# ERTP API
The ERTP API supports the following objects:
|The authority on what holds digital assets of its kind.
|Can issue new digital assets.
|Identifies the asset type of the associated Issuer and Mint.
|Holds digital assets.
|Holds digital assets that are in transit.
The ETRP API uses the following library:
|The AmountMath object has several methods which can be used to manipulate and analyze Amounts.
The ERTP API introduces and uses the following data types:
|Describes digital assets, specifying the number and Brand of assets. Note that Amounts can describe either fungible or non-fungible assets.
|Describes digital assets, specifying the properties and Brand of assets.
|Describes how much of something there is.
|Specifies whether an Amount is fungible or non-fungible.
|Specifies how to display a Brand's Amounts.