API3 is a collaborative project to deliver traditional API services to smart contract platforms in a decentralized and trust-minimized way. It is governed by a decentralized autonomous organization (DAO), namely the API3 DAO. Therefore, its code is open source and its operations are transparent.
Smart contracts running on a blockchain network can only operate on information that is accessible to and agreed upon by all nodes in the network. Thus the blockchain is walled-off from off-chain information, this is referred to as "the oracle problem”.