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.
npx agentmods add instructions/mcdxai/minecraft-dev-mcp/agents-mdgit clone --depth 1 https://github.com/MCDxAI/minecraft-dev-mcpWhat 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 | $0.01145 | $0.01145 |
| Opus 5 | $0.00573 | $0.00573 |
| Sonnet 5 | $0.00229 | $0.00229 |
| Haiku 4.5 | $0.00114 | $0.00114 |
Grade A, and why
minecraft-dev-mcp AGENTS.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 3d 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 — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENT HANDBOOK – Minecraft Dev MCP
Reference for AI/agent operators working in this repo. Grounded in CLAUDE.md and current project state.
Project Snapshot
- MCP server that lets agents decompile, remap, search, and analyze Minecraft (1.14+; obfuscated through 1.21.11).
- Phase 1 & 2 complete (core + advanced tools); 29 integration tests green as of 2025-12-06.
- Phase 3 focus: third-party mod analysis; missing piece is decompiling remapped mod JARs (see TODO).
- Stack: Node 18+/ESM-only (
"type": "module"), TS 5.7, Java 17+ (21+ for newest MC), better-sqlite3, VineFlower decompiler, tiny-remapper.
What Agents Should Prioritize
- Keep ESM intact: no CommonJS, ensure
.jsextensions on local imports after build. - Registry extraction must use the obfuscated server JAR with version-aware bundler flag; never the client JAR.
- Yarn remapping is two-step: official → intermediary → yarn; do not collapse into one pass.
- Respect cache layout in platform app data (
jars/,mappings/,remapped/,decompiled/{version}/{mapping}/,registry/{version}/,resources/,search-index/,cache.db). - VineFlower drops
libraries/,versions/,logs/in CWD during runs; temporary and gitignored.
Architecture Wayfinder (src/)
services/:version-manager(JARs),mapping-service(Yarn/Mojmap/Intermediary),remap-service(two-step Yarn),decompile-service(VineFlower),registry-service(data generator on server JAR),source-service(pipeline orchestrator).java/:tiny-remapper,vineflower,mc-data-gen(bundler vs legacy invocation),java-process(exec wrapper).downloaders/: Mojang assets/mappings, Yarn mappings, Java tool JARs.cache/: cache manager + SQLite metadata DB.utils/paths.ts: resolves OS-specific cache roots.
Available MCP Tools (for LLM surfaces)
- Phase 1 core:
get_minecraft_source,decompile_minecraft_version,list_minecraft_versions,get_registry_data. - Phase 2 analysis:
remap_mod_jar,find_mapping,search_minecraft_code,compare_versions,analyze_mixin,validate_access_widener,validate_access_transformer,compare_versions_detailed,index_minecraft_version,search_indexed,get_documentation,search_documentation. - Phase 3:
analyze_mod_jar(metadata/mixins/bytecode scan). Missing: decompile remapped mod JARs.
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.
- 3d ago First seen · 54 lines · 1,145 tokens per session scan A a6a3c32cecd5
minecraft-dev-mcp AGENTS.md is an instructions file published in the GitHub repository MCDxAI/minecraft-dev-mcp (35 stars, last pushed 27d ago), licensed MIT. It adds 1,145 tokens to every session, about $0.0057 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.
Other instructions, from other repositories
better-godot-mcp CLAUDE.md
Instructions for n24q02m/better-godot-mcp, covering claude.md - better-godot-mcp, commands, setup, lint & type check and fix.
better-godot-mcp AGENTS.md
Instructions for n24q02m/better-godot-mcp, covering agents.md - better-godot-mcp, build / lint / test commands, run a single test file, run a single test by name and mise shortcuts.
ai-rotom CLAUDE.md
Instructions for nonz250/ai-rotom, covering ai-rotom, 基本思想, 技術スタック, 開発コマンド and リポジトリ構成.
minecraft-java-fabric-claude-plugin CLAUDE.md
Instructions for chapmanjw/minecraft-java-fabric-claude-plugin, covering claude.md, commands, architecture, the three-tier, no-trivial model (0.9.0) and terrain core (tools/terrain/).
ThreeBrowserStudio AGENTS.md
Instructions for SamG-Coder/ThreeBrowserStudio: ThreeBrowser Studio is an LLM-first authoring runtime. MCP is the editor and the native WebGPU window is the shared live viewport. Preserve that product shape: do not grow a conventional inspector-heavy browser UI.
mcp-steam CLAUDE.md
Claude Code instructions for obrien-matthew/mcp-steam, a project described as: MCP server for Steam -- gaming library, achievements, stats, and store discovery for Claude and other LLM agents.