A research-stage proposal-review contract in TypeScript: an LLM proposes one action, Jev answers four pinned questions, and code produces evidence the host can consider.
Four fixed questions: addresses_task, evidence_supports, unrelated_changes, and needs_clarification, each judged against the same state.
Nothing applies a patch, executes proposed code, or grants permission; the host validates paths and diffs and decides independently.
The offline checks need no API key: pnpm install, typecheck, test, and check:secrets all run without one.
Adds an offline SHA-256 receipt binding adapter, a benchmark-only verdict helper, and synthetic routing comparisons.
The model constant stays jev-1.13.0, pinned for reproducibility rather than as proof of calibration.
Quickstart
bash
git clone https://github.com/TypeSafeAI/jev-harness.git
cd jev-harness
pnpm install --frozen-lockfile
pnpm typecheck
pnpm test
pnpm check:secrets
Watch out
MIT-licensed, but a research-stage community repository independent of the official TypeSafe AI team. Needs Node 22+ and pnpm; source-only and not published, with the proposal validator, transport, and execution runner still pending.
Pi extension that supervises a coding agent with Jev judgments: it holds risky tool calls, checks writes against project Markdown rules, and feeds most issues back to the agent as a steer instead of interrupting you. The conscience is beta and off by default.
A security hook for coding agents that asks Jev three typed questions before every tool call and scans tool results for prompt injection, with adapters for Claude Code, Codex, Copilot CLI, Gemini CLI, Cursor, pi, OpenCode and ACP.
A Pi extension that turns constraints stated in conversation into a scoped, replayable policy and checks every side-effecting tool call against it before it runs, with Jev only classifying how each message changes the policy.
cua open sourced a 706k param model that fills a whole form in one 50ms pass
the llm agent doing the same form took 23 turns and 39.6 seconds
the specialists are going to eat the generalists from the bottom
Cua
@trycua
1/ Introducing CUA-S1: a family of System One Models, small, specialized, and built for computer use.
Today we're open-sourcing CUA-S1-FORMS, the first in the family: github.com/trycua/cua
I've been using Jev by @typesafeai Here's the six things i've tried and am confident I'll still use Jev for 60 days from now.
There's many more experiments, ideas, and things I think I will use it for. It's a big deal (more on why in next post).
But I am only sharing thingsShow more
This made me rethink where AI actually fits into security engineering.
For purely engineering work, forget about ChatGPT or Claude.
TypeSafe AI just released Jev, and I think it’s going to change how we build AI into security workflows.
Instead of asking an LLM to “investigateShow more
TypeSafe AI
@typesafeai
we are officially out of stealth! join the frontier and get access to Jev on our website (link on profile)