Element (formerly known as Vector and Riot) is a Matrix web client built using the Matrix React SDK.
Element has several tiers of support for different environments:
- Supported
- Definition:
- Issues actively triaged, regressions block the release
- Last 2 major versions of Chrome, Firefox, and Edge on desktop OSes
- Last 2 versions of Safari
- Latest release of official Element Desktop app on desktop OSes
- Desktop OSes means macOS, Windows, and Linux versions for desktop devices that are actively supported by the OS vendor and receive security updates
- Definition:
- Best effort
- Definition:
- Issues accepted, regressions do not block the release
- The wider Element Products(including Element Call and the Enterprise Server Suite) do still not officially support these browsers.
- The element web project and its contributors should keep the client functioning and gracefully degrade where other sibling features (E.g. Element Call) may not function.
- Last major release of Firefox ESR and Chrome/Edge Extended Stable
- Definition:
- Community Supported
- Definition:
- Issues accepted, regressions do not block the release
- Community contributions are welcome to support these issues
- Mobile web for current stable version of Chrome, Firefox, and Safari on Android, iOS, and iPadOS
- Definition:
- Not supported
- Definition: Issues only affecting unsupported environments are closed
- Everything else
The period of support for these tiers should last until the releases specified above, plus 1 app release cycle(2 weeks). In the case of Firefox ESR this is extended further to allow it land in Debian Stable.
For accessing Element on an Android or iOS device, we currently recommend the native apps element-android and element-ios.
The easiest way to test Element is to just use the hosted copy at https://app.element.io.
The develop
branch is continuously deployed to https://develop.element.io
for those who like living dangerously.
To host your own instance of Element see Installing Element Web.
To install Element as a desktop application, see Running as a desktop app below.
We do not recommend running Element from the same domain name as your Matrix homeserver. The reason is the risk of XSS (cross-site-scripting) vulnerabilities that could occur if someone caused Element to load and render malicious user generated content from a Matrix API which then had trusted access to Element (or other apps) due to sharing the same domain.
We have put some coarse mitigations into place to try to protect against this situation, but it's still not good practice to do it in the first place. See #1977 for more details.
Unless you have special requirements, you will want to add the following to your web server configuration when hosting Element Web:
- The
X-Frame-Options: SAMEORIGIN
header, to prevent Element Web from being framed and protect from clickjacking. - The
frame-ancestors 'self'
directive to yourContent-Security-Policy
header, as the modern replacement forX-Frame-Options
(though both should be included since not all browsers support it yet, see this). - The
X-Content-Type-Options: nosniff
header, to disable MIME sniffing. - The
X-XSS-Protection: 1; mode=block;
header, for basic XSS protection in legacy browsers.
If you are using nginx, this would look something like the following:
add_header X-Frame-Options SAMEORIGIN;
add_header X-Content-Type-Options nosniff;
add_header X-XSS-Protection "1; mode=block";
add_header Content-Security-Policy "frame-ancestors 'self'";
For Apache, the configuration looks like:
Header set X-Frame-Options SAMEORIGIN
Header set X-Content-Type-Options nosniff
Header set X-XSS-Protection "1; mode=block"
Header set Content-Security-Policy "frame-ancestors 'self'"
Note: In case you are already setting a Content-Security-Policy
header
elsewhere, you should modify it to include the frame-ancestors
directive
instead of adding that last line.
Element is a modular webapp built with modern ES6 and uses a Node.js build system. Ensure you have the latest LTS version of Node.js installed.
Using yarn
instead of npm
is recommended. Please see the Yarn install
guide if you do not have it already.
- Install or update
node.js
so that yournode
is at least the current recommended LTS. - Install
yarn
if not present already. - Clone the repo:
git clone https://github.com/element-hq/element-web.git
. - Switch to the element-web directory:
cd element-web
. - Install the prerequisites:
yarn install
.- If you're using the
develop
branch, then it is recommended to set up a proper development environment (see Setting up a dev environment below). Alternatively, you can use https://develop.element.io - the continuous integration release of the develop branch.
- If you're using the
- Configure the app by copying
config.sample.json
toconfig.json
and modifying it. See the configuration docs for details. yarn dist
to build a tarball to deploy. Untaring this file will give a version-specific directory containing all the files that need to go on your web server.
Note that yarn dist
is not supported on Windows, so Windows users can run yarn build
,
which will build all the necessary files into the webapp
directory. The version of Element
will not appear in Settings without using the dist script. You can then mount the
webapp
directory on your web server to actually serve up the app, which is
entirely static content.
Element can also be run as a desktop app, wrapped in Electron. You can download a pre-built version from https://element.io/get-started or, if you prefer, build it yourself.
To build it yourself, follow the instructions at https://github.com/element-hq/element-desktop.
Many thanks to @aviraldg for the initial work on the Electron integration.
The configuration docs show how to override the desktop app's default settings if desired.
Element supports a variety of settings to configure default servers, behaviour, themes, etc. See the configuration docs for more details.
Some features of Element may be enabled by flags in the Labs
section of the settings.
Some of these features are described in labs.md.
Element requires the following URLs not to be cached, when/if you are serving Element from your own webserver:
/config.*.json
/i18n
/home
/sites
/index.html
We also recommend that you force browsers to re-validate any cached copy of Element on page load by configuring your
webserver to return Cache-Control: no-cache
for /
. This ensures the browser will fetch a new version of Element on
the next page load after it's been deployed. Note that this is already configured for you in the nginx config of our
Dockerfile.
Before attempting to develop on Element you must read the developer guide
for matrix-react-sdk
, which
also defines the design, architecture and style for Element too.
Read the Choosing an issue page for some guidance about where to start. Before starting work on a feature, it's best to ensure your plan aligns well with our vision for Element. Please chat with the team in #element-dev:matrix.org before you start so we can ensure it's something we'd be willing to merge.
You should also familiarise yourself with the "Here be Dragons" guide to the tame & not-so-tame dragons (gotchas) which exist in the codebase.
The idea of Element is to be a relatively lightweight "skin" of customisations on
top of the underlying matrix-react-sdk
. matrix-react-sdk
provides both the
higher and lower level React components useful for building Matrix communication
apps using React.
Please note that Element is intended to run correctly without access to the public internet. So please don't depend on resources (JS libs, CSS, images, fonts) hosted by external CDNs or servers but instead please package all dependencies into Element itself.
CSS hot-reload is available as an opt-in development feature. You can enable it
by defining a CSS_HOT_RELOAD
environment variable, in a .env
file in the root
of the repository. See .env.example
for documentation and an example.
Much of the functionality in Element is actually in the matrix-react-sdk
and
matrix-js-sdk
modules. It is possible to set these up in a way that makes it
easy to track the develop
branches in git and to make local changes without
having to manually rebuild each time.
First clone and build matrix-js-sdk
:
git clone https://github.com/matrix-org/matrix-js-sdk.git
pushd matrix-js-sdk
yarn link
yarn install
popd
Then similarly with matrix-react-sdk
:
git clone https://github.com/matrix-org/matrix-react-sdk.git
pushd matrix-react-sdk
yarn link
yarn link matrix-js-sdk
yarn install
popd
Clone the repo and switch to the element-web
directory:
git clone https://github.com/element-hq/element-web.git
cd element-web
Configure the app by copying config.sample.json
to config.json
and
modifying it. See the configuration docs for details.
Finally, build and start Element itself:
yarn link matrix-js-sdk
yarn link matrix-react-sdk
yarn install
yarn start
Wait a few seconds for the initial build to finish; you should see something like:
[element-js] <s> [webpack.Progress] 100%
[element-js]
[element-js] ℹ 「wdm」: 1840 modules
[element-js] ℹ 「wdm」: Compiled successfully.
Remember, the command will not terminate since it runs the web server and rebuilds source files when they change. This development server also disables caching, so do NOT use it in production.
Open http://127.0.0.1:8080/ in your browser to see your newly built Element.
Note: The build script uses inotify by default on Linux to monitor directories
for changes. If the inotify limits are too low your build will fail silently or with
Error: EMFILE: too many open files
. To avoid these issues, we recommend a watch limit
of at least 128M
and instance limit around 512
.
You may be interested in issues #15750 and #15774 for further details.
To set a new inotify watch and instance limit, execute:
sudo sysctl fs.inotify.max_user_watches=131072
sudo sysctl fs.inotify.max_user_instances=512
sudo sysctl -p
If you wish, you can make the new limits permanent, by executing:
echo fs.inotify.max_user_watches=131072 | sudo tee -a /etc/sysctl.conf
echo fs.inotify.max_user_instances=512 | sudo tee -a /etc/sysctl.conf
sudo sysctl -p
When you make changes to matrix-react-sdk
or matrix-js-sdk
they should be
automatically picked up by webpack and built.
If any of these steps error with, file table overflow
, you are probably on a mac
which has a very low limit on max open files. Run ulimit -Sn 1024
and try again.
You'll need to do this in each new terminal you open before building Element.
There are a number of application-level tests in the tests
directory; these
are designed to run with Jest and JSDOM. To run them
yarn test
See matrix-react-sdk for how to run the end-to-end tests.
To add a new translation, head to the translating doc.
For a developer guide, see the translating dev doc.
Issues are triaged by community members and the Web App Team, following the triage process.
We use issue labels to sort all incoming issues.