@AcpAgent(name = "chatbot-agent", version = "1.0")
public class ChatbotAgent {

    private static final Model MODEL = Model.CLAUDE_SONNET_4_6;

    // fromEnv() reads ANTHROPIC_API_KEY
    private final AnthropicClient anthropic = AnthropicOkHttpClient.fromEnv();

    // Per-session conversation history
    private final Map<String, List<MessageParam>> history = new ConcurrentHashMap<>();

    @Initialize
    public InitializeResponse initialize(InitializeRequest request) {
        return InitializeResponse.ok();
    }

    @NewSession
    public NewSessionResponse newSession(NewSessionRequest request) {
        return new NewSessionResponse(UUID.randomUUID().toString(), null, null);
    }

    @Prompt
    public PromptResponse prompt(PromptRequest request, SyncPromptContext context) {
        String userText = request.text();
        List<MessageParam> turns = history.computeIfAbsent(
            context.getSessionId(), k -> new ArrayList<>());

        MessageCreateParams.Builder params = MessageCreateParams.builder()
            .model(MODEL)
            .maxTokens(1024)
            .system("You are a concise, friendly assistant running as an ACP agent inside an IDE.");
        turns.forEach(params::addMessage);
        params.addUserMessage(userText);

        // Stream Claude's answer back, chunk by chunk
        StringBuilder full = new StringBuilder();
        try (StreamResponse<RawMessageStreamEvent> stream =
                 anthropic.messages().createStreaming(params.build())) {
            stream.stream().forEach(event -> event.contentBlockDelta()
                .flatMap(deltaEvent -> deltaEvent.delta().text())
                .ifPresent(textDelta -> {
                    full.append(textDelta.text());
                    context.sendMessage(textDelta.text());
                }));
        }

        // Remember this turn for the next prompt in the session
        turns.add(MessageParam.builder()
            .role(MessageParam.Role.USER).content(userText).build());
        turns.add(MessageParam.builder()
            .role(MessageParam.Role.ASSISTANT).content(full.toString()).build());

        return PromptResponse.endTurn();
    }
}

AcpAgentSupport.create(new ChatbotAgent())
    .transport(new StdioAcpAgentTransport())
    .build()
    .run();

Message msg = anthropic.messages().create(
    MessageCreateParams.builder()
        .model(Model.CLAUDE_SONNET_4_6)
        .maxTokens(1024)
        .addUserMessage(request.text())
        .build());
String answer = msg.content().stream()
    .filter(ContentBlock::isText).map(b -> b.asText().text())
    .collect(Collectors.joining());
context.sendMessage(answer);
return PromptResponse.endTurn();

export ANTHROPIC_API_KEY=sk-ant-...
./mvnw package -pl module-25-ai-chatbot-agent -q
./mvnw exec:java -pl module-25-ai-chatbot-agent