# vertical-slice

Guides .NET architecture toward feature-based vertical slices instead of layered folders. Helps structure endpoints, request models, and handlers together.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 2900 installs · ★ 789
- Author: codewithmukesh
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/codewithmukesh/dotnet-claude-kit/tree/HEAD/skills/vertical-slice/SKILL.md
- Updated: 2026-08-07
- HTML: https://affpapa.org/en/nevibecode/skills/vertical-slice

## What it does

This skill shifts .NET projects away from layered Controllers, Services, and Repositories folders. Each feature lives in its own slice with its endpoint, command, AbstractValidator rules, and response types. Cross-feature coupling drops because features do not reference each other directly. Shared logic moves into `Common/` or `Shared/`.

It provides three distinct handler implementations. The default recommendation uses source-generated Mediator via `Mediator.Abstractions` and `Mediator.SourceGenerator`, which avoids reflection and stays Native AOT compatible. The second approach follows Wolverine conventions using a static `Handle` method. The third relies on plain classes with an `ExecuteAsync` method and zero third-party packages.

Larger systems can split features into dedicated class library modules with individual DbContext instances. Relying on raw handlers without a mediator library makes sense only for smaller codebases where manual wiring beats pipeline behaviors.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add codewithmukesh/dotnet-claude-kit --skill vertical-slice -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/vertical-slice/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/vertical-slice/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add codewithmukesh/dotnet-claude-kit --skill vertical-slice -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/vertical-slice/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add codewithmukesh/dotnet-claude-kit --skill vertical-slice -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/vertical-slice/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install codewithmukesh/dotnet-claude-kit vertical-slice
```

2. **Manually: put the files in place**
- File: `.github/skills/vertical-slice/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add codewithmukesh/dotnet-claude-kit --skill vertical-slice -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/codewithmukesh/dotnet-claude-kit --path skills/vertical-slice
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/vertical-slice/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add codewithmukesh/dotnet-claude-kit --skill vertical-slice -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/codewithmukesh/dotnet-claude-kit/tree/HEAD/skills/vertical-slice/SKILL.md

## When to use it
- organize .NET API code by feature folders
- implement request handlers using source-generated Mediator
- set up convention-based handling with Wolverine
- isolate feature logic into single-file endpoints without mediator libraries

## Example prompts
- Structure the CreateOrder feature using Vertical Slice Architecture and FluentValidation.
- Implement a Native AOT compatible handler using source-generated Mediator for my .NET API.
- Show me how to write a raw handler endpoint in .NET without external mediator libraries.

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: d0d6b3e57ef3c7f8.

BEGIN THIRD-PARTY FILE d0d6b3e57ef3c7f8
````text
---
name: vertical-slice
description: >
  Vertical Slice Architecture (VSA) for .NET applications — one of several
  supported architectures in dotnet-claude-kit. Covers feature folders, endpoint
  grouping, and handler patterns for Mediator, Wolverine, and raw handler classes.
  Load this skill when the architecture-advisor recommends VSA, when working in
  an existing VSA codebase, when adding features to a feature-folder project,
  or when discussing vertical slice patterns, feature folders, or handler patterns.
---

# Vertical Slice Architecture (VSA)

## Core Principles

1. **Organize by feature, not by layer** — Each feature is a self-contained vertical slice containing its endpoint, handler, request/response types, and validation. No more jumping between Controllers/, Services/, Repositories/ folders.
2. **Minimize cross-feature coupling** — Features should not reference each other directly. Shared concerns go in a `Common/` or `Shared/` directory.
3. **One file per feature is fine** — A simple CRUD endpoint doesn't need 5 files spread across layers. Start with everything in one file, extract only when complexity demands it.
4. **The handler is the unit of work** — Each handler does one thing. No god-services with 20 methods.

## Patterns

### Feature Folder Structure

```
src/
  MyApp.Api/
    Features/
      Orders/
        CreateOrder.cs          # Request, Handler, Response, Endpoint — all in one file
        GetOrder.cs
        ListOrders.cs
        CancelOrder.cs
        Shared/
          OrderMapper.cs        # Shared within the Orders feature only
      Products/
        CreateProduct.cs
        GetProduct.cs
    Common/
      Behaviors/
        ValidationBehavior.cs   # Cross-cutting Mediator pipeline behavior
      Persistence/
        AppDbContext.cs
      Extensions/
        ServiceCollectionExtensions.cs
    Program.cs
```

### Pattern A: Mediator Handlers (Recommended Default)

Source-generated mediator — MIT licensed, no reflection, Native AOT compatible. Uses `IRequest<T>` / `IRequestHandler<TRequest, TResponse>` with pipeline behaviors. Near-identical API to MediatR but faster and free. Package: `Mediator.Abstractions` + `Mediator.SourceGenerator`.

```csharp
// Features/Orders/CreateOrder.cs

public static class CreateOrder
{
    public record Command(string CustomerId, List<OrderItemDto> Items) : IRequest<Result<OrderResponse>>;

    public record OrderItemDto(string ProductId, int Quantity);

    public record OrderResponse(Guid Id, decimal Total, DateTime CreatedAt);

    public class Validator : AbstractValidator<Command>
    {
````
END THIRD-PARTY FILE d0d6b3e57ef3c7f8

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