Quick Start

This guide shows the easiest way to embed Cactus Comments on your website.

The setup described here will use the public cactus.chat servers. If you want to host your own server, see self-hosting.


To start using Cactus Comments, you need a Matrix account. This account may be on any homeserver. If you don’t have one, you can register here.

Additionally, you need a website where you want to embed comment sections.

Register Your Site

The first thing you need to do is to register your site with Cactus Comments. To do this, start a new chat with @cactusbot:cactus.chat and type:

register <YOUR-SITE-NAME>

Where <YOUR-SITE-NAME> is a unique identifier you choose. It does not have to match your domain.

Embed Cactus Comments

To embed the Cactus Comments frontend, you need to include the following JS and CSS:

<script type="text/javascript" src="https://latest.cactus.chat/cactus.js"></script>
<link rel="stylesheet" href="https://latest.cactus.chat/style.css" type="text/css">

Then insert a <div> where you want the comment section to appear:

<div id="comment-section"></div>

Finally, you need to initialize the comment section:

  node: document.getElementById("comment-section"),
  defaultHomeserverUrl: "https://matrix.cactus.chat:8448",
  serverName: "cactus.chat",
  siteName: "<YOUR-SITE-NAME>",
  commentSectionId: "section1"

The commentSectionId can be changed to insert different comment sections. See which are valid characters for it at Matrix’s spec.

Joining Comment Section Rooms

Easiest way to join in comment section rooms is to log in with your Matrix account on the pages you embedded Cactus Comments.