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

[jongalloway]

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.