docs: add experimental a2a docs (#96)

Author: jer96

docs/user-guide/concepts/multi-agent/agent-to-agent.md

@@ -0,0 +1,134 @@
+# Agent-to-Agent (A2A) Protocol
+
+Strands Agents provides experimental support for the [Agent-to-Agent (A2A) protocol](https://a2aproject.github.io/A2A/latest/), enabling seamless communication between AI agents across different platforms and implementations.
+
+!!! warning "Experimental Feature"
+    A2A support in Strands is currently **EXPERIMENTAL**. APIs may change, and additional functionality will be added in future releases. If you encounter bugs or have feature requests, please [report them on GitHub](https://github.com/strands-agents/sdk-python/issues/new/choose).
+
+## What is Agent-to-Agent (A2A)?
+
+The Agent-to-Agent protocol is an open standard that defines how AI agents can discover, communicate, and collaborate with each other.
+
+
+### Use Cases
+
+A2A protocol support enables several powerful use cases:
+
+- **Multi-Agent Workflows**: Chain multiple specialized agents together
+- **Agent Marketplaces**: Discover and use agents from different providers
+- **Cross-Platform Integration**: Connect Strands agents with other A2A-compatible systems
+- **Distributed AI Systems**: Build scalable, distributed agent architectures
+
+Learn more about the A2A protocol:
+
+- [A2A GitHub Organization](https://github.com/a2aproject/A2A)
+- [A2A Python SDK](https://github.com/a2aproject/a2a-python)
+- [A2A Documentation](https://a2aproject.github.io/A2A/latest/)
+
+## Installation
+
+To use A2A functionality with Strands, install the package with the A2A extra:
+
+```bash
+pip install strands-agents[a2a]
+```
+
+This installs the core Strands SDK along with the necessary A2A protocol dependencies.
+
+## Basic Example
+
+Here's a simple example to get started with A2A communication:
+
+### Step 1: Install Dependencies
+
+```bash
+pip install strands-agents[a2a]
+```
+
+### Step 2: Create and Run the Server
+
+Create `server.py`:
+
+```python
+from strands import Agent
+from strands.multiagent.a2a import A2AAgent
+
+# Create a basic agent
+agent = Agent(name="AI assistant", description="A helpful AI assistant")
+
+# Wrap it with A2A capabilities
+a2a_agent = A2AAgent(agent=agent)
+
+# Start the A2A server
+print("Starting A2A server on http://localhost:9000")
+a2a_agent.serve()
+```
+
+Run the server:
+
+```bash
+python server.py
+```
+
+### Step 3: Create and Run the Client
+
+Create `client.py`:
+
+```python
+import asyncio
+from uuid import uuid4
+
+import httpx
+from a2a.client import A2ACardResolver, A2AClient
+from a2a.types import MessageSendParams, SendMessageRequest
+
+
+async def ask_agent(message: str):
+    async with httpx.AsyncClient() as httpx_client:
+        # Connect to the agent
+        resolver = A2ACardResolver(httpx_client=httpx_client, base_url="http://localhost:9000")
+
+        agent_card = await resolver.get_agent_card()
+        print(agent_card)
+        client = A2AClient(httpx_client=httpx_client, agent_card=agent_card)
+
+        # Send the message
+        request = SendMessageRequest(
+            id=str(uuid4()),
+            params=MessageSendParams(
+                message={
+                    "role": "user",
+                    "parts": [{"kind": "text", "text": message}],
+                    "messageId": uuid4().hex,
+                }
+            ),
+        )
+
+        return await client.send_message(request)
+
+
+# Example usage
+async def main():
+    message = "Tell me about agentic AI"
+    response = await ask_agent(message)
+    print(response.model_dump(mode="json", exclude_none=True))
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
+
+```
+
+Run the client (make sure your server is running first):
+
+```bash
+python client.py
+```
+
+## Troubleshooting
+
+If you encounter bugs or need to request features for A2A support:
+
+1. Check the [A2A documentation](https://a2aproject.github.io/A2A/latest/) for protocol-specific issues
+2. Report Strands-specific issues on [GitHub](https://github.com/strands-agents/sdk-python/issues/new/choose)
+3. Include relevant error messages and code samples in your reports

mkdocs.yml

@@ -93,6 +93,7 @@ nav:
         - Async Iterators: user-guide/concepts/streaming/async-iterators.md
         - Callback Handlers: user-guide/concepts/streaming/callback-handlers.md
       - Multi-agent:
+        - Agent2Agent (A2A): user-guide/concepts/multi-agent/agent-to-agent.md
         - Agents as Tools: user-guide/concepts/multi-agent/agents-as-tools.md
         - Swarm: user-guide/concepts/multi-agent/swarm.md
         - Graph: user-guide/concepts/multi-agent/graph.md