Winmd API Search

WinMD API Search

This skill helps you find the right Windows API for any capability and get its full details. It searches a local cache of all WinMD metadata from:

• Windows Platform SDK — all Windows.* WinRT APIs (always available, no restore needed)
• WinAppSDK / WinUI — bundled as a baseline in the cache generator (always available, no restore needed)
• NuGet packages — any additional packages in restored projects that contain .winmd files
• Project-output WinMD — class libraries (C++/WinRT, C#) that produce .winmd as build output

Even on a fresh clone with no restore or build, you still get full Platform SDK + WinAppSDK coverage.

When to Use This Skill

• User wants to build a feature and you need to find which API provides that capability
• User asks "how do I do X?" where X involves a platform feature (camera, files, notifications, sensors, AI, etc.)
• You need the exact methods, properties, events, or enumeration values of a type before writing code
• You're unsure which control, class, or interface to use for a UI or system task

Prerequisites

• .NET SDK 8.0 or later — required to build the cache generator. Install from dotnet.microsoft.com if not available.

Cache Setup (Required Before First Use)

All query and search commands read from a local JSON cache. You must generate the cache before running any queries.

# All projects in the repo (recommended for first run)
.\.github\skills\winmd-api-search\scripts\Update-WinMdCache.ps1

# Single project
.\.github\skills\winmd-api-search\scripts\Update-WinMdCache.ps1 -ProjectDir <project-folder>

No project restore or build is needed for baseline coverage (Platform SDK + WinAppSDK). For additional NuGet packages, the project needs dotnet restore (which generates project.assets.json) or a packages.config file.

Cache is stored at Generated Files\winmd-cache\, deduplicated per-package+version.

What gets indexed

Note: This cache directory should be in .gitignore — it's generated, not source.

How to Use

Pick the path that matches the situation:

Discover — "I don't know which API to use"

The user describes a capability in their own words. You need to find the right API.

0. Ensure the cache exists

If the cache hasn't been generated yet, run Update-WinMdCache.ps1 first — see Cache Setup above.

1. Translate user language → search keywords

Map the user's daily language to programming terms. Try multiple variations:

Start with simple everyday words. If results are weak or irrelevant, try the more technical variation.

2. Run searches

.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action search -Query "<keyword>"

This returns ranked namespaces with top matching types and the JSON file path.

If results have low scores (below 60) or are irrelevant, fall back to searching online documentation:

1. Use web search to find the right API on Microsoft Learn, for example:
   • site:learn.microsoft.com/uwp/api <capability keywords> for Windows.* APIs
   • site:learn.microsoft.com/windows/windows-app-sdk/api/winrt <capability keywords> for Microsoft.* WinAppSDK APIs
2. Read the documentation pages to identify which type matches the user's requirement.
3. Once you know the type name, come back and use -Action members or -Action enums to get the exact local signatures.

3. Read the JSON to choose the right API

Read the file at the path(s) from the top results. The JSON has all types in that namespace — full members, signatures, parameters, return types, enumeration values.

Read and decide which types and members fit the user's requirement.

4. Look up official documentation for context

The cache contains only signatures — no descriptions or usage guidance. For explanations, examples, and remarks, look up the type on Microsoft Learn:

For example, Microsoft.UI.Xaml.Controls.NavigationView maps to: https://learn.microsoft.com/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.controls.navigationview

5. Use the API knowledge to answer or write code