API3 is a project that aims to bridge the gap between blockchain technology and traditional application programming interfaces (APIs). The project's primary objective is to enable decentralized versions of APIs to be built, managed, and potentially monetized at scale. API3 strives to provide smart contracts with timely, real-world data, which is crucial for various sectors, including decentralized finance and supply chain management. The API3 token, an ERC-20 token based on the Ethereum blockchain, plays a vital role in the API3 ecosystem, allowing token holders to participate in the project's governance.

API3 works by enabling API providers to potentially operate their own nodes, thereby eliminating the need for third-party oracles. This approach aims to solve the "Blockchain Oracle Problem," which refers to the challenge of providing smart contracts with real-world data. API3's solution involves the use of a light and robust middleware called Airnode, which can be deployed in minutes. Airnode enhances transparency and aims to reduce transaction fees, making API3 a practical solution for connecting smart contracts with real-world data.

API3 has a wide range of potential use cases, particularly in sectors that rely heavily on real-time data. For instance, in the decentralized finance (DeFi) sector, API3 can provide accurate and up-to-date price data for various cryptocurrencies, enabling smart contracts to execute trades based on the most current market information. Similarly, in supply chain management, API3 can provide real-time data on product location, status, and other critical details, enabling smart contracts to automate various processes in the supply chain. API3's ability to aim to provide direct connections between APIs and smart contracts opens up numerous possibilities for blockchain integration in various industries.

API3 was unveiled in September 2020 with the release of its whitepaper, which outlined the project's goals and the challenges it aims to address. The project was brought to life by three co-founders: Heikki Vanttinen, Burak Benligiray, and Saša Milić, who have backgrounds in blockchain technology, computer science, and data science. The API3 token went live in December 2020 following a token sale that generated funding. Since its inception, API3 has been working towards its aim of enabling API providers to potentially operate their own nodes, thereby providing a direct connection between smart contracts and real-world data.