Python: Added Anthropic agent example (#850)

* Added Anthropic example

* Small fix

python/.env.example

@@ -22,3 +22,6 @@ COPILOTSTUDIOAGENT__ENVIRONMENTID=""
 COPILOTSTUDIOAGENT__SCHEMANAME=""
 COPILOTSTUDIOAGENT__TENANTID=""
 COPILOTSTUDIOAGENT__AGENTAPPID=""
+# Anthropic
+ANTHROPIC_API_KEY=""
+ANTHROPIC_MODEL=""

python/samples/getting_started/agents/anthropic/anthropic_with_openai_chat_client.py

@@ -0,0 +1,85 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import asyncio
+import os
+from random import randint
+from typing import Annotated
+
+from agent_framework.openai import OpenAIChatClient
+
+"""
+Anthropic with OpenAI Chat Client Example
+
+This sample demonstrates how to use Anthropic models through the OpenAI Chat Client by
+configuring the base URL to point to Anthropic's API. The example includes:
+
+- Setting up OpenAI Chat Client with Anthropic API configuration
+- Creating an agent with tool calling capabilities (weather function)
+- Non-streaming response example to get complete results at once
+- Streaming response example to receive results as they are generated
+
+This approach allows you to leverage Anthropic's Claude models while using the familiar
+OpenAI client interface, making it easy to switch between different model providers.
+"""
+
+
+def get_weather(
+    location: Annotated[str, "The location to get the weather for."],
+) -> str:
+    """Get the weather for a given location."""
+    conditions = ["sunny", "cloudy", "rainy", "stormy"]
+    return f"The weather in {location} is {conditions[randint(0, 3)]} with a high of {randint(10, 30)}°C."
+
+
+async def non_streaming_example() -> None:
+    """Example of non-streaming response (get the complete result at once)."""
+    print("=== Non-streaming Response Example ===")
+
+    agent = OpenAIChatClient(
+        api_key=os.getenv("ANTHROPIC_API_KEY"),
+        base_url="https://api.anthropic.com/v1/",
+        ai_model_id=os.getenv("ANTHROPIC_MODEL"),
+    ).create_agent(
+        name="WeatherAgent",
+        instructions="You are a helpful weather agent.",
+        tools=get_weather,
+    )
+
+    query = "What's the weather like in Seattle?"
+    print(f"User: {query}")
+    result = await agent.run(query)
+    print(f"Result: {result}\n")
+
+
+async def streaming_example() -> None:
+    """Example of streaming response (get results as they are generated)."""
+    print("=== Streaming Response Example ===")
+
+    agent = OpenAIChatClient(
+        api_key=os.getenv("ANTHROPIC_API_KEY"),
+        base_url="https://api.anthropic.com/v1/",
+        ai_model_id=os.getenv("ANTHROPIC_MODEL"),
+    ).create_agent(
+        name="WeatherAgent",
+        instructions="You are a helpful weather agent.",
+        tools=get_weather,
+    )
+
+    query = "What's the weather like in Portland?"
+    print(f"User: {query}")
+    print("Agent: ", end="", flush=True)
+    async for chunk in agent.run_stream(query):
+        if chunk.text:
+            print(chunk.text, end="", flush=True)
+    print("\n")
+
+
+async def main() -> None:
+    print("=== Anthropic with OpenAI Chat Client Agent Example ===")
+
+    await non_streaming_example()
+    await streaming_example()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())