What is the Toccata hard fork?

Toccata is a mandatory protocol upgrade — a hard fork — that makes Kaspa programmable at Layer 1 for the first time. A hard fork means the old and new versions of the software are incompatible: every node on the network must upgrade to v2.0.0 or later, or it will be cut off. The upgrade bundles four new sets of transaction opcodes (KIP16, KIP17, KIP20, KIP21) covering zero-knowledge proof verification, covenant programming, UTXO lineage tracking, and efficient ZK proving. For a beginner, the headline takeaway is that Kaspa can now enforce complex on-chain rules natively — something that previously required trusting a third party or a centralized coordinator.