Jevx MCP

Run Jev AI typed decisions from any MCP client — Claude, Cursor, Cline, Codex. Give it a state and the questions you branch on, get back a choice, a score or a yes/no, with a calibrated probability on every option.

Jev AI is a zero-shot decision model from TypeSafe: text or JSON in, typed values out — no dataset, fine-tune or retrain when the label set changes. Jevx is an independent playground and API for Jev AI and is not affiliated with TypeSafe AI.

Tools

| Tool | What it does | |---|---| | decide | Send a state and up to 16 typed questions, get back choices, scores and noul values with probabilities | | validate_questions | Check a question's shape locally, free and without an API key, before spending credits on a malformed request | | open_in_jevx | The URL to try or continue a decision in the browser playground |

Install

npx jevx-mcp

Claude Desktop / Claude Code

{
  "mcpServers": {
    "jevx": {
      "command": "npx",
      "args": ["-y", "jevx-mcp"],
      "env": { "JEVX_API_KEY": "sk-..." }
    }
  }
}

Create a key at jevx.org/settings/apikeys. There is no anonymous decisions endpoint — a key is required, same as running the playground signed out.

Cursor / Cline

Point the client at npx -y jevx-mcp (stdio transport) and set JEVX_API_KEY in its environment.

Question shapes

| type | criteria | returns | |---|---|---| | choice | object of option to meaning, two or more options | choice, probabilities, confidence | | score | ordered array, low to high | score, probabilities, confidence | | noul | exactly the keys true and false | value between 0 and 1, where exactly 0.5 means the model declined |

The API answers HTTP 200 with a non-zero code on a refusal (bad key, malformed request); decide and validate_questions both surface that as a normal tool error, not a silent success.

License

MIT