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Chess with Jev

Source for browser chess and Chess960 where code computes each legal move's facts and Jev picks one per turn as a typed Choice.

ProjectproductionMIT (packages/jev), GPL-3.0 (packages/chess)
View on GitHub ↗Live demo ↗

Overview

This repository is the code behind Chess with Jev on chriswijnia.com: browser chess and Chess960 where code works out every legal move's facts and Jev picks one per turn as a single typed Choice over the legal moves.

It has two packages. packages/jev is a small MIT-licensed Jev client that tries Vercel AI Gateway first and TypeSafe directly as fallback, checks answers and reports cost. packages/chess (GPL-3.0, built on chessops) computes move facts, makes Jev's move decision, generates Chess960 positions and scores finished games. Unit tests run without Jev calls. The repository is a mirror of the site's monorepo, so pull requests are applied upstream.

What the decision model decides

TypeQuestionAnswers
ChoiceWhich legal move should be played?legal moves with computed facts

How it works

  1. Compute every legal move's facts with chessops
  2. Send one Choice to Jev via the client
  3. Validate and play the move
  4. Score finished games

Strengths

  • Reusable Jev client with fallback and cost reporting
  • Unit tests without API calls

Caveats

  • Mirror repository; contributions go upstream
  • Chess package is GPL-3.0

Getting started

npm install && npm test && npm run typecheck

At a glance

Type
Project
Status
production
Language
TypeScript
Runtime
browser + Node
Has code
yes
Has tests
yes
License
MIT (packages/jev), GPL-3.0 (packages/chess)

Use cases and integrations

How curated lists describe it

  • Chess and Chess960 in the browser where code works out each legal move's facts and Jev picks one per turn as a single Choice, with its candidates drawn as arrows.

    hellogumbo/awesome-jev

Frequently asked questions

What does Jev decide?

One move per turn from the legal moves.

Can I reuse the client?

Yes, packages/jev is MIT-licensed.

Can I send pull requests?

They are read but applied in the upstream monorepo.

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