What is a covenant identifier (covenant_id) in Kaspa?

A covenant identifier (`covenant_id`) is a consensus-tracked, 32-byte label that Kaspa attaches to UTXOs so a set of coins carries a stable, network-verified lineage as it moves through transactions. In Kaspa, a UTXO is an unspent transaction output — essentially a chunk of coins waiting to be spent. A covenant is a programmable rule constraining how those coins can move in the future. The `covenant_id` travels with each output through the covenant chain, giving both the network and off-chain indexers a reliable way to track which outputs belong to the same covenant instance across many spending hops. This matters because it is the foundation for smart contract-like applications on Kaspa that need to maintain shared state without relying on a trusted third party.