Klotho — Deterministic multiplayer for Godot(.NET) 0.2.10 Scripts 4.4 Community

Submitted by user xpTURN; Apache-2.0; 2026-06-07

Klotho — Deterministic multiplayer netcode for Godot (.NET)

Engine-agnostic, pure C# deterministic simulation for rollback, lockstep, and
server-authoritative multiplayer. Determinism is built on 32.32 fixed-point math
(FP64) and a seeded RNG: given the same inputs, every peer computes identical
state — so the network sends inputs only and verifies with a hash. Frame-perfect
and cross-platform reproducible.


REQUIRES

- Godot 4.4+ with .NET (mono) support
- A C# (.NET 8) game project


FEATURES

- Netcode: P2P lockstep, rollback + client prediction, server-driven
(authoritative), dedicated server, spectator, late join, reconnect
- Deterministic core: FP64 fixed-point math, vectors / quaternions / matrices,
seeded RNG (Xorshift128+)
- ECS: sparse-set components, zero-GC frame, snapshot + rollback ring buffer
- Deterministic physics: rigid bodies, collisions, CCD, joints, triggers, static BVH
- Deterministic navigation: navmesh + A* + funnel + ORCA avoidance
- Replay: record / playback / seek / variable speed (LZ4 compressed)
- Source generator: serialization + component / command registration
- Godot adapter: Node session driver + view nodes, Resource config assets,
Task-based join helpers, console + rolling-file logging


INSTALL & SETUP

1. Install from the Asset Library (or copy the folder) so that the addon sits at
res://addons/klotho/.

2. Add one line to your game .csproj:

<Import Project="addons/klotho/Klotho.props" />

3. Build the C# solution (dotnet build, or the Godot editor's Build button).
- NuGet deps (Newtonsoft.Json, K4os.Compression.LZ4, LiteNetLib) restore
automatically via Klotho.props.

4. (Optional) Project > Project Settings > Plugins: enable "Klotho" for the
DataAsset JSON -> bytes editor tool. Build the project once before enabling.


DEDICATED SERVER (optional)

The server is a plain .NET 8 console app with no Godot dependency, running the
same core. In a separate server .csproj add:

<Import Project="addons/klotho/Klotho.Server.props" />


LINKS

- Source & docs: https://github.com/xpTURN/Klotho
- Quick start (Godot): Docs/QuickStart.Godot.md
- Install guide (Godot): Docs/Installation.Godot.md