Create custom packages

• Allows Unity to distribute new features and update existing features quickly and easily.
• Provides a platform for users to discover and share reusable components.
• Promotes Unity as an extendable and open platform.

Overview

• C# scripts
• Assemblies
• Native plug-ins
• Models, Textures, animation and audio clips, and other assets.

Procedure

1. Create an empty shell for the package using one of these methods:
   • Set up an embedded package.
   • Set up a local package.
2. Make sure the layout of your folder structure follows the package layout convention for Unity packages. For example, if you have Editor and Runtime libraries, make sure you store them under the

   Editor

   and

   Runtime

   folders.
3. If your package includes code, make sure the package layout you created has the necessary assembly definition files. For information about creating and defining assembly definition files, refer to Assembly definition and packages. For additional information, refer to Assembly definitions.
   Note

   If the console window reports a warning after adding an assembly definition file, save your project, close it, then reopen it.
4. Add your tools, libraries, and any assets your package requires.
5. Add tests to your package. Tests are essential for ensuring that the package works as expected in different scenarios:
   • Write all your Editor tests in

     Tests/Editor

     .
   • Write all your Play mode tests in

     Tests/Runtime

     .
6. If you have samples for your package, add them to the proper samples subfolder.
   Note

   Packages can contain only samples, but you can also include samples as part of a tool or template package using the same layout and JSON structure.
7. Update the

   CHANGELOG.md

   file every time you publish a new version. Identify new features, important changes, and major bug fixes in this file. For more details on the chosen changelog format, refer to the Keep a Changelog documentation.
   This step is optional for packages that you don't share, but strongly recommended for shared packages, so that users know which version best suits their needs.
   Tip

   You can provide a link to an external web page where you host this package's changelog by setting the changelogUrl property in your package's

   package.json

   manifest file.
8. You can include licenses and third-party notices in the

   LICENSE.md

   and

   THIRD PARTY NOTICES.md

   files.
   This step is optional for packages that you don't share, but strongly recommended for shared packages, so that your users don't misuse your packages or violate any third-party licenses.
   Tip

   You can provide a link to an external web page where you host this package's licensing and third-party notices. Set the link by using the licensesUrl property in your package's

   package.json

   manifest file.
9. Document your package.
   Tip

   You can provide a link to an external web page where you host this package's documentation by setting the documentationUrl property in your package's

   package.json

   manifest file.
10. Share your package.

Creating a new embedded package

1. Open the Unity Hub, and create an empty project on your computer.
   You can also use an existing project on your computer, and embed the package under your project or install the package from a local folder. However, starting with a new project makes the package contents less prone to errors.
2. Using your computer's file manager (for example the Windows File Explorer or the macOS Finder), navigate to your project folder and locate the

   Packages

   subdirectory.
3. Create a new subdirectory for your package inside the

   Packages

   folder using a name that matches the package name and follows the naming conventions. For example, if your package name is

   com.example.mypackage

   , create a subdirectory called

   com.example.mypackage

   .
   Note

   This is important if your package contains assets, because the AssetDatabase looks for an asset path that matches

   Packages/<your-package-name>/Assets

   , regardless of the actual folder name.
4. Open your preferred text editor and create a JSON file called

   package.json

   in the root of the package folder.
5. Fill out all required and recommended fields in the

   package.json

   file. You can use the package manifest example as a reference.

package.json

Creating a new local package

1. Using your computer's file manager (for example the Windows File Explorer or the macOS Finder), create a folder for your package.
   You can also use an existing location if you have already created some content for your package.
2. Open your preferred text editor and create a JSON file called

   package.json

   in the root of the package folder.
3. Fill out all required and recommended fields in the

   package.json

   file, making sure the

   name

   property follows the naming conventions. You can use the package manifest example as a reference.
4. In Unity, create a new project or open an existing project.
5. Open the Package Manager window and follow the instructions for installing a local package, using the

   package.json

   file you just created. This step is essential for ensuring the creation of the required

   .meta

   file.

package.json