Leonardo Devai
17a890cc08
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
65 lines
2.2 KiB
Markdown
65 lines
2.2 KiB
Markdown
# crypto-ticker
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A little price board for Bitcoin, Ethereum and friends that refreshes itself
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every 30 seconds, with 24-hour changes in green and red. It teaches polling:
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asking an API again on a timer.
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## Run
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Get it: `git clone https://git.devai.io/templates/crypto-ticker.git`
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Double-click `index.html` — it opens in your browser and works, as long as
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you're online (it calls the price API live). Nothing to install.
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Or serve it like production:
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```sh
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docker compose up --build
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```
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Then open http://localhost:8080.
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## How it works
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The API can't tell the page when prices change, so the page asks again on a
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timer:
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```js
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refresh(); // once now…
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setInterval(refresh, 30000); // …then every 30 seconds
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```
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Each `refresh()` is one ordinary `fetch()` to CoinGecko's free
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`/simple/price` endpoint (no key needed) with the coin ids in the query string
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and `include_24hr_change=true`. `render()` rebuilds one row per coin with
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`createElement` and `textContent`, formats prices with `Intl.NumberFormat`
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(extra decimals for coins under $1), and colors the change green `▲` or red
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`▼`.
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Polling a free API means you will sometimes be throttled. On a 429 ("too many
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requests") or a network error, the page keeps the last good prices on screen,
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says so, and simply tries again on the next tick. "Loading prices…" shows until
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the first answer arrives.
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Try it: add a coin to `COINS` (e.g. `cardano`), poll every 60 seconds to be
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gentler on the free tier, or add `include_market_cap=true` and show it.
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## Layout
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```
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index.html an empty rows box, a status line and "last updated"
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app.js COINS, refresh(), render() and the interval
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styles.css the look — green / red change colors; follows light or dark mode
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```
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## Deploy
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Push to your own GitHub repo and the shipped workflow
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(`.github/workflows/ci.yml`) tests the compose stack, publishes the image to
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GHCR, and — once you set the `DEPLOY_HOST` / `DEPLOY_USER` variables and
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`DEPLOY_KEY` secret — deploys it to your server over ssh.
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---
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Part of [devai.io](https://devai.io) — the APIs & Data track: fetch real data
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from the internet. Next up:
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[dictionary-lookup](https://git.devai.io/templates/dictionary-lookup).
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