---
title: Modules & Imports
description: Organizing code across files with module declarations and path-based imports.
icon: FolderTree
---

Mist organizes code through a file-system based module system with explicit path imports.

## Module Declarations

Each `.mist` file declares itself as a module with `pub module name;` at the top. A `package.mist` file acts like `mod.rs` — it is the entry point for its directory.

```mist
// src/utils/helper.mist
pub module helper;

pub void greet() {
    println!("Hello!");
}
```

```mist
// src/utils/package.mist
pub module utils;
// This module exports submodules and items
```

## Imports

Use the `use` keyword with a path to bring items from other modules or external crates into scope.

```mist
use std::fs;
use std::process;
use std::path::Path;
use std::collections::HashMap;

// Import specific items
use my_module::Helper;
```

### Visibility

Items can be re-exported with a visibility modifier on the import:

```mist
pub use internal::format;
```

## Sidefiles

Any non-`.mist` file in `src/` (e.g., `.rs`, `.toml`, data files) is treated as a **sidefile** — it is copied directly into the output directory `.mist/src/` during transpilation. This allows you to keep Rust helper files or configuration alongside your Mist source.

```text
src/
├── main.mist
├── helper.rs        # copied to .mist/src/helper.rs
└── config/
    └── data.json    # copied to .mist/src/config/data.json
```

## Project Structure

A typical Mist project looks like this:

```
my-project/
├── Cargo.toml
├── Mist.toml
├── src/
│   ├── main.mist
│   ├── my_api/
│   │   ├── package.mist
│   │   ├── methods.mist
│   │   └── utils.mist
└── .mist/
    └── src/
        ├── main.rs
        └── my_api/
            ├── mod.rs
            ├── methods.rs
            └── utils.rs
```

The `.mist/src/` directory contains the transpiled Rust output.