Version: 2021.3
Creating samples for packages
Versioning

Package manifest

Unity uses a 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. Unity currently supports three UI systems. More info
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, a brief description of the package, and 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. Refer to the example for a sample package manifest file.

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

Required properties

If these properties aren’t present, either the registry refuses the package when it’s published, or the Package Manager can’t 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 in 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.

Recommended properties

The Package Manager can install packages in a project even if the recommended properties don’t have valid values or are missing.

However, you should assign values for these properties to ensure that your package is discoverable and to 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. This field supports UTF–8 character codes. 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 Manager considers the package 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 isn’t compatible with Unity doesn’t appear in the Package Manager window.

Optional properties

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

Property JSON Type Description
author Object The 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/"
}
changelogUrl String Custom location for this package’s changelog specified as a URL. For example:
"changelogUrl": "https://example.com/changelog.html"

Note: When the Package Manager can’t reach the URL location (for example, if there is a network issue), it does the following:

- If the package is installed, the Package Manager opens a file browser displaying the CHANGELOG.md file in the package cache.
- If the package isn’t installed, the Package Manager displays a warning that an offline changelog isn’t available.
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 doesn’t support range syntax, only SemVer versions.
documentationUrl String Custom location for this package’s documentation specified as a URL. For example:
"documentationUrl": "https://example.com/"

Note: When the Package Manager can’t reach the URL location (for example, if there is a network issue), it does the following:

- If the package is installed, the Package Manager opens a file browser displaying the Documentation~ folder in the package cache.
- If the package isn’t installed, the Package Manager displays a warning that offline documentation isn’t available.
hideInEditor Boolean 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.
licensesUrl String Custom location for this package’s license information specified as a URL. For example:
"licensesUrl": "https://example.com/licensing.html"

Note: When the Package Manager can’t reach the URL location (for example, if there is a network issue), it does the following:

- If the package is installed, it opens a file browser displaying the LICENSE.md file in the package cache.
- If the package isn’t installed, the Package Manager displays a warning that offline license information isn’t available.
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. This might be the case if the package needs newly introduced APIs, or uses existing APIs that have 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 recommended unity property, this property has no effect.

A package that isn’t compatible with Unity doesn’t appear in the Package Manager window.

Package manifest example

{
  "name": "com.[company-name].[package-name]",
  "version": "1.2.3",
  "displayName": "Package Example",
  "description": "This is an example package",
  "unity": "2019.1",
  "unityRelease": "0b5",
  "documentationUrl": "https://example.com/",
  "changelogUrl": "https://example.com/changelog.html",
  "licensesUrl": "https://example.com/licensing.html",
  "dependencies": {
    "com.[company-name].some-package": "1.0.0",
    "com.[company-name].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