Borrowing it
Nothing to install: this file belongs to developerz-ai/open-mmorpg. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/developerz-ai/open-mmorpg/main/CLAUDE.mdgit clone --depth 1 https://github.com/developerz-ai/open-mmorpgWrote 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.
[](https://agentmods.dev/instructions/developerz-ai/open-mmorpg/claude-md)<a href="https://agentmods.dev/instructions/developerz-ai/open-mmorpg/claude-md"><img src="https://agentmods.dev/badge/instructions/developerz-ai/open-mmorpg/claude-md/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.
<a href="https://agentmods.dev/instructions/developerz-ai/open-mmorpg/claude-md"><img src="https://agentmods.dev/badge/instructions/developerz-ai/open-mmorpg/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.02022 | $0.02022 |
| Opus 5.5 | $0.00809 | $0.00809 |
| Sonnet 5.5 | $0.00404 | $0.00404 |
| Haiku 4.5 | $0.00202 | $0.00202 |
Grade A, and why
open-mmorpg CLAUDE.md 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 14d 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.
How it starts
The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Open-MMORPG
The best open-core MMORPG engine · Rust (server + client) · Bun/SolidJS operator web · original IP · MIT · AI-native. Server-authoritative, horizontally scaled, data-driven, moddable.
Response Rules
- Execute. No preamble, no "I'll start by…", no restating the task.
- Lead with the action or answer. Reasoning after, only if non-obvious.
- Parallel tool calls when independent. Read before speculating.
- Disagree when the user is wrong. State the correction.
- Terse. Fragments OK. Code/commands/paths stay exact.
- End: 1–2 sentence summary max.
Standards — read before non-trivial work
This repo follows developerz-ai gold standards: ../gold-standards-in-ai/docs/. Defaults from there apply unless a doc here overrides. Highest-value: 00-philosophy.md, stack/rust-apis.md, architecture/solid-srp.md, writing-for-agents/.
Binding decisions (do NOT re-litigate)
- Rust everywhere — server, client (Bevy), tooling, MCP. Exception:
apps/webis Bun+SolidJS (standard web product). →docs/initial-idea/03-tech-stack.md - Server-authoritative, always. Client sends intent, never state.
- Ownership writes → YugabyteDB directly, in a transaction. Never via cache/bus. #1 anti-dupe rule. →
docs/architecture/04-data-and-consistency.md - Content is data, core is compiled. Factions/classes/quests change with no recompile. →
docs/architecture/05-ecs-and-scripting.md - Open formats only — glTF / heightmap / zstd. No proprietary tooling.
- Original IP only. Never extract/rip any game asset, name, or table. →
docs/initial-idea/01-legal-and-licensing.md - Horizontal from day 1. Autoscaled shards, no realm caps, no queues.
Architecture
- Core is compiled (
crates/), content is data (content/). If changing a faction needscargo build, the split is wrong. persistenceis the only crate that writes ownership.cache(Dragonfly) has no ownership-write API — the dupe path must not compile.simis deterministic — same inputs → same state (replay, anti-cheat re-sim).ecs-core+content-schemaare pure — types + logic, no I/O.- Wire types live in
crates/protocol— single source of truth server↔client. - Topology: edge →
gateway→shard(s) → cross-shard bus +worldsvc; state in Yugabyte (durable) + Dragonfly (ephemeral). →docs/architecture/02-server-topology.md
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.
- 14d ago First seen · 108 lines · 2,022 tokens per session scan A ee59ca188f9f
open-mmorpg CLAUDE.md is an instructions file published in the GitHub repository developerz-ai/open-mmorpg (11 stars, last pushed 5d ago), licensed MIT. It adds 2,022 tokens to every session, about $0.0081 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 2026-10-02.
Other instructions, from other repositories
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AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
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AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).