For Server Developers
Get started building your own server to use in Claude for Desktop and other clients.
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.
What we’ll be building
Many LLMs do not currently have the ability to fetch the forecast and severe weather alerts. Let’s use MCP to solve that!
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):
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 as well as a list of other clients here.
Core MCP Concepts
MCP servers can provide three main types of capabilities:
- Resources: File-like data that can be read by clients (like API responses or file contents)
- Tools: Functions that can be called by the LLM (with user approval)
- Prompts: Pre-written templates that help users accomplish specific tasks
This tutorial will primarily focus on tools.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
Prerequisite knowledge
This quickstart assumes you have familiarity with:
- Python
- LLMs like Claude
System requirements
- Python 3.10 or higher installed.
- You must use the Python MCP SDK 1.2.0 or higher.
Set up your environment
First, let’s install uv
and set up our Python project and environment:
Make sure to restart your terminal afterwards to ensure that the uv
command gets picked up.
Now, let’s create and set up our project:
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 weather.py
:
The FastMCP class uses Python type hints and docstrings to automatically generate tool definitions, making it easy to create and maintain MCP tools.
Helper functions
Next, let’s add our helper functions for querying and formatting the data from the National Weather Service API:
Implementing tool execution
The tool execution handler is responsible for actually executing the logic of each tool. Let’s add it:
Running the server
Finally, let’s initialize and run the server:
Your server is complete! Run uv run weather.py
to confirm that everything’s working.
Let’s now test your server from an existing MCP host, Claude for Desktop.
Testing your server with Claude for Desktop
Claude for Desktop is not yet available on Linux. Linux users can proceed to the Building a client tutorial to build an MCP client that connects to the server we just built.
First, make sure you have Claude for Desktop installed. You can install the latest version here. 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 installed:
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:
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.
Make sure you pass in the absolute path to your server.
This tells Claude for Desktop:
- There’s an MCP server named “weather”
- To launch it by running
uv --directory /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather run weather.py
Save the file, and restart Claude for Desktop.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
Prerequisite knowledge
This quickstart assumes you have familiarity with:
- Python
- LLMs like Claude
System requirements
- Python 3.10 or higher installed.
- You must use the Python MCP SDK 1.2.0 or higher.
Set up your environment
First, let’s install uv
and set up our Python project and environment:
Make sure to restart your terminal afterwards to ensure that the uv
command gets picked up.
Now, let’s create and set up our project:
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 weather.py
:
The FastMCP class uses Python type hints and docstrings to automatically generate tool definitions, making it easy to create and maintain MCP tools.
Helper functions
Next, let’s add our helper functions for querying and formatting the data from the National Weather Service API:
Implementing tool execution
The tool execution handler is responsible for actually executing the logic of each tool. Let’s add it:
Running the server
Finally, let’s initialize and run the server:
Your server is complete! Run uv run weather.py
to confirm that everything’s working.
Let’s now test your server from an existing MCP host, Claude for Desktop.
Testing your server with Claude for Desktop
Claude for Desktop is not yet available on Linux. Linux users can proceed to the Building a client tutorial to build an MCP client that connects to the server we just built.
First, make sure you have Claude for Desktop installed. You can install the latest version here. 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 installed:
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:
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.
Make sure you pass in the absolute path to your server.
This tells Claude for Desktop:
- There’s an MCP server named “weather”
- To launch it by running
uv --directory /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather run weather.py
Save the file, and restart Claude for Desktop.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
Prerequisite knowledge
This quickstart assumes you have familiarity with:
- TypeScript
- LLMs like Claude
System requirements
For TypeScript, make sure you have the latest version of Node installed.
Set up your environment
First, let’s install Node.js and npm if you haven’t already. You can download them from nodejs.org. Verify your Node.js installation:
For this tutorial, you’ll need Node.js version 16 or higher.
Now, let’s create and set up our project:
Update your package.json to add type: “module” and a build script:
Create a tsconfig.json
in the root of your project:
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
:
Helper functions
Next, let’s add our helper functions for querying and formatting the data from the National Weather Service API:
Implementing tool execution
The tool execution handler is responsible for actually executing the logic of each tool. Let’s add it:
Running the server
Finally, implement the main function to run the server:
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
Claude for Desktop is not yet available on Linux. Linux users can proceed to the Building a client tutorial to build an MCP client that connects to the server we just built.
First, make sure you have Claude for Desktop installed. You can install the latest version here. 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 installed:
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:
This tells Claude for Desktop:
- There’s an MCP server named “weather”
- Launch it by running
node /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather/build/index.js
Save the file, and restart Claude for Desktop.
This is a quickstart demo based on Spring AI MCP auto-configuration and boot starters. To learn how to create sync and async MCP Servers, manually, consult the Java SDK Server documentation.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
For more information, see the MCP Server Boot Starter reference documentation. For manual MCP Server implementation, refer to the MCP Server Java SDK documentation.
System requirements
- Java 17 or higher installed.
- Spring Boot 3.3.x or higher
Set up your environment
Use the Spring Initializer to bootstrap the project.
You will need to add the following dependencies:
Then configure your application by setting the application properties:
The Server Configuration Properties documents all available properties.
Now let’s dive into building your server.
Building your server
Weather Service
Let’s implement a WeatherService.java that uses a REST client to query the data from the National Weather Service API:
The @Service
annotation with auto-register the service in your application 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 Application
Uses the the MethodToolCallbackProvider
utils to convert the @Tools
into actionable callbacks used by the MCP server.
Running the server
Finally, let’s build the server:
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
Claude for Desktop is not yet available on Linux.
First, make sure you have Claude for Desktop installed. You can install the latest version here. 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 installed:
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:
Make sure you pass in the absolute path to your server.
This tells Claude for Desktop:
- There’s an MCP server named “my-weather-server”
- 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:
Use MCP Client Boot Starter
Create a new boot starter application using the spring-ai-starter-mcp-client
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 Desktop configuration:
When you start your client application, the auto-configuration will create, automatically MCP clients from the claude_desktop_config.json.
For more information, see the MCP Client Boot Starters reference documentation.
More Java MCP Server examples
The 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.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
Prerequisite knowledge
This quickstart assumes you have familiarity with:
- Kotlin
- LLMs like Claude
System requirements
- Java 17 or higher installed.
Set up your environment
First, let’s install java
and gradle
if you haven’t already.
You can download java
from official Oracle JDK website.
Verify your java
installation:
Now, let’s create and set up your project:
After running gradle init
, you will be presented with options for creating your project.
Select Application as the project type, Kotlin as the programming language, and Java 17 as the Java version.
Alternatively, you can create a Kotlin application using the IntelliJ IDEA project wizard.
After creating the project, add the following dependencies:
Also, add the following plugins to your build script:
Now let’s dive into building your server.
Building your server
Setting up the instance
Add a server initialization function:
Weather API helper functions
Next, let’s add functions and data classes for querying and converting responses from the National Weather Service API:
Implementing tool execution
The tool execution handler is responsible for actually executing the logic of each tool. Let’s add it:
Running the server
Finally, implement the main function to run the server:
Make sure to run ./gradlew 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
Claude for Desktop is not yet available on Linux. Linux users can proceed to the Building a client tutorial to build an MCP client that connects to the server we just built.
First, make sure you have Claude for Desktop installed. You can install the latest version here. 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 installed:
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:
This tells Claude for Desktop:
- There’s an MCP server named “weather”
- Launch it by running
java -jar /ABSOLUTE/PATH/TO/PARENT/FOLDER/weather/build/libs/weather-0.1.0-all.jar
Save the file, and restart Claude for Desktop.
Let’s get started with building our weather server! You can find the complete code for what we’ll be building here.
Prerequisite knowledge
This quickstart assumes you have familiarity with:
- C#
- LLMs like Claude
- .NET 8 or higher
System requirements
- .NET 8 SDK or higher installed.
Set up your environment
First, let’s install dotnet
if you haven’t already. You can download dotnet
from official Microsoft .NET website. Verify your dotnet
installation:
Now, let’s create and set up your project:
After running dotnet new console
, you will be presented with a new C# project.
You can open the project in your favorite IDE, such as Visual Studio or Rider.
Alternatively, you can create a C# application using the Visual Studio project wizard.
After creating the project, add NuGet package for the Model Context Protocol SDK and hosting:
Now let’s dive into building your server.
Building your server
Open the Program.cs
file in your project and replace its contents with the following code:
When creating the ApplicationHostBuilder
, ensure you use CreateEmptyApplicationBuilder
instead of CreateDefaultBuilder
. This ensures that the server does not write any additional messages to the console. This is only neccessary for servers using STDIO transport.
This code sets up a basic console application that uses the Model Context Protocol SDK to create an MCP server with standard I/O transport.
Weather API helper functions
Next, define a class with the tool execution handlers for querying and converting responses from the National Weather Service API:
Running the server
Finally, run the server using the following command:
This will start the server and listen for incoming requests on standard input/output.
Testing your server with Claude for Desktop
Claude for Desktop is not yet available on Linux. Linux users can proceed to the Building a client tutorial to build an MCP client that connects to the server we just built.
First, make sure you have Claude for Desktop installed. You can install the latest version
here. 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 installed:
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:
This tells Claude for Desktop:
- There’s an MCP server named “weather”
- Launch it by running
dotnet run /ABSOLUTE/PATH/TO/PROJECT
Save the file, and restart Claude for Desktop.
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 icon:
After clicking on the hammer icon, you should see two tools listed:
If your server isn’t being picked up by Claude for Desktop, proceed to the 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?
Since this is the US National Weather service, the queries will only work for US locations.
What’s happening under the hood
When you ask a question:
- The client sends your question to Claude
- Claude analyzes the available tools and decides which one(s) to use
- The client executes the chosen tool(s) through the MCP server
- The results are sent back to Claude
- Claude formulates a natural language response
- The response is displayed to you!
Troubleshooting
For more advanced troubleshooting, check out our guide on Debugging MCP
Next steps
Building a client
Learn how to build your own MCP client that can connect to your server
Example servers
Check out our gallery of official MCP servers and implementations
Debugging Guide
Learn how to effectively debug MCP servers and integrations
Building MCP with LLMs
Learn how to use LLMs like Claude to speed up your MCP development
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