implementing self-hosted webmentions

Origin

I discovered Webmention reading the IndieWeb specification.

No API key. No OAuth. No third-party platform accounts. Just two URLs:

• Source: who linked to me
• Target: my page

The source server sends a POST request to my /webmention endpoint. My server verifies that the link really exists. If it exists, I save the mention. If it does not exist, I discard it.

That is it.

No intermediaries. No algorithms. No platform lock-in.

The Connection

Why does the Monolith archive this? Because Webmention is pure sovereignty.

When someone links to my article on another IndieWeb site, I know. Not because Facebook tells me. Not because Twitter notifies me. But because the protocol itself delivers it to me.

It is the decentralized web working as it should:

• You publish on your domain.
• I publish on my domain.
• If you link to me, I know.
• Neither of us depends on a central platform.

The Challenge

The technical challenge was implementing the server on OpenBSD.

There is no “install and forget” plugin. I had to:

1. Configure relayd to forward /webmention to Node.js (port 3000)
2. Write the Node script that verifies links
3. Save mentions in a local JSON
4. Expose an /api/mentions API to read them
5. Display mentions in the Astro frontend

The psychological challenge was accepting that not all mentions arrive.

If a site does not support Webmention, I do not know. If someone links to me on Medium or LinkedIn, I receive nothing.

But it is a limit I willingly accept. I prefer 10 mentions on sovereign sites to 1000 likes on platforms that own me.

Peace of Mind

Now that I have written this, I have clarified the value of Webmention:

• They are direct notifications, without intermediaries.
• They are verified, not spoofable.
• They are under my control (my server, my database).
• They are interoperable (anyone can implement them).

Peace of Mind comes from knowing that every mention I receive is an act of respect. Someone took the time to link to me on their own domain, not to click “share” on a platform button.

The Monolith is not an island. It is a node in the network.

Technical Note:

• Endpoint: POST /webmention (source + target)
• Verification: GET source → search for target in content
• Storage: /var/www/webmention/data/mentions.json
• API: GET /api/mentions?target=URL
• Frontend: Astro Webmentions.astro component (client-side fetch)
• Cache: 5 minutes in localStorage for performance
• Zero dependencies: all self-hosted on OpenBSD