configure-slice

name	configure-slice
license	MIT
type	atomic
description	Creates and configures Hanami 2.x Slices by registering providers, setting up container dependencies, customizing auto-registration paths, and managing slice-level settings. Use when configuring slice setup, modular app structure, Hanami component registration, dependency injection, provider registration, container imports/exports, or autoloading for a Hanami 2.x Slice.
metadata	{"ecosystem_sources":["hanami/hanami","dry-rb/dry-system"],"tags":["slices","configuration","settings","providers"],"version":"1.0.0"}

configure-slice

Use this skill when configuring Hanami 2.x Slices.

Core principle: Each Slice configures its own container, settings, and providers independently of the main app.

---

Quick Reference

Scenario	Approach
Configure a Slice	Edit slices/<name>/config/slice.rb
Define slice-level settings	Use config.settings in the Slice class
Register slice providers	Use register_provider in the Slice class
Configure auto-registration	Set config.auto_register_paths
Exclude paths from auto-registration	Set config.no_auto_register_paths
Access slice settings	target[:settings] in providers or slice.settings
Override main app config	Define config in the Slice that takes precedence
Container imports	import from: :other_slice
Container exports	export ["component.key"]

---

Core Rules

1. Create the Slice configuration file:

   # slices/api/config/slice.rb
   # frozen_string_literal: true
   
   module MyApp
     module Slices
       module Api
         class Slice < Hanami::Slice
           # Slice-level configuration
         end
       end
     end
   end
   

2. Define slice-level settings:

   class Slice < Hanami::Slice
     config.settings do
       setting :api_key, constructor: Types::String
       setting :rate_limit, default: 100, constructor: Types::Integer
     end
   end
   

3. Register slice-specific providers:

   class Slice < Hanami::Slice
     register_provider(:api_client) do
       start do
         client = ApiClient.new(
           api_key: target[:settings].api_key,
           base_url: "https://api.example.com"
         )
         register("api.client", client)
       end
     end
   end
   

4. Configure auto-registration paths:

   class Slice < Hanami::Slice
     config.auto_register_paths = ["app/actions", "app/views", "app/repos"]
     config.no_auto_register_paths = ["app/relations", "app/structs", "app/entities"]
   end
   

5. Import components from another Slice:

   class Slice < Hanami::Slice
     import from: :main do
       # Import all exported components from the main slice
     end
   end
   

6. Export components for other slices:

   class Slice < Hanami::Slice
     export ["repositories.users", "services.auth"]
   end
   

7. Override main app configuration for slice-specific needs:

   class Slice < Hanami::Slice
     # Use a different database for this slice
     config.database_url = target[:settings].database_url
   end
   

8. Keep configuration minimal. Only override defaults when necessary. Prefer convention over configuration.

9. Verify configuration after changes. Run bundle exec hanami console and confirm components resolve correctly:

   # Verify settings are loaded
   MyApp::Slices::Api::Slice[:settings].api_key  # => expected value
   
   # Verify a registered provider component is available
   MyApp::Slices::Api::Slice["api.client"]  # => #<ApiClient ...>
   
   # Verify an imported component resolves
   MyApp::Slices::Api::Slice["repositories.users"]  # => #<Repositories::Users ...>
   

---

Common Mistakes

Mistake	Reality
"I'll duplicate main app configuration in every slice"	Slices inherit main app configuration. Only override when the slice genuinely needs different behavior.
"I'll forget to export components other slices depend on"	If Slice B imports from Slice A, Slice A must export those components. Verify with Slice["component.key"] in the console.
"I'll use ENV directly instead of slice settings"	Use config.settings for typed, validated configuration. Access via target[:settings].
"I'll configure auto-registration to include ROM-managed directories"	Never auto-register relations/, structs/, or entities/. ROM manages these.

---

Integration

Related Skill	When to chain
create-slice	Configuration follows slice creation. Understand slices before configuring.
register-provider	Slice-specific providers are registered in slice configuration.
manage-settings	Slice-level settings are defined in the Slice class.
inject-dependencies	Configured components are injected via Deps[].
create-new-slice (workflow)	Full workflow includes configuration step.