Cleaner and more direct since it uses the system's chmod command directly rather than going through Node.js.
1172 lines
32 KiB
Text
1172 lines
32 KiB
Text
---
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title: "For Server Developers"
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description: "Get started building your own server to use in Claude for Desktop and other clients."
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---
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In this tutorial, we'll build a simple MCP weather server and connect it to a host, Claude for Desktop. We'll start with a basic setup, and then progress to more complex use cases.
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### What we'll be building
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Many LLMs (including Claude) do not currently have the ability to fetch the forecast and severe weather alerts. Let's use MCP to solve that!
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We'll build a server that exposes two tools: `get-alerts` and `get-forecast`. Then we'll connect the server to an MCP host (in this case, Claude for Desktop):
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<Frame>
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<img src="/images/weather-alerts.png" />
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</Frame>
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<Frame>
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<img src="/images/current-weather.png" />
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</Frame>
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<Note>
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Servers can connect to any client. We've chosen Claude for Desktop here for simplicity, but we also have guides on [building your own client](/quickstart/client) as well as a [list of other clients here](/clients).
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</Note>
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<Accordion title="Why Claude for Desktop and not Claude.ai?">
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Because servers are locally run, MCP currently only supports desktop hosts. Remote hosts are in active development.
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</Accordion>
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### Core MCP Concepts
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MCP servers can provide three main types of capabilities:
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1. **Resources**: File-like data that can be read by clients (like API responses or file contents)
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2. **Tools**: Functions that can be called by the LLM (with user approval)
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3. **Prompts**: Pre-written templates that help users accomplish specific tasks
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This tutorial will primarily focus on tools.
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<Tabs>
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<Tab title='Python'>
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Let's get started with building our weather server! [You can find the complete code for what we'll be building here.](https://github.com/modelcontextprotocol/quickstart-resources/tree/main/weather-server-python)
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### Prerequisite knowledge
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This quickstart assumes you have familiarity with:
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- Python
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- LLMs like Claude
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### System requirements
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- Python 3.10 or higher installed.
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- You must use the Python MCP SDK 1.2.0 or higher.
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### Set up your environment
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First, let's install `uv` and set up our Python project and environment:
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<CodeGroup>
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```bash MacOS/Linux
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curl -LsSf https://astral.sh/uv/install.sh | sh
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```
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```powershell Windows
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powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
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```
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</CodeGroup>
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Make sure to restart your terminal afterwards to ensure that the `uv` command gets picked up.
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Now, let's create and set up our project:
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<CodeGroup>
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```bash MacOS/Linux
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# Create a new directory for our project
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uv init weather
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cd weather
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# Create virtual environment and activate it
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uv venv
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source .venv/bin/activate
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# Install dependencies
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uv add "mcp[cli]" httpx
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# Create our server file
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touch weather.py
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```
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```powershell Windows
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# Create a new directory for our project
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uv init weather
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cd weather
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# Create virtual environment and activate it
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uv venv
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.venv\Scripts\activate
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# Install dependencies
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uv add mcp[cli] httpx
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# Create our server file
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new-item weather.py
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```
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</CodeGroup>
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Now let's dive into building your server.
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## Building your server
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### Importing packages and setting up the instance
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Add these to the top of your `weather.py`:
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```python
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from typing import Any
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import httpx
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from mcp.server.fastmcp import FastMCP
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# Initialize FastMCP server
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mcp = FastMCP("weather")
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# Constants
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NWS_API_BASE = "https://api.weather.gov"
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USER_AGENT = "weather-app/1.0"
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```
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The FastMCP class uses Python type hints and docstrings to automatically generate tool definitions, making it easy to create and maintain MCP tools.
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### Helper functions
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Next, let's add our helper functions for querying and formatting the data from the National Weather Service API:
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```python
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async def make_nws_request(url: str) -> dict[str, Any] | None:
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"""Make a request to the NWS API with proper error handling."""
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headers = {
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"User-Agent": USER_AGENT,
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"Accept": "application/geo+json"
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}
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async with httpx.AsyncClient() as client:
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try:
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response = await client.get(url, headers=headers, timeout=30.0)
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response.raise_for_status()
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return response.json()
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except Exception:
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return None
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def format_alert(feature: dict) -> str:
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"""Format an alert feature into a readable string."""
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props = feature["properties"]
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return f"""
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Event: {props.get('event', 'Unknown')}
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Area: {props.get('areaDesc', 'Unknown')}
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Severity: {props.get('severity', 'Unknown')}
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Description: {props.get('description', 'No description available')}
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Instructions: {props.get('instruction', 'No specific instructions provided')}
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"""
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```
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### Implementing tool execution
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The tool execution handler is responsible for actually executing the logic of each tool. Let's add it:
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```python
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@mcp.tool()
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async def get_alerts(state: str) -> str:
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"""Get weather alerts for a US state.
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Args:
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state: Two-letter US state code (e.g. CA, NY)
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"""
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url = f"{NWS_API_BASE}/alerts/active/area/{state}"
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data = await make_nws_request(url)
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if not data or "features" not in data:
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return "Unable to fetch alerts or no alerts found."
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if not data["features"]:
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return "No active alerts for this state."
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alerts = [format_alert(feature) for feature in data["features"]]
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return "\n---\n".join(alerts)
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@mcp.tool()
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async def get_forecast(latitude: float, longitude: float) -> str:
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"""Get weather forecast for a location.
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Args:
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latitude: Latitude of the location
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longitude: Longitude of the location
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"""
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# First get the forecast grid endpoint
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points_url = f"{NWS_API_BASE}/points/{latitude},{longitude}"
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points_data = await make_nws_request(points_url)
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if not points_data:
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return "Unable to fetch forecast data for this location."
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# Get the forecast URL from the points response
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forecast_url = points_data["properties"]["forecast"]
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forecast_data = await make_nws_request(forecast_url)
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if not forecast_data:
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return "Unable to fetch detailed forecast."
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# Format the periods into a readable forecast
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periods = forecast_data["properties"]["periods"]
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forecasts = []
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for period in periods[:5]: # Only show next 5 periods
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forecast = f"""
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{period['name']}:
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Temperature: {period['temperature']}°{period['temperatureUnit']}
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Wind: {period['windSpeed']} {period['windDirection']}
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Forecast: {period['detailedForecast']}
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"""
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forecasts.append(forecast)
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return "\n---\n".join(forecasts)
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```
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### Running the server
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Finally, let's initialize and run the server:
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```python
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if __name__ == "__main__":
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# Initialize and run the server
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mcp.run(transport='stdio')
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```
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Your server is complete! Run `uv run weather.py` to confirm that everything's working.
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Let's now test your server from an existing MCP host, Claude for Desktop.
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## Testing your server with Claude for Desktop
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<Note>
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Claude for Desktop is not yet available on Linux. Linux users can proceed to the [Building a client](/quickstart/client) tutorial to build an MCP client that connects to the server we just built.
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</Note>
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First, make sure you have Claude for Desktop installed. [You can install the latest version
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here.](https://claude.ai/download) If you already have Claude for Desktop, **make sure it's updated to the latest version.**
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We'll need to configure Claude for Desktop for whichever MCP servers you want to use. To do this, open your Claude for Desktop App configuration at `~/Library/Application Support/Claude/claude_desktop_config.json` in a text editor. Make sure to create the file if it doesn't exist.
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For example, if you have [VS Code](https://code.visualstudio.com/) installed:
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<Tabs>
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<Tab title="MacOS/Linux">
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```bash
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code ~/Library/Application\ Support/Claude/claude_desktop_config.json
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```
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</Tab>
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<Tab title="Windows">
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```powershell
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code $env:AppData\Claude\claude_desktop_config.json
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```
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</Tab>
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</Tabs>
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You'll then add your servers in the `mcpServers` key. The MCP UI elements will only show up in Claude for Desktop if at least one server is properly configured.
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In this case, we'll add our single weather server like so:
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<Tabs>
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<Tab title="MacOS/Linux">
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```json Python
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{
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"mcpServers": {
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"weather": {
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"command": "uv",
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"args": [
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"--directory",
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"/ABSOLUTE/PATH/TO/PARENT/FOLDER/weather",
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"run",
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"weather.py"
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]
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}
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}
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}
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```
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</Tab>
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<Tab title="Windows">
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```json Python
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{
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"mcpServers": {
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"weather": {
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"command": "uv",
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"args": [
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"--directory",
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"C:\\ABSOLUTE\\PATH\\TO\\PARENT\\FOLDER\\weather",
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"run",
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"weather.py"
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]
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}
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}
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}
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```
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</Tab>
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</Tabs>
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<Warning>
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You may need to put the full path to the `uv` executable in the `command` field. You can get this by running `which uv` on MacOS/Linux or `where uv` on Windows.
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</Warning>
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<Note>
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Make sure you pass in the absolute path to your server.
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</Note>
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This tells Claude for Desktop:
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1. There's an MCP server named "weather"
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2. To launch it by running `uv --directory /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather run weather`
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Save the file, and restart **Claude for Desktop**.
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</Tab>
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<Tab title='Node'>
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Let's get started with building our weather server! [You can find the complete code for what we'll be building here.](https://github.com/modelcontextprotocol/quickstart-resources/tree/main/weather-server-typescript)
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|
|
|
### Prerequisite knowledge
|
|
|
|
This quickstart assumes you have familiarity with:
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|
- TypeScript
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|
- LLMs like Claude
|
|
|
|
### System requirements
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|
|
For TypeScript, make sure you have the latest version of Node installed.
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|
|
### Set up your environment
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|
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First, let's install Node.js and npm if you haven't already. You can download them from [nodejs.org](https://nodejs.org/).
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Verify your Node.js installation:
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```bash
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node --version
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npm --version
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```
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For this tutorial, you'll need Node.js version 16 or higher.
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|
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Now, let's create and set up our project:
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|
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<CodeGroup>
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```bash MacOS/Linux
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# Create a new directory for our project
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mkdir weather
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cd weather
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|
|
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# Initialize a new npm project
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npm init -y
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|
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# Install dependencies
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npm install @modelcontextprotocol/sdk zod
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npm install -D @types/node typescript
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|
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# Create our files
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mkdir src
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touch src/index.ts
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```
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|
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```powershell Windows
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# Create a new directory for our project
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md weather
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cd weather
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# Initialize a new npm project
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npm init -y
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# Install dependencies
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npm install @modelcontextprotocol/sdk zod
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npm install -D @types/node typescript
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# Create our files
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md src
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new-item src\index.ts
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```
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</CodeGroup>
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Update your package.json to add type: "module" and a build script:
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```json package.json
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{
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"type": "module",
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"bin": {
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"weather": "./build/index.js"
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},
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"scripts": {
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"build": "tsc && chmod 755 build/index.js",
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},
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"files": [
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"build"
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],
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}
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```
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Create a `tsconfig.json` in the root of your project:
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|
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```json tsconfig.json
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{
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"compilerOptions": {
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"target": "ES2022",
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"module": "Node16",
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"moduleResolution": "Node16",
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"outDir": "./build",
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"rootDir": "./src",
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"strict": true,
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"esModuleInterop": true,
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"skipLibCheck": true,
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"forceConsistentCasingInFileNames": true
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},
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"include": ["src/**/*"],
|
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"exclude": ["node_modules"]
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}
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```
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|
|
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Now let's dive into building your server.
|
|
|
|
## Building your server
|
|
|
|
### Importing packages and setting up the instance
|
|
|
|
Add these to the top of your `src/index.ts`:
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```typescript
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import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
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import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
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import { z } from "zod";
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const NWS_API_BASE = "https://api.weather.gov";
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const USER_AGENT = "weather-app/1.0";
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// Create server instance
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const server = new McpServer({
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name: "weather",
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version: "1.0.0",
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});
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```
|
|
|
|
### Helper functions
|
|
|
|
Next, let's add our helper functions for querying and formatting the data from the National Weather Service API:
|
|
|
|
```typescript
|
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// Helper function for making NWS API requests
|
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async function makeNWSRequest<T>(url: string): Promise<T | null> {
|
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const headers = {
|
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"User-Agent": USER_AGENT,
|
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Accept: "application/geo+json",
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};
|
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|
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try {
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const response = await fetch(url, { headers });
|
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if (!response.ok) {
|
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throw new Error(`HTTP error! status: ${response.status}`);
|
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}
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return (await response.json()) as T;
|
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} catch (error) {
|
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console.error("Error making NWS request:", error);
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return null;
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}
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}
|
|
|
|
interface AlertFeature {
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properties: {
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event?: string;
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areaDesc?: string;
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severity?: string;
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status?: string;
|
|
headline?: string;
|
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};
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}
|
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|
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// Format alert data
|
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function formatAlert(feature: AlertFeature): string {
|
|
const props = feature.properties;
|
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return [
|
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`Event: ${props.event || "Unknown"}`,
|
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`Area: ${props.areaDesc || "Unknown"}`,
|
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`Severity: ${props.severity || "Unknown"}`,
|
|
`Status: ${props.status || "Unknown"}`,
|
|
`Headline: ${props.headline || "No headline"}`,
|
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"---",
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|
].join("\n");
|
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}
|
|
|
|
interface ForecastPeriod {
|
|
name?: string;
|
|
temperature?: number;
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|
temperatureUnit?: string;
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windSpeed?: string;
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|
windDirection?: string;
|
|
shortForecast?: string;
|
|
}
|
|
|
|
interface AlertsResponse {
|
|
features: AlertFeature[];
|
|
}
|
|
|
|
interface PointsResponse {
|
|
properties: {
|
|
forecast?: string;
|
|
};
|
|
}
|
|
|
|
interface ForecastResponse {
|
|
properties: {
|
|
periods: ForecastPeriod[];
|
|
};
|
|
}
|
|
```
|
|
|
|
### Implementing tool execution
|
|
|
|
The tool execution handler is responsible for actually executing the logic of each tool. Let's add it:
|
|
|
|
```typescript
|
|
// Register weather tools
|
|
server.tool(
|
|
"get-alerts",
|
|
"Get weather alerts for a state",
|
|
{
|
|
state: z.string().length(2).describe("Two-letter state code (e.g. CA, NY)"),
|
|
},
|
|
async ({ state }) => {
|
|
const stateCode = state.toUpperCase();
|
|
const alertsUrl = `${NWS_API_BASE}/alerts?area=${stateCode}`;
|
|
const alertsData = await makeNWSRequest<AlertsResponse>(alertsUrl);
|
|
|
|
if (!alertsData) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: "Failed to retrieve alerts data",
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
const features = alertsData.features || [];
|
|
if (features.length === 0) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: `No active alerts for ${stateCode}`,
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
const formattedAlerts = features.map(formatAlert);
|
|
const alertsText = `Active alerts for ${stateCode}:\n\n${formattedAlerts.join("\n")}`;
|
|
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: alertsText,
|
|
},
|
|
],
|
|
};
|
|
},
|
|
);
|
|
|
|
server.tool(
|
|
"get-forecast",
|
|
"Get weather forecast for a location",
|
|
{
|
|
latitude: z.number().min(-90).max(90).describe("Latitude of the location"),
|
|
longitude: z.number().min(-180).max(180).describe("Longitude of the location"),
|
|
},
|
|
async ({ latitude, longitude }) => {
|
|
// Get grid point data
|
|
const pointsUrl = `${NWS_API_BASE}/points/${latitude.toFixed(4)},${longitude.toFixed(4)}`;
|
|
const pointsData = await makeNWSRequest<PointsResponse>(pointsUrl);
|
|
|
|
if (!pointsData) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: `Failed to retrieve grid point data for coordinates: ${latitude}, ${longitude}. This location may not be supported by the NWS API (only US locations are supported).`,
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
const forecastUrl = pointsData.properties?.forecast;
|
|
if (!forecastUrl) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: "Failed to get forecast URL from grid point data",
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
// Get forecast data
|
|
const forecastData = await makeNWSRequest<ForecastResponse>(forecastUrl);
|
|
if (!forecastData) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: "Failed to retrieve forecast data",
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
const periods = forecastData.properties?.periods || [];
|
|
if (periods.length === 0) {
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: "No forecast periods available",
|
|
},
|
|
],
|
|
};
|
|
}
|
|
|
|
// Format forecast periods
|
|
const formattedForecast = periods.map((period: ForecastPeriod) =>
|
|
[
|
|
`${period.name || "Unknown"}:`,
|
|
`Temperature: ${period.temperature || "Unknown"}°${period.temperatureUnit || "F"}`,
|
|
`Wind: ${period.windSpeed || "Unknown"} ${period.windDirection || ""}`,
|
|
`${period.shortForecast || "No forecast available"}`,
|
|
"---",
|
|
].join("\n"),
|
|
);
|
|
|
|
const forecastText = `Forecast for ${latitude}, ${longitude}:\n\n${formattedForecast.join("\n")}`;
|
|
|
|
return {
|
|
content: [
|
|
{
|
|
type: "text",
|
|
text: forecastText,
|
|
},
|
|
],
|
|
};
|
|
},
|
|
);
|
|
```
|
|
|
|
### Running the server
|
|
|
|
Finally, implement the main function to run the server:
|
|
|
|
```typescript
|
|
async function main() {
|
|
const transport = new StdioServerTransport();
|
|
await server.connect(transport);
|
|
console.error("Weather MCP Server running on stdio");
|
|
}
|
|
|
|
main().catch((error) => {
|
|
console.error("Fatal error in main():", error);
|
|
process.exit(1);
|
|
});
|
|
```
|
|
|
|
Make sure to run `npm run build` to build your server! This is a very important step in getting your server to connect.
|
|
|
|
Let's now test your server from an existing MCP host, Claude for Desktop.
|
|
|
|
## Testing your server with Claude for Desktop
|
|
|
|
<Note>
|
|
Claude for Desktop is not yet available on Linux. Linux users can proceed to the [Building a client](/quickstart/client) tutorial to build an MCP client that connects to the server we just built.
|
|
</Note>
|
|
|
|
First, make sure you have Claude for Desktop installed. [You can install the latest version
|
|
here.](https://claude.ai/download) If you already have Claude for Desktop, **make sure it's updated to the latest version.**
|
|
|
|
We'll need to configure Claude for Desktop for whichever MCP servers you want to use. To do this, open your Claude for Desktop App configuration at `~/Library/Application Support/Claude/claude_desktop_config.json` in a text editor. Make sure to create the file if it doesn't exist.
|
|
|
|
For example, if you have [VS Code](https://code.visualstudio.com/) installed:
|
|
|
|
<Tabs>
|
|
<Tab title="MacOS/Linux">
|
|
```bash
|
|
code ~/Library/Application\ Support/Claude/claude_desktop_config.json
|
|
```
|
|
</Tab>
|
|
<Tab title="Windows">
|
|
```powershell
|
|
code $env:AppData\Claude\claude_desktop_config.json
|
|
```
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
You'll then add your servers in the `mcpServers` key. The MCP UI elements will only show up in Claude for Desktop if at least one server is properly configured.
|
|
|
|
In this case, we'll add our single weather server like so:
|
|
|
|
<Tabs>
|
|
<Tab title="MacOS/Linux">
|
|
<CodeGroup>
|
|
```json Node
|
|
{
|
|
"mcpServers": {
|
|
"weather": {
|
|
"command": "node",
|
|
"args": [
|
|
"/ABSOLUTE/PATH/TO/PARENT/FOLDER/weather/build/index.js"
|
|
]
|
|
}
|
|
}
|
|
}
|
|
```
|
|
</CodeGroup>
|
|
</Tab>
|
|
<Tab title="Windows">
|
|
<CodeGroup>
|
|
```json Node
|
|
{
|
|
"mcpServers": {
|
|
"weather": {
|
|
"command": "node",
|
|
"args": [
|
|
"C:\\PATH\\TO\\PARENT\\FOLDER\\weather\\build\\index.js"
|
|
]
|
|
}
|
|
}
|
|
}
|
|
```
|
|
</CodeGroup>
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
This tells Claude for Desktop:
|
|
1. There's an MCP server named "weather"
|
|
2. Launch it by running `node /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather/build/index.js`
|
|
|
|
Save the file, and restart **Claude for Desktop**.
|
|
</Tab>
|
|
<Tab title='Java'>
|
|
|
|
<Note>
|
|
This is a quickstart demo based on Spring AI MCP auto-configuraiton and boot starters.
|
|
To learn how to create sync and async MCP Servers, manually, consult the [Java SDK Server](/sdk/java/mcp-server) documentation.
|
|
</Note>
|
|
|
|
|
|
Let's get started with building our weather server!
|
|
[You can find the complete code for what we'll be building here.](https://github.com/spring-projects/spring-ai-examples/tree/main/model-context-protocol/weather/starter-stdio-server)
|
|
|
|
For more information, see the [MCP Server Boot Starter](https://docs.spring.io/spring-ai/reference/api/mcp/mcp-server-boot-starter-docs.html) reference documentation.
|
|
For manual MCP Server implementation, refer to the [MCP Server Java SDK documentation](/sdk/java/mcp-server).
|
|
|
|
### System requirements
|
|
|
|
- Java 17 or higher installed.
|
|
- [Spring Boot 3.3.x](https://docs.spring.io/spring-boot/installing.html) or higher
|
|
|
|
### Set up your environment
|
|
|
|
Use the [Spring Initizer](https://start.spring.io/) to bootstrat the project.
|
|
|
|
You will need to add the following dependencies:
|
|
|
|
<Tabs>
|
|
<Tab title="Maven">
|
|
```xml
|
|
<dependencies>
|
|
<dependency>
|
|
<groupId>org.springframework.ai</groupId>
|
|
<artifactId>spring-ai-mcp-server-spring-boot-starter</artifactId>
|
|
</dependency>
|
|
|
|
<dependency>
|
|
<groupId>org.springframework</groupId>
|
|
<artifactId>spring-web</artifactId>
|
|
</dependency>
|
|
</dependencies>
|
|
```
|
|
</Tab>
|
|
<Tab title="Gradle">
|
|
```groovy
|
|
dependencies {
|
|
implementation platform("org.springframework.ai:spring-ai-mcp-server-spring-boot-starter")
|
|
implementation platform("org.springframework:spring-web")
|
|
}
|
|
```
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
Then configure your application by setting the applicaiton properties:
|
|
|
|
<CodeGroup>
|
|
|
|
```bash application.properties
|
|
spring.main.bannerMode=off
|
|
logging.pattern.console=
|
|
```
|
|
|
|
```yaml application.yml
|
|
logging:
|
|
pattern:
|
|
console:
|
|
spring:
|
|
main:
|
|
banner-mode: off
|
|
```
|
|
</CodeGroup>
|
|
|
|
The [Server Configuration Properties](https://docs.spring.io/spring-ai/reference/api/mcp/mcp-server-boot-starter-docs.html#_configuration_properties) documents all available properties.
|
|
|
|
Now let's dive into building your server.
|
|
|
|
## Building your server
|
|
|
|
### Weather Service
|
|
|
|
Let's implement a [WeatheService.java](https://github.com/spring-projects/spring-ai-examples/blob/main/model-context-protocol/weather/starter-stdio-server/src/main/java/org/springframework/ai/mcp/sample/server/WeatherService.java) that uses a REST client to query the data from the National Weather Service API:
|
|
|
|
```java
|
|
@Service
|
|
public class WeatherService {
|
|
|
|
private final RestClient restClient;
|
|
|
|
public WeatherService() {
|
|
this.restClient = RestClient.builder()
|
|
.baseUrl("https://api.weather.gov")
|
|
.defaultHeader("Accept", "application/geo+json")
|
|
.defaultHeader("User-Agent", "WeatherApiClient/1.0 (your@email.com)")
|
|
.build();
|
|
}
|
|
|
|
@Tool(description = "Get weather forecast for a specific latitude/longitude")
|
|
public String getWeatherForecastByLocation(
|
|
double latitude, // Latitude coordinate
|
|
double longitude // Longitude coordinate
|
|
) {
|
|
// Returns detailed forecast including:
|
|
// - Temperature and unit
|
|
// - Wind speed and direction
|
|
// - Detailed forecast description
|
|
}
|
|
|
|
@Tool(description = "Get weather alerts for a US state")
|
|
public String getAlerts(
|
|
@ToolParam(description = "Two-letter US state code (e.g. CA, NY") String state)
|
|
) {
|
|
// Returns active alerts including:
|
|
// - Event type
|
|
// - Affected area
|
|
// - Severity
|
|
// - Description
|
|
// - Safety instructions
|
|
}
|
|
|
|
// ......
|
|
}
|
|
```
|
|
|
|
The `@Service` annotation with auto-register the service in your applicaiton context.
|
|
The Spring AI `@Tool` annotation, making it easy to create and maintain MCP tools.
|
|
|
|
The auto-configuration will automatically register these tools with the MCP server.
|
|
|
|
### Create your Boot Applicaiton
|
|
|
|
```java
|
|
@SpringBootApplication
|
|
public class McpServerApplication {
|
|
|
|
public static void main(String[] args) {
|
|
SpringApplication.run(McpServerApplication.class, args);
|
|
}
|
|
|
|
@Bean
|
|
public ToolCallbackProvider weatherTools(WeatherService weatherService) {
|
|
return MethodToolCallbackProvider.builder().toolObjects(weatherService).build();
|
|
}
|
|
}
|
|
```
|
|
|
|
Uses the the `MethodToolCallbackProvider` utils to convert the `@Tools` into actionalble callbackes used by the MCP server.
|
|
|
|
### Running the server
|
|
|
|
Finally, let's build the server:
|
|
|
|
```bash
|
|
./mvnw clean install
|
|
```
|
|
|
|
This will generate a `mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar` file within the `target` folder.
|
|
|
|
Let's now test your server from an existing MCP host, Claude for Desktop.
|
|
|
|
## Testing your server with Claude for Desktop
|
|
|
|
<Note>
|
|
Claude for Desktop is not yet available on Linux.
|
|
</Note>
|
|
|
|
First, make sure you have Claude for Desktop installed.
|
|
[You can install the latest version here.](https://claude.ai/download) If you already have Claude for Desktop, **make sure it's updated to the latest version.**
|
|
|
|
We'll need to configure Claude for Desktop for whichever MCP servers you want to use.
|
|
To do this, open your Claude for Desktop App configuration at `~/Library/Application Support/Claude/claude_desktop_config.json` in a text editor.
|
|
Make sure to create the file if it doesn't exist.
|
|
|
|
For example, if you have [VS Code](https://code.visualstudio.com/) installed:
|
|
|
|
<Tabs>
|
|
<Tab title="MacOS/Linux">
|
|
```bash
|
|
code ~/Library/Application\ Support/Claude/claude_desktop_config.json
|
|
```
|
|
</Tab>
|
|
<Tab title="Windows">
|
|
```powershell
|
|
code $env:AppData\Claude\claude_desktop_config.json
|
|
```
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
You'll then add your servers in the `mcpServers` key.
|
|
The MCP UI elements will only show up in Claude for Desktop if at least one server is properly configured.
|
|
|
|
In this case, we'll add our single weather server like so:
|
|
|
|
<Tabs>
|
|
<Tab title="MacOS/Linux">
|
|
```json java
|
|
{
|
|
"mcpServers": {
|
|
"spring-ai-mcp-weather": {
|
|
"command": "java",
|
|
"args": [
|
|
"-Dspring.ai.mcp.server.stdio=true",
|
|
"-jar",
|
|
"/ABSOLUTE/PATH/TO/PARENT/FOLDER/mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar"
|
|
]
|
|
}
|
|
}
|
|
}
|
|
```
|
|
</Tab>
|
|
|
|
<Tab title="Windows">
|
|
```json java
|
|
{
|
|
"mcpServers": {
|
|
"spring-ai-mcp-weather": {
|
|
"command": "java",
|
|
"args": [
|
|
"-Dspring.ai.mcp.server.transport=STDIO",
|
|
"-jar",
|
|
"C:\\ABSOLUTE\\PATH\\TO\\PARENT\\FOLDER\\weather\\mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar"
|
|
]
|
|
}
|
|
}
|
|
}
|
|
```
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
<Note>
|
|
Make sure you pass in the absolute path to your server.
|
|
</Note>
|
|
|
|
This tells Claude for Desktop:
|
|
1. There's an MCP server named "my-weather-server"
|
|
2. To launch it by running `java -jar /ABSOLUTE/PATH/TO/PARENT/FOLDER/mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar`
|
|
|
|
Save the file, and restart **Claude for Desktop**.
|
|
|
|
## Testing your server with Java client
|
|
|
|
### Create a MCP Client manually
|
|
|
|
Use the `McpClient` to connect to the server:
|
|
|
|
```java
|
|
var stdioParams = ServerParameters.builder("java")
|
|
.args("-jar", "/ABSOLUTE/PATH/TO/PARENT/FOLDER/mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar")
|
|
.build();
|
|
|
|
var stdioTransport = new StdioClientTransport(stdioParams);
|
|
|
|
var mcpClient = McpClient.sync(stdioTransport).build();
|
|
|
|
mcpClient.initialize();
|
|
|
|
ListToolsResult toolsList = mcpClient.listTools();
|
|
|
|
CallToolResult weather = mcpClient.callTool(
|
|
new CallToolRequest("getWeatherForecastByLocation",
|
|
Map.of("latitude", "47.6062", "longitude", "-122.3321")));
|
|
|
|
CallToolResult alert = mcpClient.callTool(
|
|
new CallToolRequest("getAlerts", Map.of("state", "NY")));
|
|
|
|
mcpClient.closeGracefully();
|
|
```
|
|
|
|
### Use MCP Client Boot Starter
|
|
|
|
Create a new boot starter applicaiton using the `spring-ai-mcp-client-spring-boot-starter` dependency:
|
|
|
|
```xml
|
|
<dependency>
|
|
<groupId>org.springframework.ai</groupId>
|
|
<artifactId>spring-ai-mcp-client-spring-boot-starter</artifactId>
|
|
</dependency>
|
|
```
|
|
|
|
and set the `spring.ai.mcp.client.stdio.servers-configuration` property to point to your `claude_desktop_config.json`.
|
|
You can re-use the existing Anthropic Destop configuration:
|
|
|
|
```properties
|
|
spring.ai.mcp.client.stdio.servers-configuration=file:PATH/TO/claude_desktop_config.json
|
|
```
|
|
|
|
When you stasrt your client applicaiton, the auto-configuration will create, automatically MCP clients from the claude_desktop_config.json.
|
|
|
|
For more information, see the [MCP Client Boot Starters](https://docs.spring.io/spring-ai/reference/api/mcp/mcp-server-boot-client-docs.html) reference documentation.
|
|
|
|
## More Java MCP Server examples
|
|
|
|
The [starter-webflux-server](https://github.com/spring-projects/spring-ai-examples/tree/main/model-context-protocol/weather/starter-webflux-server) demonstrates how to create a MCP server using SSE transport.
|
|
It showcases how to define and register MCP Tools, Resources, and Prompts, using the Spring Boot's auto-configuration capabilities.
|
|
|
|
</Tab>
|
|
</Tabs>
|
|
|
|
### Test with commands
|
|
|
|
Let's make sure Claude for Desktop is picking up the two tools we've exposed in our `weather` server. You can do this by looking for the hammer <img src="/images/claude-desktop-mcp-hammer-icon.svg" style={{display: 'inline', margin: 0, height: '1.3em'}} /> icon:
|
|
|
|
<Frame>
|
|
<img src="/images/visual-indicator-mcp-tools.png" />
|
|
</Frame>
|
|
|
|
After clicking on the hammer icon, you should see two tools listed:
|
|
|
|
<Frame>
|
|
<img src="/images/available-mcp-tools.png" />
|
|
</Frame>
|
|
|
|
If your server isn't being picked up by Claude for Desktop, proceed to the [Troubleshooting](#troubleshooting) section for debugging tips.
|
|
|
|
If the hammer icon has shown up, you can now test your server by running the following commands in Claude for Desktop:
|
|
|
|
- What's the weather in Sacramento?
|
|
- What are the active weather alerts in Texas?
|
|
|
|
<Frame>
|
|
<img src="/images/current-weather.png" />
|
|
</Frame>
|
|
<Frame>
|
|
<img src="/images/weather-alerts.png" />
|
|
</Frame>
|
|
|
|
<Note>
|
|
Since this is the US National Weather service, the queries will only work for US locations.
|
|
</Note>
|
|
|
|
## What's happening under the hood
|
|
|
|
When you ask a question:
|
|
|
|
1. The client sends your question to Claude
|
|
2. Claude analyzes the available tools and decides which one(s) to use
|
|
3. The client executes the chosen tool(s) through the MCP server
|
|
4. The results are sent back to Claude
|
|
5. Claude formulates a natural language response
|
|
6. The response is displayed to you!
|
|
|
|
## Troubleshooting
|
|
|
|
<AccordionGroup>
|
|
<Accordion title="Claude for Desktop Integration Issues">
|
|
**Getting logs from Claude for Desktop**
|
|
|
|
Claude.app logging related to MCP is written to log files in `~/Library/Logs/Claude`:
|
|
|
|
- `mcp.log` will contain general logging about MCP connections and connection failures.
|
|
- Files named `mcp-server-SERVERNAME.log` will contain error (stderr) logging from the named server.
|
|
|
|
You can run the following command to list recent logs and follow along with any new ones:
|
|
```bash
|
|
# Check Claude's logs for errors
|
|
tail -n 20 -f ~/Library/Logs/Claude/mcp*.log
|
|
```
|
|
|
|
**Server not showing up in Claude**
|
|
|
|
1. Check your `claude_desktop_config.json` file syntax
|
|
2. Make sure the path to your project is absolute and not relative
|
|
3. Restart Claude for Desktop completely
|
|
|
|
**Tool calls failing silently**
|
|
|
|
If Claude attempts to use the tools but they fail:
|
|
|
|
1. Check Claude's logs for errors
|
|
2. Verify your server builds and runs without errors
|
|
3. Try restarting Claude for Desktop
|
|
|
|
**None of this is working. What do I do?**
|
|
|
|
Please refer to our [debugging guide](/docs/tools/debugging) for better debugging tools and more detailed guidance.
|
|
</Accordion>
|
|
<Accordion title="Weather API Issues">
|
|
**Error: Failed to retrieve grid point data**
|
|
|
|
This usually means either:
|
|
1. The coordinates are outside the US
|
|
2. The NWS API is having issues
|
|
3. You're being rate limited
|
|
|
|
Fix:
|
|
|
|
- Verify you're using US coordinates
|
|
- Add a small delay between requests
|
|
- Check the NWS API status page
|
|
|
|
**Error: No active alerts for [STATE]**
|
|
|
|
This isn't an error - it just means there are no current weather alerts for that state. Try a different state or check during severe weather.
|
|
</Accordion>
|
|
|
|
</AccordionGroup>
|
|
|
|
<Note>
|
|
For more advanced troubleshooting, check out our guide on [Debugging MCP](/docs/tools/debugging)
|
|
</Note>
|
|
|
|
## Next steps
|
|
|
|
<CardGroup cols={2}>
|
|
<Card
|
|
title="Building a client"
|
|
icon="outlet"
|
|
href="/quickstart/client"
|
|
>
|
|
Learn how to build your own MCP client that can connect to your server
|
|
</Card>
|
|
<Card
|
|
title="Example servers"
|
|
icon="grid"
|
|
href="/examples"
|
|
>
|
|
Check out our gallery of official MCP servers and implementations
|
|
</Card>
|
|
<Card
|
|
title="Debugging Guide"
|
|
icon="bug"
|
|
href="/docs/tools/debugging"
|
|
>
|
|
Learn how to effectively debug MCP servers and integrations
|
|
</Card>
|
|
<Card
|
|
title="Building MCP with LLMs"
|
|
icon="comments"
|
|
href="/building-mcp-with-llms"
|
|
>
|
|
Learn how to use LLMs like Claude to speed up your MCP development
|
|
</Card>
|
|
</CardGroup>
|