Embedded dependencies

Any package that appears under your project’s Packages folder is embedded in that project. You can create an embedded packageAn embedded package is a mutable package that you store under the Packages directory at the root of a Unity project. This differs from most packages which you download from a package server and are immutable. More info
See in Glossary in several ways:

• Create a new package directly in your project’s Packages folder.
• Place a copy of a Unity package in your project’s Packages folder.
• Use a C# script to embed a version of a package that’s already installed.

Embedded packages don’t need to appear in the project manifest as a dependency. However, if you embedded a version of an installed package, your project manifest still lists the dependency on the original installed version. In that case, the package on disk takes priority over the version of the package listed as a dependency, so it doesn’t need to be removed from the project manifest. For example, if the project manifest specifies a dependency on version 1.3.1 of the com.unity.example package but the project also has an embedded package with that name, the Package Manager uses the embedded package, regardless of its apparent version, instead of downloading version 1.3.1 from the registry.

Make sure you track the contents of your embedded packages, and any changes you make to it. If your Unity project is under source control, add any packages embedded in that project to the same source control.

Create a new custom package

To embed a new package, create your new package content inside a folder under the Packages folder. For more information, follow the instructions for creating your own custom package.

Typically, your new package remains embedded in your project until you are ready to share it with other users and test it in other projects. You can use different methods to share your package, for example, you can host the package on a scoped registry.

Copy a Unity package to your project folder

A package installed from a registry is immutableYou cannot change the contents of an immutable (read-only) package. This is the opposite of mutable. Most packages are immutable, including packages downloaded from the package registry or by Git URL.
See in Glossary, which means you can’t edit it. If you want to edit a package, you can make it mutableYou can change the contents of a mutable package. This is the opposite of immutable. Only Local packages and Embedded packages are mutable.
See in Glossary by copying it to the Packages subfolder in your project folder. This package type is called an embedded package, and it overrides what’s in your package cache. Later, you can delete that embedded package’s folder from the Packages subfolder, and the Package Manager will automatically change to the immutable, cached package.

To copy a Unity package to your project folder:

1. Use the Package Manager window to select the UPM packageA Package managed by the Unity Package Manager. Refer to Packages.
   See in Glossary you want to copy from the Unity Registry or In Project context.

2. Open the Manage dropdown in the details panel.

3. Select Customize.

The package now appears with the Custom label. You can edit the package, which was copied to the Packages folder of your project.

You can delete the embedded package and the Package Manager will automatically revert to the immutable, cached package. Consider backing up the folder for the embedded package, otherwise you’ll lose any changes you made to the package. Use either of the following methods to delete the embedded version of a package:

• Use the Package Manager’s Manage dropdown to Remove the embedded package.
• Use your file browser or command line to locate the Packages folder of your project. Then, delete the folder for that package from your Packages folder.

Additional resources

• Project manifestEach Unity project has a project manifest, which acts as an entry point for the Package Manager. This file must be available in the <project>/Packages directory. The Package Manager uses it to configure many things, including a list of dependencies for that project, as well as any package repository to query for packages. More info
  See in Glossary
• Use a script to embed a package in your project