Jev Guard

Jev Guard fix-under-watch

Jev Guard runs the test suite in project/ on every edit and asks Jev (TypeSafe's System One model) to judge each change: how much closer to the goal, how risky, how confident. The pane draws those as meters, a history chart and a run log. The goal is to make the tests pass and the verdict go green with a fix Jev trusts.

The loop

1. Edit project/score.js (that's the work). Jev Guard auto-judges on each edit, or step it with "Judge now" / node "$JEV_DSH/toolchain/check.mjs".
2. Watch the meters: toward (progress), trust (Jev's confidence in the exact change), risk (a red flag on a shaky edit). The run log shows PASS/FAIL per test run with what changed.
3. Iterate until node project/test.js prints ALL TESTS PASS and the viewer verdict reads as a passing/green judgment.

Reading Jev

Jev's scores are layered on real test results: the suite is the ground truth, Jev is the overlay. A focused, honest fix — correct logic, nothing special-cased, nothing extra — is what reads as high trust / low risk. A hack that greps the test names or returns constants will pass the tests but Jev's risk meter will go red.

Verifying

• node "$JEV_DSH/toolchain/check.mjs" validates the workspace (goal.json + project/test.js present and runnable).
• node project/test.js is the real check: exit 0 + ALL TESTS PASS is done.
• Watch the viewer verdict flip to a green/god-met judgment, not just the tests passing.

Driving Jev yourself

toolchain/jev.mjs exports a small client. Example (from the workspace) — ask Jev's opinion on an implementation choice:

node --input-type=module -e '
import { evaluate, jev } from "$JEV_DSH/toolchain/jev.mjs";
const res = await evaluate({
  state: "Implement sumTo(5) by looping, vs a closed-form n*(n+1)/2. Which is more likely a correct, maintainable fix for a tiny module?",
  questions: {
    risky: jev.score({0:"safe",1:"risky",2:"reckless"}, "How risky is switching to the closed-form?"),
  },
});
console.log(JSON.stringify(res.answers, null, 2));
'

Without TYPESAFE_API_KEY this uses the deterministic mock; set the key to hit live Jev.