KT1

KT1 is the prefix used for originated smart contract addresses on the Tezos blockchain. It identifies a contract that was created by an origination operation, in contrast to tz1, tz2, and tz3 addresses that identify public-key-hash accounts.

Originated contracts are created by an origination operation that provides the contract’s code (written in Michelson or in higher-level languages compiled to Michelson) and an initial storage. When the operation is applied, Tezos assigns a new KT1 address to the contract. The KT1 address is then used to interact with the contract by sending transactions that invoke its entry points with parameters.

Control of a KT1 contract is defined by its on-chain code and storage rather than a single private key. Contracts can call other contracts, move funds, or modify their own storage according to their logic. Interactions typically require gas and storage fees and may be initiated by another account or by a calling contract, depending on the contract’s design.

Representation and usage: KT1 addresses are Base58Check-encoded with the KT1 prefix and appear in wallets, explorers, and RPC interfaces. They are widely used in the Tezos ecosystem for a variety of applications, including DeFi, non-fungible tokens, and governance mechanisms.

In practice, KT1 addresses coexist with tz1/tz2/tz3 addresses; a KT1 marks a smart contract, while the tz prefixes identify public keys. Understanding KT1 addresses helps in tracing contract deployment, interactions, and on-chain state within Tezos-based projects.