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nix-option-types

Defines Nix module options using mkOption, type combinators, and submodule patterns.

1|Updated Aug 21, 2023
Search Tags:#configuration#nix#types#module options#nixos#submodule#mkoption
One-click install
npx skills add https://github.com/jmuchovej/homelab --skill nix-option-types-jmuchovej
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: nix-option-types
Source: https://github.com/jmuchovej/homelab/tree/main/src/modules/ai-tools/skills/nix-option-types
Command: npx skills add https://github.com/jmuchovej/homelab --skill nix-option-types-jmuchovej

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Writing Nix modules requires choosing the correct option types and declaration helpers, and picking the wrong type or forgetting a default leads to confusing evaluation errors. This Skill provides ready-to-use patterns for declaring options correctly the first time. ## Core Features & Use Cases - Helper Selection Guidance: Shows when to use mkEnableOption, mkPackageOption, or mkOption for common declaration scenarios. - Type Reference Patterns: Covers basic types (str, int, port, path, package), collection types (listOf, attrsOf, enum, nullOr, either), and validated port ranges. - Submodule Pattern: Demonstrates attrsOf submodule declarations for nested service configuration with per-instance options. - Use Case: When adding a new service to a NixOS or Home Manager module, use these patterns to declare an enable flag, a validated port option, and a package option with sensible defaults. ## Quick Start Ask the AI to define Nix module options for a new service including an enable flag, a port, and a package using mkOption and the appropriate types.

Frequently Asked Questions about nix-option-types

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I define options in a Nix module with mkOption?▼

Use mkOption with a type, default, and description to declare module options. For boolean enable flags, prefer mkEnableOption, and for package options use lib.mkPackageOption, which handles defaults automatically.

What Nix option type should I use for a list or attribute set?▼

Use types.listOf for lists and types.attrsOf for attribute sets, wrapping the element type such as types.listOf types.str. For a fixed set of allowed values, use types.enum with a list of permitted strings.

When should I use mkEnableOption vs mkOption in Nix?▼

Use mkEnableOption for boolean enable flags since it generates a standard description and defaults to false. Use mkOption for everything else, including strings, integers, ports, paths, and composite types.

How do I create nested submodule options in Nix?▼

Wrap types.submodule inside types.attrsOf to declare named instances of a nested option set. Each submodule defines its own options block, letting users configure entries like services.myService with enable and port fields.

Does Nix validate port numbers in module options?▼

Yes, types.port validates that values fall within the 1-65535 range at evaluation time. Declaring an option with types.port catches invalid port assignments before the configuration is built.

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