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    <title>DEV Community: Joan Mz Linux</title>
    <description>The latest articles on DEV Community by Joan Mz Linux (@linuxbcn).</description>
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      <title>How I used Cloudflare Pages + GitHub API as a free backend for a family caregiving app</title>
      <dc:creator>Joan Mz Linux</dc:creator>
      <pubDate>Sun, 31 May 2026 09:42:00 +0000</pubDate>
      <link>https://dev.to/linuxbcn/how-i-used-cloudflare-pages-github-api-as-a-free-backend-for-a-family-caregiving-app-3136</link>
      <guid>https://dev.to/linuxbcn/how-i-used-cloudflare-pages-github-api-as-a-free-backend-for-a-family-caregiving-app-3136</guid>
      <description>&lt;h1&gt;
  
  
  How I used Cloudflare Pages + GitHub API as a free backend for a family caregiving app
&lt;/h1&gt;

&lt;p&gt;My grandfather has chronic heart and respiratory disease. He needs oxygen 24/7, morphine, and a palli&lt;/p&gt;

&lt;p&gt;ative care team visiting regularly. Coordinating between professional caregivers, family members spread across different cities, and his medical team was a constant mess of WhatsApp messages, forgotten medication doses, and nobody knowing who was there last Tuesday.&lt;/p&gt;

&lt;p&gt;I built &lt;strong&gt;Cuida&lt;/strong&gt; to fix this. It's a PWA that runs entirely on free-tier infrastructure — no monthly bills, no third-party databases, no vendor lock-in.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;→ &lt;a href="https://github.com/112books/cuida" rel="noopener noreferrer"&gt;github.com/112books/cuida&lt;/a&gt;&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F351067qxw39z23b383ci.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F351067qxw39z23b383ci.png" alt="Home screen and medication view" width="800" height="479"&gt;&lt;/a&gt;&lt;/p&gt;




&lt;h2&gt;
  
  
  The problem: coordinating home care is a mess
&lt;/h2&gt;

&lt;p&gt;When someone in your family needs continuous care, you quickly end up with:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;A shared WhatsApp group that's too noisy to be useful&lt;/li&gt;
&lt;li&gt;Nobody knowing the exact medication schedule (especially doses and &lt;em&gt;why&lt;/em&gt; each drug exists)&lt;/li&gt;
&lt;li&gt;No clear protocol for when something goes wrong at 2am&lt;/li&gt;
&lt;li&gt;Professional caregivers with no written handoff from the family&lt;/li&gt;
&lt;li&gt;Doctors asking "how has he been this week?" and nobody has notes&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;What you need is a shared dashboard that everyone — family, caregivers, doctors — can check from their phone in 10 seconds.&lt;/p&gt;




&lt;h2&gt;
  
  
  Why not use an existing app?
&lt;/h2&gt;

&lt;p&gt;I looked. The options were:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Generic care apps&lt;/strong&gt;: US-centric, $30-50/month, required uploading patient data to their servers&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Note-sharing apps&lt;/strong&gt; (Notion, Google Docs): no structure, no push notifications, not mobile-optimised&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;WhatsApp&lt;/strong&gt;: already failing us&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The core requirements were: free, private (data doesn't leave the family), works offline, push notifications without keeping the app open, and something I could customise for our specific situation (oxygen, morphine, PADES palliative team).&lt;/p&gt;

&lt;p&gt;So I built it.&lt;/p&gt;




&lt;h2&gt;
  
  
  The architecture: Cloudflare Pages + GitHub API as a database
&lt;/h2&gt;

&lt;p&gt;The stack is deliberately boring:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Frontend&lt;/strong&gt;: vanilla HTML + CSS + JS (no framework, no build step)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Backend&lt;/strong&gt;: Cloudflare Pages Functions (serverless, runs at the edge)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Database&lt;/strong&gt;: a JSON file in a private GitHub repo, read/written via GitHub API&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Push notifications&lt;/strong&gt;: Web Push / VAPID (W3C standard, no Firebase)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Cron jobs&lt;/strong&gt;: GitHub Actions&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Total cost: &lt;strong&gt;€0/month&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fe5vi68ysvu6dzmd5fogz.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fe5vi68ysvu6dzmd5fogz.png" alt="All screens overview" width="800" height="479"&gt;&lt;/a&gt;&lt;/p&gt;




&lt;h2&gt;
  
  
  Data sync: reading and writing JSON via GitHub API
&lt;/h2&gt;

&lt;p&gt;This is the part people find surprising. There's no database. All patient data lives in a single JSON file (&lt;code&gt;app/dades.json&lt;/code&gt;) in a private GitHub repo. The Cloudflare Pages Function reads and writes it via the GitHub API.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Reading data (GET):&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// functions/api/dades.js&lt;/span&gt;
&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;onRequest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;env&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;url&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;`https://api.github.com/repos/&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;REPO&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/contents/app/dades.json`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Authorization&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`token &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;GITHUB_TOKEN&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Accept&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/vnd.github.v3+json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;content&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;atob&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;content&lt;/span&gt;&lt;span class="p"&gt;));&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Response&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;content&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Content-Type&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Writing data (POST)&lt;/strong&gt; is the same but includes the current file SHA (required by GitHub API to avoid conflicts) and creates a commit:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Get current SHA first, then write&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;writeRes&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;method&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;PUT&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Authorization&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`token &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;GITHUB_TOKEN&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;...&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="na"&gt;body&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Actualització dades&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;btoa&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;newData&lt;/span&gt;&lt;span class="p"&gt;)),&lt;/span&gt;
    &lt;span class="na"&gt;sha&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;currentSha&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="p"&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Every write creates a real git commit. You get a full audit trail of every change for free.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Tradeoffs:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;GitHub API has a rate limit (5000 req/hour with auth — more than enough for a family app)&lt;/li&gt;
&lt;li&gt;Not suitable for high-frequency writes (but caregiving data changes a few times a day at most)&lt;/li&gt;
&lt;li&gt;SHA conflict if two devices write simultaneously — we handle this with a &lt;code&gt;pull --rebase&lt;/code&gt; discipline&lt;/li&gt;
&lt;/ul&gt;




&lt;h2&gt;
  
  
  Push notifications with Web Push / VAPID (without Firebase)
&lt;/h2&gt;

&lt;p&gt;Most tutorials send push notifications through Firebase Cloud Messaging. We skip that entirely and use the W3C Web Push standard directly.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Setup:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;node scripts/generar-claus-vapid.js
&lt;span class="c"&gt;# Outputs: VAPID_PUBLIC_KEY and VAPID_PRIVATE_KEY (JWK format)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Subscribing from the browser:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;registration&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nb"&gt;navigator&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;serviceWorker&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;ready&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;subscription&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;registration&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pushManager&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;subscribe&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;userVisibleOnly&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;applicationServerKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;urlBase64ToUint8Array&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;VAPID_PUBLIC_KEY&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;});&lt;/span&gt;
&lt;span class="c1"&gt;// POST subscription to /api/suscripcions → saved in data/subs.json via GitHub API&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Sending a notification (from Cloudflare Function):&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;encrypt&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;web-push&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="c1"&gt;// or implement VAPID signing manually&lt;/span&gt;

&lt;span class="k"&gt;for &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;sub&lt;/span&gt; &lt;span class="k"&gt;of&lt;/span&gt; &lt;span class="nx"&gt;subscriptions&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;sub&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;endpoint&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;method&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;POST&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Authorization&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;vapidAuthHeader&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Content-Type&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/octet-stream&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Content-Encoding&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;aes128gcm&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;TTL&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;86400&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="na"&gt;body&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;encryptedPayload&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;It works on Android and iOS 16.4+ (when installed as a PWA). No Firebase account, no SDK, no data going through Google's servers.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fwp17rh9zwmvqjvsr8qo2.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fwp17rh9zwmvqjvsr8qo2.png" alt="Medication grouped by meal" width="780" height="1688"&gt;&lt;/a&gt;&lt;/p&gt;




&lt;h2&gt;
  
  
  Cron jobs with GitHub Actions
&lt;/h2&gt;

&lt;p&gt;Medication reminders run 3 times a day. The "I'm alone" safety check runs every 15 minutes. Both are GitHub Actions workflows that call a Cloudflare Pages Function endpoint.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/notificacions.yml&lt;/span&gt;
&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;cron&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;6&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*'&lt;/span&gt;    &lt;span class="c1"&gt;# 8:00 local time&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;cron&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;30&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;11&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*'&lt;/span&gt;  &lt;span class="c1"&gt;# 13:30 local time&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;cron&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;19&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*'&lt;/span&gt;   &lt;span class="c1"&gt;# 21:00 local time&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;enviar-push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-latest&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
          &lt;span class="s"&gt;TOKEN=$(cat .github/workflows/_cron-token.txt)&lt;/span&gt;
          &lt;span class="s"&gt;curl -X POST "${CUIDA_URL}/api/notificacions" \&lt;/span&gt;
            &lt;span class="s"&gt;-H "X-Cron-Token: ${TOKEN}"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;






&lt;h2&gt;
  
  
  Auth for crons: why a repo-stored token beats a shared secret
&lt;/h2&gt;

&lt;p&gt;This deserves its own section because I wasted two days on it.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;What I tried first:&lt;/strong&gt; a shared secret stored as a GitHub Actions secret and a Cloudflare environment variable. Sounds simple. In practice, keeping two values in two independent systems byte-identical is surprisingly hard. Cloudflare doesn't apply env var changes until the next deploy. GitHub Actions masks secrets in logs, so you can't verify the value. I synced it manually 4+ times and it kept failing.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;What I tried second:&lt;/strong&gt; GitHub OIDC — the workflow requests a signed JWT from GitHub, the Cloudflare function verifies it cryptographically against GitHub's public JWKS. Elegant, but I had a subtle bug: &lt;code&gt;atob()&lt;/code&gt; requires standard base64 but JWTs use base64url (&lt;code&gt;-&lt;/code&gt; and &lt;code&gt;_&lt;/code&gt; instead of &lt;code&gt;+&lt;/code&gt; and &lt;code&gt;/&lt;/code&gt;). The decode failed silently inside a &lt;code&gt;catch {}&lt;/code&gt; block.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;What actually works:&lt;/strong&gt; the token lives in one file in the repo (&lt;code&gt;_cron-token.txt&lt;/code&gt;). The workflow reads it via &lt;code&gt;actions/checkout&lt;/code&gt;. The Cloudflare function has the same value hardcoded as a constant — deployed from the same repo, same commit. They are &lt;em&gt;literally the same file&lt;/em&gt;. It's impossible for them to desync.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// functions/api/notificacions.js&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;CRON_TOKEN&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;your-hex-token-here&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;onRequest&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;env&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;received&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;X-Cron-Token&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;received&lt;/span&gt; &lt;span class="o"&gt;!==&lt;/span&gt; &lt;span class="nx"&gt;CRON_TOKEN&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Response&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Unauthorized&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;401&lt;/span&gt; &lt;span class="p"&gt;});&lt;/span&gt;
  &lt;span class="c1"&gt;// ... send push notifications&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The repo is private, so the token is as secret as any environment variable.&lt;/p&gt;




&lt;h2&gt;
  
  
  The "I'm alone" safety mode
&lt;/h2&gt;

&lt;p&gt;This is the feature that required the most thinking. When the patient is home alone, they activate a 1–4 hour timer. If they don't press "I'm OK" before the timer runs out, the whole family gets a push notification.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F7yox7rzezgsp991wu9xr.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F7yox7rzezgsp991wu9xr.png" alt="Emergency protocols" width="780" height="1688"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;The state is simple:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="nl"&gt;"estic_sol"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"actiu"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"fins"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"2026-05-31T15:00:00.000Z"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"activat"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"2026-05-31T13:00:00.000Z"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"alerta"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;false&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The GitHub Actions cron runs every 15 minutes and calls &lt;code&gt;/api/estic-sol-check&lt;/code&gt;. The function reads the current state, checks if &lt;code&gt;fins&lt;/code&gt; has passed, and if so sets &lt;code&gt;alerta: true&lt;/code&gt; and sends SOS push notifications to all subscribers.&lt;/p&gt;

&lt;p&gt;The "I'm OK" button calls &lt;code&gt;/api/estic-be&lt;/code&gt; — no authentication required, since the worst an attacker can do is tell us the patient is fine.&lt;/p&gt;




&lt;h2&gt;
  
  
  PWA: service worker, offline support, installable
&lt;/h2&gt;

&lt;p&gt;The service worker caches all static assets. When offline, the app shows the last loaded data (useful when the caregiver arrives somewhere with no signal and needs the emergency protocols).&lt;/p&gt;

&lt;p&gt;The push handler in the service worker decides what notification to show based on the data:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="nb"&gt;self&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;addEventListener&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;push&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;event&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;event&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;

  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;estic_sol&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;alerta&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// SOS notification — requireInteraction: true, max urgency&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// Medication reminder — show which pills for this meal&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;On iOS, the app must be installed as a PWA (Add to Home Screen) for push notifications to work. On Android, it works from the browser.&lt;/p&gt;




&lt;h2&gt;
  
  
  What I'd do differently
&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Configurable notification times.&lt;/strong&gt; They're hardcoded in the GitHub Actions cron schedule right now. It works, but changing them requires editing a YAML file.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Conflict handling for concurrent writes.&lt;/strong&gt; If two family members edit data simultaneously, the second write fails with a GitHub API SHA mismatch. Right now you just retry. A proper solution would use optimistic locking.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;iCal integration for the caregiver schedule.&lt;/strong&gt; We store the caregiver schedule as structured data, but importing it from an existing calendar would save a lot of manual entry.&lt;/p&gt;




&lt;h2&gt;
  
  
  Try it / fork it
&lt;/h2&gt;

&lt;p&gt;The repo is public, MIT licensed, and has a detailed deploy guide:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;→ &lt;a href="https://github.com/112books/cuida" rel="noopener noreferrer"&gt;github.com/112books/cuida&lt;/a&gt;&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Deploy takes about 20 minutes following the README. You'll need a Cloudflare account (free tier is more than enough) and a GitHub account for the private data repo.&lt;/p&gt;

&lt;p&gt;If you're coordinating care for someone at home, I hope it's useful.&lt;/p&gt;




&lt;p&gt;&lt;em&gt;Built by &lt;a href="https://linuxbcn.com" rel="noopener noreferrer"&gt;LinuxBCN&lt;/a&gt;. Made from a real situation — my grandfather is doing OK.&lt;/em&gt;&lt;/p&gt;

</description>
      <category>cloudflarechallenge</category>
      <category>github</category>
      <category>javascript</category>
      <category>webdev</category>
    </item>
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