Chainlink Guide

The following chart explains Chainlink's Direct Request model.

[0] When a transaction is submitted, it triggers a request on the Consumer smart contract. The JobID and input parameters are specified.

[1] The Consumer smart contract sends this request to a specific Oracle smart contract with the input parameters and payment in LINK.

[2] The Oracle smart contract receives payment in LINK for the request and passed it to a Chainlink Node.

[3] Chainlink Node receives a request and executes it by initiating the job/external adapter specified in the Consumer contract.

[4] Chainlink Node requests a Third-Party API premium or free data with the input parameters and receives the expected response.

[5] Chainlink Node parses and encodes the response, preparing the data to be committed on-chain.

[6] Chainlink Node Wallet invokes the callback function on the Oracle Contract and pays the transaction gas fee on specific blockchain.

[7] Oracle smart contract commits the prepared data on-chain writing it to the Consumer smart contract.

[8] Consumer smart contract receives the fulfilled request making the data available to be read on-chain.