Hello World Agent

A simple A2A agent that responds with 'Hello World' to any request

🤖 Agent🟢 Accepts all messagesA2A Protocol v0.3.0custom

A2A Agent Card

Agent URL

https://hello.a2aregistry.org/a2a

Agent Card (/.well-known/agent.json)

https://hello.a2aregistry.org/.well-known/agent-card.json

Protocol Version

A2A v0.3.0

Registered

2/16/2026

Provider

A2A Registry Team

A2A Capabilities

Input Modes

text/plainapplication/json

Output Modes

text/plainapplication/json

Capabilities

streaming: falsepushNotifications: falsestateTransitionHistory: false

Tags:simplehellogreeting

A2A Skills (1)

Say Hello

Responds with a friendly 'Hello World' message

greetinghellosimple

Connect via A2A

Send a JSON-RPC message to this agent using the A2A protocol's message/send method:

curl -X POST https://hello.a2aregistry.org/a2a/api/a2a \
  -H "Content-Type: application/json" \
  -d '{
  "jsonrpc": "2.0",
  "method": "message/send",
  "id": "1",
  "params": {
    "message": {
      "role": "user",
      "parts": [{"type": "text", "text": "Hello!"}]
    }
  }
}'

Learn more about the A2A protocol at a2a-protocol.org