.. image:: ./docs/element_logo_white_bg.svg
   :height: 60px

**Element Synapse - Matrix homeserver implementation**

|support| |development| |documentation| |license| |pypi| |python|

Synapse is an open source `Matrix <https://matrix.org>`__ homeserver
implementation, written and maintained by `Element <https://element.io>`_.
`Matrix <https://github.com/matrix-org>`__ is the open standard for secure and
interoperable real-time communications. You can directly run and manage the
source code in this repository, available under an AGPL license (or
alternatively under a commercial license from Element).

There is no support provided by Element unless you have a subscription from
Element.

🚀 Getting started
==================

This component is developed and maintained by `Element <https://element.io>`_.
It gets shipped as part of the **Element Server Suite (ESS)** which provides the
official means of deployment.

ESS is a Matrix distribution from Element with focus on quality and ease of use.
It ships a full Matrix stack tailored to the respective use case.

There are three editions of ESS:

- `ESS Community <https://github.com/element-hq/ess-helm>`_ - the free Matrix
  distribution from Element tailored to small-/mid-scale, non-commercial
  community use cases
- `ESS Pro <https://element.io/server-suite>`_ - the commercial Matrix
  distribution from Element for professional use
- `ESS TI-M <https://element.io/server-suite/ti-messenger>`_ - a special version
  of ESS Pro focused on the requirements of TI-Messenger Pro and ePA as
  specified by the German National Digital Health Agency Gematik


🛠️ Standalone installation and configuration
============================================

The Synapse documentation describes `options for installing Synapse standalone
<https://element-hq.github.io/synapse/latest/setup/installation.html>`_. See
below for more useful documenation links.

- `Synapse configuration options <https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html>`_
- `Synapse configuration for federation <https://element-hq.github.io/synapse/latest/federate.html>`_
- `Using a reverse proxy with Synapse <https://element-hq.github.io/synapse/latest/reverse_proxy.html>`_
- `Upgrading Synapse <https://element-hq.github.io/synapse/develop/upgrade.html>`_

Platform dependencies
---------------------

Synapse uses a number of platform dependencies such as Python and PostgreSQL,
and aims to follow supported upstream versions. See the `deprecation policy
<https://element-hq.github.io/synapse/latest/deprecation_policy.html>`_ for more
details.


Security note
-------------

Matrix serves raw, user-supplied data in some APIs — specifically the `content
repository endpoints`_.

.. _content repository endpoints: https://matrix.org/docs/spec/client_server/latest.html#get-matrix-media-r0-download-servername-mediaid

Whilst we make a reasonable effort to mitigate against XSS attacks (for
instance, by using `CSP`_), a Matrix homeserver should not be hosted on a
domain hosting other web applications. This especially applies to sharing
the domain with Matrix web clients and other sensitive applications like
webmail. See
https://developer.github.com/changes/2014-04-25-user-content-security for more
information.

.. _CSP: https://github.com/matrix-org/synapse/pull/1021

Ideally, the homeserver should not simply be on a different subdomain, but on
a completely different `registered domain`_ (also known as top-level site or
eTLD+1). This is because `some attacks`_ are still possible as long as the two
applications share the same registered domain.

.. _registered domain: https://tools.ietf.org/html/draft-ietf-httpbis-rfc6265bis-03#section-2.3

.. _some attacks: https://en.wikipedia.org/wiki/Session_fixation#Attacks_using_cross-subdomain_cookie

To illustrate this with an example, if your Element Web or other sensitive web
application is hosted on ``A.example1.com``, you should ideally host Synapse on
``example2.com``. Some amount of protection is offered by hosting on
``B.example1.com`` instead, so this is also acceptable in some scenarios.
However, you should *not* host your Synapse on ``A.example1.com``.

Note that all of the above refers exclusively to the domain used in Synapse's
``public_baseurl`` setting. In particular, it has no bearing on the domain
mentioned in MXIDs hosted on that server.

Following this advice ensures that even if an XSS is found in Synapse, the
impact to other applications will be minimal.

🎯 Troubleshooting and support
==============================

🚀 Professional support
-----------------------

Enterprise quality support for Synapse including SLAs is available as part of an
`Element Server Suite (ESS) <https://element.io/pricing>`_ subscription.

If you are an existing ESS subscriber then you can raise a `support request <https://ems.element.io/support>`_
and access the `Element product documentation <https://docs.element.io>`_.

🤝 Community support
--------------------

The `Admin FAQ <https://element-hq.github.io/synapse/latest/usage/administration/admin_faq.html>`_
includes tips on dealing with some common problems. For more details, see
`Synapse's wider documentation <https://element-hq.github.io/synapse/latest/>`_.

For additional support installing or managing Synapse, please ask in the community
support room |room|_ (from a matrix.org account if necessary). We do not use GitHub
issues for support requests, only for bug reports and feature requests.

.. |room| replace:: ``#synapse:matrix.org``
.. _room: https://matrix.to/#/#synapse:matrix.org

.. |docs| replace:: ``docs``
.. _docs: docs


🛠️ Development
==============

We welcome contributions to Synapse from the community!
The best place to get started is our
`guide for contributors <https://element-hq.github.io/synapse/latest/development/contributing_guide.html>`_.
This is part of our broader `documentation <https://element-hq.github.io/synapse/latest>`_, which includes
information for Synapse developers as well as Synapse administrators.

Developers might be particularly interested in:

* `Synapse's database schema <https://element-hq.github.io/synapse/latest/development/database_schema.html>`_,
* `notes on Synapse's implementation details <https://element-hq.github.io/synapse/latest/development/internal_documentation/index.html>`_, and
* `how we use git <https://element-hq.github.io/synapse/latest/development/git.html>`_.

Alongside all that, join our developer community on Matrix:
`#synapse-dev:matrix.org <https://matrix.to/#/#synapse-dev:matrix.org>`_, featuring real humans!

Copyright and Licensing
=======================

  | Copyright 2014–2017 OpenMarket Ltd
  | Copyright 2017 Vector Creations Ltd
  | Copyright 2017–2025 New Vector Ltd
  | Copyright 2025 Element Creations Ltd

This software is dual-licensed by Element Creations Ltd (Element). It can be
used either:

(1) for free under the terms of the GNU Affero General Public License (as
    published by the Free Software Foundation, either version 3 of the License,
    or (at your option) any later version); OR

(2) under the terms of a paid-for Element Commercial License agreement between
    you and Element (the terms of which may vary depending on what you and
    Element have agreed to).

Unless required by applicable law or agreed to in writing, software distributed
under the Licenses is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the Licenses for the
specific language governing permissions and limitations under the Licenses.

Please contact `licensing@element.io <mailto:licensing@element.io>`_ to purchase
an Element commercial license for this software.


.. |support| image:: https://img.shields.io/badge/matrix-community%20support-success
  :alt: (get community support in #synapse:matrix.org)
  :target: https://matrix.to/#/#synapse:matrix.org

.. |development| image:: https://img.shields.io/matrix/synapse-dev:matrix.org?label=development&logo=matrix
  :alt: (discuss development on #synapse-dev:matrix.org)
  :target: https://matrix.to/#/#synapse-dev:matrix.org

.. |documentation| image:: https://img.shields.io/badge/documentation-%E2%9C%93-success
  :alt: (Rendered documentation on GitHub Pages)
  :target: https://element-hq.github.io/synapse/latest/

.. |license| image:: https://img.shields.io/github/license/element-hq/synapse
  :alt: (check license in LICENSE file)
  :target: LICENSE

.. |pypi| image:: https://img.shields.io/pypi/v/matrix-synapse
  :alt: (latest version released on PyPi)
  :target: https://pypi.org/project/matrix-synapse

.. |python| image:: https://img.shields.io/pypi/pyversions/matrix-synapse
  :alt: (supported python versions)
  :target: https://pypi.org/project/matrix-synapse