MCP App: Template Catalog Browser — Searchable template library with parameter preview

Summary

Create an interactive Template Catalog Browser MCP App for exploring the 100+ installed .NET templates with filtering, search, and parameter preview.

MCP Apps Pattern: Exploring complex data

Browsing templates via text means repeated "show me web templates" / "what parameters does webapi have?" conversations. A card grid with filters lets users explore visually — filter by language, type, or author, and preview parameters before deciding.

Design

• Card grid: Each template as a card showing name, short name, language, and type
• Filter bar: Dropdowns for language (C#, F#, VB), type (project, item, solution), and free-text search
• Parameter preview: Click a template card to expand and show its parameters with types and defaults
• Quick create: "Create with Copilot" button that sends a pre-filled prompt to chat
• Grouping: Group by template type (Web, Console, Library, Test, etc.)

Data Sources

• TemplateEngineHelper.GetInstalledTemplatesAsync() — full template list with metadata
• TemplateEngineHelper.GetTemplateDetailsAsync(shortName) — per-template parameters
• DotnetSdk tool with ListTemplates and TemplateInfo actions

Resource URI

ui://dotnet-mcp/template-catalog

Priority

Medium-High — strong data exploration showcase, low effort since data is already structured.

Start by locating the MCP App implementation and the TemplateEngineHelper.GetInstalledTemplatesAsync() and GetTemplateDetailsAsync(shortName) entry points, then inspect the DotnetSdk ListTemplates and TemplateInfo actions. Implement the template catalog at ui://dotnet-mcp/template-catalog with the listed filters, grouping, parameter preview, and Copilot creation flow; done means users can browse templates and inspect their parameters.