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+# WinGet REST Source Development Guide
+
+## Project Overview
+
+This repository is the reference implementation for a **Windows Package Manager REST source** — an Azure-hosted package source that a WinGet client can query. It includes both the deployable Azure Functions REST API and a PowerShell module for provisioning/managing REST source infrastructure.
+
+- **`src/WinGet.RestSource.Functions`** - Azure Functions implementing the REST API endpoints (manifest search, get, information)
+- **`src/WinGet.RestSource`** - Core models and business logic shared by the Functions app
+- **`src/WinGet.RestSource.Infrastructure`** - Data access layer (CosmosDB)
+- **`src/WinGet.RestSource.AppConfig`** - Application configuration
+- **`src/WinGet.RestSource.PowershellSupport`** / **`Tools/PowershellModule`** - `Microsoft.WinGet.RestSource` PowerShell module for creating/managing REST sources on Azure
+- **`src/WinGet.RestSource.UnitTest`** / **`IntegrationTest`** / **`Fuzzing`** - Test projects
+- **`src/WinGet.RestSource.Utils`** - Shared utility code
+
+## Building, Testing, and Running
+
+### Prerequisites
+
+- [Git LFS](https://git-lfs.github.com/)
+- Visual Studio 2022 with **.NET desktop development**, **Azure development**, and **ASP.NET and web development** workloads
+
+### Building
+
+Open `src\WinGet.RestSource.sln` in Visual Studio and build. Command-line builds of the solution also work.
+
+### Running Locally
+
+1. Run `generate_self_sign_cert.ps1` in `src\WinGet.RestSource.Functions` to create a local HTTPS dev cert (used automatically via `launchSettings.json`).
+2. Provision a CosmosDB instance (database `WinGet`, collection `Manifests` if using the ARM templates).
+3. Copy `local.settings.template.json` to `local.settings.json` and populate connection info.
+4. For fully anonymous local testing, set HttpTrigger level to `Anonymous` for `InformationGet`, `ManifestSearchPost`, and `ManifestGet`.
+5. Run `WinGet.RestSource.Functions` via F5 in Visual Studio.
+6. Add as a WinGet source: `winget source add -n "winget-pkgs-restsource" -a https://localhost:7071/api/ -t "Microsoft.Rest"`.
+
+### Testing
+
+- **Unit tests**: require the [Cosmos DB Emulator](https://docs.microsoft.com/azure/cosmos-db/local-emulator?tabs=ssl-netstd21); configure via `WinGet.RestSource.UnitTest\Test.runsettings.template.json` → `Test.runsettings.json`.
+- **Integration tests**: require a deployed REST source endpoint and the [winget client](https://github.com/microsoft/winget-cli) installed locally; configure via `WinGet.RestSource.IntegrationTest\Test.runsettings.template.json`. Destructive/write tests are disabled by default (`RunWriteTests`).
+- Run tests from Visual Studio Test Explorer (`Test > Run All Tests`).
+
+## Architecture & Key Patterns
+
+- **Azure Functions HTTP triggers** map directly to REST endpoints consumed by the WinGet client's `Microsoft.Rest` source type.
+- **CosmosDB** is the backing store for manifest documents; access is abstracted through the Infrastructure layer.
+- The **PowerShell module** (`Microsoft.WinGet.RestSource`) wraps ARM/Azure CLI operations to stand up the Functions app, CosmosDB, and supporting resources declaratively.
+- REST endpoint contracts should stay in sync with the WinGet client's expectations in [microsoft/winget-cli](https://github.com/microsoft/winget-cli) — check client-side REST source parsing when changing response shapes.
+
+## Naming Conventions
+
+- C# code follows StyleCop rules in `stylecop.json`.
+- Namespaces follow `Microsoft.WindowsPackageManager.Rest.<Area>`.
+
+## Contributing
+
+- Review `CONTRIBUTING.md` (root) for workflow and CLA requirements.
+- Documentation for the PowerShell module lives in `Tools/PowershellModule/doc/WingetRestSource.md`.