template-instantiation

name	template-instantiation
description	Skill for creating .NET projects from templates with correct parameters, smart defaults, and constraint validation. Use when a user wants to scaffold a new project, solution, or item from a dotnet new template. Covers parameter selection, dry-run preview, multi-template orchestration, and post-creation verification. DO NOT use for template authoring, build failures, or NuGet package management.

Template Instantiation

When to Use

Invoke this skill when:

• User explicitly asks to create a project/solution/item from a template
• User describes a project they want and the right template has been identified (via template-discovery skill)
• User wants to add an item template (e.g., class, interface, razor page) to an existing project

Step 1: Verify Parameters

Before calling template_instantiate, ensure you have:

1. Template short name — from search/list results
2. Project name — usually provided by user
3. Output path — where to create the project
4. Parameters — framework, auth, feature flags, etc.

Use template_inspect if you need to verify available parameters and their valid values.

Step 2: Preview with Dry Run

Always offer a dry run before creation:

template_dry_run with:
  shortName: "webapi"
  name: "MyService"
  output: "./src/MyService"
  parameters: { "framework": "net10.0", "use-controllers": "true" }

Review the output file list with the user before proceeding.

Step 3: Instantiate

template_instantiate with:
  shortName: "webapi"
  name: "MyService"
  output: "./src/MyService"
  parameters: { "framework": "net10.0", "use-controllers": "true" }

The tool handles:

• Auto-resolve: If template isn't installed, auto-searches NuGet → installs → creates
• Parameter validation: Reports invalid values with suggestions
• Constraint checks: Validates OS, SDK version, workload requirements
• Post-actions: Runs restore, opens files, executes scripts as defined by the template

Step 4: Post-Creation Verification

After instantiation:

1. Verify the project builds: dotnet build ./src/MyService
2. Check for expected files (Program.cs, .csproj, etc.)
3. If adding to a solution, run: dotnet sln add ./src/MyService

Smart Defaults

The MCP server suggests parameter relationships:

• EnableAot=true → suggests net9.0 or later
• --auth Individual → appropriate identity packages
• --use-controllers false → minimal API pattern

Use template_suggest_parameters for parameter suggestions with human-readable rationale.

Post-Creation Intelligence

The template_instantiate tool automatically adapts output to the target environment:

CPM (Central Package Management)

If Directory.Packages.props exists in any parent directory:

• Strips Version attributes from generated .csproj PackageReferences
• Adds <PackageVersion> entries to Directory.Packages.props (skips existing entries)

Latest NuGet Versions

By default (resolveLatestVersions: true), queries the NuGet V3 API for every PackageReference and replaces template-hardcoded versions with the latest stable release. In CPM mode, latest versions go into Directory.Packages.props.

Multi-Template Workflows

For complex project structures, use template_compose for orchestrated multi-step creation, or chain template operations:

1. Solution + Web API + Test Project

1. template_instantiate: "sln" → MySolution
2. template_instantiate: "webapi" → src/MyApi
3. template_instantiate: "xunit" → test/MyApi.Tests
4. dotnet sln add src/MyApi test/MyApi.Tests
5. Add ProjectReference from test → src

2. MAUI App + Class Library + Tests

1. template_instantiate: "maui" → src/MyApp
2. template_instantiate: "classlib" → src/MyApp.Core
3. template_instantiate: "mstest" → test/MyApp.Tests

Error Recovery

Error	Resolution
Template not found	Use template_search to find alternatives; auto-resolve will install from NuGet
Invalid parameter value	Tool returns valid options with "did you mean...?" suggestions
SDK constraint failed	Install required SDK version or use --framework to target available SDK
Workload missing	Install workload: dotnet workload install <workload>
Output directory exists	Choose a different --output path or confirm overwrite

Cross-Reference

• Finding the right template → template-discovery skill
• Creating templates from existing projects → template-authoring skill
• Build failures after creation → MSBuild skills (common-build-errors, nuget-restore-failures)