nushell/docs/commands/module.md

---
title: module
layout: command
version: 0.59.1
---

Define a custom module

## Signature

```> module (module_name) (block)```

## Parameters

 -  `module_name`: module name
 -  `block`: body of the module

## Examples

Define a custom command in a module and call it
```shell
> module spam { export def foo [] { "foo" } }; use spam foo; foo
```

Define an environment variable in a module and evaluate it
```shell
> module foo { export env FOO_ENV { "BAZ" } }; use foo FOO_ENV; $env.FOO_ENV
```

Define a custom command that participates in the environment in a module and call it
```shell
> module foo { export def-env bar [] { let-env FOO_BAR = "BAZ" } }; use foo bar; bar; $env.FOO_BAR
```