vibe-coding-starter-pack-3d-multiplayer: Instructions file for Claude Code

Vibe Coding Starter Pack: 3D Multiplayer

3D multiplayer game starter kit — React 19 + Three.js + SpacetimeDB 2.0.1 (Rust backend).

Architecture

• server/ — SpacetimeDB Rust module (compiled to WASM, runs on SpacetimeDB server)
• client/ — Vite + React + React Three Fiber frontend

Data flow: client input (20Hz) → WebSocket → updatePlayerInput reducer → server updates PlayerData table → subscription pushes changes → all clients render.

Key Files

Server (Rust)

• server/src/lib.rs — Tables (PlayerData, LoggedOutPlayerData, GameTickSchedule), reducers (register_player, update_player_input), lifecycle handlers (init, identity_connected, identity_disconnected)
• server/src/player_logic.rs — calculate_new_position(), update_input_state(), update_players_logic() (game tick placeholder)
• server/src/common.rs — Shared types: Vector3, InputState. Constants: PLAYER_SPEED = 7.5, SPRINT_MULTIPLIER = 1.8

Client (TypeScript/React)

• client/src/App.tsx — SpacetimeDB connection, input handling (keyboard/mouse), game loop (requestAnimationFrame throttled to 20Hz), state management
• client/src/components/Player.tsx — FBX model loading, animation system, client-side prediction, camera follow/orbital modes, nametags
• client/src/components/GameScene.tsx — R3F Canvas, sky, lighting, shadows, ground plane, player rendering
• client/src/components/DebugPanel.tsx — Collapsible dev panel: status, player list, controls reference, model checker
• client/src/components/PlayerUI.tsx — HUD overlay: health/mana bars, damage flash
• client/src/components/JoinGameDialog.tsx — Username + class selection modal
• client/src/simulation.ts — Bot load-testing tool (spawns N SpacetimeDB clients)
• client/src/generated/ — Auto-generated bindings (do NOT edit manually)

SpacetimeDB v2 API Patterns

Server (Rust)

// Table macro uses `accessor`, not `name`
#[spacetimedb::table(name = "player", public)]
#[derive(Clone, Debug)]
pub struct PlayerData {
    #[primary_key]
    pub identity: Identity,
    // ...
}

// ctx.sender() is a METHOD in v2 (not a field)
// ctx.timestamp is still a FIELD (not a method)
let caller = ctx.sender();
let time = ctx.timestamp;