moxygen

moxygen is a C++ implementation of Media over QUIC Transport (MoQT). It provides a library for building MoQT publishers, subscribers, and relays, along with a working relay server, sample applications, and protocol conformance and interop tooling.

The library is transport-agnostic — WebTransport, raw QUIC, or QMUX-on-TCP — coroutine-based, and built on folly, mvfst, and proxygen.

Documentation

Protocol support

New integrations should target draft-16 until draft-18 interop testing completes.

Version negotiation happens over ALPN, using either standard (moqt-NN) or Meta-specific ALPNs. The binaries accept --versions to restrict the offered set (for example --versions 16,18); the default offers everything supported. See moxygen/MoQVersions.h for the version and ALPN constants.

Repository layout

Building

git clone https://github.com/facebookexperimental/moxygen.git
cd moxygen

There are two ways to build moxygen. Both read the same pinned dependency revisions from build/deps/github_hashes/, so they produce the same versions of folly, fizz, wangle, mvfst, and proxygen — they differ in what they build for you and what kind of build tree you end up with.

Use the standalone build if you want a normal CMake workflow, or you are co-developing moxygen alongside a dependency. Use getdeps if you want the path most likely to work unattended, or you are packaging moxygen. The Docker image below is not a third build system — it runs getdeps inside a container and ships only the relay.

Standalone CMake

Fetches the pinned dependency revisions using CMake's FetchContent and produces a plain CMake build tree. See standalone/README.md for dependency overrides, build caching, and troubleshooting.

./standalone/install-system-deps.sh
cmake -B _build -S standalone -G Ninja
cmake --build _build -j$(nproc)

Binaries land in the build tree mirroring the source layout, for example _build/moxygen/relay/moqrelayserver and _build/moxygen/samples/text-client/moqtextclient.

Run the tests with:

ctest --test-dir _build

The first configure downloads roughly 500MB of dependency source. To avoid re-downloading it on a clean build, set -DFETCHCONTENT_BASE_DIR to a shared location.

getdeps

Builds moxygen and its Meta dependencies from the same pinned revisions, and also builds or installs the third-party dependencies. This is the build exercised by the Linux and macOS CI jobs, and the one the Docker image uses.

./build/fbcode_builder/getdeps.py install-system-deps --recursive moxygen
./build/fbcode_builder/getdeps.py build --allow-system-packages --src-dir=. moxygen

Once the dependencies are built, rebuild just moxygen with:

./build/fbcode_builder/getdeps.py build --src-dir=. --no-deps moxygen

Binaries are installed under:

MOXYGEN_BIN=$(./build/fbcode_builder/getdeps.py show-inst-dir moxygen)/bin

Run the tests with:

./build/fbcode_builder/getdeps.py test --src-dir=. moxygen

Docker

Builds a container image running the relay server, and requires no local toolchain. The header of docker/Dockerfile documents the supported environment variables and certificate mounts.

docker build -t moqrelay -f docker/Dockerfile .
docker run --rm -p 4433:4433/udp moqrelay

Using moxygen from another CMake project

moxygen installs a CMake package. After building and installing, use find_package(moxygen REQUIRED) and link the targets you need, such as moxygen::moxygen_moq or moxygen::moxygen_relay_moq_relay. moxygen can also be consumed directly via FetchContent or add_subdirectory.

Testing and interop

• Unit tests — getdeps.py test moxygen, or ctest --test-dir _build for the standalone build.
• Conformance suite — 50 scenarios driving moqtest_client against a relay, covering forwarding preferences, group and object layouts, extensions, and end-of-group markers. See CONFORMANCE_README.md.
• moqtest_server and moqtest_client — an implementation of the moq-test-00 parameterized test protocol, for testing against other MoQT implementations.
• Interop client — moxygen/moqtest/interop/, exercised in CI by the docker-interop-client workflow.
• moqperf_test_client — throughput and latency measurement.

Related projects

• moq-encoder-player — a browser-based MoQT encoder and player built on WebCodecs. See READMOQMEDIA.md for how to run it against moxygen.

Contributing

Issues and pull requests are welcome. moxygen is developed inside Meta's monorepo and mirrored to GitHub, so accepted changes land internally first and then appear here.

License

moxygen is licensed under the Apache License 2.0. See LICENSE.