Cratis/VerticalSlices

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to add a validation rule, business rule, or uniqueness constraint to an existing command in a Cratis-based project.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to create a strongly-typed domain identifier or value (such as ProjectId, AuthorName, InvoiceNumber) in a Cratis-based project. Produces a ConceptAs record with the correct conversions and sentinel values.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when creating a NEW Cratis documentation page under Documentation/ (tutorial, how-to, explanation, reference, or recipe). Handles where the file goes (which product repo), sidebar wiring (toc.yml + Diátaxis bucket), and verifying it renders. Trigger on add/create/write a new docs page, document a new…

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to add a database table, column, relationship, or other schema change via Entity Framework Core in a Cratis-based project.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to add a Chronicle projection to a Cratis-based project. Favor model-bound projections by default, and only fall back to declarative/fluent IProjectionFor projections when model-bound attributes cannot express the behavior cleanly. Enforces the AutoMap-first rule and Chronicle-specific join…

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to add a Chronicle reactor (automation or translation) to a Cratis-based project. Reactors observe events and produce side effects.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when a read model genuinely needs an IReducerFor — when model-bound projection attributes and fluent IProjectionFor cannot express the state transition. Reducers are the last-resort escape hatch, not a default. Covers the admission checklist, method signatures, nullable-current handling, passivity, and…

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to add OpenTelemetry tracing to a class in a Cratis Chronicle Kernel project. Produces Traces.cs companion files using the [Span] source-generator pattern from Cratis.Traces, registers IActivitySource as a keyed DI service, and injects it into the target class.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill for authentication, authorization, or identity in a Cratis Arc project — backend, frontend, or both. Covers identity providers (IProvideIdentityDetails), protecting commands/queries with authorization attributes, Microsoft Identity Platform, connecting backend identity to React, multi-tenant identity…

Cratis/VerticalSlices

Skill Claude CodeCodex

Execute a Cratis Arc command from backend code via ICommandPipeline — the scopeless and scoped overloads, typed Execute , pre-flight Validate, and reading CommandResult. Use when a reactor, background job, scheduled task, integration test, or backend service needs to run a command without going through HTTP.

Cratis/VerticalSlices

Skill Claude CodeCodex

Step-by-step guidance for creating a Cratis Arc command — [Command] record, Handle() method, CommandValidator, proxy generation, and React .use() hook with CommandDialog. Use when adding or creating a command, wiring up a form or button to the backend, working with IEventLog, CommandResult, CommandValidator…

Cratis/VerticalSlices

Skill Claude CodeCodex

Reference for Cratis C# coding conventions — formatting, naming, records, nullable handling, exceptions, logging, and DI. Use whenever writing C# in a Cratis project, deciding between record vs class, checking naming rules, applying formatting conventions, handling null safety, creating exception types, or asking "how…

Cratis/VerticalSlices

Skill Claude CodeCodex

Step-by-step guidance for building a React page in a Cratis Arc application — DataPage lists, CommandDialog toolbar actions, row selection, details components, observable queries, and MVVM. Use when building or modifying a page that lists/displays data, adding a table, wiring Add/Edit/Delete, or connecting a component…

Cratis/VerticalSlices

Skill Claude CodeCodex

Step-by-step guidance for creating a Cratis Chronicle read model from scratch — defining events, choosing between projection and reducer, [ReadModel] record with static query methods, and the generated TypeScript proxy in React. Use when creating a read model, working with [EventType], [ReadModel], IProjectionFor…

Cratis/VerticalSlices

Skill Claude CodeCodex

Step-by-step guidance for writing C# specs in Cratis with BDD Specification by Example — the Establish/Because/should pattern, for/when/and folder hierarchy, reusable given/ contexts, NSubstitute mocking, and the in-process scenario family. Use when writing C# unit or integration specs or structuring the for/when/and…

Cratis/VerticalSlices

Skill Claude CodeCodex

Step-by-step guidance for writing TypeScript specs in Cratis using BDD-style Specification by Example — the given()/describe/it pattern, for/when/ folder hierarchy, reusable context classes, Sinon mocking, and Chai assertions. Use whenever writing TypeScript specs or tests, creating spec files/folders, using the…

Cratis/VerticalSlices

Skill Claude CodeCodex

Explains how vertical feature slices are structured in a Cratis Chronicle + Arc application — folder layout, the single backend .cs file, the four slice types (State Change/View/Automation/Translation), and how features compose slices. Use when asking how slices work, where files go, or which slice type to choose. To…

Cratis/VerticalSlices

Skill Claude CodeCodex

Create and maintain Mermaid eventmodeling diagrams (EventModel.md) for a Cratis module or feature. Use when adding, renaming, moving, or deleting modules/features/slices, commands, events, read models, automations, translations, or cross-module event flows — to keep the diagram in sync with the code.

Cratis/VerticalSlices

Skill Claude CodeCodex

Attach audit/correlation metadata to every appended Cratis event without polluting event types — via ICanProvideAdditionalEventInformation, plus event tags and the built-in EventContext fields. Use for correlation IDs, tenant/actor context, and other cross-cutting concerns that should travel with events but are not…

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill to diagnose why a Cratis slice misbehaves — read model not updating, TypeScript proxy missing, command rejected unexpectedly, projection/observer quarantined, AutoMap mismatch, reactor side effects not appended, or specs flaking. Symptom → likely cause → the rule/skill that owns the fix. Use when…

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill when asked to wire up a type that needs to enumerate every implementation of an interface (handlers, strategies, filters, validators, formatters, providers) in a Cratis-based C# project. Enforces IInstancesOf over IEnumerable and removes hand-maintained DI registrations.

Cratis/VerticalSlices

Skill Claude CodeCodex

Use this skill to change, fix, or improve Cratis documentation whose source is under Documentation/ in a product or contributing repo. Docs are split across repos (each product owns its Documentation/ folder; the Documentation repo aggregates), so it finds the real source file, edits, syncs, and verifies. Trigger on…

Cratis/VerticalSlices

Skill Claude CodeCodex

Design a Cratis event model before writing code — decide stream boundaries, commands, events, read models, automations/translations, compliance subjects, and the spec outline. Use this when behavior, event vocabulary, stream boundaries, or a multi-slice flow is not yet settled, before implementing a slice.

Cratis/VerticalSlices

Skill Claude CodeCodex

Evolve a Cratis Chronicle event schema without breaking replay — add a new generation and an EventTypeMigration so old stored events upcast into the new shape. Use when an event needs a new required property, a renamed property, or a structural change after events of the prior shape already exist.