Vault is a new Android library that simplifies persistence of data from Contentful via SQLite, enabling developers to easily define Java representations for their existing Contentful models and generate boilerplate code. It provides a lightweight runtime with an ORM-like API for pulling resources from the generated database. The library can be used to simplify syncing content between local storage and the server, reducing development time and improving user experience. Vault is open source and available on GitHub, offering customer support and regular updates.