.. contents:: Introduction ============ Matrix is an ambitious new ecosystem for open federated Instant Messaging and VoIP. The basics you need to know to get up and running are: - Everything in Matrix happens in a room. Rooms are distributed and do not exist on any single server. Rooms can be located using convenience aliases like ``#matrix:matrix.org`` or ``#test:localhost:8448``. - Matrix user IDs look like ``@matthew:matrix.org`` (although in the future you will normally refer to yourself and others using a third party identifier (3PID): email address, phone number, etc rather than manipulating Matrix user IDs) The overall architecture is:: client <----> homeserver <=====================> homeserver <----> client https://somewhere.org/_matrix https://elsewhere.net/_matrix ``#matrix:matrix.org`` is the official support room for Matrix, and can be accessed by any client from https://matrix.org/docs/projects/try-matrix-now or via IRC bridge at irc://irc.freenode.net/matrix. Synapse is currently in rapid development, but as of version 0.5 we believe it is sufficiently stable to be run as an internet-facing service for real usage! About Matrix ============ Matrix specifies a set of pragmatic RESTful HTTP JSON APIs as an open standard, which handle: - Creating and managing fully distributed chat rooms with no single points of control or failure - Eventually-consistent cryptographically secure synchronisation of room state across a global open network of federated servers and services - Sending and receiving extensible messages in a room with (optional) end-to-end encryption[1] - Inviting, joining, leaving, kicking, banning room members - Managing user accounts (registration, login, logout) - Using 3rd Party IDs (3PIDs) such as email addresses, phone numbers, Facebook accounts to authenticate, identify and discover users on Matrix. - Placing 1:1 VoIP and Video calls These APIs are intended to be implemented on a wide range of servers, services and clients, letting developers build messaging and VoIP functionality on top of the entirely open Matrix ecosystem rather than using closed or proprietary solutions. The hope is for Matrix to act as the building blocks for a new generation of fully open and interoperable messaging and VoIP apps for the internet. Synapse is a reference "homeserver" implementation of Matrix from the core development team at matrix.org, written in Python/Twisted for clarity and simplicity. It is intended to showcase the concept of Matrix and let folks see the spec in the context of a codebase and let you run your own homeserver and generally help bootstrap the ecosystem. In Matrix, every user runs one or more Matrix clients, which connect through to a Matrix homeserver. The homeserver stores all their personal chat history and user account information - much as a mail client connects through to an IMAP/SMTP server. Just like email, you can either run your own Matrix homeserver and control and own your own communications and history or use one hosted by someone else (e.g. matrix.org) - there is no single point of control or mandatory service provider in Matrix, unlike WhatsApp, Facebook, Hangouts, etc. We'd like to invite you to join #matrix:matrix.org (via https://matrix.org/docs/projects/try-matrix-now), run a homeserver, take a look at the Matrix spec at https://matrix.org/docs/spec and API docs at https://matrix.org/docs/api, experiment with the APIs and the demo clients, and report any bugs via github. Thanks for using Matrix! [1] End-to-end encryption is currently in beta. Synapse Installation ==================== Synapse is the reference python/twisted Matrix homeserver implementation. System requirements: - POSIX-compliant system (tested on Linux & OS X) - Python 2.7 - At least 1GB of free RAM if you want to join large public rooms like #matrix:matrix.org Synapse is written in python but some of the libraries is uses are written in C. So before we can install synapse itself we need a working C compiler and the header files for python C extensions. Installing prerequisites on Ubuntu or Debian:: sudo apt-get install build-essential python2.7-dev libffi-dev \ python-pip python-setuptools sqlite3 \ libssl-dev python-virtualenv libjpeg-dev libxslt1-dev Installing prerequisites on ArchLinux:: sudo pacman -S base-devel python2 python-pip \ python-setuptools python-virtualenv sqlite3 Installing prerequisites on CentOS 7:: sudo yum install libtiff-devel libjpeg-devel libzip-devel freetype-devel \ lcms2-devel libwebp-devel tcl-devel tk-devel \ python-virtualenv libffi-devel openssl-devel sudo yum groupinstall "Development Tools" Installing prerequisites on Mac OS X:: xcode-select --install sudo easy_install pip sudo pip install virtualenv Installing prerequisites on Raspbian:: sudo apt-get install build-essential python2.7-dev libffi-dev \ python-pip python-setuptools sqlite3 \ libssl-dev python-virtualenv libjpeg-dev sudo pip install --upgrade pip sudo pip install --upgrade ndg-httpsclient sudo pip install --upgrade virtualenv Installing prerequisites on openSUSE:: sudo zypper in -t pattern devel_basis sudo zypper in python-pip python-setuptools sqlite3 python-virtualenv \ python-devel libffi-devel libopenssl-devel libjpeg62-devel To install the synapse homeserver run:: virtualenv -p python2.7 ~/.synapse source ~/.synapse/bin/activate pip install --upgrade setuptools pip install https://github.com/matrix-org/synapse/tarball/master This installs synapse, along with the libraries it uses, into a virtual environment under ``~/.synapse``. Feel free to pick a different directory if you prefer. In case of problems, please see the _`Troubleshooting` section below. Alternatively, Silvio Fricke has contributed a Dockerfile to automate the above in Docker at https://registry.hub.docker.com/u/silviof/docker-matrix/. Also, Martin Giess has created an auto-deployment process with vagrant/ansible, tested with VirtualBox/AWS/DigitalOcean - see https://github.com/EMnify/matrix-synapse-auto-deploy for details. Configuring synapse ------------------- Before you can start Synapse, you will need to generate a configuration file. To do this, run (in your virtualenv, as before):: cd ~/.synapse python -m synapse.app.homeserver \ --server-name my.domain.name \ --config-path homeserver.yaml \ --generate-config \ --report-stats=[yes|no] ... substituting an appropriate value for ``--server-name``. The server name determines the "domain" part of user-ids for users on your server: these will all be of the format ``@user:my.domain.name``. It also determines how other matrix servers will reach yours for `Federation`_. For a test configuration, set this to the hostname of your server. For a more production-ready setup, you will probably want to specify your domain (``example.com``) rather than a matrix-specific hostname here (in the same way that your email address is probably ``user@example.com`` rather than ``user@email.example.com``) - but doing so may require more advanced setup - see `Setting up Federation`_. This command will generate you a config file that you can then customise, but it will also generate a set of keys for you. These keys will allow your Home Server to identify itself to other Home Servers, so don't lose or delete them. It would be wise to back them up somewhere safe. If, for whatever reason, you do need to change your Home Server's keys, you may find that other Home Servers have the old key cached. If you update the signing key, you should change the name of the key in the ``.signing.key`` file (the second word) to something different. The default configuration exposes two TCP ports: 8008 and 8448. Port 8008 is configured without TLS; it is not recommended this be exposed outside your local network. Port 8448 is configured to use TLS with a self-signed certificate. This is fine for testing with but you will almost certainly want to use another certificate for production purposes. You can do so by changing ``tls_certificate_path``, ``tls_private_key_path`` and ``tls_dh_params_path`` in ``homeserver.yaml``; alternatively, you can use a reverse-proxy, but be sure to read `Using a reverse proxy with Synapse`_ when doing so. Registering a user ------------------ You will need at least one user on your server in order to use a Matrix client. Users can be registered either `via a Matrix client`__, or via a commandline script. .. __: `client-user-reg`_ To get started, is easiest to use the command line to register new users:: $ source ~/.synapse/bin/activate $ synctl start # if not already running $ register_new_matrix_user -c homeserver.yaml https://localhost:8448 New user localpart: erikj Password: Confirm password: Success! This process uses a setting ``registration_shared_secret`` in ``homeserver.yaml``, which is shared between Synapse itself and the ``register_new_matrix_user`` script. It doesn't matter what it is (a random value is generated by ``--generate-config``), but it should be kept secret, as anyone with knowledge of it can register users on your server even if ``enable_registration`` is ``false``. Setting up a TURN server ------------------------ For reliable VoIP calls to be routed via this homeserver, you MUST configure a TURN server. See ``_ for details. Running Synapse =============== To actually run your new homeserver, pick a working directory for Synapse to run (e.g. ``~/.synapse``), and:: cd ~/.synapse source ./bin/activate synctl start Connecting to Synapse from a client =================================== The easiest way to try out your new Synapse installation is by connecting to it from a web client. We recommend the one at http://riot.im/app. You will need to specify a "Custom server" when you log on or register: set this to ``https://localhost:8448`` - remember to specify the port (``:8448``) unless you changed the configuration. (Leave the identity server as the default - see `Identity servers`_.) If all goes well you should at least be able to log in, create a room, and start sending messages. (The homeserver runs a web client by default at https://localhost:8448/, though as of the time of writing it is somewhat outdated and not really recommended - https://github.com/matrix-org/synapse/issues/1527). .. _`client-user-reg`: Registering a new user from a client ------------------------------------ By default, registration of new users via Matrix clients is disabled. To enable it, specify ``enable_registration: true`` in ``homeserver.yaml``. (It is then recommended to also set up CAPTCHA - see ``_.) Once ``enable_registration`` is set to ``true``, it is possible to register a user via `riot.im `_ or other Matrix clients. Your new user name will be formed partly from the ``server_name`` (see `Configuring synapse`_), and partly from a localpart you specify when you create the account. Your name will take the form of:: @localpart:my.domain.here (pronounced "at localpart on my dot domain dot here"). As when logging in, you will need to specify a "Custom server". Specify your desired ``localpart`` in the 'User name' box. Security Note ============= Matrix serves raw user generated data in some APIs - specifically the `content repository endpoints `_. Whilst we have tried to mitigate against possible XSS attacks (e.g. https://github.com/matrix-org/synapse/pull/1021) we recommend running matrix homeservers on a dedicated domain name, to limit any malicious user generated content served to web browsers a matrix API from being able to attack webapps hosted on the same domain. This is particularly true of sharing a matrix webclient and server on the same domain. See https://github.com/vector-im/vector-web/issues/1977 and https://developer.github.com/changes/2014-04-25-user-content-security for more details. Platform Specific Instructions ============================== Debian ------ Matrix provides official Debian packages via apt from http://matrix.org/packages/debian/. Note that these packages do not include a client - choose one from https://matrix.org/docs/projects/try-matrix-now/ (or build your own with one of our SDKs :) Fedora ------ Oleg Girko provides Fedora RPMs at https://obs.infoserver.lv/project/monitor/matrix-synapse ArchLinux --------- The quickest way to get up and running with ArchLinux is probably with Ivan Shapovalov's AUR package from https://aur.archlinux.org/packages/matrix-synapse/, which should pull in all the necessary dependencies. Alternatively, to install using pip a few changes may be needed as ArchLinux defaults to python 3, but synapse currently assumes python 2.7 by default: pip may be outdated (6.0.7-1 and needs to be upgraded to 6.0.8-1 ):: sudo pip2.7 install --upgrade pip You also may need to explicitly specify python 2.7 again during the install request:: pip2.7 install https://github.com/matrix-org/synapse/tarball/master If you encounter an error with lib bcrypt causing an Wrong ELF Class: ELFCLASS32 (x64 Systems), you may need to reinstall py-bcrypt to correctly compile it under the right architecture. (This should not be needed if installing under virtualenv):: sudo pip2.7 uninstall py-bcrypt sudo pip2.7 install py-bcrypt During setup of Synapse you need to call python2.7 directly again:: cd ~/.synapse python2.7 -m synapse.app.homeserver \ --server-name machine.my.domain.name \ --config-path homeserver.yaml \ --generate-config ...substituting your host and domain name as appropriate. FreeBSD ------- Synapse can be installed via FreeBSD Ports or Packages contributed by Brendan Molloy from: - Ports: ``cd /usr/ports/net/py-matrix-synapse && make install clean`` - Packages: ``pkg install py27-matrix-synapse`` NixOS ----- Robin Lambertz has packaged Synapse for NixOS at: https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/services/misc/matrix-synapse.nix Windows Install --------------- Synapse can be installed on Cygwin. It requires the following Cygwin packages: - gcc - git - libffi-devel - openssl (and openssl-devel, python-openssl) - python - python-setuptools The content repository requires additional packages and will be unable to process uploads without them: - libjpeg8 - libjpeg8-devel - zlib If you choose to install Synapse without these packages, you will need to reinstall ``pillow`` for changes to be applied, e.g. ``pip uninstall pillow`` ``pip install pillow --user`` Troubleshooting: - You may need to upgrade ``setuptools`` to get this to work correctly: ``pip install setuptools --upgrade``. - You may encounter errors indicating that ``ffi.h`` is missing, even with ``libffi-devel`` installed. If you do, copy the ``.h`` files: ``cp /usr/lib/libffi-3.0.13/include/*.h /usr/include`` - You may need to install libsodium from source in order to install PyNacl. If you do, you may need to create a symlink to ``libsodium.a`` so ``ld`` can find it: ``ln -s /usr/local/lib/libsodium.a /usr/lib/libsodium.a`` Troubleshooting =============== Troubleshooting Installation ---------------------------- Synapse requires pip 1.7 or later, so if your OS provides too old a version you may need to manually upgrade it:: sudo pip install --upgrade pip Installing may fail with ``Could not find any downloads that satisfy the requirement pymacaroons-pynacl (from matrix-synapse==0.12.0)``. You can fix this by manually upgrading pip and virtualenv:: sudo pip install --upgrade virtualenv You can next rerun ``virtualenv -p python2.7 synapse`` to update the virtual env. Installing may fail during installing virtualenv with ``InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.`` You can fix this by manually installing ndg-httpsclient:: pip install --upgrade ndg-httpsclient Installing may fail with ``mock requires setuptools>=17.1. Aborting installation``. You can fix this by upgrading setuptools:: pip install --upgrade setuptools If pip crashes mid-installation for reason (e.g. lost terminal), pip may refuse to run until you remove the temporary installation directory it created. To reset the installation:: rm -rf /tmp/pip_install_matrix pip seems to leak *lots* of memory during installation. For instance, a Linux host with 512MB of RAM may run out of memory whilst installing Twisted. If this happens, you will have to individually install the dependencies which are failing, e.g.:: pip install twisted On OS X, if you encounter clang: error: unknown argument: '-mno-fused-madd' you will need to export CFLAGS=-Qunused-arguments. Troubleshooting Running ----------------------- If synapse fails with ``missing "sodium.h"`` crypto errors, you may need to manually upgrade PyNaCL, as synapse uses NaCl (http://nacl.cr.yp.to/) for encryption and digital signatures. Unfortunately PyNACL currently has a few issues (https://github.com/pyca/pynacl/issues/53) and (https://github.com/pyca/pynacl/issues/79) that mean it may not install correctly, causing all tests to fail with errors about missing "sodium.h". To fix try re-installing from PyPI or directly from (https://github.com/pyca/pynacl):: # Install from PyPI pip install --user --upgrade --force pynacl # Install from github pip install --user https://github.com/pyca/pynacl/tarball/master ArchLinux ~~~~~~~~~ If running `$ synctl start` fails with 'returned non-zero exit status 1', you will need to explicitly call Python2.7 - either running as:: python2.7 -m synapse.app.homeserver --daemonize -c homeserver.yaml ...or by editing synctl with the correct python executable. Upgrading an existing Synapse ============================= The instructions for upgrading synapse are in `UPGRADE.rst`_. Please check these instructions as upgrading may require extra steps for some versions of synapse. .. _UPGRADE.rst: UPGRADE.rst .. _federation: Setting up Federation ===================== Federation is the process by which users on different servers can participate in the same room. For this to work, those other servers must be able to contact yours to send messages. As explained in `Configuring synapse`_, the ``server_name`` in your ``homeserver.yaml`` file determines the way that other servers will reach yours. By default, they will treat it as a hostname and try to connect to port 8448. This is easy to set up and will work with the default configuration, provided you set the ``server_name`` to match your machine's public DNS hostname. For a more flexible conversation, you can set up a DNS SRV record. This allows you to run your server on a machine that might not have the same name as your domain name. For example, you might want to run your server at ``synapse.example.com``, but have your Matrix user-ids look like ``@user:example.com``. (A SRV record also allows you to change the port from the default 8448. However, if you are thinking of using a reverse-proxy, be sure to read `Reverse-proxying the federation port`_ first.) To use a SRV record, first create your SRV record and publish it in DNS. This should have the format ``_matrix._tcp. IN SRV 10 0 ``. The DNS record should then look something like:: $ dig -t srv _matrix._tcp.example.com _matrix._tcp.example.com. 3600 IN SRV 10 0 8448 synapse.example.com. You can then configure your homeserver to use ```` as the domain in its user-ids, by setting ``server_name``:: python -m synapse.app.homeserver \ --server-name \ --config-path homeserver.yaml \ --generate-config python -m synapse.app.homeserver --config-path homeserver.yaml If you've already generated the config file, you need to edit the ``server_name`` in your ``homeserver.yaml`` file. If you've already started Synapse and a database has been created, you will have to recreate the database. If all goes well, you should be able to connect to your server with a client, and then join a room via federation. (Try ``#matrix-dev:matrix.org`` as a first step. "Matrix HQ"'s sheer size and activity level tends to make even the largest boxes pause for thought.) Troubleshooting --------------- The typical failure mode with federation is that when you try to join a room, it is rejected with "401: Unauthorized". Generally this means that other servers in the room couldn't access yours. (Joining a room over federation is a complicated dance which requires connections in both directions). So, things to check are: * If you are trying to use a reverse-proxy, read `Reverse-proxying the federation port`_. * If you are not using a SRV record, check that your ``server_name`` (the part of your user-id after the ``:``) matches your hostname, and that port 8448 on that hostname is reachable from outside your network. * If you *are* using a SRV record, check that it matches your ``server_name`` (it should be ``_matrix._tcp.``), and that the port and hostname it specifies are reachable from outside your network. Running a Demo Federation of Synapses ------------------------------------- If you want to get up and running quickly with a trio of homeservers in a private federation, there is a script in the ``demo`` directory. This is mainly useful just for development purposes. See ``_. Using PostgreSQL ================ As of Synapse 0.9, `PostgreSQL `_ is supported as an alternative to the `SQLite `_ database that Synapse has traditionally used for convenience and simplicity. The advantages of Postgres include: * significant performance improvements due to the superior threading and caching model, smarter query optimiser * allowing the DB to be run on separate hardware * allowing basic active/backup high-availability with a "hot spare" synapse pointing at the same DB master, as well as enabling DB replication in synapse itself. For information on how to install and use PostgreSQL, please see `docs/postgres.rst `_. .. _reverse-proxy: Using a reverse proxy with Synapse ================================== It is possible to put a reverse proxy such as `nginx `_, `Apache `_ or `HAProxy `_ 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. The most important thing to know here is that Matrix clients and other Matrix servers do not necessarily need to connect to your server via the same port. Indeed, clients will use port 443 by default, whereas other servers default to port 8448. Where these are different, we refer to the 'client port' and the 'federation port'. The next most important thing to know is that using a reverse-proxy on the federation port has a number of pitfalls. It is possible, but be sure to read `Reverse-proxying the federation port`_. The recommended setup is therefore to configure your reverse-proxy on port 443 for client connections, but to also expose port 8448 for server-server connections. All the Matrix endpoints begin ``/_matrix``, so an example nginx configuration might look like:: server { listen 443 ssl; listen [::]:443 ssl; server_name matrix.example.com; location /_matrix { proxy_pass http://localhost:8008; proxy_set_header X-Forwarded-For $remote_addr; } } You will also want to set ``bind_address: 127.0.0.1`` and ``x_forwarded: true`` for port 8008 in ``homeserver.yaml`` to ensure that client IP addresses are recorded correctly. Having done so, you can then use ``https://matrix.example.com`` (instead of ``https://matrix.example.com:8448``) as the "Custom server" when `Connecting to Synapse from a client`_. Reverse-proxying the federation port ------------------------------------ There are two issues to consider before using a reverse-proxy on the federation port: * Due to the way SSL certificates are managed in the Matrix federation protocol (see `spec `_), Synapse needs to be configured with the path to the SSL certificate, *even if you do not terminate SSL at Synapse*. * Synapse does not currently support SNI on the federation protocol (`bug #1491 `_), which means that using name-based virtual hosting is unreliable. Furthermore, a number of the normal reasons for using a reverse-proxy do not apply: * Other servers will connect on port 8448 by default, so there is no need to listen on port 443 (for federation, at least), which avoids the need for root privileges and virtual hosting. * A self-signed SSL certificate is fine for federation, so there is no need to automate renewals. (The certificate generated by ``--generate-config`` is valid for 10 years.) If you want to set up a reverse-proxy on the federation port despite these caveats, you will need to do the following: * In ``homeserver.yaml``, set ``tls_certificate_path`` to the path to the SSL certificate file used by your reverse-proxy, and set ``no_tls`` to ``True``. (``tls_private_key_path`` will be ignored if ``no_tls`` is ``True``.) * In your reverse-proxy configuration, if there are other virtual hosts on the same port, make sure that Synapse is the default. * If your reverse-proxy is not listening on port 8448, publish a SRV record to tell other servers how to find you. See `Setting up Federation`_. When updating the SSL certificate, just update the file pointed to by ``tls_certificate_path``: there is no need to restart synapse. (You may like to use a symbolic link to help make this process atomic.) The most common mistake when setting up federation is not to tell Synapse about your SSL certificate. To check it, you can visit ``https://matrix.org/federationtester/api/report?server_name=``. Unfortunately, there is no UI for this yet, but, you should see ``"MatchingTLSFingerprint": true``. If not, check that ``Certificates[0].SHA256Fingerprint`` (the fingerprint of the certificate presented by your reverse-proxy) matches ``Keys.tls_fingerprints[0].sha256`` (the fingerprint of the certificate Synapse is using). 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. This process is very security-sensitive, as there is obvious risk of spam if it is too easy to sign up for Matrix accounts or harvest 3PID data. In the longer term, we hope to create a decentralised system to manage it (`matrix-doc #712 `_), but in the meantime, the role of managing trusted identity in the Matrix ecosystem is farmed out to a cluster of known trusted ecosystem partners, who run 'Matrix Identity Servers' such as `Sydent `_, whose role is purely to authenticate and track 3PID logins and publish end-user public keys. You can host your own copy of Sydent, but this will prevent you reaching other users in the Matrix ecosystem via their email address, and prevent them finding you. We therefore recommend that you use one of the centralised identity servers at ``https://matrix.org`` or ``https://vector.im`` for now. To reiterate: the Identity server will only be used if you choose to associate an email address with your account, or send an invite to another user via their email address. URL Previews ============ Synapse 0.15.0 introduces a new API for previewing URLs at ``/_matrix/media/r0/preview_url``. This is disabled by default. To turn it on you must enable the ``url_preview_enabled: True`` config parameter and explicitly specify the IP ranges that Synapse is not allowed to spider for previewing in the ``url_preview_ip_range_blacklist`` configuration parameter. This is critical from a security perspective to stop arbitrary Matrix users spidering 'internal' URLs on your network. At the very least we recommend that your loopback and RFC1918 IP addresses are blacklisted. This also requires the optional lxml and netaddr python dependencies to be installed. Password reset ============== If a user has registered an email address to their account using an identity server, they can request a password-reset token via clients such as Vector. A manual password reset can be done via direct database access as follows. First calculate the hash of the new password:: $ source ~/.synapse/bin/activate $ ./scripts/hash_password Password: Confirm password: $2a$12$xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Then update the `users` table in the database:: UPDATE users SET password_hash='$2a$12$xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' WHERE name='@test:test.com'; Synapse Development =================== To check out a synapse for development, clone the git repo into a working directory of your choice:: git clone https://github.com/matrix-org/synapse.git cd synapse Synapse has a number of external dependencies, that are easiest to install using pip and a virtualenv:: virtualenv env source env/bin/activate python synapse/python_dependencies.py | xargs -n1 pip install pip install setuptools_trial mock This will run a process of downloading and installing all the needed dependencies into a virtual env. Once this is done, you may wish to run Synapse's unit tests, to check that everything is installed as it should be:: python setup.py test This should end with a 'PASSED' result:: Ran 143 tests in 0.601s PASSED (successes=143) Building Internal API Documentation =================================== Before building internal API documentation install sphinx and sphinxcontrib-napoleon:: pip install sphinx pip install sphinxcontrib-napoleon Building internal API documentation:: python setup.py build_sphinx Help!! Synapse eats all my RAM! =============================== Synapse's architecture is quite RAM hungry currently - we deliberately cache a lot of recent room data and metadata in RAM in order to speed up common requests. We'll improve this in future, but for now the easiest way to either reduce the RAM usage (at the risk of slowing things down) is to set the almost-undocumented ``SYNAPSE_CACHE_FACTOR`` environment variable. Roughly speaking, a SYNAPSE_CACHE_FACTOR of 1.0 will max out at around 3-4GB of resident memory - this is what we currently run the matrix.org on. The default setting is currently 0.1, which is probably around a ~700MB footprint. You can dial it down further to 0.02 if desired, which targets roughly ~512MB. Conversely you can dial it up if you need performance for lots of users and have a box with a lot of RAM.