Add Scenario 15: MCP App with Semantic Search

[Copilot]

Implements a new scenario demonstrating MCP Apps - the new MCP extension that enables servers to provide interactive UI components to clients like VS Code.

Changes

New Scenario: scenarios/15-MCPApp

• eShopMcpApp: MCP server using ModelContextProtocol.AspNetCore (v0.7.0-preview.1) with embedded HTML search UI
• Products API: Semantic search via Azure OpenAI embeddings + in-memory vector store
• Aspire orchestration: SQL Server, Azure OpenAI integration

MCP Tools Exposed

Tool	Description
ProductSearch	Opens interactive search UI (MCP App pattern)
SemanticSearchProducts	AI-powered vector search
KeywordSearchProducts	Traditional SQL LIKE search

Example Tool Definition

[McpServerTool]
[Description("Open an interactive product search UI")]
[McpMeta("ui", JsonValue = """{ "resourceUri": "ui://product-search/app.html" }""")]
public static ProductSearchResult ProductSearch(string? query = "") { ... }

[McpServerResource(UriTemplate = "ui://product-search/app.html", MimeType = "text/html")]
public static async Task<string> GetProductSearchUI() => await ProductSearchHtmlProvider.GetHtml();

Documentation

• README with MCP Apps explanation, architecture diagram, setup instructions
• Links to official MCP Apps spec and samples

Stack

• .NET 10, Aspire 13.0.1, MCP SDK 0.7.0-preview.1

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• elbruno.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Goal

Implement a new scenario in eShopLite that will create a MCP Server with search operations for the eShopLite product database.
The MCP Server will also implement a MCP App that allow the user to search products using semantic search.

Task

• Check the blog and the resources of the blog to see how to implement a MCP App
• Implement this as a new scenario, scenario 15
• Update the necessary docs to include an explanation of how MCP Apps works and what is the eShopLite MCP App
• in the new scenario, update the projects to use .NET 10, and the latest packages version
• check the references for the necessary content
• add / include any extra features that will support and complete the scenario

Reference

• C# Sample MCP App repo: https://github.com/elbruno/mcpapp-colorpicker
• C# Sample MCP App blog: https://elbruno.com/2026/01/28/building-an-mcp-app-with-c-a-color-picker-sample/

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