engineering-game-backend-architecture

engineering-game-backend-architecture is a skill for Claude Code from fcsouza/agent-skills. It costs 54 tokens per session (2,687 once invoked), scanned A, original, GPL-3.0.

A guide for designing game back ends, the server-side systems that run multiplayer games. It covers game servers, WebSocket connections for two-way live communication, rooms, timed game loops, and server-authoritative rules.

In plain words
What is it for?
Use it when building multiplayer rooms, WebSocket features, game ticks, or an Elysia-based server that controls gameplay.
Why use it?
It helps structure multiplayer systems so the server manages shared game state and player connections consistently. It also provides guidance for real-time communication and recurring game updates.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the game-dev plugin — 25 skills, 7 commands, 3 agents, 5 hooks, 3 MCP servers shipped together

Good fit Use it when building multiplayer rooms, WebSocket features, game ticks, or an Elysia-based server that controls gameplay.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/fcsouza/agent-skills/game-backend-architecture
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add fcsouza/agent-skills --skill game-backend-architecture
Clone the repo
git clone --depth 1 https://github.com/fcsouza/agent-skills

Made for: Claude Code.

Or install game-dev, the plugin that ships this one along with the rest of its 25 skills, 7 commands, 3 agents, 5 hooks, 3 MCP servers.

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.

agentmods badge for engineering-game-backend-architecture

README.md
[![agentmods](https://agentmods.dev/badge/skills/fcsouza/agent-skills/game-backend-architecture/github.svg)](https://agentmods.dev/skills/fcsouza/agent-skills/game-backend-architecture)
Your own site
<a href="https://agentmods.dev/skills/fcsouza/agent-skills/game-backend-architecture"><img src="https://agentmods.dev/badge/skills/fcsouza/agent-skills/game-backend-architecture/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.

agentmods 80×15 button for engineering-game-backend-architecture

Your own site · 80×15
<a href="https://agentmods.dev/skills/fcsouza/agent-skills/game-backend-architecture"><img src="https://agentmods.dev/badge/skills/fcsouza/agent-skills/game-backend-architecture.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,687 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00054 $0.02687
Opus 5 $0.00027 $0.01344
Sonnet 5 $0.00011 $0.00537
Haiku 4.5 $0.00005 $0.00269

Measured 10d ago against content hash 90ee616da2bd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

engineering-game-backend-architecture scanned grade A with 0 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 10d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (boilerplate/game-loop.ts, boilerplate/room-manager.ts, boilerplate/server.ts, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/game-dev/engineering/game-backend-architecture/SKILL.md · 297 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

  1. 10d ago First seen · 297 lines · 54 tokens per session scan A 90ee616da2bd

Subscribe to this mod's changes

engineering-game-backend-architecture is a skill published in the GitHub repository fcsouza/agent-skills (20 stars, last pushed 2d ago), licensed GPL-3.0. It adds 54 tokens to every session and 2,687 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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