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 skills add chapmanjw/minecraft-java-fabric-claude-plugin --skill setup-connectgit clone --depth 1 https://github.com/chapmanjw/minecraft-java-fabric-claude-pluginWrote 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/skills/chapmanjw/minecraft-java-fabric-claude-plugin/setup-connect)<a href="https://agentmods.dev/skills/chapmanjw/minecraft-java-fabric-claude-plugin/setup-connect"><img src="https://agentmods.dev/badge/skills/chapmanjw/minecraft-java-fabric-claude-plugin/setup-connect/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/skills/chapmanjw/minecraft-java-fabric-claude-plugin/setup-connect"><img src="https://agentmods.dev/badge/skills/chapmanjw/minecraft-java-fabric-claude-plugin/setup-connect.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 | $0.00074 | $0.02286 |
| Opus 5.5 | $0.00030 | $0.00914 |
| Sonnet 5.5 | $0.00015 | $0.00457 |
| Haiku 4.5 | $0.00007 | $0.00229 |
Grade B, and why
setup-connect scanned grade B with 1 finding 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.
Reads MCP configurationmediumAgent snooping
mcp.json carries server URLs and auth tokens; reading it lets a mod discover and abuse other integrations.
write `.mcp.json` with the token pulled from an environment variable instead of How it starts
The opening of the file, as written. The whole thing — 221 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Connect Claude to the Minecraft world (Step 4 of 4)
This is the final phase of the Minecraft Java MCP setup. It assumes Phase 3
(setup-server) is done: the mod is running and /healthz returns OK.
Before starting, get from the user:
- The
/mcpURL —http://<host>:<port>/mcp, e.g.http://localhost:8765/mcp. Uselocalhostonly if Claude runs on the same machine as Minecraft; otherwise the host's LAN IP or hostname. If the mod uses TLS, the scheme ishttps. - The bearer token — only for a dedicated/remote setup (the token captured in Phase 3). A single-player localhost setup has no token.
Name the server
minecraft-java. The builder agent and skills in this plugin expect MCP tools under that name (mcp__minecraft-java__*). Use exactlyminecraft-javaas the server name below.
One or two servers? (world + inspection)
The mod exposes two MCP servers from one jar. Connect whichever match the user's setup:
minecraft-java— the world server (read/write the world:level_*,block_*,entity_*, …). Runs wherever a Minecraft server runs — a dedicated server, or single-player's integrated server. Defaulthttp://localhost:8765/mcp. Always connect this.minecraft-java-client— the inspection server: SEE the world the way a player does.view_capturereturns the player's actual first-person frame as a PNG;sense_crosshair/sense_raycast/sense_entities/sense_screen/client_statusread client-side perception. Runs inside a real, rendered client. Defaulthttp://localhost:8766/mcp. Connect this only when a real client is running (see patterns below). Name it exactlyminecraft-java-client—exec-inspectlooks formcp__minecraft-java-client__*.
The three supported patterns:
| Pattern | What's running | Connect |
|---|---|---|
| Server-only | a dedicated/headless server | minecraft-java only |
| Client-only | a single-player client (its integrated server runs too) | both — one process serves 8765 (world) + 8766 (inspection) |
| Server + client combo | a dedicated server + a separate client joined to it | both — minecraft-java on the server host:8765, minecraft-java-client on the client host:8766 |
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 · 221 lines · 74 tokens per session scan B 95d12e62780b
setup-connect is a skill published in the GitHub repository chapmanjw/minecraft-java-fabric-claude-plugin (8 stars, last pushed 1mo ago), licensed MIT. It adds 74 tokens to every session and 2,286 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it B with 1 finding (reads mcp configuration). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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