Yggdrasil Multiplayer Peer for Godot

A GDExtension that provides a MultiplayerPeerExtension backed by Yggdrasil, enabling peer-to-peer multiplayer over the Yggdrasil mesh network.

What's the point of this?

• Zero hosting costs for games
• Session discovery can be done by the PROTOCOL. (multicast session discovery)
• Future: VOIP traffic can be done over tunnel
• Bypasses CGNAT horribleness, needing to forward port
• Uses IPV6 addressing internally
• Encrypted by default
• Supports QUIC protocol transport and TCP, this means you can essentially make QUIC "droppless" for game networking swapping from WiFi to 4G for example on outages.
• You can use micro-networks per-session so the number of players is the peer count on the network
• You can use a relay for all your players.

Benchmark data:

Throughput Summary (60KB packets):
  Total          MB/s
  -----          ----
  1MB          129.22
  8MB          233.54
  32MB         302.03
  64MB         328.07
  128MB        330.81
  512MB        337.81
  1GB          336.94

Latency Summary (echo RTT, 100 pings):
  Hops            Avg RTT      Per-hop
  ----            -------      -------
  1             188.638µs     94.319µs
  2             167.677µs     41.919µs
  4             491.584µs     61.448µs
  8             586.865µs     36.679µs
  16            988.346µs     30.885µs
  64           3.562252ms      27.83µs

Stability notes:

• Connections need more work to resolve hop latency with the godot side, and also to implement unreliable transfer via QUIC. (fixed: 9 Feb 2026)
• Crashes don't seem common but the network hanging is common if you use mutilple nodes in a chain, when you use nodes direct to each other via their address it seems to be ok. (fixed: 9 Feb 2026)
• I've tested with netfox netbrawler demo and it works but eventually introduces overhead as the game progresses, I believe due to the missing support for QUIC Unreliable packets, but I cannot be sure of this until I have more unit tests. (fixed in PR #2)
• This is not production ready, yggdrasil is not even finished yet.
• Throughput on LAN is OK but not tested wider internet yet.
• RFC 9221 - UDP Unreliable Transfer Implemented (added: 9 Feb 2026)

Supported Platforms

Platform	Architecture
macOS	universal (arm64 + x86_64)
Linux	x86_64
Windows	x86_64
Android	arm64
iOS	arm64

Prerequisites

• Go 1.24+
• Python 3 + SCons (pip install scons)
• C/C++ toolchain (Xcode on macOS, GCC/MinGW on Linux/Windows)

Building

Clone with submodules:

git clone --recursive https://github.com/RevoluPowered/yggdrasil-multiplayer-peer-godot.git
cd yggdrasil-multiplayer-peer-godot

Build (this builds both the Go static library and the GDExtension):

scons               # macOS universal debug (default)
scons target=template_release  # release build
scons platform=linux arch=x86_64
scons platform=windows arch=x86_64 use_mingw=yes

The build automatically:

1. Compiles libyggdrasil.a from the yggdrasil-go submodule
2. Builds the C++ GDExtension, statically linking the Go library
3. Deploys the result to ../netfox/addons/yggdrasil/bin/

Project Structure

.
├── SConstruct              # Build system (SCons)
├── yggdrasil_peer.gdextension
├── src/                    # C++ GDExtension source
│   ├── yggdrasil_peer.cpp
│   ├── yggdrasil_peer.h
│   └── register_types.cpp
├── godot-cpp/              # Submodule: Godot C++ bindings
├── yggdrasil-go/           # Submodule: Yggdrasil with C library support
│   └── contrib/lib/        # Go → C static library (libyggdrasil.a)
└── bin/                    # Build output (gitignored)

Running Tests

cd yggdrasil-go
go test -v ./contrib/lib/