Note

The repository's documentation website: slayhorizon.github.io/godot-tiny-mmo/
Latest research note: Byte-Level Networking Protocol for MMO Scalability

Godot Tiny MMO

Experimental open-source MMORPG framework built with Godot 4.
Inspired by proven MMO systems, this project pushes the boundaries of what can be achieved with Godot in large-scale multiplayer.
It explores scalable multiplayer architecture, efficient byte-packed networking, while staying clear and simple in our learning journey.

• Cross-platform: browser + desktop + mobile
• Unified codebase: Client & multiple servers in one repo
  • Faster iteration, develop in one place, test in one click
  • Separate export presets for clean client/server builds
• "Custom netcode" but stay simple
  • No reliance on Godot’s MultiplayerSynchronizer/Spawner for better control
  • Packed protocol format (efficient PackedByteArray instead of string-based messages) for hot synchronization
  • Entity interpolation, multi-map instances, seamless transitions
• True MMOO architecture
  • Gateway server: authentication & routing
  • Master server: orchestrator, account management & bridge between gateways and world servers
  • World server: host multiple concurrent maps and instances; the place where gameplay actually happens

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See more screenshots:

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Features

See current and planned features:

• Client-Server connection through WebSocketMultiplayerPeer

• Playable on web browser and desktop

• Network architecture (see diagram below)

• Authentication system through gateway server with Login UI

• Account Creation for permanent player accounts

• Server Selection UI to let the player choose between different servers

• QAD Database to save persistent data

• Guest Login option for quick access

• Game version check to ensure client compatibility

• Character Creation

• Basic RPG class system with three initial classes: Knight, Rogue, Wizard

• Weapons at least one usable weapon per class

• Basic combat system

• Entity synchronization for players within the same instance

• Entity interpolation to handle rubber banding

• Instance-based chat for localized communication

• Instance-based maps with traveling between different map instances

  • Three different maps: Overworld, Dungeon Entrance, Dungeon
  • Private instances for solo players or small groups

• Server-side anti-cheat (basic validation for speed hacks, teleport hacks, etc.)

• Server-side NPCs (AI logic processed on the server)

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Getting Started

To run the project, follow these steps:

1. Open the project in Godot 4.4 or 4.5.
2. Go to Debug tab, select "Customizable Run Instance...".
3. Enable Multiple Instances and set the count to 4 or more.
4. Under Feature Tags, ensure you have:
   • Exactly one "gateway-server" tag.
   • Exactly one "master-server" tag.
   • Exactly one "world-server" tag.
   • At least one or more "client" tags.
5. (Optional) Under Launch Arguments:
   • For servers, add --headless to prevent empty windows.
   • For any, add --config=config_file_path.cfg to use non-default config path.
6. Run the project (Press F5).

Setup example (More details in the wiki How to use "Customize Run Instances...":

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Contributing

Feel free to fork the repository and submit a pull request if you have ideas or improvements!
You can also open an Issue to discuss bugs or feature requests.

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Credits

Thanks to everyone who made this project possible:

• Maps designed by @higaslk
• Valuable help and feedback: @Jackiefrost, @d-Cadrius and multiple anonymous contributors
• Also @Anokolisa for allowing us to use its assets for this open source project!

License

Source code under the MIT License.