A technical guide for a starter project that builds 3D multiplayer web games. It documents a Rust backend, a React and TypeScript frontend, and SpacetimeDB for shared game data and communication.

Use it when working on the starter project's game loop, rendering, player controls, data subscriptions, or backend game logic.

It gives an agent the project's architecture, setup details, and development patterns to follow.

techguide — Cursor rule for Cursor by Glavin001/vibe-land-old

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo

git clone --depth 1 https://github.com/Glavin001/vibe-land-old

agentmods

npx agentmods add rules/glavin001/vibe-land-old/techguide

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

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<a href="https://agentmods.dev/rules/glavin001/vibe-land-old/techguide"><img src="https://agentmods.dev/badge/rules/glavin001/vibe-land-old/techguide/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

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Per session 4,512 This file is loaded in full into every session.

When invoked 4,512 The same file — it is already loaded in full.

Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 100% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

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Model	Per session	Once invoked
Fable 5.1	$0.04512	$0.04512
Opus 5.5	$0.01805	$0.01805
Sonnet 5.5	$0.00902	$0.00902
Haiku 4.5	$0.00451	$0.00451

Measured 1mo ago against content hash d7d3e54695e0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

techguide scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

* Install: `curl https://sh.rustup.rs -sSf | sh`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

* Install: `curl https://sh.rustup.rs -sSf | sh`

Origin

This is a copy

100% identical to techguide — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.cursor/rules/techguide.mdc · 302 lines

How it starts

The opening of the file, as written. The whole thing — 302 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vibe Coding Starter Pack: 3D Multiplayer - Technical Guide

This document describes the architecture, setup, workflow, and key development patterns for the Vibe Coding Starter Pack 3D Multiplayer project. SpacetimeDB v2.0.1 is used throughout.

1. Project Overview

Goal: Provide a foundation for building 3D multiplayer web games using SpacetimeDB as the backend.
Backend: SpacetimeDB module written in Rust (server/). Handles game logic, state management, and data persistence. Compiled to WASM.
Frontend: Client application built with Vite, React 19, TypeScript, and React Three Fiber (client/). Connects to SpacetimeDB via WebSocket, subscribes to data, calls reducers, and renders the game state.

2. Game Architecture

The starter pack uses a modular, component-based architecture with the following core systems:

Core Game Loop: Managed in client/src/App.tsx, which initializes all components and runs the input send cycle at 20Hz
Rendering System: Handled by Three.js via React Three Fiber with scene setup in client/src/components/GameScene.tsx
Character System: Player controls, FBX model loading, animations, and client-side prediction in client/src/components/Player.tsx
UI System: HUD elements and feedback in client/src/components/PlayerUI.tsx and client/src/components/DebugPanel.tsx
Multiplayer System: Client-server communication in client/src/App.tsx and server-side code in server/src/ directory
Load Testing: Bot simulation in client/src/simulation.ts for stress-testing with configurable bot count

3. Core SpacetimeDB v2 Concepts

Tables: Relational data storage defined as Rust structs with #[spacetimedb::table]. Key tables include player and logged_out_player. Tables must be marked public for client access. The name = "..." attribute defines the SQL table name; the accessor = "..." attribute defines the Rust accessor name used in ctx.db. Table names in client SQL subscriptions are case-sensitive (e.g., name = "player" requires SELECT * FROM player).
Reducers: Atomic, transactional Rust functions (#[spacetimedb::reducer]) that modify table state. Triggered by client calls or internal events. Key reducers: register_player, update_player_input, lifecycle reducers (identity_connected, identity_disconnected).
Subscriptions: Clients subscribe to SQL queries (e.g., SELECT * FROM player) using conn.subscriptionBuilder(). IMPORTANT: Register .onApplied() and .onError() callbacks before calling .subscribe() — in v2, backfill data fires immediately on subscribe.
Generated Bindings: The spacetime generate command creates TypeScript code (client/src/generated/) based on the Rust module's schema, providing type-safe access to tables, reducers, and types on the client. Types are in generated/types.ts.
Identity: Represents a unique, authenticated user. In v2 reducers: ctx.sender() (method call with parentheses). On client: conn.identity. Used as the primary key for player-related tables.

Read the full file on GitHub · 302 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 302 lines · 4,512 tokens per session scan C d7d3e54695e0

Subscribe to this mod's changes

techguide is a cursor rule published in the GitHub repository Glavin001/vibe-land-old (3 stars, last pushed 6mo ago), licensed MIT. It adds 4,512 tokens to every session, about $0.0180 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). It is 100% identical to techguide, differing in 8 lines, and is treated as a copy.

Game development

techguide