5.6 KiB

Matrix Viewer

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Note The Matrix Public Archive has been renamed to Matrix Viewer to better reflect what it actually does and doesn't do. It's a viewer for world-readable Matrix rooms and doesn't actually archive anything.

In the vein of feature parity with Gitter, the goal is to make an accessible public site for world_readable Matrix rooms like Gitter's archives which search engines can index and keep all of the content accessible/available.

Room directory homepage Room view
A reference for how the Matrix Viewer homepage looks. Search bar where you can find thousands of rooms using Matrix and homeserver selector. Grid of room cards showing the results. A reference for how the Matrix Viewer looks. Showing off a day of messages in on 2021-08-06. There is a date picker calendar in the right sidebar and a traditional chat app layout on the left.

Demo videos

The demo's refer to this project as the "Matrix Public Archive" which has now been renamed to "Matrix Viewer".

  • May 2023: Introducing, the shiny new public instance of the Matrix Public Archive that everyone can share and link to.
  • Aug 2022 (blog post): A quick intro of what the project looks like, the goals, what it accomplishes, and how it's a new portal into the Matrix ecosystem.
  • Oct 2022: Showing off the room directory landing page used to browse everything available in the archive.

Technical overview

We server-side render (SSR) the Hydrogen Matrix client on a Node.js server (since both use JavaScript) and serve pages on the fly (with some Cloudflare caching on top) when someone requests /r/${year}/${month}/${day}. To fetch the events for a given day/time, we use MSC3030's /timestamp_to_event endpoint to jump to a given day in the timeline and fetch the messages from a Matrix homeserver.

Re-using Hydrogen gets us pretty and native(to Element) looking styles and keeps the maintenance burden of supporting more event types in Hydrogen.


See the FAQ page.



Get the app running

$ npm install
$ npm run build

# Edit `config/config.user-overrides.json` so that `matrixServerUrl` points to
# your homeserver and has `matrixAccessToken` defined
$ cp config/config.default.json config/config.user-overrides.json

$ npm run start


# Clone and install the `matrix-viewer` project
$ git clone
$ cd matrix-viewer
$ npm install

# Edit `config/config.user-overrides.json` so that `matrixServerUrl` points to
# your homeserver and has `matrixAccessToken` defined
$ cp config/config.default.json config/config.user-overrides.json

# This will watch for changes, rebuild bundles and restart the server
$ npm run start-dev

If you want to make changes to the underlying Hydrogen SDK as well, you can locally link it into this project with the following instructions:

# We need to use a draft branch of Hydrogen to get the custom changes needed for
# `matrix-viewer` to run. Hopefully soon, we can get all of the custom
# changes mainlined so this isn't necessary.
$ git clone
$ cd hydrogen-web
$ git checkout madlittlemods/matrix-public-archive-scratch-changes
$ yarn install
$ yarn build:sdk
$ cd target/ && npm link && cd ..
$ cd ..

$ cd matrix-viewer
$ npm link hydrogen-view-sdk

Running tests

See the testing documentation.


See the tracing documentation.