VerticalSlices: Skill for Claude Code

Review changed code against all Cratis project standards and produce a structured report.

C# Architecture

• Each slice is its own folder <Module>/<Feature>/<Slice>/<Slice>.cs with all backend artifacts — no top-level Features/ wrapper
• Commands: record type with Handle() directly on them — no separate handler classes
• Business rejection returns a ValidationResult / Result<TEvent, ValidationResult> (or validator) — never thrown from Provide()/Handle() (a throw is HTTP 500, not a validation error)
• Fetched/computed handler data is in Provide(), not inline in Handle()
• Events: record type, no mutable/nullable properties, past tense, never carry the event-source id
• Identity concepts derive from EventSourceId<T> (not ConceptAs<Guid>)
• Projections: AutoMap is on by default — .AutoMap() only after .NoAutoMap(); projections consume events, never read models
• Model-bound query custom paths use [Path("...")], not [Route]
• No service locator (IServiceProvider not injected); discover implementations with IInstancesOf<T>, not IEnumerable<T>
• Namespace matches folder under the app source root (<RootNamespace>.<Module>.<Feature>.<Slice>)

C# Code Style

• File-scoped namespaces; using directives alphabetically sorted
• No unused using directives
• is null / is not null — never == null / != null
• var preferred over explicit types
• No postfixes: Async, Impl, Service on class names
• No regions
• All public types, methods, and properties have multiline XML doc comments
• <summary> tags always multiline — never /// <summary>Text</summary> on one line
• Methods with parameters include <param name="..."> for each
• Non-void methods include <returns>
• Custom exception types only — never InvalidOperationException, ArgumentException, etc.
• Exception XML docs start with "The exception that is thrown when …"
• Copyright header on every file
• Strongly-typed Concepts for all domain IDs/values (no raw Guid/string in domain models)