# Package layout for UPM packages

> Explore the standard folder and file layout generated for UPM packages.

Explore the folder and file layout for Unity Package Manager (UPM) packages.

When you [create the package structure](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-pkg-structure/cus-create.md), the Package Manager creates the following folder and file layout, which is consistent with UPM packages from the Unity Registry:

```lang-plain
<package-root>
  ├── package.json
  ├── README.md
  ├── CHANGELOG.md
  ├── Third Party Notices.md
  ├── Editor
  │   ├── <organization-name>.<package-name>.Editor.asmdef
  │   └── EditorExample.cs
  ├── Runtime
  │   ├── <organization-name>.<package-name>.asmdef
  │   └── RuntimeExample.cs
  ├── Tests
  │   ├── Editor
  │   │   ├── <organization-name>.<package-name>.Editor.Tests.asmdef
  │   │   └── EditorExampleTest.cs
  │   └── Runtime
  │        ├── <organization-name>.<package-name>.Tests.asmdef
  │        └── RuntimeExampleTest.cs
  ├── Samples
  │        ├── Example
  │        └── ...
  └── Documentation
       └── <package-name>.md
```

| **File or folder**       | **Description**                                                                                                                                                                                                                                                                                                                                                                                                                      |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `package.json`           | The [package manifest](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-pkg-manifest/upm-manifest-pkg.md), which defines the package dependencies and other metadata. This file name must be lowercase.                                                                                                                                                                                                        |
| `README.md`              | Developer package documentation. This documentation helps developers who want to change the package or push a new change on the package's main branch.                                                                                                                                                                                                                                                                               |
| `CHANGELOG.md`           | Description of package changes in reverse chronological order. It's good practice to use a standard format, like [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).                                                                                                                                                                                                                                                            |
| `Third Party Notices.md` | Contains information that's required to meet [legal requirements](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-legal.md) for third-party code or dynamic link libraries (DLL) used in your package.                                                                                                                                                                                                        |
| `Editor/`                | Contains assets (which can include scripts and libraries) for tools and utilities used in the Unity Editor. Unlike folders under the project's `Assets` folder, this is only a convention and doesn't affect the asset import pipeline. Refer to [Create or edit the assembly definitions](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-asmdef.md) to configure Editor-specific assemblies in this folder. |
| `Runtime/`               | Contains assets (which can include scripts and libraries) for tools and utilities used at runtime. This is only a convention and doesn't affect the asset import pipeline. Refer to [Assembly definition and packages](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-asmdef.md) to configure runtime assemblies in this folder.                                                                             |
| `Tests/`                 | Folder to store any [tests included](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-tests.md) in the package.                                                                                                                                                                                                                                                                                                |
| `Tests/Editor/`          | Editor platform-specific tests folder. Refer to [Create or edit the assembly definitions](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-asmdef.md) to configure Editor-specific test assemblies in this folder.                                                                                                                                                                                             |
| `Tests/Runtime/`         | Runtime platform-specific tests. Refer to [Create or edit the assembly definitions](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-asmdef.md) to configure runtime test assemblies in this folder.                                                                                                                                                                                                           |
| `Samples/`               | Folder to store any [samples included](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-samples.md) in the package.                                                                                                                                                                                                                                                                                            |
| `Documentation/`         | Folder to store any [documentation included](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-document.md) in the package.                                                                                                                                                                                                                                                                                     |

> **Note:**
>
> The **Create package** function names the `Documentation` and `Samples` folders without a trailing tilde (`~`). This differs from packages installed from the Unity registry, where the included tilde hides these folders in the **Project** window. When you [export your UPM package](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/cus-export.md), Unity automatically adds the tilde to the `Samples` folder to match the behavior of registry packages. For more information about hidden assets, refer to [Reserved folder name reference](/engine/6000.7/manual/get-started/project-configuration/special-folders.md).

## Additional resources

* [Package creation](/engine/6000.7/manual/packages-list/cus-pkg-lp.md)
* [Package development workflow](/engine/6000.7/manual/packages-list/cus-pkg-lp/cus-pkg-development/custom-packages.md)
* [Reserved folder name reference](/engine/6000.7/manual/get-started/project-configuration/special-folders.md)