Add a new MCP example

Author: RussellLuo

README.md

@@ -444,6 +444,7 @@ triage = AgentSpec(
 
 - [patterns](examples/patterns)
 - [mcp](examples/mcp)
+- [mcp-new](examples/mcp-new)
 - [structured-outputs](examples/structured-outputs)
 - [deepseek-r1](examples/deepseek-r1)
 - [translator](examples/translator)

examples/mcp-new/README.md

@@ -0,0 +1,57 @@
+# Model Context Protocol
+
+This example demonstrates how to implement an agent that can use tools provided by MCP ([Model Context Protocol][1]) servers.
+
+
+## Prerequisites
+
+- Install `coagent` (see [Installation](../../README.md#installation)).
+- Start a NATS server (see [Distributed](../../README.md#distributed)).
+
+
+## Quick Start
+
+Set the environment variables for your model:
+
+```bash
+export MODEL_ID="your-model-id"
+export MODEL_BASE_URL="your-base-url"
+export MODEL_API_KEY="your-api-key"
+```
+
+### Run the local agent
+
+Run the agent as a script:
+
+```bash
+python examples/mcp-new/local_agent.py
+```
+
+### Run the daemon agent
+
+First start the MCP server using SSE in one terminal:
+
+```bash
+python examples/mcp-new/server.py -t sse
+```
+
+Then run the agent as a daemon in another terminal:
+
+```bash
+python examples/mcp-new/daemon_agent.py
+```
+
+Next, connect to the MCP server in the third terminal:
+
+```bash
+coagent mcp_server:server1 -H type:Connect -d '{"transport": "sse", "params": {"url": "http://localhost:8080/sse"}}'
+```
+
+Finally, communicate with the MCP agent using the `coagent` CLI:
+
+```bash
+coagent mcp -H type:ChatMessage --chat -d '{"role": "user", "content": "What is the weather like in Beijing"}'
+```
+
+
+[1]: https://modelcontextprotocol.io/

examples/mcp-new/daemon_agent.py

@@ -0,0 +1,30 @@
+import asyncio
+
+from coagent.agents import ChatAgent
+from coagent.agents.mcp_server import MCPServer
+from coagent.core import AgentSpec, idle_loop, new, set_stderr_logger
+from coagent.runtimes import NATSRuntime
+
+
+server = AgentSpec("mcp_server", new(MCPServer))
+
+agent = AgentSpec(
+    "mcp",
+    new(
+        ChatAgent,
+        mcp_servers=["server1"],
+        system="You are a helpful Weather Reporter",
+    ),
+)
+
+
+async def main():
+    async with NATSRuntime.from_servers() as runtime:
+        await runtime.register(server)
+        await runtime.register(agent)
+        await idle_loop()
+
+
+if __name__ == "__main__":
+    set_stderr_logger("TRACE")
+    asyncio.run(main())

examples/mcp-new/local_agent.py

@@ -0,0 +1,60 @@
+import asyncio
+
+from coagent.agents import ChatAgent, ChatMessage
+from coagent.agents.mcp_server import MCPServer, MCPServerStdioParams, Connect, Close
+from coagent.core import AgentSpec, new, set_stderr_logger, logger
+from coagent.runtimes import LocalRuntime
+
+
+server = AgentSpec("mcp_server", new(MCPServer))
+
+agent = AgentSpec(
+    "mcp",
+    new(
+        ChatAgent,
+        mcp_servers=["server1"],
+        system="You are a helpful Weather Reporter",
+    ),
+)
+
+
+async def main():
+    async with LocalRuntime() as runtime:
+        await runtime.register(server)
+        await runtime.register(agent)
+
+        logger.info("Connecting to the server")
+        await server.run(
+            Connect(
+                transport="stdio",
+                params=MCPServerStdioParams(
+                    command="python",
+                    args=["examples/mcp-new/server.py"],
+                ),
+            ).encode(),
+            session_id="server1",
+        )
+
+        logger.info("Chatting with the agent")
+        result = await agent.run(
+            ChatMessage(
+                role="user",
+                content="What is the weather like in Beijing",
+            ).encode(),
+            stream=True,
+        )
+        async for chunk in result:
+            msg = ChatMessage.decode(chunk)
+            print(msg.content, end="", flush=True)
+
+        logger.info("Close the server")
+        await server.run(
+            Close().encode(),
+            session_id="server1",
+            request=False,
+        )
+
+
+if __name__ == "__main__":
+    set_stderr_logger()
+    asyncio.run(main())

examples/mcp-new/server.py

@@ -0,0 +1,30 @@
+import argparse
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP("Weather", port=8080)
+
+
+@mcp.prompt()
+def system_prompt(role: str) -> str:
+    """Create a system prompt."""
+    return f"You are a helpful {role}."
+
+
+@mcp.tool()
+def query_weather(city: str) -> str:
+    """Query the weather in the given city."""
+    return f"The weather in {city} is sunny."
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "-t",
+        "--transport",
+        default="stdio",
+        choices=["stdio", "sse"],
+        help="Transport protocol to use",
+    )
+    args = parser.parse_args()
+
+    mcp.run(transport=args.transport)

examples/notification/README.md

@@ -25,7 +25,7 @@ Then create a subscription via a proxy agent in another terminal:
 coagent proxy -H type:Subscribe --stream --filter .content -d '{"user_id": "1"}'
 ```
 
-Finally, send a notification to the center agent in a third terminal, and then observe the output in the second terminal:
+Finally, send a notification to the center agent in the third terminal, and then observe the output in the second terminal:
 
 ```bash
 coagent center:singleton -H type:Notify -d '{"user_id": "1", "notification": {"type": "created", "content": "Hello, world!"}}'