scaffold-write

---

name: scaffold-write description: Adds a new write operation (command/mutation) to the Backend with Event Sourcing, Wolverine commands, and Projections. Use this when implementing POST, PUT, PATCH, or DELETE endpoints.

Follow this guide to implement a state-changing operation in the Backend (ApiService) using strict project standards.

1. Define the Domain Event

   • Create a record in src/BookStore.ApiService/Events/.
   • Naming: Past tense (e.g., BookPublished, not PublishBook).
   • Timestamps: MUST use DateTimeOffset (never DateTime).
   • IDs: MUST use Guid.CreateVersion7() (never Guid.NewGuid()).
   • Example:

     Copypublic record BookPublished(Guid Id, DateTimeOffset Timestamp);
     

2. Define the Command

   • Create a record in src/BookStore.ApiService/Commands/{Resource}/ (e.g., Commands/Books/).
   • Template: templates/Command.cs

3. Implement the Wolverine Handler

   • Create/Update src/BookStore.ApiService/Handlers/{Resource}/{Resource}Handlers.cs.
   • Template: templates/Handler.cs

4. Expose the Endpoint (Backend)

   • Open src/BookStore.ApiService/Endpoints/{Resource}Endpoints.cs.
   • Template: templates/Endpoint.cs

5. Update Read Model (Projections)

   • Open src/BookStore.ApiService/Projections/{Resource}Projection.cs.
   • Implement Create or Apply methods.

6. Enable Real-time Updates (SSE)

   • Notification: Create record {Event}Notification in src/Shared/BookStore.Shared/Notifications/DomainEventNotifications.cs.
   • Listener: Update src/BookStore.ApiService/Infrastructure/MartenCommitListener.cs.
     • Add case {Resource}Projection proj: in ProcessDocumentChangeAsync.
     • Implement Handle{Resource}ChangeAsync to .NotifyAsync() the new notification.
   • Reference: See real-time-notifications for the complete data flow.

7. Client Integration

   • Interface: Create src/Client/BookStore.Client/I{Action}{Resource}Endpoint.cs manually.
   • DTOs: If a Request DTO is needed, create it in src/Shared/BookStore.Shared/Models/ (do not rely on auto-generation).
   • Registration: Add to BookStoreClientExtensions.cs.

// turbo 8. Verify

• Run /verify-feature to ensure build, format, and tests pass.

Related Skills

Prerequisites:

• For complex aggregates, consider /scaffold-aggregate first to create the domain model

Next Steps:

• /scaffold-read - Add query endpoints for the new resource
• /scaffold-frontend-feature - Create UI for the new feature
• /scaffold-test - Create integration tests
• /verify-feature - Complete verification

Specialized Skills:

• /scaffold-aggregate - Generate event-sourced aggregates with Apply methods
• /scaffold-projection - Generate read model projections for queries

See Also:

• scaffold-aggregate - Detailed aggregate patterns
• scaffold-projection - Projection creation
• wolverine-guide - Wolverine command/handler patterns
• ApiService AGENTS.md - Backend patterns and conventions