> ## Documentation Index
> Fetch the complete documentation index at: https://lab.pollack.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# 24 spring boot client

# Module 24: Spring Boot Client

Use the autoconfigured ACP client in a Spring Boot application. Connect to agents with just properties — no manual transport or client construction.

## Prerequisites

* Java 21+ (Spring Boot 4.x requirement)
* [Module 23: Spring Boot Agent](/acp-java-sdk/tutorial/23-spring-boot-agent) built and available

## What You'll Learn

* Injecting `AcpSyncClient` from autoconfiguration
* Configuring the client transport via `application.properties`
* Property-driven transport selection (stdio vs WebSocket)

## Dependencies

Same starter as the agent side:

```xml theme={null}
<dependency>
    <groupId>org.springaicommunity</groupId>
    <artifactId>acp-spring-boot-starter</artifactId>
    <version>0.11.0</version>
</dependency>
```

## The Client

The autoconfigured `AcpSyncClient` is injected like any Spring bean:

```java theme={null}
@SpringBootApplication
public class ClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(ClientApplication.class, args);
    }

    @Bean
    CommandLineRunner demo(AcpSyncClient client) {
        return args -> {
            // Initialize the connection
            client.initialize();

            // Create a session
            String cwd = System.getProperty("user.dir");
            var session = client.newSession(new NewSessionRequest(cwd, List.of()));

            // Send a prompt
            var response = client.prompt(new PromptRequest(
                session.sessionId(),
                List.of(new TextContent("Hello from Spring Boot client!"))));

            System.out.println("Stop reason: " + response.stopReason());
        };
    }
}
```

## Configuration

**application.properties:**

```properties theme={null}
# Connect to the module-23 agent via stdio transport
spring.acp.client.transport.stdio.command=java
spring.acp.client.transport.stdio.args=-jar,module-23-spring-boot-agent/target/module-23-spring-boot-agent-1.0.0-SNAPSHOT.jar

# Increase timeout for Spring Boot agent startup
spring.acp.client.request-timeout=60s
```

The autoconfiguration detects the `stdio.command` property and creates a `StdioAcpClientTransport` that launches the agent as a subprocess.

## What the Autoconfiguration Does

1. **Detects transport properties** — `stdio.command` triggers stdio transport; `websocket.uri` triggers WebSocket
2. **Creates `AcpSyncClient` and `AcpAsyncClient`** — configured with timeout and client capabilities
3. **Manages shutdown** — `DisposableBean` calls `closeGracefully()` on context close

## Transport Selection

The autoconfiguration picks the transport based on which properties are set:

| Properties Set                               | Transport Created             |
| -------------------------------------------- | ----------------------------- |
| `spring.acp.client.transport.stdio.command`  | `StdioAcpClientTransport`     |
| `spring.acp.client.transport.websocket.uri`  | `WebSocketAcpClientTransport` |
| `spring.acp.client.transport.type=stdio`     | Explicit stdio selection      |
| `spring.acp.client.transport.type=websocket` | Explicit WebSocket selection  |

## Build & Run

```bash theme={null}
# Build both the agent and client
./mvnw package -pl module-23-spring-boot-agent,module-24-spring-boot-client -q

# Run the client (from repo root)
./mvnw spring-boot:run -pl module-24-spring-boot-client
```

## Client Configuration Properties

| Property                                                | Default     | Description                     |
| ------------------------------------------------------- | ----------- | ------------------------------- |
| `spring.acp.client.request-timeout`                     | `30s`       | Request timeout                 |
| `spring.acp.client.transport.type`                      | auto-detect | `stdio` or `websocket`          |
| `spring.acp.client.transport.stdio.command`             | —           | Command to launch agent         |
| `spring.acp.client.transport.stdio.args`                | —           | Command arguments               |
| `spring.acp.client.transport.stdio.env.*`               | —           | Environment variables           |
| `spring.acp.client.transport.websocket.uri`             | —           | WebSocket URI                   |
| `spring.acp.client.transport.websocket.connect-timeout` | `10s`       | Connection timeout              |
| `spring.acp.client.capabilities.read-text-file`         | `true`      | Advertise file read capability  |
| `spring.acp.client.capabilities.write-text-file`        | `true`      | Advertise file write capability |
| `spring.acp.client.capabilities.terminal`               | `false`     | Advertise terminal capability   |

[View on GitHub](https://github.com/markpollack/acp-java-tutorial/tree/main/module-24-spring-boot-client)