The open source smart contract blockchain project Chainlink has reached a cooperation with Swiss blockchain and IoT company Hdac Technology. Hdac said that the purpose of this cooperation is to overcome Oracle (Oracle) problems. When data is obtained and delivered off-chain and subsequently used During the calculation on the chain, the problem of data reliability will appear, which is the Oracle problem. The Oracle problem is one of the biggest challenges to commercializing smart contract technology, because most contract conditions are based on off-chain data and events. With Chainlink, Hdac can ensure that its blockchain-based DApp and IoT services have reliable data.