# Applicationbuildproperty The ApplicationBuildProperty is an element that adds meaning to the [ApplicationBuild](https://docs.i3d.net/game-hosting/elements/application/applicationbuild) element. E.g. you can define that an application uses a certain network port, or requires a password, together with a preset password, or have the system generate a unique password for each ApplicationInstance. These properties are necessary for the system to work properly. {% hint style="info" %} You cannot create an ApplicationBuildProperty yourself. They will be inherited from the [Application](https://docs.i3d.net/game-hosting/elements/application) and its [ApplicationProperty](https://docs.i3d.net/game-hosting/elements/application/applicationproperty) elements the ApplicationBuild is based on. You CAN override property values if you need to. {% endhint %} ## Element structure | Property | Value type | Required | Read-only | Description | | ------------- | ---------- | --------------------- | --------- | -------------------------------- | | propertyId | string | N/A | Yes | Unique identifier of the element | | propertyType | int | Yes | No | Type ID of the property | | propertyKey | string | Yes | No | The name of the property | | propertyValue | mixed | Only for network port | No | The value of the property | Table 1: ApplicationBuildProperty element structure ## propertyKey constraints The characters allowed for a propertyKey are : `a-z, 0-9, -, _` A property key must start with a lowercase character. The maximum length of a propertyKey is 50 characters. ## propertyValue constraints Any UTF-8 character is allowed in a propertyValue. The maximum length of a propertyValue is 150 characters. ## propertyType ApplicationBuildProperty elements consist of a `propertyType`, a `propertyKey` and a `propertyValue`. The `propertyType` indicates the functionality of the property. The `propertyKey` gives the property a name and the `value` a value. Not all property types require a value. E.g. if you have a property of `propertyType` `password16`, you can leave `propertyValue` empty. This means we will generate a password, in this case with a length of 16 characters. If however you do enter a `propertyValue`, then we take that as the password and the system will not generate a new random password. You can find all available property types and usages in the next chapter. ## Available property types A propertyType is indicated by a numerical ID. The following types are available: | ID | Type | Value type | Value required? | Description | | -- | -------------------------- | ----------------------------------- | --------------- | ----------------------------------------------------------------------------------------------------------------------------- | | 0 | raw value | mixed | yes | A custom raw value. This property's key and value will be passed to ApplicationBuilds, ApplicationInstances and labels as-is. | | 1 | public network port | 0 or a number between 10240 - 29999 | yes | Indicates a default or random network port for your application to use. | | 2 | password8 | string | no | An 8 character password. If no value provided, we generate a unique password for every ApplicationInstance. | | 3 | password16 | string | no | A 16 character password. If no value provided, we generate a unique password for every ApplicationInstance. | | 4 | password24 | string | no | A 24 character password. If no value provided, we generate a unique password for every ApplicationInstance. | | 5 | public network port range | a number between 2 and 200 | yes | A number indicating the size of the desired port range. | | 6 | private network port | 0 or a number between 30000 - 49151 | yes | Indicates a default or random network port for your application to use. | | 7 | private network port range | a number between 2 and 200 | yes | A number indicating the size of the desired private port range. | Table 2: Property types ## Property inheritance An ApplicationBuild's properties will be inherited by all [ApplicationInstance](https://docs.i3d.net/game-hosting/elements/application/applicationinstance) elements deployed for said ApplicationBuild. ## Property value overrides An ApplicationProperty's value can be overridden at later stages, in the listed order: 1. an ApplicationBuild will inherit an Application's properties. Its values can be overridden in the ApplicationBuild ([API documentation](https://docs.i3d.net/api/api_one#v3-applicationbuild)) 2. a DeploymentRegion can override a property on a per-region basis. This can be useful if you want to define different property values for each deployment region, allowing you to start your applications with region-based startup parameters ([API documentation](https://docs.i3d.net/api/api_one#v3-applicationbuild)) As such, an override on DeploymentRegion level always wins. If no override for a DeploymentRegion is present, an override of the ApplicationBuild will win. If no override for an ApplicationBuild is present, the original property value defined for the Application will win. ## Property usage Every property you define will become available as platform variables that can be used in configuration related properties: ApplicationBuild.startupParameters and ApplicationBuildConfiguration.configContents. Please see the [platform variables](https://docs.i3d.net/game-hosting/elements/application/platform-variables) topic for more details. ## Restrictions You can assign any number of ApplicationBuildProperty to an ApplicationBuild. There is no limitation there. The only rule is that you must have unique propertyKey names per ApplicationBuild. ## Relations See also: [Application element relations](https://docs.i3d.net/game-hosting/elements/application/element-relations) ## Related topics * [Orchestrator Overview](https://docs.i3d.net/game-hosting/game-integration/orchestratoroverview) * [Game Deployment Quick Start Guide](https://docs.i3d.net/game-hosting/overview/quick-start) * [i3d.net API documentation](https://www.i3d.net/docs/api/v3/all/)