Feature Flags Demo (.NET 9.0)

Created as part of this blog post: https://www.oettle.me/blog/targeted-feature-flags

This project demonstrates feature flag management in a .NET 9.0 Web API using Azure App Configuration and Microsoft.FeatureManagement. It supports user targeting and dynamic feature control.

Prerequisites

• .NET 9.0 SDK
• Azure Developer CLI (azd)
• (Optional) Visual Studio 2022+ or VS Code

Quickstart: Deploy with azd

This project uses Azure Developer CLI (azd) to provision all required Azure resources—including App Configuration—automatically.

1. Clone the repository

git clone https://github.com/<your-org>/feature_flags.git
cd feature_flags

2. Login to Azure

az login

3. Provision resources and deploy

azd up

This command will:

• Provision all required Azure resources (App Configuration, etc.)
• Deploy the application
• Output endpoints and connection info

4. Run the API locally

cd src/FeatureFlagApi
pwsh
 dotnet restore
 dotnet run

The API will start on https://localhost:5001 (or as configured).

API Endpoints

• GET /feature-flag — Returns if the Demo feature is enabled for the current user.
• GET /enabled-flags — Lists all enabled feature flags for the current user.

Feature Targeting

User targeting is implemented via DemoTargetingContextAccessor and UserService. You can customize user/group logic in these files.

Troubleshooting

• Ensure you have run azd up and resources are provisioned.
• For more info, see Microsoft Learn: Feature Management.

Resources

• Azure Developer CLI Docs
• Azure App Configuration Docs
• Feature Management for .NET
• Quickstart: ASP.NET Core + App Configuration