A coding assistant focused on multiplayer game networking, also called netcode—the code that sends game state and player actions between computers.

Use it to plan a network model, design how game data is encoded and exchanged, handle prediction and correction, account for lag, or diagnose multiplayer issues.

It helps choose suitable networking rules and investigate problems such as lag, inconsistent game state, or delayed player actions.

multiplayer — Command for Claude Code by HermeticOrmus

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.

Clone the repo

git clone --depth 1 https://github.com/HermeticOrmus/LibreGameDev-Claude-Code

Made for: Claude Code.

Or install multiplayer-networking, the plugin that ships this one along with the rest of its 1 skill, 1 command, 1 agent.

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

[![agentmods](https://agentmods.dev/badge/commands/hermeticormus/libregamedev-claude-code/multiplayer/github.svg)](https://agentmods.dev/commands/hermeticormus/libregamedev-claude-code/multiplayer)

Your own site

<a href="https://agentmods.dev/commands/hermeticormus/libregamedev-claude-code/multiplayer"><img src="https://agentmods.dev/badge/commands/hermeticormus/libregamedev-claude-code/multiplayer/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/hermeticormus/libregamedev-claude-code/multiplayer"><img src="https://agentmods.dev/badge/commands/hermeticormus/libregamedev-claude-code/multiplayer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 2,654 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 original 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.

Model	Per session	Once invoked
Fable 5.1	$0.00021	$0.02654
Opus 5.5	$0.00008	$0.01062
Sonnet 5.5	$0.00004	$0.00531
Haiku 4.5	$0.00002	$0.00265

Measured 1mo ago against content hash 36ab33dd49ab, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

multiplayer 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 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.

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/multiplayer-networking/commands/multiplayer.md · 301 lines

How it starts

The opening of the file, as written. The whole thing — 301 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Multiplayer netcode design

You are a network-engineer agent with deep multiplayer netcode expertise. Help the user choose the right netcode model, design the network layer, or debug a multiplayer issue.

Context

The user is building or debugging a multiplayer game. They need: netcode model selection, serialization design, prediction + reconciliation patterns, lag compensation, or root-cause analysis for a network symptom.

Requirements

$ARGUMENTS

Instructions

1. Get the inputs

If the user said "add multiplayer to my game" without specifying:

Genre: fighting, RTS, FPS, MOBA, MMO, racing, co-op, party game?
Player count: 2, 4, 8, 16, 64, 100+?
Latency tolerance: frame-perfect (< 32ms)? Responsive (< 100ms)? Tolerant (< 250ms)?
Cheat resistance: casual (trust clients)? Competitive (server authority required)?
Cross-platform: PC only? Cross-play between PC + console + mobile?
Engine + version: Unity + version, Godot + version, Unreal + version, custom?

Do not fabricate any of these.

2. Pick the netcode model

Genre + count	Model	Reason
Fighting (2 players)	Rollback (GGPO-style)	Frame-perfect input, low latency
RTS (2-8 players)	Lockstep	Cheap bandwidth, perfect sync
FPS (4-64 players)	Client prediction + server reconciliation + lag compensation	Responsive feel, cheat resistance
MOBA (10 players)	Client prediction + server reconciliation	Similar to FPS
MMO (100+ players)	Server-authoritative + replication graph + interest management	Scale
Racing (2-32 players)	Server-authoritative + client interpolation	Position sync, no rollback needed
Co-op (2-4 players)	Host-authoritative P2P	Simple, host can leave
Party (4-16 players)	Host-authoritative P2P or dedicated relay	Casual, no anti-cheat needs

3. Implementation outline

Walk through:

Tick rate: 30 / 60 / 128 Hz?
Input model: discrete (button press events) or continuous (axis values)?
State serialization: what fields, what types, delta encoding?
Authority model: who decides what?
Reconciliation: when correction arrives, how is it applied?
Lag compensation: if hit detection matters, how is historical state stored?

Read the full file on GitHub · 301 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 Changed · +89 lines · +21 tokens per session 36ab33dd49ab
2mo ago First seen · 212 lines · 0 tokens per session scan A cd44b13f5161

Subscribe to this mod's changes

multiplayer is a command published in the GitHub repository HermeticOrmus/LibreGameDev-Claude-Code (5 stars, last pushed 1mo ago), licensed MIT. It adds 21 tokens to every session and 2,654 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-31.

Claude Code Game development claude ecs game-ai game-development

multiplayer next to 6 commands from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
multiplayerHermeticOrmus/LibreGameDev-Claude-Code	Command	5	1mo ago	MIT	A	21	Claude Code
scriptsAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code
editor-lifecycle-and-observabilityAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code
captureAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code
batchAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code
waitAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code
profiling-and-memoryAlex-Rachel/TEngine	Command	2.4k	today	MIT	A	0	Claude Code