OpenUI Forge — Java

Build generative UI apps with a React frontend + Java Spring Boot (WebFlux) backend. The backend forwards OpenAI's SSE stream to the browser via a reactive WebClient and a Flux<String> controller, pairing with openAIAdapter() on the frontend.

Activation Triggers

• "openui java", "openui spring", "openui spring boot backend"
• "generative ui java", "java streaming ui backend", "webflux openui"

Prerequisites

• Node.js >= 22 (24 LTS recommended) + React >= 18.3.1 (19+ recommended) (frontend)
• Java 21 LTS recommended (Spring Boot 4.x requires Java 17+; it builds against Java up to 26)
• Maven 3.9+ (or Gradle 8+)
• Spring Boot 4.0.x (current stable line; 4.1.x is the latest). Boot 3.5.x also works but reached end of OSS support on 2026-06-30.
• OPENAI_API_KEY environment variable set

Quick Start