judgment

Rust crate and jud CLI where a decision is a .jud rubric file answered by a System One model, type-checked and testable without a key.

Pluginbeta

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Overview

judgment provides typed, calibrated judgments from TypeSafe System One models and any server that speaks the same wire format, as a Rust crate and the jud command line. A decision is written as a .jud rubric file or as Rust types: the questions to ask about a JSON state and the policy that turns answers into verdicts. You pipe a state in and get one verdict per question out, such as actionable yes with probability 0.97, desk billing with confidence 0.87, and tone at level angry.

The crate makes four things properties of the types: an answer can only be read as what was asked, a probability is a probability, a transient failure does not fail the decision, and the decision is testable without a key through recorded answers. A record and tune loop lets thresholds be tested against labelled cases and tuned from recorded answers. TYPESAFE_BASE_URL points it at other compatible servers. It installs via mise, Homebrew, cargo or Docker, and ships a Claude Code plugin. It is not affiliated with TypeSafe.

What the decision model decides

Type	Question	Answers
Yes / no	Is this event actionable?	—
Choice	Which desk should handle this event?	—
Score	What is the tone of this message?	—

How it works

Write a .jud rubric with questions and thresholds
Pipe a JSON state into jud
Model answers; types verify each answer before it is read
Policy turns answers into verdicts
Record answers and tune thresholds against labelled cases

Strengths

Type system prevents misreading answers
Testable offline with recorded answers
Works with any compatible server
Multiple install routes with checksums and attestations

Caveats

Example recordings are scripted, not model output
Rust-centric
Unofficial

Getting started

brew install chussenot/tap/jud, then cat event.json | jud triage.jud (set TYPESAFE_API_KEY for live answers).

At a glance

Type: Plugin
Status: beta
Language: Rust
Runtime: crate, CLI, Docker, Claude Code plugin
Has code: yes
Has tests: yes

Use cases and integrations

Infra / SDKs / Integrations537

Claude Code373

How curated lists describe it

Typed, calibrated judgments from System One models: a decision written as a…
wh000wh000/awesome-jev-live
Typed, calibrated judgments from System One models: a decision written as a .jud file or as Rust types, answered by a model, verified before it is read, testable with no key. Rust crate, jud CLI (cat event.json | jud triage.jud), Claude Code plugin. Not affiliated with TypeSafe AI.
hellogumbo/awesome-jev

Frequently asked questions

What is a .jud file?

A rubric: the questions to ask about a JSON state and the policy that turns answers into verdicts.

Can I test without a key?

Yes, recorded answers replay with no key or network.

Does it only work with TypeSafe?

No, any server speaking the same wire format works via TYPESAFE_BASE_URL.

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