A2A Agent Client

Author: Nacos
Version: 0.0.1
Type: Tool Plugin

Overview

A2A Agent Client is a Dify plugin that enables discovering and invoking remote A2A (Agent-to-Agent) agents. It supports multi-agent collaboration by allowing dynamic selection from pre-configured agents.

Features

• Two Discovery Modes

  • Nacos Mode: Discover agents from Nacos Agent Registry by name
  • URL Mode: Discover agents directly via their URLs

• Multi-Agent Collaboration: Configure multiple agents and let LLM dynamically select the most suitable one based on task requirements

• Two Tools

  • get_a2a_agent_information: Get information of all configured agents (name, description, skills)
  • call_a2a_agent: Call a selected agent with a query message

Installation

1. Download the plugin package (.difypkg file)
2. Go to your Dify instance → Plugins → Install Plugin
3. Upload the .difypkg file
4. Configure provider credentials

Configuration

Provider Credentials

Parameter	Description	Required
nacos_addr	Nacos server address (e.g., 127.0.0.1:8848). Required for Nacos mode only.	No
nacos_username	Nacos username	No
nacos_password	Nacos password	No
nacos_accessKey	Aliyun AccessKey (for MSE Nacos)	No
nacos_secretKey	Aliyun SecretKey (for MSE Nacos)	No

Tool Parameters

Get A2A Agent Information

Parameter	Description	Form
discovery_type	Discovery method: nacos or url	User Config
available_agent_names	Comma-separated agent names (Nacos mode)	User Config
available_agent_urls	JSON mapping of names to URLs (URL mode)	User Config
namespace_id	Nacos namespace ID (default: public)	User Config

Call A2A Agent

Parameter	Description	Form
discovery_type	Discovery method: nacos or url	User Config
available_agent_names	Comma-separated agent names (Nacos mode)	User Config
available_agent_urls	JSON mapping of names to URLs (URL mode)	User Config
namespace_id	Nacos namespace ID (default: public)	User Config
target_agent	Agent to call (selected by LLM)	LLM
query	Message to send to the agent	LLM

Usage Examples

Nacos Mode

discovery_type: nacos
available_agent_names: translator_agent,search_agent,code_agent
namespace_id: public

URL Mode

discovery_type: url
available_agent_urls: {"translator_agent":"http://host1:8080/.well-known/agent.json","search_agent":"http://host2:8080/.well-known/agent.json"}

Workflow

┌─────────────────────────────────────────────────────┐
│  1. LLM calls get_a2a_agent_information            │
│     → Returns all agents' name, description, skills │
└─────────────────────────┬───────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────┐
│  2. LLM analyzes task requirements                  │
│     → Selects the most suitable agent              │
└─────────────────────────┬───────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────┐
│  3. LLM calls call_a2a_agent                        │
│     → target_agent + query                         │
└─────────────────────────┬───────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────┐
│  4. Remote A2A Agent processes and responds         │
└─────────────────────────────────────────────────────┘

Requirements

• Dify >= 0.4.0
• Python 3.12+
• nacos-maintainer-sdk-python >= 0.5.1

License

Apache 2.0

Links

• GitHub Repository
• Nacos
• A2A Protocol
• Dify