Creating custom packages

The Unity Package Manager is the official package management system for Unity. It does the following:

• 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.

You can use the Package Manager to define Project dependencies, resolve package dependencies, download and add packages as needed, and integrate content in your Projects.

For general information on what a package is and how the Unity Package Manager works, see the PackagesPackages are collections of Assets to be shared and re-used in Unity. There are two types of packages supported in Unity: Asset packages and packages available through the Unity Package Manager (UPM). Packages available through the Unity Package Manager are a fundamental method of delivering Unity functionality. More info
See in Glossary documentation.

Overview

Packages can contain the following:

• C# scripts
• Assemblies
• Native plugins
• Models, Textures, animation and audio clipsA container for audio data in Unity. Unity supports mono, stereo and multichannel audio assets (up to eight channels). Unity can import .aif, .wav, .mp3, and .ogg audio file format, and .xm, .mod, .it, and .s3m tracker module formats. More info
  See in Glossary, and other Assets.

Each package also contains a Package manifestEach package has a manifest, which provides information about the package to the Package Manager. The manifest contains information such as the name of the package, its version, a description for users, dependencies on other packages (if any), and other details. More info
See in Glossary file that includes information such as the package name, its version, a list of its dependencies, and the URL to its repository.

To create a new package:

1. Create an empty shell for the package using one of these methods:

   • Set up an embedded package.
   • Set up a local package.

2. Implement your tools, libraries, and any Assets your package requires.

3. Make sure the layout of your package follows the package layout convention for Unity packages.

4. 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 Playmode Tests in Tests/Runtime.

5. Rename and update the assembly definition files.

6. You can update the CHANGELOG.md file every time you publish a new version. Every new feature or bug fix should have a trace in this file. For more details on the chosen changelog format, see the Keep a Changelog documentation.

   This 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.

7. You can include licenses and third-party notices in the LICENSE.md and THIRD PARTY NOTICES.md files.

   This 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.

8. Share your package.

Creating a new embedded package

Follow these instructions if you want to create a custom package inside your Project folder.

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 it as a local package. 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 subfolder.

3. Create a new subfolder for your package inside the Packages folder.

4. Open your preferred text editor and create a JSON file called package.json.

5. Save it under the new package root folder you created.

6. Fill out all required and mandatory fields in the package manifest (package.json) file.

When you reopen Unity, the new package appears in the Package Manager window and in the Project window, where you can view and modify the package contents. If you select the package.json file in the Project window, you can also modify its contents directly in the InspectorA Unity window that displays information about the currently selected GameObject, Asset or Project Settings, alowing you to inspect and edit the values. More info
See in Glossary window.

Creating a new local package

Follow these instructions if you want to create a custom package outside your Project folder:

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’ve already created some content for your 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 they are stored under the Editor and Runtime folders.

3. Open your preferred text editor and create a JSON file called package.json.

4. Save it under the package root folder.

5. Fill out all required and mandatory fields in the package manifest (package.json) file.

6. In Unity, create a new Project or open an existing Project.

7. Open the Packages window and follow the instructions for installing a local package, using the package.json file you just created.

The new package appears in the Package Manager window and in the Project window, where you can view and modify the package contents. If you select the package.json file in the Project window, you can also modify its contents directly in the Inspector window.

• Custom Packages added in Unity 2019.1 NewIn20191