This is part II of my stream-of-conciousness/not-very-thought-out series about sending a SMS notification to myself using a Supabase Edge Function + Webhook.

Why Not Twilio?

• I purchased a number from which I was hopefully going to send SMS messages from, but then had to fill out a few pages of verification forms. This was pretty involved and asked me to link to my terms of service (I don’t have one), and provide sample messages that I intend to send.
• Instead of spending a lot of time on this, I tried to handwaive the requirements and make my intention clear - that I would simply be messaging myself and no one else, so I am implicitly opting in.
• My case was rejected by Twilio and after a bit more online research, I’ve found that this really isn’t a good solution for a solo endeavor and that Twilio seems to be much more geared towards enterprise solutions.

Next up: ntfy.sh

Someone posted about ntfy.sh on Reddit, and this seems like it’s a better fit. It appears to be a simple POST that goes to a unique topic on their API, which triggers a push notification from their specific app. I just want to get over this hurdle and then might take a look at some other service that sends an email or sms, but based on the documentation, this seems simple and quick to get up and running.

1. Downloaded the app on my phone.
2. Created a new topic: philly-metal-new-show.
3. Updated my edge function to the following:

Deno.serve(async (req) => {
  try {
    const payload = await req.json();
    console.log("payload:", JSON.stringify(payload, null, 2));

    const { record } = payload;
    console.log("record:", JSON.stringify(record, null, 2));

    const body =
      `🚨 New show submitted 🚨\n` +
      `date: ${record.show_date}\n` +
      `venue: ${record.venue}\n` +
      `description: ${record.description}\n` +
      `url: ${record.url}`;

    console.log("body:", body);

    const response = await fetch("https://ntfy.sh/philly-metal-new-show", {
      method: "POST",
      headers: {
        "Content-Type": "text/plain; charset=utf-8",
      },
      body,
    });

    if (!response.ok) {
      throw new Error(`ntfy failed with status ${response.status}`);
    }

    return new Response(JSON.stringify({ message: "Notification sent" }), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error);

    console.error("Function error:", error);

    return new Response(JSON.stringify({ error: message }), {
      status: 500,
      headers: { "Content-Type": "application/json" },
    });
  }
});

This worked! I like this quite a lot, though it’s not the full-fledged SMS feature I had in mind. I’m happy that this was another free solution, even though I lost $20 to Twilio that I will hopefully be able to use for Molly’s photo blog.

Here’s evidence of the end-to-end feature!

One Caveat

I received some 429 errors due to being rate limited. From what I can tell, this is because the IP address for the Supabase webhook is static, so it seems to be the same for a large userbase of Supabase users, meaning if others are spamming the free-tier notification service, I might be rate limited and have my POST request returned with a 429.

I may end up self-hosting, or seeing if there is a way of provisioning a specific IP address to avoid the issue.

Props to ntfy.sh for a really awesome open-source framework!