, Hono handles the API layer, and it’s all TypeScript.