Leonardo Devai
bb45a78a9c
Pinned 2026 toolchains (Go 1.26, Rust 1.98/edition 2024, Python 3.14 + uv, Node 24, Zig 0.16, NixOS 26.05), postgres 18 / mongo 8, lockfiles built from, non-root runtimes, .dockerignore, per-project LICENSE, READMEs with the git.devai.io clone line, checkout@v7 CI. Security fixes in the legacy Rust APIs (any-password login, self-assigned admin, hard-coded JWT secret), JWT alg/exp/sub enforcement across the blog series, safe markdown links in the frontends, and many smaller bugs — every project was built, run and exercised end to end. Adds scripts/publish.sh + a CI publish job that splits every folder into its own repo at git.devai.io/templates/<folder>. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01128fhuZbgivaSJvtMf4s1G
2.3 KiB
currency-converter
Type an amount, pick two currencies, and see the conversion at the latest European Central Bank rate, from the free Frankfurter API. It teaches building URLs with query parameters, and filling dropdowns from data an API gives you.
Run
Get it: git clone https://git.devai.io/templates/currency-converter.git
Double-click index.html — it opens in your browser and works, as long as
you're online (it calls the exchange-rate API live). Nothing to install.
Or serve it like production:
docker compose up --build
Then open http://localhost:8080.
How it works
Two calls to https://api.frankfurter.dev/v1, no key needed:
/currenciesanswers{ "AUD": "Australian Dollar", … }. The code loops over it and adds an<option>per currency to both dropdowns./latest?from=USD&to=EURanswers with the rate for that pair. Everything after the?is the query string:name=valuepairs joined by&that tell one endpoint what you want. Change the dropdowns, change the URL, get a different answer.
The rate is fetched only when a dropdown changes. Typing an amount just
multiplies by the rate you already have, so the page reacts instantly and
doesn't call the API on every keystroke. Intl.NumberFormat formats the result
as money in the target currency, and the line above it shows the ECB date the
rate is from (the ECB publishes on working days). "Loading…" and error
messages cover the waits and failures.
Try it: add a "swap ⇅" button that trades the two currencies, convert to
several at once with to=EUR,GBP,JPY, or chart a week of rates from
/2026-09-01..2026-09-07.
Layout
index.html the amount box, two dropdowns and the result
app.js loadCurrencies(), loadRate() and showResult()
styles.css the look; follows your system's light or dark mode
Deploy
Push to your own GitHub repo and the shipped workflow
(.github/workflows/ci.yml) tests the compose stack, publishes the image to
GHCR, and — once you set the DEPLOY_HOST / DEPLOY_USER variables and
DEPLOY_KEY secret — deploys it to your server over ssh.
Part of devai.io — the APIs & Data track: fetch real data from the internet. Next up: crypto-ticker.