Overview

Quilkin is a UDP proxy, specifically designed for use with multiplayer dedicated game servers.

What is Quilkin?

Quilkin on open source is a non-transparent UDP proxy specifically designed for use with large scale multiplayer dedicated game servers deployments, to ensure security, access control, telemetry data, metrics and more.

It is designed to be used behind game clients as well as in front of dedicated game servers.

Quilkin's aim is to pull the above functionality out of bespoke, monolithic dedicated game servers and clients, and provide standard, composable modules that can be reused across a wide set of multiplayer games, so that game developers can instead focus on their game specific aspects of building a multiplayer game.

Why use Quilkin?

Some of Quilkin's advantages:

• Lower development and operational costs for securing, monitoring and making reliable multiplayer game servers and their communications.
• Provide entry-point redundancy for your game clients to connect to - making it much harder to take down your game servers.
• Multiple integration patterns, allowing you to choose the level of integration that makes sense for your architecture.
• Remove non-game specific computation out of your game server's processing loop - and save that precious CPU for your game simulation!

Major Features

Quilkin incorporates these abilities:

• Non-transparent proxying of UDP data, the internal state of your game architecture is not visible to bad actors.
• Out of the box metrics for UDP packet information.
• Composable tools for access control and security.
• Able to be utilised as a standalone binary, with no client/server changes required or as a Rust library depending on how deep an integration you wish for your system.
• Integration with Game Server hosting platforms such as Agones.
• Can be integrated with C/C++ code bases via FFI.

Quilkin Architecture

Quilkin is broken up into three main components

• Providers are data collection sources to enable quilkin to see its environment.
• Services provide the the core business logic for handling UDP traffic as well meta control-plane functionality.
• Configuration controls what a given instance is able to do, what services it runs, and providers it pulls from.

architecture-beta
    group services(cloud)[Services]
    group public(cloud)[Public Client API] in services
    group private(cloud)[Internal Service API] in services
    group providers(cloud)[Providers]
    group config(cloud)[Configuration]

    service udp(internet)[UDP] in public
    service qcmp(internet)[QCMP UDP] in public
    junction sp1 in services
    junction sp3 in services

    service metrics(internet)[Administration] in private
    service grpc(internet)[gRPC] in private
    service http(internet)[HTTP] in private
    junction sp2 in services
    junction sp4 in services

    service k8s(cloud)[Kubernetes] in providers
    service fs(disk)[Filesystem] in providers
    service xds(cloud)[gRPC] in providers
    service cli(disk)[CLI] in providers
    junction p1 in providers
    junction p2 in providers

    service filters(disk)[Filterchains] in config
    service endpoints(disk)[Endpoints] in config
    service gameservers(server)[Game Servers] in config
    service mmdb(server)[Maxmind DB] in config
    junction c1 in config
    junction c2 in config

    service quilkin(server)[Quilkin]

    sp1:T -- R:udp
    sp1:L -- R:qcmp
    sp1:B -- T:sp3

    sp2:T -- B:sp3
    sp2:L -- R:grpc
    sp2:B -- R:metrics
    sp4:L -- R:metrics
    sp4:B -- R:http
    sp4:T -- B:sp2
    sp3:R -- L:quilkin

    quilkin:R -- L:p1
    p1:T -- L:fs
    p1:R -- L:k8s
    p1:B -- T:p2
    p2:R -- L:xds
    p2:B -- L:cli
    c2:L -- R:mmdb
    c2:R -- L:gameservers
    c1:T -- B:c2
    c1:R -- L:endpoints
    c1:L -- R:filters
    c1:B -- T:quilkin

What Next?

Quilkin provides a variety of different services depending on your use-case. The primary service is proxy, which runs a reverse UDP proxy. To see a basic usage of the command-line interface run through the netcat with Quilkin quickstart.

For more advanced usage, you might also be interested in:

• Checking out the installation guide
• Having a look at the example projects for basic configuration examples.
• Checking out the example deployment architecture for deploying quilkin for your game network.

$ quilkin --help
{"timestamp":"2025-10-01T14:54:43.161671Z","level":"INFO","fields":{"message":"Starting Quilkin","version":"0.10.0-dev","commit":"b371d7fac285879ea33bcd409bd027f42827c4fc"},"target":"quilkin::cli","filename":"src/cli.rs","threadId":"ThreadId(1)"}
{"timestamp":"2025-10-01T14:54:43.161829Z","level":"ERROR","fields":{"message":"fatal error","error":"no service, provider, or command specified, shutting down"},"target":"quilkin","filename":"src/main.rs","threadId":"ThreadId(1)"}