decisions-judge-mcp

A small MCP server exposing a single judge tool: send natural language plus JSON application state, get back typed judgments — yes/no probability (noul), choice among options, or score on ordered levels — in one fast request, with model/usage metadata. Failures return a {fallback: true, error} envelope instead of blocking, so it is safe to compose into agent workflows.

Currently backed by the TypeSafe System One model (Jev) via @typesafe-ai/sdk. The provider-neutral judge primitive maps naturally onto related decision APIs such as OpenRouter alphadecisions.

Flagship consumer: clouatre-labs/agentic-coder-skill.

Tool: judge

Input:

• state — JSON object or string (application state)

• questions — map of name → {type: "noul"|"choice"|"score", instructions, criteria?}

  • noul: criteria omitted; answer is a yes/no probability

  • choice: criteria is {option: description|null}

  • score: criteria is an ordered array of level descriptions

• timeout_ms — optional, max 60000

Output: {answers, model, usage} on success, {fallback: true, error} on failure.

Related MCP server: jev-mcp

Install

Requires Node >= 20 and TYPESAFE_API_KEY in the environment (TYPESAFE_AI_TOKEN is accepted as a legacy fallback).

# recommended: run on demand via npx (no global install)
npx -y decisions-judge-mcp

# or pin a version for supply-chain reproducibility
npx -y decisions-judge-mcp@1.0.2

# or install globally
npm i -g decisions-judge-mcp

Tip: unpinned npx -y decisions-judge-mcp always runs the latest published version. For deterministic, supply-chain-hardened setups, pin an exact version or install globally and update deliberately.

MCP client configuration

All examples use npx -y, the standard pattern for Node-based MCP servers (see Context7 and Brave Search). Swap in decisions-judge-mcp@<version> in the args if you prefer pinning.

pi (~/.config/pi/mcp.json or equivalent):

{
  "mcpServers": {
    "decisions-judge": {
      "command": "npx",
      "args": ["-y", "decisions-judge-mcp"],
      "env": { "TYPESAFE_API_KEY": "..." }
    }
  }
}

Claude Code — one command:

claude mcp add --scope user decisions-judge \
  --env TYPESAFE_API_KEY=... -- npx -y decisions-judge-mcp

Or in ~/.claude.json:

{
  "mcpServers": {
    "decisions-judge": {
      "command": "npx",
      "args": ["-y", "decisions-judge-mcp"],
      "env": { "TYPESAFE_API_KEY": "..." }
    }
  }
}

goose (~/.config/goose/config.yaml):

mcp:
  servers:
    decisions-judge:
      command: npx
      args:
        - -y
        - decisions-judge-mcp
      env:
        TYPESAFE_API_KEY: "..."

Windows note: some clients need cmd /c npx on Windows:

{
  "command": "cmd",
  "args": ["/c", "npx", "-y", "decisions-judge-mcp"]
}

Development

npm ci
node --check server.mjs
node scripts/smoke.mjs         # MCP stdio initialize handshake
node bin/decisions-judge-mcp   # stdio server; needs TYPESAFE_API_KEY to answer

License

Apache-2.0 — see LICENSE.