API3

API3 published its whitepaper in September 2020, written by Burak Benligiray, Saša Milić and Heikki Vänttinen, and the API3 token went live in December 2020. The project is built around the first-party oracle: the company that owns an API runs the oracle node for it with Airnode, signs its data with its own key and answers for it. In a third-party design, separate node operators read the same API and pass the data on.

API3 calls its aggregated data feeds dAPIs. A developer buys a plan for a data feed on the Api3 Market and integrates it within minutes, and the catalog covers all major EVM networks. API3 lists more than 100 data feeds on every chain it supports.

Oracle extractable value, OEV, is the profit a bot can make by acting first on a fresh oracle update, for example by liquidating a loan that the new price has made unsafe. API3 auctions the privilege of triggering these updates and pays 80 percent of the revenue to the protocol that uses the feed. According to API3, OEV Rewards have paid out $416,069 in total, and nine lending protocols were among the early recipients.

OEV is a close relative of maximal extractable value, the profit from ordering transactions on a blockchain. A lending protocol that recovers OEV keeps money that would otherwise go to searchers and validators.

Holders of the API3 token stake it in the pool of the API3 DAO, which gives them votes on proposals and a share of the staking rewards. The staked tokens were also designed to back a coverage pool that compensates users for losses from faulty feeds. DefiLlama counted $22 million in value secured by API3 feeds across 44 protocols in September 2026.

API3 also runs AirnodeHub, an early-access marketplace where AI agents find, call and pay for APIs, and each response pays the data provider. API3 notes that this product is still changing and may take a different direction.

API3 crypto usually means the API3 token of the API3 project, a network of first-party oracles. Holders stake the token in the API3 DAO to vote on proposals and to earn staking rewards.

API3 holders stake their tokens in a single pool of the API3 DAO. Staked tokens give voting power in the DAO and earn rewards, and unstaked tokens become free only after a waiting period of one week.

Airnode is open-source software from API3 that lets a data provider run its own oracle node. The provider signs every response with its own key, so a smart contract can check that the data came from that provider.

OEV is the money a bot earns by acting first on an oracle update, mostly through liquidations of loans. API3 auctions that chance and pays 80 percent of the proceeds to the protocol that reads the feed.