000_hello_acp

[Sync] Hello ACP

This is a simple AgentEx agent that just says hello and acknowledges the user's message to show which ACP methods need to be implemented for the sync ACP type. The simplest agent type: synchronous request/response pattern with a single @acp.on_message_send handler. Best for stateless operations that complete immediately.

What You'll Learn

• Building a basic synchronous agent
• The @acp.on_message_send handler pattern
• When to use sync vs async agents

Prerequisites

• Development environment set up (see main repo README)
• Backend services running: make dev from repository (agentex) root

Quick Start

cd examples/tutorials/00_sync/000_hello_acp
uv run agentex agents run --manifest manifest.yaml

Key Code

@acp.on_message_send
async def handle_message_send(params: SendMessageParams):
    return TextContent(
        author="agent",
        content=f"Echo: {params.content.content}"
    )

That's it - one handler, immediate response. No task creation, no state management.

When to Use

• Simple chatbots with no memory requirements
• Quick Q&A or information lookup agents
• Prototyping and testing agent responses
• Operations that complete in under a second

Why This Matters

Sync agents are the simplest way to get started with AgentEx. They're perfect for learning the basics and building stateless agents. Once you need conversation memory or task tracking, you'll graduate to async agents.

Next: 010_multiturn - Add conversation memory to your agent