spring-boot-embabel-chat

Spring Boot Embabel Agent Chat Sample

A real-time AI agent chat using the Embabel Agent Framework and Atmosphere. Embabel agents handle planning, tool calling, and orchestration — Atmosphere streams the agent events (progress, tool calls, streaming texts) to the browser over WebSocket in real time.

How It Works

Agent — ChatAssistantAgent.java

An Embabel @Agent class defines the agent's behavior:

@Agent(name = "chat-assistant",
       description = "A helpful chat assistant that answers user questions")
public class ChatAssistantAgent {

    @Action(description = "Answer the user's question")
    public String answer(String userMessage) {
        return "Answer the following question clearly and concisely: " + userMessage;
    }
}

Server — EmbabelChat.java + AgentRunner.java

A @ManagedService endpoint at /atmosphere/embabel-chat:

1. Client sends a prompt via WebSocket
2. @Message handler delegates to AgentRunner which creates a StreamingSession
3. AgentRunner looks up the chat-assistant agent on the Embabel AgentPlatform
4. Calls agentPlatform.runAgentFrom() with an AtmosphereOutputChannel — agent events stream to the browser

var session = StreamingSessions.start(resource);
var agent = agentPlatform.agents().stream()
        .filter(a -> "chat-assistant".equals(a.getName()))
        .findFirst().orElseThrow();

var agentRequest = new AgentRequest("chat-assistant", channel -> {
    var options = ProcessOptions.DEFAULT.withOutputChannel(channel);
    agentPlatform.runAgentFrom(agent, options, Map.of("userMessage", userMessage));
    return Unit.INSTANCE;
});
Thread.startVirtualThread(() -> ADAPTER.stream(agentRequest, session));

Client — index.html

Same streaming UI as the other AI samples — connects over WebSocket, renders streaming texts and progress events.

Configuration

The Embabel platform auto-configures via Spring AI. Set your LLM API key:

export OPENAI_API_KEY=sk-...
# Or use any OpenAI-compatible provider:
export LLM_BASE_URL=https://generativelanguage.googleapis.com/v1beta/openai
export LLM_API_KEY=AIza...
export LLM_MODEL=gemini-2.5-flash

Build & Run

./mvnw spring-boot:run -pl samples/spring-boot-embabel-chat

Open http://localhost:8082 in your browser.

Project Structure

spring-boot-embabel-chat/
├── pom.xml
└── src/main/
    ├── java/.../embabelchat/
    │   ├── EmbabelChatApplication.java   # Spring Boot entry point
    │   ├── EmbabelChat.java              # @ManagedService endpoint
    │   ├── ChatAssistantAgent.java       # @Agent definition
    │   ├── AgentRunner.java              # AgentPlatform bridge
    │   └── LlmConfig.java               # Configuration
    └── resources/
        ├── application.yml
        └── static/
            ├── index.html
            └── assets/                    # Bundled atmosphere.js client

See Also

• AI / LLM Streaming Guide
• AI chat sample — built-in LLM client
• LangChain4j sample — LangChain4j adapter