Room Plugins

Room plugins are where your game rules live.

Use plugins when you want custom room behavior such as:

• movement simulation
• combat resolution
• inventory updates
• game-specific events/messages

Two plugin modes

1) Rust plugin (compile-time)

Best when:

• you control server build/deploy
• you want native Rust performance and direct code integration

2) WASM plugin (runtime-loaded)

Best when:

• you want to ship new room logic without rebuilding data-plane image
• you want a stable host/plugin boundary

Configured through NEXIS_WASM_ROOM_PLUGINS.

Rust plugin authors can use the helper crate published on crates.io:

[dependencies]
nexis_wasm_plugin = "0.1.5"
serde_json = "1"

Message contract inside plugins

Room message payload in plugin on_message:

{
  "type": "player.move",
  "data": { "x": 10, "y": 4, "seq": 18 }
}

This means your plugin can define custom gameplay types freely (player.move, shoot, chat.send, etc.).

Minimal plugin logic pattern

1. Read input.type.
2. Parse input.data.
3. Compute next authoritative state.
4. Return updated state and optional emitted event.

References

• Tutorial: Create a Custom Room Plugin
• Example code: examples/wasm-plugins/counter_rust_plugin

Plugin Message Path

Typed Plugin I/O

function onMessage(input: PluginInput): PluginOutput {
  if (input.type === 'inc') {
    return {
      state: { counter: 1 },
      event: { type: 'counter.updated', data: { counter: 1 } },
    };
  }

  return { state: {} };
}