Chainlink

Chainlink enables smart contracts on any blockchain to leverage extensive off-chain resources, such as tamper-proof price data, verifiable randomness, automation functions, external APIs, and much more.

Blockchains are highly secure and reliable networks for value exchange but lack the functionality to natively fetch external data or send data to off-chain systems in a manner that retains end-to-end tamper-resistance.

Through the use of secure oracles, Chainlink extends the functionality of blockchains by connecting smart contracts to real-world data, events, payments, and off-chain computation in a highly tamper-resistant and reliable manner.