# Cairo Modules Files

> Explain how Cairo modules are split across files and folders, and how `mod` declarations map to files; use when a request involves organizing modules into multiple files in Cairo.

- Skill: `majiayu000/cairo-modules-files` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/cairo-modules-files`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/cairo-modules-files/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/cairo-modules-files

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# Cairo Modules in Files

## Overview
Explain how module declarations map to files and folders in a Cairo package.

## Quick Use
- Read `references/modules-files.md` before answering.
- Show the relationship between `mod` declarations and file names.
- Remind that `use` does not load modules; only `mod` does.

## Response Checklist
- Declare a module with `mod name;` in the parent file.
- Place the module body in `name.cairo` or `name/mod.cairo`.
- Declare submodules in the module file and place them in `name/submodule.cairo`.

## Example Requests
- "Where should I put `mod hosting;`?"
- "How do I split a module into multiple files?"
- "Why doesn't `use` load my module?"

## Cairo by Example
- [File hierarchy](https://cairo-by-example.xyz/mod/split)