mcp-server-example

MCP Server Example

This project demonstrates a basic implementation of an MCP (Model Context Protocol) server using .NET. It provides endpoints for interacting with MCP clients and includes tools for testing and debugging, such as the MCP Inspector. The example also shows how to integrate with external services like GitLab using user secrets for configuration.

Tools

AzureTool

• GetAzureSubscriptionsAsync: Retrieves a list of Azure subscriptions and their IDs.
• GetListOfResourceGroupsAsync: Retrieves a list of Azure resource groups for a given subscription.
• GetVirtualMachinesMatchTagKeyAsync: Retrieves all virtual machine names and their tags from a subscription where the VM has a tag that matches a specified tag key.
• GetResourcesInResourceGroupAsync: Retrieves all resources within a specified resource group.
• GetResourcePropertiesAsync: Retrieves a dictionary of properties and metadata for a specific Azure resource based on its resource ID.

[!NOTE] Prompts:

• retrieve a list of azure subscriptions and their ids
• retrieve a list of resource groups in ???
• retrieve all the resource ids and types in resource group ???
• retrieve all the properties and metadata for azure resource ???

---

Actual prompt: retrieve all resource groups in the developmentsub subscription. For each resource group, retrieve all resources. Cross-check the resource types with those that can integrate with Azure Key Vault. Finally, produce a markdown table that includes the resource group, resource ID, resource name, and resource type.

WhoIsTool

• WhoIs: Provides domain registration and ownership information for a given domain.

GitLabTools

• SearchGroupsAsync: Returns a list of GitLab groups based on a search pattern.
• GetProjectsInGroupAsync: Returns a list of projects in a specified GitLab group.
• GetVariablesInProjectAsync: Returns a list of variables in a GitLab project, masking variable values if they are set as masked (leaving the last 4 characters visible).
• AddAzureConsumptionBudgetAsync: Checks for and adds an Azure consumption budget to a GitLab project via a Merge Request

[!NOTE] Prompts:

• retrieve list of projects in gitlab from the ??? group
• retrieve a list of projects in a specified GitLab group.
• retrieve a list of variables in a specified GitLab project
• using the ??? gitlab project, check for an azure consumption budget in the ??? branch, and add if not found

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Actual prompts:

• retrieve list of projects in gitlab from the upe group
• retrieve a list of variables in a specified GitLab project, masking variable values if they are set as masked (leaving the last 4 characters visible).
• using the subscription-siem gitlab project, check for an azure consumption budget in the "feat/kitcheng/init" branch, and add if not found
• Get a list of GitLab groups using the search pattern upe as a markdown table with name, web_url (as 'click me'), parent_id, and an emoji for has_subgroups. Group by parent id. Include group id in brackets after the name. Then create a tree structure nesting groups by parent id and group id.

How to run

[!NOTE] To run the GitLabTool tools it requires both a PAT and a domain. Please follow the instructions here

dotnet build
dotnet run

You'll see an output similar to this:

Building...
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://localhost:5168
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development

Copy the Http URL as you'll need this when you run the MCP Inspector (see the next section).

How to debug/test

If you're not receiving the responses you expect, or if you want to test and interact with your MCP server(s) outside of the VSCode environment, you can use the MCP Inspector. This tool provides a user-friendly interface for testing and debugging your MCP servers. Access the MCP Inspector source code here.

To install the inspector, enter this into your terminal:

npx @modelcontextprotocol/inspector dotnet run

This then starts the MCP Inspector. Click on the HTTP URL to access the Inspector:

Starting MCP inspector...
⚙️ Proxy server listening on port 6277
🔍 MCP Inspector is up and running at http://127.0.0.1:6274 🚀
New SSE connection

Using the HTTP Url you copied earlier, select the Transport Type dropdown and set to SSE and paste this into URL (please add /sse to the end) text box and press the Connect button:

.

To see what tools are available, now press the List Tools button (located in the centre of the UI). This will reveal:

Now it's over to you to experiment!

User Secrets

If the project is missing a <UserSecretsId> then run this to setup user secrets for this project:

dotnet user-secrets init

GitLab PAT

dotnet user-secrets set "GitLab:Token" "<your-token-value>"

GitLab Domain

dotnet user-secrets set "GitLab:Domain" "<your-domain-value>"