MCP adapter

judge-mcp lives in the judge-mcp/ directory of the repository. It is a thin stdio adapter: every tool call runs an already-built cargo-judge binary and returns its --format json output to the MCP client. No state, no cloud, no network beyond that local subprocess. It is not published to a registry, and it is not a requirement of judge.

Build

cd judge-mcp
npm install
npm run build   # produces dist/index.js

It needs Node.js 18 or newer and the cargo-judge binary. JUDGE_BINARY sets the path to the binary; by default cargo-judge must be on PATH. If the binary cannot be started, the affected tool call returns an error explaining how to fix it; the server itself still starts.

Client configuration

{
  "mcpServers": {
    "judge": {
      "command": "node",
      "args": ["/absolute/path/to/judge-mcp/dist/index.js"],
      "env": {
        "JUDGE_BINARY": "/absolute/path/to/cargo-judge"
      }
    }
  }
}

Tools

Tool	Runs
analyze	cargo-judge --format json
health	cargo-judge health --format json [--score]
dupes	cargo-judge dupes --format json [--mode ...]
dead_code	cargo-judge dead-code --format json (needs a --features deep build)
explain_finding	cargo-judge explain-rule <rule-id> --format json
inspect_symbol	cargo-judge explain <item-path> --why-live --format json (needs a --features deep build)
fix_preview	cargo-judge fix-preview <pattern-id> --format json

All tools are read-only; cargo-judge never modifies code. explain_finding explains the rule behind a finding (evidence class, preconditions, exclusions, verdict effect), not the individual occurrence, because the CLI has no per-finding explain command.