Lectura rápida
Empieza por la explicación más corta y útil antes de profundizar.
An on-chain account that stores up to 256 pubkeys, enabling v0 transactions to reference accounts by 1-byte index instead of full 32-byte pubkeys. ALTs dramatically reduce transaction size when interacting with many accounts (e.g., DEX routing). ALTs must be created and populated in advance; entries become active after a slot delay.