In the first part we created our first MCP server with FastMCP and learned how to expose functions as tools, filter them by tags, and compose servers. In this chapter we configure the **transport layer**, control which arguments are exposed, access the request **context**, and create our first **resource**.
⚠️ This chapter continues the code from the previous part. To run it, you need the environment and server from Part 1.
Disclaimer: This post has been translated to English using a machine translation model. Please, let me know if you find any mistakes.
📚 **This entry is part of the _MCP with FastMCP_ series**, divided into four chapters that are read in order:
> * Part 1: First server and tools
* 👉 **Part 2: Transport, context and resources**
* Part 3: Advanced Resources and Prompts
* Part 4: HTTP, authentication and client
Transport layer
If we do not specify the transport layer to the MCP server, stdio is used by default. But we can specify it using the transport parameter when we run it
mcp.run(
transport="stdio")However, if the client and the server are not on the same computer, we can use http as the transport layer
MCP Server
On the server, we only need to indicate that we want to use http as the transport layer, the host, and the port.
mcp.run(
transport="streamable-http",
host="0.0.0.0",port=8000,
)InputPython%%writefile gitHub_MCP_server/github_server.pyimport httpxfrom typing import Optionalfrom fastmcp import FastMCPfrom github import GITHUB_TOKEN, create_github_headers# Create FastMCP servermcp = FastMCP(name="GitHubMCP",instructions="This server provides tools, resources and prompts to interact with the GitHub API.",include_tags={"public"},exclude_tags={"first_issue"})sub_mcp = FastMCP(name="SubMCP",)@mcp.tool(tags={"public", "production"})async def list_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 10 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=10"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"private", "development"})async def list_more_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 100 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=100"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"public", "first_issue"})async def first_repository_issue(owner: str, repo_name: str) -> list[dict]:"""Gets the first issue ever created in a GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list containing information about the first issue created"""# Get the first issue by sorting by creation date in ascending orderapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=all&sort=created&direction=asc&per_page=1"print(f"Fetching first issue from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No issues found for this repository.")return [{"message": "No issues found for this repository."}]first_issue = issues_data[0]# Create a detailed summary of the first issuesummary = f"#{first_issue.get('number', 'N/A')}: {first_issue.get('title', 'No title')}"if first_issue.get('comments', 0) > 0:summary += f" ({first_issue.get('comments')} comments)"issue_info = {"number": first_issue.get("number"),"title": first_issue.get("title"),"user": first_issue.get("user", {}).get("login"),"url": first_issue.get("html_url"),"state": first_issue.get("state"),"comments": first_issue.get("comments"),"created_at": first_issue.get("created_at"),"updated_at": first_issue.get("updated_at"),"body": first_issue.get("body", "")[:500] + "..." if len(first_issue.get("body", "")) > 500 else first_issue.get("body", ""),"summary": summary}print(f"Found first issue: #{first_issue.get('number')} created on {first_issue.get('created_at')}")# Add context informationresult = {"repository": f"{owner}/{repo_name}","note": "This is the very first issue created in this repository","first_issue": issue_info}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@sub_mcp.tool(tags={"public"})def hello_world() -> str:"""Returns a simple greeting."""return "Hello, world!"mcp.mount("sub_mcp", sub_mcp)if __name__ == "__main__":print("DEBUG: Starting FastMCP GitHub server...")print(f"DEBUG: Server name: {mcp.name}")# Initialize and run the server, run with uv run client.py http://localhost:8000/mcpmcp.run(transport="streamable-http",host="0.0.0.0",port=8000,)Copied
Overwriting gitHub_MCP_server/github_server.py
MCP Client
In the client, what needs to change is that before we made the connection by passing the server path (async def connect_to_server(self, server_script_path: str)), whereas now we do it by passing the server URL (async def connect_to_server(self, server_url: str)).
InputPython%%writefile client_MCP/client.pyimport sysimport asynciofrom contextlib import AsyncExitStackfrom anthropic import Anthropicfrom dotenv import load_dotenvfrom fastmcp import Client# Load environment variables from .env fileload_dotenv()class FastMCPClient:"""FastMCP client that integrates with Claude to process user queriesand use tools exposed by a FastMCP server."""def __init__(self):"""Initialize the FastMCP client with Anthropic and resource management."""self.exit_stack = AsyncExitStack()self.anthropic = Anthropic()self.client = Noneasync def connect_to_server(self, server_url: str):"""Connect to the specified FastMCP server via HTTP.Args:server_url: URL of the HTTP server (e.g., "http://localhost:8000")"""print(f"🔗 Connecting to FastMCP HTTP server: {server_url}")# Create FastMCP client for HTTP connection using SSE transportself.client = Client(server_url)# Note: FastMCP Client automatically detects HTTP URLs and uses SSE transportprint("✅ Client created successfully")async def list_available_tools(self):"""List available tools in the FastMCP server."""try:# Get list of tools from the server using FastMCP contextasync with self.client as client:tools = await client.list_tools()if tools:print(f" 🛠️ Available tools ({len(tools)}):")print("=" * 50)for tool in tools:print(f"📋 {tool.name}")if tool.description:print(f" Description: {tool.description}")# Show parameters if availableif hasattr(tool, 'inputSchema') and tool.inputSchema:if 'properties' in tool.inputSchema:params = list(tool.inputSchema['properties'].keys())print(f" Parameters: {', '.join(params)}")print()else:print("⚠️ No tools found in the server")except Exception as e:print(f"❌ Error listing tools: {str(e)}")async def process_query(self, query: str) -> str:"""Process a user query, interacting with Claude and FastMCP tools.Args:query: User queryReturns:str: Final processed response"""try:# Use FastMCP context for all operationsasync with self.client as client:# Get available toolstools_list = await client.list_tools()# Prepare tools for Claude in correct formatclaude_tools = []for tool in tools_list:claude_tool = {"name": tool.name,"description": tool.description or f"Tool {tool.name}","input_schema": tool.inputSchema or {"type": "object", "properties": {}}}claude_tools.append(claude_tool)# Create initial message for Claudemessages = [{"role": "user","content": query}]# First call to Clauderesponse = self.anthropic.messages.create(model="claude-3-5-sonnet-20241022",max_tokens=6000,messages=messages,tools=claude_tools if claude_tools else None)# Process Claude's responseresponse_text = ""for content_block in response.content:if content_block.type == "text":response_text += content_block.textelif content_block.type == "tool_use":# Claude wants to use a tooltool_name = content_block.nametool_args = content_block.inputtool_call_id = content_block.idprint(f"🔧 Claude wants to use: {tool_name}")print(f"📝 Arguments: {tool_args}")try:# Execute tool on the FastMCP servertool_result = await client.call_tool(tool_name, tool_args)print(f"✅ Tool executed successfully")# Add tool result to the conversationmessages.append({"role": "assistant","content": response.content})# Format result for Claudeif tool_result:# Convert result to string format for Clauderesult_content = str(tool_result)messages.append({"role": "user","content": [{"type": "tool_result","tool_use_id": tool_call_id,"content": f"Tool result: {result_content}"}]})else:messages.append({"role": "user","content": [{"type": "tool_result","tool_use_id": tool_call_id,"content": "Tool executed without response content"}]})# Second call to Claude with the tool resultfinal_response = self.anthropic.messages.create(model="claude-3-5-sonnet-20241022",max_tokens=6000,messages=messages,tools=claude_tools if claude_tools else None)# Extract text from the final responsefor final_content in final_response.content:if final_content.type == "text":response_text += final_content.textexcept Exception as e:error_msg = f"❌ Error executing {tool_name}: {str(e)}"print(error_msg)response_text += f" {error_msg}"return response_textexcept Exception as e:error_msg = f"❌ Error processing query: {str(e)}"print(error_msg)return error_msgasync def chat_loop(self):"""Main chat loop with user interaction."""print(" 🤖 FastMCP HTTP client started. Write 'quit', 'q', 'exit', 'salir' to exit.")print("💬 You can ask questions about GitHub repositories!")print("📚 The client can use tools from the FastMCP HTTP server")print("🌐 Connected via Server-Sent Events (SSE)")print("-" * 60)while True:try:# Request user inputuser_input = input(" 👤 You: ").strip()if user_input.lower() in ['quit', 'q', 'exit', 'salir']:print("👋 Bye!")breakif not user_input:continueprint(" 🤔 Claude is thinking...")# Process queryresponse = await self.process_query(user_input)# Show responseprint(f" 🤖 Claude: {response}")except KeyboardInterrupt:print(" 👋 Disconnecting...")breakexcept Exception as e:print(f" ❌ Error in chat: {str(e)}")continueasync def cleanup(self):"""Clean up resources and close connections."""print("🧹 Cleaning up resources...")# FastMCP Client cleanup is handled automatically by context managerawait self.exit_stack.aclose()print("✅ Resources released")async def main():"""Main function that initializes and runs the FastMCP client."""# Verify command line argumentsif len(sys.argv) != 2:print("❌ Usage: python client.py <http_server_url>")print("📝 Example: python client.py http://localhost:8000")print("📝 Note: Now connects to HTTP server instead of executing script")sys.exit(1)server_url = sys.argv[1]# Validate URL formatif not server_url.startswith(('http://', 'https://')):print("❌ Error: Server URL must start with http:// or https://")print("📝 Example: python client.py http://localhost:8000")sys.exit(1)# Create and run clientclient = FastMCPClient()try:# Connect to the serverawait client.connect_to_server(server_url)# List available tools after connectionawait client.list_available_tools()# Start chat loopawait client.chat_loop()except Exception as e:print(f"❌ Fatal error: {str(e)}")finally:# Ensure resources are cleaned upawait client.cleanup()if __name__ == "__main__":# Entry point of the scriptasyncio.run(main())Copied
Overwriting client_MCP/client.py
MCP test via http
To test it, we first need to run the client so that the URL and port are brought up.
InputPython!cd gitHub_MCP_server && source .venv/bin/activate && uv run github_server.pyCopied
/Users/macm1/Documents/web/portafolio/posts/gitHub_MCP_server/github_server.py:240: DeprecationWarning: Mount prefixes are now optional and the first positional argument should be the server you want to mount.mcp.mount("sub_mcp", sub_mcp)DEBUG: Starting FastMCP GitHub server...DEBUG: Server name: GitHubMCP[06/28/25 10:33:36] INFO Starting MCP server 'GitHubMCP' with ]8;id=281189;file:///Users/macm1/Documents/web/portafolio/posts/gitHub_MCP_server/.venv/lib/python3.11/site-packages/fastmcp/server/server.py\server.py]8;;\:]8;id=128713;file:///Users/macm1/Documents/web/portafolio/posts/gitHub_MCP_server/.venv/lib/python3.11/site-packages/fastmcp/server/server.py#1297\1297]8;;\transport 'streamable-http' onhttp://0.0.0.0:8000/mcp/INFO: Started server process [89401]INFO: Waiting for application startup.INFO: Application startup complete.INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
Now we run the client, giving it the MCP server URL.
InputPython!cd client_MCP && source .venv/bin/activate && uv run client.py http://localhost:8000/mcpCopied
🔗 Connecting to FastMCP HTTP server: http://localhost:8000/mcp✅ Client created successfully🛠️ Available tools (2):==================================================📋 sub_mcp_hello_worldDescription: Returns a simple greeting.Parameters:📋 list_repository_issuesDescription: Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issueParameters: owner, repo_name🤖 FastMCP HTTP client started. Write 'quit', 'q', 'exit', 'salir' to exit.💬 You can ask questions about GitHub repositories!📚 The client can use tools from the FastMCP HTTP server🌐 Connected via Server-Sent Events (SSE)------------------------------------------------------------👤 You:
We can see that the connection has been established without any problem.
Server returned to STDIO
We reestablish STDIO as the server transport layer
InputPython%%writefile gitHub_MCP_server/github_server.pyimport httpxfrom typing import Optionalfrom fastmcp import FastMCPfrom github import GITHUB_TOKEN, create_github_headers# Create FastMCP servermcp = FastMCP(name="GitHubMCP",instructions="This server provides tools, resources and prompts to interact with the GitHub API.",include_tags={"public"},exclude_tags={"first_issue"})sub_mcp = FastMCP(name="SubMCP",)@mcp.tool(tags={"public", "production"})async def list_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 10 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=10"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"private", "development"})async def list_more_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 100 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=100"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"public", "first_issue"})async def first_repository_issue(owner: str, repo_name: str) -> list[dict]:"""Gets the first issue ever created in a GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list containing information about the first issue created"""# Get the first issue by sorting by creation date in ascending orderapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=all&sort=created&direction=asc&per_page=1"print(f"Fetching first issue from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No issues found for this repository.")return [{"message": "No issues found for this repository."}]first_issue = issues_data[0]# Create a detailed summary of the first issuesummary = f"#{first_issue.get('number', 'N/A')}: {first_issue.get('title', 'No title')}"if first_issue.get('comments', 0) > 0:summary += f" ({first_issue.get('comments')} comments)"issue_info = {"number": first_issue.get("number"),"title": first_issue.get("title"),"user": first_issue.get("user", {}).get("login"),"url": first_issue.get("html_url"),"state": first_issue.get("state"),"comments": first_issue.get("comments"),"created_at": first_issue.get("created_at"),"updated_at": first_issue.get("updated_at"),"body": first_issue.get("body", "")[:500] + "..." if len(first_issue.get("body", "")) > 500 else first_issue.get("body", ""),"summary": summary}print(f"Found first issue: #{first_issue.get('number')} created on {first_issue.get('created_at')}")# Add context informationresult = {"repository": f"{owner}/{repo_name}","note": "This is the very first issue created in this repository","first_issue": issue_info}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@sub_mcp.tool(tags={"public"})def hello_world() -> str:"""Returns a simple greeting."""return "Hello, world!"mcp.mount("sub_mcp", sub_mcp)if __name__ == "__main__":print("DEBUG: Starting FastMCP GitHub server...")print(f"DEBUG: Server name: {mcp.name}")# Initialize and run the servermcp.run(transport="stdio")Copied
Overwriting gitHub_MCP_server/github_server.py
Excluded arguments
MCP Server
Suppose we want to have traceability of the user ID of the person who made a request; we would have to add a parameter to the tool that is executed with that information. But that information is irrelevant to the LLM, and even for security reasons, we might not want that ID to be exposed.
So that a parameter is not passed to the LLM, when defining a tool we can specify that a parameter be excluded using exclude_args.
InputPython%%writefile gitHub_MCP_server/github_server.pyimport httpxfrom fastmcp import FastMCPfrom github import GITHUB_TOKEN, create_github_headersUSER_ID = 1234567890# Create FastMCP servermcp = FastMCP(name="GitHubMCP",instructions="This server provides tools, resources and prompts to interact with the GitHub API.",include_tags={"public"},exclude_tags={"first_issue"})sub_mcp = FastMCP(name="SubMCP",)@mcp.tool(tags={"public", "production"},exclude_args=["user_id"], # user_id has to be injected by server, not provided by LLM)async def list_repository_issues(owner: str, repo_name: str, user_id: int = USER_ID) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 10 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=10"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary,"requested_by_user_id": user_id}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"private", "development"})async def list_more_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 100 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=100"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"public", "first_issue"})async def first_repository_issue(owner: str, repo_name: str) -> list[dict]:"""Gets the first issue ever created in a GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list containing information about the first issue created"""# Get the first issue by sorting by creation date in ascending orderapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=all&sort=created&direction=asc&per_page=1"print(f"Fetching first issue from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No issues found for this repository.")return [{"message": "No issues found for this repository."}]first_issue = issues_data[0]# Create a detailed summary of the first issuesummary = f"#{first_issue.get('number', 'N/A')}: {first_issue.get('title', 'No title')}"if first_issue.get('comments', 0) > 0:summary += f" ({first_issue.get('comments')} comments)"issue_info = {"number": first_issue.get("number"),"title": first_issue.get("title"),"user": first_issue.get("user", {}).get("login"),"url": first_issue.get("html_url"),"state": first_issue.get("state"),"comments": first_issue.get("comments"),"created_at": first_issue.get("created_at"),"updated_at": first_issue.get("updated_at"),"body": first_issue.get("body", "")[:500] + "..." if len(first_issue.get("body", "")) > 500 else first_issue.get("body", ""),"summary": summary}print(f"Found first issue: #{first_issue.get('number')} created on {first_issue.get('created_at')}")# Add context informationresult = {"repository": f"{owner}/{repo_name}","note": "This is the very first issue created in this repository","first_issue": issue_info}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@sub_mcp.tool(tags={"public"})def hello_world() -> str:"""Returns a simple greeting."""return "Hello, world!"mcp.mount("sub_mcp", sub_mcp)if __name__ == "__main__":print("DEBUG: Starting FastMCP GitHub server...")print(f"DEBUG: Server name: {mcp.name}")# Initialize and run the servermcp.run(transport="stdio")Copied
Overwriting gitHub_MCP_server/github_server.py
As can be seen, in the tool list_repository_issues, we have indicated that the user_id parameter should be excluded.
@mcp.tool(
tags={"public", "production"},
exclude_args=["user_id"], # user_id has to be injected by server, not provided by LLM)
async def list_repository_issues(owner: str, repo_name: str, user_id: int = USER_ID) -> list[dict]:Although later we return "requested_by_user_id": user_id
result = {
"total_found": len(issues_summary),
"repository": f"{owner}/{repo_name}",
"note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues",
"issues": issues_summary,"requested_by_user_id": user_id
}That is, we are passing the ID to the LLM in the result. But in this case, it is so that when executing the tool, we can see that it was executed with that ID.
Context
We can pass context information from the server to the client and vice versa.
MCP Server
Let's add context to our MCP server.
InputPython%%writefile gitHub_MCP_server/github_server.pyimport httpxfrom fastmcp import FastMCP, Contextfrom github import GITHUB_TOKEN, create_github_headersUSER_ID = 1234567890# Create FastMCP servermcp = FastMCP(name="GitHubMCP",instructions="This server provides tools, resources and prompts to interact with the GitHub API.",include_tags={"public"},exclude_tags={"first_issue"})sub_mcp = FastMCP(name="SubMCP",)@mcp.tool(tags={"public", "production"},exclude_args=["user_id"], # user_id has to be injected by server, not provided by LLM)async def list_repository_issues(owner: str, repo_name: str, ctx: Context, user_id: int = USER_ID) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')ctx: The context of the requestuser_id: The user ID (automatically injected by the server)Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 10 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=10"ctx.info(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:ctx.info("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})ctx.info(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary,"requested_by_user_id": user_id}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"ctx.error(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:ctx.error(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"private", "development"})async def list_more_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 100 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=100"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"public", "first_issue"})async def first_repository_issue(owner: str, repo_name: str) -> list[dict]:"""Gets the first issue ever created in a GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list containing information about the first issue created"""# Get the first issue by sorting by creation date in ascending orderapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=all&sort=created&direction=asc&per_page=1"print(f"Fetching first issue from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No issues found for this repository.")return [{"message": "No issues found for this repository."}]first_issue = issues_data[0]# Create a detailed summary of the first issuesummary = f"#{first_issue.get('number', 'N/A')}: {first_issue.get('title', 'No title')}"if first_issue.get('comments', 0) > 0:summary += f" ({first_issue.get('comments')} comments)"issue_info = {"number": first_issue.get("number"),"title": first_issue.get("title"),"user": first_issue.get("user", {}).get("login"),"url": first_issue.get("html_url"),"state": first_issue.get("state"),"comments": first_issue.get("comments"),"created_at": first_issue.get("created_at"),"updated_at": first_issue.get("updated_at"),"body": first_issue.get("body", "")[:500] + "..." if len(first_issue.get("body", "")) > 500 else first_issue.get("body", ""),"summary": summary}print(f"Found first issue: #{first_issue.get('number')} created on {first_issue.get('created_at')}")# Add context informationresult = {"repository": f"{owner}/{repo_name}","note": "This is the very first issue created in this repository","first_issue": issue_info}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@sub_mcp.tool(tags={"public"})def hello_world() -> str:"""Returns a simple greeting."""return "Hello, world!"mcp.mount("sub_mcp", sub_mcp)if __name__ == "__main__":print("DEBUG: Starting FastMCP GitHub server...")print(f"DEBUG: Server name: {mcp.name}")# Initialize and run the servermcp.run(transport="stdio")Copied
Overwriting gitHub_MCP_server/github_server.py
We have replaced all the print statements with ctx.info. In this way, all those information lines can now be printed in the client if we want.
We will use it later
Create a resource
Let's create a static resource in our MCP
MCP Server
We can convert a function on our server into a resource using the @mcp.resource(<ENDPOINT>) decorator.
A resource is an endpoint that provides us with information. While a tool can make changes and/or perform actions, a resource only provides us with information.
Let's see it with an example.
InputPython%%writefile gitHub_MCP_server/github_server.pyimport httpxfrom fastmcp import FastMCP, Contextfrom github import GITHUB_TOKEN, create_github_headersUSER_ID = 1234567890# Create FastMCP servermcp = FastMCP(name="GitHubMCP",instructions="This server provides tools, resources and prompts to interact with the GitHub API.",include_tags={"public"},exclude_tags={"first_issue"})sub_mcp = FastMCP(name="SubMCP",)@mcp.tool(tags={"public", "production"},exclude_args=["user_id"], # user_id has to be injected by server, not provided by LLM)async def list_repository_issues(owner: str, repo_name: str, ctx: Context, user_id: int = USER_ID) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')ctx: The context of the requestuser_id: The user ID (automatically injected by the server)Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 10 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=10"ctx.info(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:ctx.info("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})ctx.info(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary,"requested_by_user_id": user_id}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"ctx.error(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:ctx.error(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"private", "development"})async def list_more_repository_issues(owner: str, repo_name: str) -> list[dict]:"""Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list of dictionaries, each containing information about an issue"""# Limit to first 100 issues to avoid very long responsesapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=open&per_page=100"print(f"Fetching issues from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No open issues found for this repository.")return [{"message": "No open issues found for this repository."}]issues_summary = []for issue in issues_data:# Create a more concise summarysummary = f"#{issue.get('number', 'N/A')}: {issue.get('title', 'No title')}"if issue.get('comments', 0) > 0:summary += f" ({issue.get('comments')} comments)"issues_summary.append({"number": issue.get("number"),"title": issue.get("title"),"user": issue.get("user", {}).get("login"),"url": issue.get("html_url"),"comments": issue.get("comments"),"summary": summary})print(f"Found {len(issues_summary)} open issues.")# Add context informationresult = {"total_found": len(issues_summary),"repository": f"{owner}/{repo_name}","note": "Showing first 10 open issues" if len(issues_summary) == 10 else f"Showing all {len(issues_summary)} open issues","issues": issues_summary}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.tool(tags={"public", "first_issue"})async def first_repository_issue(owner: str, repo_name: str) -> list[dict]:"""Gets the first issue ever created in a GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')Returns:list[dict]: A list containing information about the first issue created"""# Get the first issue by sorting by creation date in ascending orderapi_url = f"https://api.github.com/repos/{owner}/{repo_name}/issues?state=all&sort=created&direction=asc&per_page=1"print(f"Fetching first issue from {api_url}...")async with httpx.AsyncClient() as client:try:response = await client.get(api_url, headers=create_github_headers())response.raise_for_status()issues_data = response.json()if not issues_data:print("No issues found for this repository.")return [{"message": "No issues found for this repository."}]first_issue = issues_data[0]# Create a detailed summary of the first issuesummary = f"#{first_issue.get('number', 'N/A')}: {first_issue.get('title', 'No title')}"if first_issue.get('comments', 0) > 0:summary += f" ({first_issue.get('comments')} comments)"issue_info = {"number": first_issue.get("number"),"title": first_issue.get("title"),"user": first_issue.get("user", {}).get("login"),"url": first_issue.get("html_url"),"state": first_issue.get("state"),"comments": first_issue.get("comments"),"created_at": first_issue.get("created_at"),"updated_at": first_issue.get("updated_at"),"body": first_issue.get("body", "")[:500] + "..." if len(first_issue.get("body", "")) > 500 else first_issue.get("body", ""),"summary": summary}print(f"Found first issue: #{first_issue.get('number')} created on {first_issue.get('created_at')}")# Add context informationresult = {"repository": f"{owner}/{repo_name}","note": "This is the very first issue created in this repository","first_issue": issue_info}return [result]except httpx.HTTPStatusError as e:error_message = e.response.json().get("message", "No additional message from API.")if e.response.status_code == 403 and GITHUB_TOKEN:error_message += " (Rate limit with token or token lacks permissions?)"elif e.response.status_code == 403 and not GITHUB_TOKEN:error_message += " (Rate limit without token. Consider creating a .env file with GITHUB_TOKEN.)"print(f"GitHub API error: {e.response.status_code}. {error_message}")return [{"error": f"GitHub API error: {e.response.status_code}","message": error_message}]except Exception as e:print(f"An unexpected error occurred: {str(e)}")return [{"error": f"An unexpected error occurred: {str(e)}"}]@mcp.resource("resource://server_info", tags={"public"})def server_info() -> str:"""Returns information about the server."""return "This is the MCP GitHub server development for MaximoFN blog post"@sub_mcp.tool(tags={"public"})def hello_world() -> str:"""Returns a simple greeting."""return "Hello, world!"mcp.mount("sub_mcp", sub_mcp)if __name__ == "__main__":print("DEBUG: Starting FastMCP GitHub server...")print(f"DEBUG: Server name: {mcp.name}")# Initialize and run the servermcp.run(transport="stdio")Copied
Overwriting gitHub_MCP_server/github_server.py
As we can see, we have created the resource server_info which returns a text string with the server information
It is important to see that we have declared the resource://server_info endpoint, which is mandatory every time we create resources
Additionally, we have added the public tag, since our MCP server only includes the tools or resources that have the public tag.
mcp = FastMCP(
name="GitHubMCP",
instructions="This server provides tools, resources, and prompts to interact with the GitHub API.",
include_tags={"public"},
exclude_tags={"first_issue"}
)MCP Client
Now we have to make our client able to see the resources of our MCP server.
InputPython%%writefile client_MCP/client.pyimport sysimport asynciofrom contextlib import AsyncExitStackfrom anthropic import Anthropicfrom dotenv import load_dotenvfrom fastmcp import Client# Load environment variables from .env fileload_dotenv()class FastMCPClient:"""FastMCP client that integrates with Claude to process user queriesand use tools and resources exposed by a FastMCP server."""def __init__(self):"""Initialize the FastMCP client with Anthropic and resource management."""self.exit_stack = AsyncExitStack()self.anthropic = Anthropic()self.client = Noneasync def connect_to_server(self, server_script_path: str):"""Connect to the specified FastMCP server.Args:server_script_path: Path to the server script (Python)"""print(f"🔗 Connecting to FastMCP server: {server_script_path}")# Determine the server type based on the extensionif not server_script_path.endswith('.py'):raise ValueError(f"Unsupported server type. Use .py files. Received: {server_script_path}")# Create FastMCP clientself.client = Client(server_script_path)# Note: FastMCP Client automatically infers transport from .py filesprint("✅ Client created successfully")async def list_available_tools(self):"""List available tools in the FastMCP server."""try:# Get list of tools from the server using FastMCP contextasync with self.client as client:tools = await client.list_tools()if tools:print(f" 🛠️ Available tools ({len(tools)}):")print("=" * 50)for tool in tools:print(f"📋 {tool.name}")if tool.description:print(f" Description: {tool.description}")# Show parameters if availableif hasattr(tool, 'inputSchema') and tool.inputSchema:if 'properties' in tool.inputSchema:params = list(tool.inputSchema['properties'].keys())print(f" Parameters: {', '.join(params)}")print()else:print("⚠️ No tools found in the server")except Exception as e:print(f"❌ Error listing tools: {str(e)}")async def list_available_resources(self):"""List available resources in the FastMCP server."""try:# Get list of resources from the server using FastMCP contextasync with self.client as client:resources = await client.list_resources()if resources:print(f" 📚 Available resources ({len(resources)}):")print("=" * 50)for resource in resources:print(f"📄 {resource.uri}")if resource.name:print(f" Name: {resource.name}")if resource.description:print(f" Description: {resource.description}")if resource.mimeType:print(f" MIME Type: {resource.mimeType}")print()else:print("⚠️ No resources found in the server")except Exception as e:print(f"❌ Error listing resources: {str(e)}")async def read_resource(self, resource_uri: str):"""Read a specific resource from the server.Args:resource_uri: URI of the resource to readReturns:str: Resource content"""try:async with self.client as client:result = await client.read_resource(resource_uri)return resultexcept Exception as e:print(f"❌ Error reading resource {resource_uri}: {str(e)}")return Noneasync def process_query(self, query: str) -> str:"""Process a user query, interacting with Claude and FastMCP tools and resources.Args:query: User queryReturns:str: Final processed response"""try:# Use FastMCP context for all operationsasync with self.client as client:# Get available tools and resourcestools_list = await client.list_tools()resources_list = await client.list_resources()# Prepare tools for Claude in correct formatclaude_tools = []for tool in tools_list:claude_tool = {"name": tool.name,"description": tool.description or f"Tool {tool.name}","input_schema": tool.inputSchema or {"type": "object", "properties": {}}}claude_tools.append(claude_tool)# Add a special tool for reading resourcesif resources_list:# Convert URIs to strings to avoid AnyUrl object issuesresource_uris = [str(r.uri) for r in resources_list]claude_tools.append({"name": "read_mcp_resource","description": "Read a resource from the MCP server. Available resources: " +", ".join(resource_uris),"input_schema": {"type": "object","properties": {"resource_uri": {"type": "string","description": "URI of the resource to read"}},"required": ["resource_uri"]}})# Create initial message for Claudemessages = [{"role": "user","content": query}]# First call to Clauderesponse = self.anthropic.messages.create(model="claude-3-5-sonnet-20241022",max_tokens=6000,messages=messages,tools=claude_tools if claude_tools else None)# Process Claude's responseresponse_text = ""for content_block in response.content:if content_block.type == "text":response_text += content_block.textelif content_block.type == "tool_use":# Claude wants to use a tooltool_name = content_block.nametool_args = content_block.inputtool_call_id = content_block.idprint(f"🔧 Claude wants to use: {tool_name}")print(f"📝 Arguments: {tool_args}")try:if tool_name == "read_mcp_resource":# Handle resource readingresource_uri = tool_args.get("resource_uri")if resource_uri:tool_result = await client.read_resource(resource_uri)print(f"📖 Resource read successfully: {resource_uri}")# Better handling of resource resultif hasattr(tool_result, 'content'):# If it's a resource response object, extract contentif hasattr(tool_result.content, 'text'):result_content = tool_result.content.textelse:result_content = str(tool_result.content)else:# If it's already a string or simple objectresult_content = str(tool_result)else:tool_result = "Error: No resource URI provided"result_content = tool_resultelse:# Execute regular tool on the FastMCP servertool_result = await client.call_tool(tool_name, tool_args)print(f"✅ Tool executed successfully")result_content = str(tool_result)# Add tool result to the conversationmessages.append({"role": "assistant","content": response.content})# Format result for Claudeif tool_result:messages.append({"role": "user","content": [{"type": "tool_result","tool_use_id": tool_call_id,"content": f"Tool result: {result_content}"}]})else:messages.append({"role": "user","content": [{"type": "tool_result","tool_use_id": tool_call_id,"content": "Tool executed without response content"}]})# Second call to Claude with the tool resultfinal_response = self.anthropic.messages.create(model="claude-3-5-sonnet-20241022",max_tokens=6000,messages=messages,tools=claude_tools if claude_tools else None)# Extract text from the final responsefor final_content in final_response.content:if final_content.type == "text":response_text += final_content.textexcept Exception as e:error_msg = f"❌ Error executing {tool_name}: {str(e)}"print(error_msg)response_text += f" {error_msg}"return response_textexcept Exception as e:error_msg = f"❌ Error processing query: {str(e)}"print(error_msg)return error_msgasync def chat_loop(self):"""Main chat loop with user interaction."""print(" 🤖 FastMCP client started. Write 'quit', 'q', 'exit', 'salir' to exit.")print("💬 You can ask questions about GitHub repositories!")print("📚 The client can use tools and resources from the FastMCP server")print("-" * 60)while True:try:# Request user inputuser_input = input(" 👤 You: ").strip()if user_input.lower() in ['quit', 'q', 'exit', 'salir']:print("👋 Bye!")breakif not user_input:continueprint(" 🤔 Claude is thinking...")# Process queryresponse = await self.process_query(user_input)# Show responseprint(f" 🤖 Claude: {response}")except KeyboardInterrupt:print(" 👋 Disconnecting...")breakexcept Exception as e:print(f" ❌ Error in chat: {str(e)}")continueasync def cleanup(self):"""Clean up resources and close connections."""print("🧹 Cleaning up resources...")# FastMCP Client cleanup is handled automatically by context managerawait self.exit_stack.aclose()print("✅ Resources released")async def main():"""Main function that initializes and runs the FastMCP client."""# Verify command line argumentsif len(sys.argv) != 2:print("❌ Usage: python client.py <path_to_fastmcp_server>")print("📝 Example: python client.py ../MCP_github/github_server.py")sys.exit(1)server_script_path = sys.argv[1]# Create and run clientclient = FastMCPClient()try:# Connect to the serverawait client.connect_to_server(server_script_path)# List available tools and resources after connectionawait client.list_available_tools()await client.list_available_resources()# Start chat loopawait client.chat_loop()except Exception as e:print(f"❌ Fatal error: {str(e)}")finally:# Ensure resources are cleaned upawait client.cleanup()if __name__ == "__main__":# Entry point of the scriptasyncio.run(main())Copied
Overwriting client_MCP/client.py
We have created the list_available_resources and read_resource methods to be able to read the resources we have on the MCP server.
resource test
We run the client in order to test the resource that we have created
InputPython!cd client_MCP && source .venv/bin/activate && python client.py ../gitHub_MCP_server/github_server.pyCopied
🔗 Connecting to FastMCP server: ../gitHub_MCP_server/github_server.py✅ Client created successfully/Users/macm1/Documents/web/portafolio/posts/gitHub_MCP_server/github_server.py:255: DeprecationWarning: Mount prefixes are now optional and the first positional argument should be the server you want to mount.mcp.mount("sub_mcp", sub_mcp)[06/28/25 11:09:01] INFO Starting MCP server 'GitHubMCP' with transport 'stdio' server.py:1246🛠️ Available tools (2):==================================================📋 sub_mcp_hello_worldDescription: Returns a simple greeting.Parameters:📋 list_repository_issuesDescription: Lists open issues for a given GitHub repository.Args:owner: The owner of the repository (e.g., 'modelcontextprotocol')repo_name: The name of the repository (e.g., 'python-sdk')ctx: The context of the requestuser_id: The user ID (automatically injected by the server)Returns:list[dict]: A list of dictionaries, each containing information about an issueParameters: owner, repo_name📚 Available resources (1):==================================================📄 resource://server_infoName: server_infoDescription: Returns information about the server.MIME Type: text/plain🤖 FastMCP client started. Write 'quit', 'q', 'exit', 'salir' to exit.💬 You can ask questions about GitHub repositories!📚 The client can use tools and resources from the FastMCP server------------------------------------------------------------👤 You: Tell me the server info🤔 Claude is thinking...🔧 Claude wants to use: read_mcp_resource📝 Arguments: {'resource_uri': 'resource://server_info'}📖 Resource read successfully: resource://server_info🤖 Claude: I'll help you read the server information using the `read_mcp_resource` function with the specific resource URI for server info.The server information indicates that this is the MCP GitHub server development environment for MaximoFN blog post.👤 You: q👋 Bye!🧹 Cleaning up resources...✅ Resources released
We see that it gives us a list of resources
📚 Available resources (1):
==================================================
📄 resource://server_info
Name: server_info
Description: Returns information about the server.
MIME Type: text/plainAnd that when we request the server information, it uses the resource server_info that we just created.
👤 You: Tell me the server info
🤔 Claude is thinking...
🔧 Claude quiere usar: read_mcp_resource
📝 Arguments: {'resource_uri': 'resource://server_info'}📖 Resource read successfully: resource://server_info
🤖 Claude: Te ayudaré a leer la información del servidor usando la función `read_mcp_resource` con el URI específico del recurso para la información del servidor. La información del servidor indica que este es el entorno de desarrollo del servidor MCP de GitHub para la publicación del blog de MaximoFN.---
➡️ **Continue in Part 3: advanced resources and prompts**.