# Core

- [Catchup](/0.1.8/api/core/catchup.md): Get balls units between 2 main chain ids.
- [Get hash tree](/0.1.8/api/core/get-hash-tree.md): Get units between balls.
- [Get light props](/0.1.8/api/core/get-light-props.md): Get light client properties.
- [Post joint](/0.1.8/api/core/post-joint.md): Post an unit on Byteball network.
- [Pick divisible coins for amount](/0.1.8/api/core/pick-divisible-coins-for-amount.md): Get spendable inputs from a specific amount and asset.
- [Heartbeat](/0.1.8/api/core/heartbeat.md): Send heartbeat to notify the node you are awake.