Version: 2019.4
Creating samples for packages
Versioning
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Package manifest

Unity uses the package manifest file (package.json) to manage information about a specific version of a specific package. The package manifest is always at the root of the package and contains crucial information about the package, such as its registered name and version number. It also defines useful information to communicate to the user, such as a user-friendly name that appears in the UI(User Interface) Allows a user to interact with your application. More info
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and a brief description of the package, as well as the earliest version of Unity the package is compatible with.

The package manifest uses the JSON (JavaScript Object Notation) syntax to describe what the package contains. The file’s format is similar to npm’s package.json format, but uses different semantics for some of its properties.

The Package Manager reads this manifest to find out what the package contains, how to unpack its contents, and what information to show the user in the Package Manager window. The manifest stores this information in a series of required, mandatory, and optional properties.

Required properties

These properties are required. If they are not present, either the registry refuses the package when it is published, or the Package Manager cannot fetch or load the package.

Property JSON Type Description
name String The officially registered package name. This name must conform to the Unity Package Manager naming convention, which uses reverse domain name notation. For more information about the naming convention, see Naming your package.

Note: This is a unique identifier, not the user-friendly name that appears in the list view on the Package Manager window.
version string The package version number (MAJOR.MINOR.PATCH).

For example, “3.2.1” indicates that this is the 3rd major release, the 2nd minor release, and the first patch.

This value must respect Semantic Versioning. For more information, see Versioning.

Mandatory properties

These properties are technically optional, and the Package Manager can still install them in a project even if they do not contain valid values or are missing. However, you should give values for these properties, to make your package easily discoverable and provide a better experience for users.

Property JSON Type Description
description String A brief description of the package. This is the text that appears in the details view of the Package Manager window. Any UTF–8 character code is supported. This means that you can use special formatting character codes, such as line breaks (\n) and bullets (\u25AA).
displayName String A user-friendly name to appear in the Unity Editor (for example, in the Project Browser, the Package Manager window, etc.).

For example, Unity Timeline, ProBuilder, In App Purchasing.
unity String Indicates the lowest Unity version the package is compatible with. If omitted, the package is considered compatible with all Unity versions.

The expected format is “<MAJOR>.<MINOR>” (for example, 2018.3). To point to a specific patch, use the unityRelease property as well.

Note: A package that is not compatible with Unity will not appear in the Package Manager window.

Optional properties

These properties are optional, meaning that you can omit them. However, if they are present, they must have a valid value.

Property JSON Type Description
author Object Author of the package.

This object contains one required field (name) and two optional fields (email) and (url).

For example:
{ "name" : "John Doe",
   "email" : "john.doe@example.com",
   "url" : "http://john.doe.example.com/"
}
dependencies Object A map of package dependencies. Keys are package names, and values are specific versions. They indicate other packages that this package depends on.

Note: The Package Manager does not support range syntax, only SemVer versions.
hideInEditor Boolean Normally, the Package Manager hides most packages automatically (the implicit value is “true”), but you can set this property to “false” to make sure that your package and its assets are always visible.
keywords Array of Strings An array of keywords used by the Package Manager search APIs. This helps users find relevant packages.
license String Identifier for an OSS license using the SPDX identifier format, or a string such as “See LICENSE.md file”.

Note: If you omit this property in your package manifest, your package must contain a LICENSE.md file.
samples Array of Objects List of samples included in the package. Each sample contains a display name, a description, and the path to the sample folder starting at the Samples~ folder itself:

{
   "displayName": "<name-to-appear-in-the-UI>",
   "description": "<brief-description>",
   "path": "Samples~/<sample-subfolder>"
}

For more information, see Creating samples for packages.
type String A constant that provides additional information to the Package Manager.

Reserved for internal use.
unityRelease String Part of a Unity version indicating the specific release of Unity that the package is compatible with. You can use this property when an updated package requires changes made during the Unity alpha/beta development cycle (for example, if it needs newly introduced APIs, or uses existing APIs that changed in a non-backward-compatible way without API Updater rules).

The expected format is “<UPDATE><RELEASE>” (for example, 0b4).

Note: If you omit the unity property, this property has no effect.

A package that is not compatible with Unity does not appear in the Package Manager window.

Package manifest example

{
  "name": "com.unity.example",
  "version": "1.2.3",
  "displayName": "Package Example",
  "description": "This is an example package",
  "unity": "2019.1",
  "unityRelease": "0b5",
  "dependencies": {
    "com.unity.some-package": "1.0.0",
    "com.unity.other-package": "2.0.0"
 },
 "keywords": [
    "keyword1",
    "keyword2",
    "keyword3"
  ],
  "author": {
    "name": "Unity",
    "email": "unity@example.com",
    "url": "https://www.unity3d.com"
  }
}


Creating samples for packages
Versioning