Definition
An ABI (Application Binary Interface) in blockchain, particularly in EVM-based systems, is a formal specification that defines how external entities interact with a compiled smart contract at the bytecode level. It describes the contract’s callable functions, events, and data structures in a machine-readable format, including names, argument and return types, and encoding rules for requests and responses.
In Simple Terms
An ABI is a technical description of a smart contract’s public surface. It lists what functions and events exist and how data must be formatted so software can communicate correctly with the contract’s compiled code.
Context and Usage
ABI is central to interaction between smart contracts and off-chain or on-chain callers in EVM-compatible environments. It is typically generated from high-level contract source code and consumed by tools, libraries, and RPC clients to construct and decode transaction payloads and logs. ABI definitions enable consistent, deterministic communication with deployed contract bytecode across different implementations and platforms.