Open Heart Protocol

The Open Heart protocol lets an anonymous user sends an emoji reaction to a URL.

How

Set up an endpoint to receive an Open Heart POST request like this one:

curl -d '🥨' -X POST 'https://api.oh.dddddddddzzzz.org/github.com/dddddddddzzzz/OpenHeart'

A Open Heart message should contain of a single emoji sequence. However, the emoji sequence may be followed by arbitrary data which the server is expected to ignore.

This allows HTML <form>s to post reactions using the Open Heart protocol through an empty input. In this case, the payload will be 🥨=.

---

Optionally, a GET request to the same URL may respond with the emoji reaction counts.

curl 'https://api.oh.dddddddddzzzz.org/github.com/dddddddddzzzz/OpenHeart'

The response should be a JSON object mapping Emoji (as Strings) to their count (as Numbers):

{"❤️": 14,"🫀": 12,"🥨": 22}

If reaction counts are write-only, the server should respond with a 403 or a 404.

Usage

In its simplest form, you can put this on your website:

<form action="<your server endpoint>" method="POST" enctype="text/plain">
  <button name="🥨">🥨</button>
</form>

However, we have also created <open-heart> for a better user experience.

Server code

To get started quickly, you can use our public OpenHeart API, but we do recommend owning your own data whenever possible.

Here are some code example get your own endpoint running quickly:

• With Cloudflare Worker & Cloudflare KV
• With Glitch and fasify

We welcome examples using other languages and services. Please send us a pull request!

Questions

Why not WebMention?

This is much, much, much simpler.

What happens after POST?

The author of the endpoint decides.

What if the someone repeatedly sends emoji to my server?

It shows they may be quite enthusiastic.

In all seriousness, our public API is built on Cloudflare Worker which comes with rate limiting and DDoS protection.

What if I don't want to receive some emoji?

Create a server-side allow list or disallow list and respond with a 400.