Merge pull request #18 from alvinwatner/feat-mcp-client

feat: integrate langchain-mcp-adapters to support MCP

Author: paulkr

README.md

@@ -110,7 +110,58 @@ agent = initialize_agent(
 result = agent.run("What actions are available in Gmail?")
 print(result)
 ```
+### Using Model Context Protocol (MCP) Tools
 
+The SDK supports integration with [Model Context Protocol (MCP)](https://modelcontextprotocol.io/) servers, allowing you to connect to external tool providers via the MCP protocol.
+
+```python
+import asyncio
+from langchain.agents import AgentType
+from langchain_openai import ChatOpenAI
+from pica_langchain import PicaClient, create_pica_agent
+from pica_langchain.models import PicaClientOptions
+
+# Configure MCP servers
+mcp_options = {
+    "math": {
+        "command": "python",
+        "args": ["./path/to/math_server.py"],
+        "transport": "stdio",
+    },
+    "weather": {
+        "url": "http://localhost:8000/sse",
+        "transport": "sse",
+    }
+}
+
+async def main():
+    # Create client with async initialization
+    pica_client = await PicaClient.create(
+        secret="your-pica-secret",
+        options=PicaClientOptions(
+            connectors=["*"],  # Initialize all available connections
+            mcp_options=mcp_options,  # Add MCP server options
+        ),
+    )
+
+    # Create an agent with both Pica and MCP tools
+    llm = ChatOpenAI(temperature=0, model="gpt-4o")
+    agent = create_pica_agent(
+        client=pica_client,
+        llm=llm,
+        agent_type=AgentType.OPENAI_FUNCTIONS,
+    )
+
+    # Use both Pica platform actions and MCP tools
+    result = await agent.ainvoke({
+        "input": "Calculate 25 * 17, then check the weather in New York, finally list all connectors Pica supported"
+    })
+    
+    print(result["output"])
+
+if __name__ == "__main__":
+    asyncio.run(main())
+```
 
 ## Development
 

examples/mcp_server/math_server.py

@@ -0,0 +1,28 @@
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP("Math")
+
+@mcp.tool()
+def add(a: int, b: int) -> int:
+    """Add two numbers"""
+    return a + b
+
+@mcp.tool()
+def subtract(a: int, b: int) -> int:
+    """Subtract b from a"""
+    return a - b
+
+@mcp.tool()
+def multiply(a: int, b: int) -> int:
+    """Multiply two numbers"""
+    return a * b
+
+@mcp.tool()
+def divide(a: int, b: int) -> float:
+    """Divide a by b"""
+    if b == 0:
+        return "Error: Cannot divide by zero"
+    return a / b
+
+if __name__ == "__main__":
+    mcp.run(transport="stdio")

examples/mcp_server/weather_server.py

@@ -0,0 +1,19 @@
+"""
+Run this MCP server with:
+    python examples/mcp_server/weather_server.py
+or:
+    python3 examples/mcp_server/weather_server.py
+"""
+
+from typing import List
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP("Weather")
+
+@mcp.tool()
+async def get_weather(location: str) -> str:
+    """Get weather for location."""
+    return "It's always sunny in New York"
+
+if __name__ == "__main__":
+    mcp.run(transport="sse")

examples/use_with_mcp.py

@@ -0,0 +1,75 @@
+"""
+Example demonstrating how to use pica-langchain with MCP.
+"""
+
+import os
+import sys
+import asyncio
+
+from langchain_openai import ChatOpenAI
+from langchain.agents import AgentType
+from pica_langchain import PicaClient, create_pica_agent
+from pica_langchain.models import PicaClientOptions
+
+# Configure MCP servers
+mcp_options = {
+    "math": {
+        "command": "python",
+        "args": ["./examples/mcp_server/math_server.py"],
+        "transport": "stdio",
+    },
+    "weather": {
+        "url": "http://0.0.0.0:8000/sse",
+        "transport": "sse",
+    }
+}
+
+def get_env_var(name: str) -> str:
+    """Get environment variable or exit if not set."""
+    value = os.environ.get(name)
+
+    if not value:
+        print(f"ERROR: {name} environment variable must be set")
+        sys.exit(1)
+
+    return value
+
+
+async def main():
+    pica_client = await PicaClient.create(
+        secret=get_env_var("PICA_SECRET"),
+        options=PicaClientOptions(
+            mcp_options=mcp_options,
+        ),
+    )
+
+    llm = ChatOpenAI(
+        temperature=0,
+        model="gpt-4o",
+    )
+
+    # Create an agent with Pica tools
+    agent = create_pica_agent(
+        client=pica_client,
+        llm=llm,
+        agent_type=AgentType.OPENAI_FUNCTIONS,
+    )
+
+    import signal
+
+    def handle_sigterm(*args):
+        print("\nReceived shutdown signal. Cleaning up...")
+        sys.exit(0)
+        
+    signal.signal(signal.SIGTERM, handle_sigterm)
+    signal.signal(signal.SIGINT, handle_sigterm)
+
+    result = await agent.ainvoke(
+        {"input": ("First, calculate 25 * 17, then check weather in New York, finally list all connectors Pica supported")}
+    )
+
+    print(f"\nWorkflow Result:\n {result}")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

pica_langchain/__init__.py

@@ -6,7 +6,7 @@
 
 from .client import PicaClient
 from .tools import GetAvailableActionsTool, GetActionKnowledgeTool, ExecuteTool, PromptToConnectPlatformTool
-from .utils import create_pica_tools, create_pica_agent
+from .utils import create_pica_tools, create_pica_agent, get_tools_from_client
 from .models import (
     Connection,
     ConnectionDefinition,
@@ -25,6 +25,7 @@
     "PromptToConnectPlatformTool",
     "create_pica_tools",
     "create_pica_agent",
+    "get_tools_from_client",
     "Connection",
     "ConnectionDefinition",
     "AvailableAction",