0558GitHub
Jev Workbench: versioned judgment functions over HTTP and MCP
Define and test a typed Jev judgment in a local UI, then call the same immutable version from a backend or coding agent.
The public server, TypeSafe provider, and versioning documentation were inspected on October 1, 2026. Published configurations are immutable and client grants pin callers to explicit function versions. Uncertain decisions can return needs_review, and the vendor key stays on the local service. The bundled no-key demo uses simulated answers; it is separate from the real Jev provider and is not evidence of live-model accuracy.
molis-ai/jev-workbenchREADME ↗
# Jev Workbench English · [中文](README.zh.md) **Write a judgment once. Call it from everywhere.** Jev Workbench is a local service for building *judgment functions* on top of TypeSafe's Jev — small, versioned decisions like "is this ticket about billing?" or "does this evidence support that claim?". You define one in the browser, try it on real input, and publish it. From then on the **same published version** answers both your backend over HTTP and your coding agents over MCP. The TypeSafe vendor key never leaves this machine. Callers get a scoped client token that is pinned to the function versions you granted. ## Try it in a minute, without a key Node.js 24 and pnpm 11.9.0, from the repository root: ```sh pnpm install --frozen-lockfile pnpm build pnpm demo ``` A browser opens on [127.0.0.1:17430](http://127.0.0.1:17430) with a seeded `ticket_route@1`, four saved cases, and a restricted demo client. Every answer is simulated — no network, no charges — and a banner says so on every screen. Type one of these into the sample input and hit **Run preview**: | Input | Result | |---|---| | `Please refund the duplicate charge.` | `ok`, `department=billing` | | `unclear, needs review` | `needs_review`, `department=null` | | `simulate error` | 502 `UPSTREAM_UNAVAILABLE` | | `simulate timeout` | 504 `UPSTREAM_TIMEOUT` | Or drive it from the shell: ```sh pnpm demo:call # the happy path pnpm demo:call 'unclear, needs review' pnpm demo status # is it running? pnpm demo open # new admin session pnpm demo stop ``` Demo state lives in `~/.jev-workbench-demo` and never touches production data. If you still have a database from an older Chinese demo, delete that directory and run `pnpm demo` again.