From an app developer's perspective, this SDK will encapsulate the most complex aspects of using Zcash, freeing the developer to focus on UI and UX, rather than scanning blockchains and building commitment trees! Internally, the SDK is structured as follows:
| **RustBackend** | Wraps and simplifies the rust library and exposes its functionality to the Kotlin SDK |
# Checkpoints
To improve the speed of syncing with the Zcash network, the SDK contains a series of embedded checkpoints. These should be updated periodically, as new transactions are added to the network. Checkpoints are stored under the [sdk-lib's assets](../sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint) directory as JSON files. Checkpoints for both mainnet and testnet are bundled into the SDK.
To update the checkpoints, see [Checkmate](https://github.com/zcash-hackworks/checkmate).
We generally recommend adding new checkpoints every few weeks. By convention, checkpoints are added in block
increments of 2,500 for mainnet and 10,000 for testnet. These increments provide a reasonable tradeoff in terms of number of checkpoints versus performance.
Note: If you're updating the checkpoints with the Checkmate tool, it'll generate several checkpoint files from input parameters for you. Mostly you can filter out the first and the last one, as the first is probably already imported in the project and the last one does not follow the round rule.
