jevwire

# jevwire

**Jev** is TypeSafe AI's [System One](https://docs.typesafe.ai/concepts/system-one) model: a fast,
calibrated classifier. You give it a state and a map of typed questions — yes/no, pick-one,
rate-on-a-rubric — and it answers every one in parallel with a probability over the answer space
*you* defined. It never generates text, so the answer is always inside your schema.

**jevwire** wires it into a harness. The repository is
[Brainwires/jevwire](https://github.com/Brainwires/jevwire); the npm package is still published as
`jevwire` and the Claude Code plugin is `jev`.

It is three things:

- **7 MCP tools** — `jev_rank`, `jev_pick`, `jev_verify`, `jev_evaluate`, `jev_gate_action`, `jev_next_step`,
  `jev_list_models`.
- **An embeddable library** — `JevDecisionModel` plus a pure `run*` function per tool, so mandatory
  checks can live in your harness instead of in a tool an agent may decline to call.
- **A Claude Code plugin** — hooks that put judgments at the harness boundaries: before a tool
  call, after a fetched result, before the turn ends. Everything they decide is addressed to Claude,
  not to you: a note about a call that already ran, or a single `deny` Claude can answer. As of
  0.3.0 they never prompt you.

It is **not** for generation, arithmetic, counting, date comparison, or multi-hop reasoning. It
answers bounded questions over text you hand it. Anything numeric or ordered should be extracted as
a choice over enumerated options and compared in code.

Release 0.4.0 has been exercised against the live TypeSafe API on **2026-09-18**. Every latency,
token count and cost figure quoted in this README comes from that run or the 0.3.0 one it is compared
against.

## Install

Node >= 20 for all three routes.

### Claude Code plugin

```
/plugin marketplac