# OJ

> Rust-native React build tool aimed at agents and CI

**Category:** Next.js  
**Pricing:** open-source  
**URL:** https://github.com/lovablelabs/oj  
**GitHub:** https://github.com/lovablelabs/oj  
**Added:** 2026-09-18

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## The Hook

OJ is a Rust Vite-shaped build tool that optimizes memory and cold start when agents and CI spawn many React builds.

## What's Good

MIT (lovablelabs/oj). Drop-in-minded React toolchain with streaming SSR (`oj dev --ssr` / `oj build --ssr`), Fast Refresh, and a persistent Node plugin host for Vite/Rollup-style plugins. Built where many parallel agent/CI builds make Vite’s memory profile expensive. Intro notes at rapha.land. ★~409.

## The Catch

Vs Vite (default SPA/library toolchain) and Rolldown/Oxc-adjacent Rust tooling: OJ is the agent/CI-memory-oriented React builder, not the ecosystem default yet. Young Lovable Labs surface — verify plugin compatibility before you rip Vite out of a production app.

## Verdict

MIT Rust React builder. Reach for it when parallel agent/CI builds make Vite’s memory cost the bottleneck.