Marketplace mcp-patterns

Model Context Protocol (MCP) server patterns for building integrations with Claude Code. Triggers on: mcp server, model context protocol, tool handler, mcp resource, mcp tool.

install

source · Clone the upstream repo

git clone https://github.com/aiskillstore/marketplace

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/aiskillstore/marketplace "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/0xdarkmatter/mcp-patterns" ~/.claude/skills/aiskillstore-marketplace-mcp-patterns && rm -rf "$T"

manifest: skills/0xdarkmatter/mcp-patterns/SKILL.md

MCP Patterns

Model Context Protocol (MCP) server patterns for building integrations with Claude Code.

Basic MCP Server (Python)

from mcp.server import Server
from mcp.server.stdio import stdio_server

app = Server("my-server")

@app.list_tools()
async def list_tools():
    return [
        {
            "name": "my_tool",
            "description": "Does something useful",
            "inputSchema": {
                "type": "object",
                "properties": {
                    "query": {"type": "string", "description": "Search query"}
                },
                "required": ["query"]
            }
        }
    ]

@app.call_tool()
async def call_tool(name: str, arguments: dict):
    if name == "my_tool":
        result = await do_something(arguments["query"])
        return {"content": [{"type": "text", "text": result}]}
    raise ValueError(f"Unknown tool: {name}")

async def main():
    async with stdio_server() as (read_stream, write_stream):
        await app.run(read_stream, write_stream, app.create_initialization_options())

if __name__ == "__main__":
    import asyncio
    asyncio.run(main())

Project Layout

my-mcp-server/
├── src/
│   └── my_server/
│       ├── __init__.py
│       ├── server.py       # Main server logic
│       ├── tools.py        # Tool handlers
│       └── resources.py    # Resource handlers
├── pyproject.toml
└── README.md

Claude Desktop Configuration

Basic Configuration

{
  "mcpServers": {
    "my-server": {
      "command": "python",
      "args": ["-m", "my_server"],
      "env": {
        "MY_API_KEY": "your-key-here"
      }
    }
  }
}

With uv (Recommended)

{
  "mcpServers": {
    "my-server": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/my-server", "python", "-m", "my_server"],
      "env": {
        "MY_API_KEY": "your-key-here"
      }
    }
  }
}

Quick Reference

Pattern	Use Case	Reference
Tool validation	Input sanitization with Pydantic	`./references/tool-patterns.md`
Error handling	Graceful failure responses	`./references/tool-patterns.md`
Multiple tools	CRUD-style tool registration	`./references/tool-patterns.md`
Static resources	Config/settings exposure	`./references/resource-patterns.md`
Dynamic resources	Database-backed resources	`./references/resource-patterns.md`
Environment auth	API key from env vars	`./references/auth-patterns.md`
OAuth tokens	Token refresh with TTL	`./references/auth-patterns.md`
SQLite cache	Persistent state storage	`./references/state-patterns.md`
In-memory cache	TTL-based caching	`./references/state-patterns.md`
Manual testing	Quick validation script	`./references/testing-patterns.md`
pytest async	Unit tests for tools	`./references/testing-patterns.md`

Common Issues

Issue	Solution
Server not starting	Check `command` path, ensure dependencies installed
Tool not appearing	Verify `list_tools()` returns valid schema
Auth failures	Check env vars are set in config, not shell
Timeout errors	Add timeout to httpx calls, use async properly
JSON parse errors	Ensure `call_tool` returns proper content structure

Official Documentation

https://modelcontextprotocol.io - MCP specification
https://modelcontextprotocol.io/docs/concepts/tools - Tools reference
https://modelcontextprotocol.io/docs/concepts/resources - Resources reference
https://github.com/modelcontextprotocol/python-sdk - Python SDK
https://github.com/modelcontextprotocol/servers - Official MCP servers

Additional Resources

For detailed patterns, load:

```
./references/tool-patterns.md
```
- Validation, error handling, multi-tool registration
```
./references/resource-patterns.md
```
- Static and dynamic resource exposure
```
./references/auth-patterns.md
```
- Environment variables, OAuth token refresh
```
./references/state-patterns.md
```
- SQLite persistence, in-memory caching
```
./references/testing-patterns.md
```
- Manual test scripts, pytest async patterns