it would be nice if this could interop with pre-existing feature configured with IFeatureManagement in appsetting.json and operate on those

Here is the roadmap with a list of all possible features to add in the next releases:

• Native Feature value types
  • boolean
  • integer
  • decimal
  • string
  • List of choices
• Extended feature value types
  • Color
    • Color Picker on the UI
    • With validation
    • Custom display
  • Date
    • Timestamp on the UI
    • With validation
    • Custom display
  • Json
    • Textarea on the UI
    • With validation
    • Auto format
  • Prefix/suffix (only for UI)
• Feature definitions
  • Static configuration (current) = ResetOnStartup
  • Improved Configuration Builder (better readability, maintainability & type checking)
  • Load from appsettings.json
  • Dynamic configuration (with CreateFeature, UpdateFeature and RemoveFeature)
• Storage Providers (via EF Core)
  • In memory
  • SQL Server
  • PostgreSQL
  • MySQL
  • SQLite
  • Custom Storage Provider?
• Feature types
  • Global feature configuration (default as ServerFeature) manual changes allowed
  • Client feature configuration (default as ClientFeature) manual changes allowed
  • Time window feature configuration (after date, before date, between dates) requires HostedService
  • Group feature configuration
  • Client rollout feature configuration (% of clients - with Slider UI) requires HostedService
  • Group rollout feature configuration (% of groups - with Slider UI) requires HostedService
  • Custom feature configuration?
• User Interface
  • Display list of features (with the best component for the job)
  • Add details on each feature (icon for feature type, tags : client vs. server / rollout / group / time window)
  • Button to display/hide disabled features
  • Search features
  • Group features (display features on categories)
  • Allow HTML customization
  • Allow CSS customization
  • Pass down props from url (ex: authentication scheme & value)
• Authentication
  • Allow/Disallow read right
  • Allow/Disallow write right
  • readonly property to disable UI components
  • Authentication schemes like Query params or Headers (API usage + UI selection)
• Realtime updates
  • Feature updated event handlers (both server and client features)
  • API (websocket) realtime events
  • Automatically update the UI using realtime events
• Documentation
  • Basic documentation (goals, code documentation/usage, images)
  • Split documentation by feature/domain (like here)
• Improvements ideas
  • Caching
  • GraphQL API to replace the REST API (real-time subscription for free)

A .NET client library to consume features API. Should be working on all kind of .NET client applications: Console, Windows app, Blazor, etc...

• Load (all) features (on startup?)
• Get all feature values
• Get feature value
• Set feature value (if possible)
• Provide authentication mechanism (set globally vs. per call)
• Generate client library using Source Generators (by providing a schema file)