Dendrite

Dendrite is a second-generation Matrix homeserver written in Go. It intends to provide an efficient, reliable and scalable alternative to Synapse:

• Efficient: A small memory footprint with better baseline performance than an out-of-the-box Synapse.
• Reliable: Implements the Matrix specification as written, using the same test suite as Synapse as well as a brand new Go test suite.
• Scalable: can run on multiple machines and eventually scale to massive homeserver deployments.

As of October 2020 (current progress below), Dendrite has now entered beta which means:

• Dendrite is ready for early adopters. We recommend running in Monolith mode with a PostgreSQL database.
• Dendrite has periodic semver releases. We intend to release new versions as we land significant features.
• Dendrite supports database schema upgrades between releases. This means you should never lose your messages when upgrading Dendrite.
• Breaking changes will not occur on minor releases. This means you can safely upgrade Dendrite without modifying your database or config file.

This does not mean:

• Dendrite is bug-free. It has not yet been battle-tested in the real world and so will be error prone initially.
• Dendrite is feature-complete. There may be client or federation APIs that are not implemented.
• Dendrite is ready for massive homeserver deployments. You cannot shard each microservice, only run each one on a different machine.

Currently, we expect Dendrite to function well for small (10s/100s of users) homeserver deployments as well as P2P Matrix nodes in-browser or on mobile devices. In the future, we will be able to scale up to gigantic servers (equivalent to matrix.org) via polylith mode.

If you have further questions, please take a look at our FAQ or join us in:

• #dendrite:matrix.org - General chat about the Dendrite project, for users and server admins alike
• #dendrite-dev:matrix.org - The place for developers, where all Dendrite development discussion happens
• #dendrite-alerts:matrix.org - Release notifications and important info, highly recommended for all Dendrite server admins

Requirements

See the Planning your Installation page for more information on requirements.

To build Dendrite, you will need Go 1.18 or later.

For a usable federating Dendrite deployment, you will also need:

• A domain name (or subdomain)
• A valid TLS certificate issued by a trusted authority for that domain
• SRV records or a well-known file pointing to your deployment

Also recommended are:

• A PostgreSQL database engine, which will perform better than SQLite with many users and/or larger rooms
• A reverse proxy server, such as nginx, configured like this sample

The Federation Tester can be used to verify your deployment.

Get started

If you wish to build a fully-federating Dendrite instance, see the Installation documentation. For running in Docker, see build/docker.

The following instructions are enough to get Dendrite started as a non-federating test deployment using self-signed certificates and SQLite databases:

$ git clone https://github.com/matrix-org/dendrite
$ cd dendrite
$ ./build.sh

# Generate a Matrix signing key for federation (required)
$ ./bin/generate-keys --private-key matrix_key.pem

# Generate a self-signed certificate (optional, but a valid TLS certificate is normally
# needed for Matrix federation/clients to work properly!)
$ ./bin/generate-keys --tls-cert server.crt --tls-key server.key

# Copy and modify the config file - you'll need to set a server name and paths to the keys
# at the very least, along with setting up the database connection strings.
$ cp dendrite-sample.monolith.yaml dendrite.yaml

# Build and run the server:
$ ./bin/dendrite-monolith-server --tls-cert server.crt --tls-key server.key --config dendrite.yaml

# Create an user account (add -admin for an admin user).
# Specify the localpart only, e.g. 'alice' for '@alice:domain.com'
$ ./bin/create-account --config dendrite.yaml -username alice

Then point your favourite Matrix client at http://localhost:8008 or https://localhost:8448.

Progress

We use a script called Are We Synapse Yet which checks Sytest compliance rates. Sytest is a black-box homeserver test rig with around 900 tests. The script works out how many of these tests are passing on Dendrite and it updates with CI. As of August 2022 we're at around 83% CS API coverage and 95% Federation coverage, though check CI for the latest numbers. In practice, this means you can communicate locally and via federation with Synapse servers such as matrix.org reasonably well, although there are still some missing features (like Search).

We are prioritising features that will benefit single-user homeservers first (e.g Receipts, E2E) rather than features that massive deployments may be interested in (User Directory, OpenID, Guests, Admin APIs, AS API). This means Dendrite supports amongst others:

• Core room functionality (creating rooms, invites, auth rules)
• Room versions 1 to 10 supported
• Backfilling locally and via federation
• Accounts, profiles and devices
• Published room lists
• Typing
• Media APIs
• Redaction
• Tagging
• Context
• E2E keys and device lists
• Receipts
• Push
• Guests
• User Directory
• Presence

Contributing

We would be grateful for any help on issues marked as Are We Synapse Yet. These issues all have related Sytests which need to pass in order for the issue to be closed. Once you've written your code, you can quickly run Sytest to ensure that the test names are now passing.

If you're new to the project, see our Contributing page to get up to speed, then look for Good First Issues. If you're familiar with the project, look for Help Wanted issues.