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Synapse
Synapse is now actively maintained at element-hq/synapse
Synapse is an open-source Matrix homeserver developed
from 2019 through 2023 as part of the Matrix.org Foundation. The Matrix.org
Foundation is not able to resource maintenance of Synapse and it
continues to be developed by Element;
additionally you have the choice of other Matrix homeservers.
See The future of Synapse and Dendrite
blog post for more information.
Briefly, Matrix is an open standard for communications on the internet, supporting
federation, encryption and VoIP. Matrix.org has more to say about the goals of the
Matrix project, and the formal specification describes the technical details.
Contents
Synapse is now actively maintained at element-hq/synapse
Installing and configuration
Using a reverse proxy with Synapse
Upgrading an existing Synapse
Platform dependencies
Security note
Testing a new installation
Registering a new user from a client
Troubleshooting and support
Identity Servers
Development
Installing and configuration
The Synapse documentation describes how to install Synapse. We recommend using
Docker images or Debian packages from Matrix.org.
Synapse has a variety of config options
which can be used to customise its behaviour after installation.
There are additional details on how to configure Synapse for federation here.
Using a reverse proxy with Synapse
It is recommended to put a reverse proxy such as
nginx,
Apache,
Caddy,
HAProxy or
relayd in front of Synapse. One advantage of
doing so is that it means that you can expose the default https port (443) to
Matrix clients without needing to run Synapse with root privileges.
For information on configuring one, see the reverse proxy docs.
Upgrading an existing Synapse
The instructions for upgrading Synapse are in the upgrade notes.
Please check these instructions as upgrading may require extra steps for some
versions of Synapse.
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
for more details.
Security note
Matrix serves raw, user-supplied data in some APIs -- specifically the content
repository endpoints.
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.
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.
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.
Testing a new installation
The easiest way to try out your new Synapse installation is by connecting to it
from a web client.
Unless you are running a test instance of Synapse on your local machine, in
general, you will need to enable TLS support before you can successfully
connect from a client: see
TLS certificates.
An easy way to get started is to login or register via Element at
https://app.element.io/#/login or https://app.element.io/#/register respectively.
You will need to change the server you are logging into from matrix.org
and instead specify a Homeserver URL of https://<server_name>:8448
(or just https://<server_name> if you are using a reverse proxy).
If you prefer to use another client, refer to our
client breakdown.
If all goes well you should at least be able to log in, create a room, and
start sending messages.
Registering a new user from a client
By default, registration of new users via Matrix clients is disabled. To enable
it:
In the
registration config section
set enable_registration: true in homeserver.yaml.
Then either:
set up a CAPTCHA, or
set enable_registration_without_verification: true in homeserver.yaml.
We strongly recommend using a CAPTCHA, particularly if your homeserver is exposed to
the public internet. Without it, anyone can freely register accounts on your homeserver.
This can be exploited by attackers to create spambots targetting the rest of the Matrix
federation.
Your new user name will be formed partly from the server_name, and partly
from a localpart you specify when you create the account. Your name will take
the form of:
@localpart:my.domain.name
(pronounced "at localpart on my dot domain dot name").
As when logging in, you will need to specify a "Custom server". Specify your
desired localpart in the 'User name' box.
Troubleshooting and support
The Admin FAQ
includes tips on dealing with some common problems. For more details, see
Synapse's wider documentation.
For additional support installing or managing Synapse, please ask in the community
support room #synapse:matrix.org (from a matrix.org account if necessary). We do not use GitHub
issues for support requests, only for bug reports and feature requests.
Identity Servers
Identity servers have the job of mapping email addresses and other 3rd Party
IDs (3PIDs) to Matrix user IDs, as well as verifying the ownership of 3PIDs
before creating that mapping.
They are not where accounts or credenti
Read the full README on GitHub
