Java UI for Admin Panels and realtime web apps

This is a pure-Java toolkit for stateful, server-rendered live applications like admin interfaces and internal tools.

No need for writing JavaScript and rely on thousands of transitive npm dependencies. No need for REST endpoints, frameworks like React, frontend build steps and managing client-side state.

• Server-Side-Rendering (SSR) architecture like in Elixir Phoenix LiveView, Blazor Server but for Java.
• Software Engineers: build UIs in plain modern Java with no annotations and implicit control flows; components can be tested in isolation. The Java HTML DSL is linear and composable. That makes it easy for coding LLMs (like Claude or Codex) to generate valid DSL HTML and a component tree.
• At runtime, the AI agent natively understands the application's structure, navigates the UI, and queues up the actions with Human-in-the-loop for approvals.
• This project aims for zero third-party runtime dependencies.

What does the code look like?

import rsp.component.View;
import rsp.component.definitions.InitialStateComponent;
import rsp.jetty.WebServer;

import static rsp.dsl.Html.*;

public final class Counter {
   static void main(final String[] args) {
      final ComponentView<Integer> view = newState -> state ->
              html(
                      body(
                              h1("Current count: " + state),
                              button(on("click", _ -> newState.setState(state + 1)),
                                     text("Increment"))
                      )
              );

      final var server = new WebServer(8080, _ -> new InitialStateComponent<>(0, view));
      server.start();
      server.join();
   }
}

This is a complete runnable interactive web application. For more examples check the examples/README.md.

Getting started

1. Prerequisites

   • Java 25 -- virtual threads, sealed interfaces and pattern matching
   • Maven 3.9

2. Clone the repository

git clone https://github.com/vadimv/server-components.git
cd server-components

3. Build the project

mvn install

4. Run the included admin example

mvn exec:java -pl examples -Dexec.mainClass="rsp.app.posts.CrudApp"

Open http://localhost:8085, click Sign in, and explore the Posts/Comments admin app.

By default, CrudApp uses RegexAgentService, a deterministic regex-based agent stub included in the repository. It is meant for demos and local validation, so you can try the AI workflow without setting up Anthropic, Ollama, or any other LLM backend.

5. Try a few prompts

• open comments
• go to page 2
• open comments and go to page 2 and select all

6. Generate your own admin app

Once you've run the example, open your favorite AI coding assistant in the project root and paste a prompt like this:

Read examples/src/main/java/rsp/app/posts/CrudApp.java. Generate a similar realtime admin tool for managing Employees and Departments. Create mock services and a new EmployeeAdminApp.java using the same routing, composition, and AI-agent integration patterns.

7. Upgrade to a full LLM agent

When you're ready, run CrudApp with -Dai.agent=claude or -Dai.agent=ollama and connect your preferred model backend.

Docs

• Core
• Compositions
• Examples