# KCC Oracle ## Overview A blockchain oracle is a bridge between the blockchain and the real world. These oracles allow real-world data to enter the blockchain. This data could be anything from price information to weather reports. Oracles can also be bi-directional and "send" data out to the real world. With the sharp rise of various DeFi applications, a stable and reliable decentralized oracle service is key to premium DeFi projects. Hence, the arrival of KCC Oracle addresses the need for KCC-based smart contracts to access external data. Please read through them carefully and understand the underlying risks before using Oracle. ## Reliability ### Data Sources KCC Oracle sources price data from multiple centralized exchanges (CEXs) and from the decentralized finance (DeFi) applications and aggregates the data using a weighted formula. ### Data Signing KCC Oracle has two roles: transmitter and signer. The signer signs data, and the transmitter is responsible for transmitting the signed data up the chain. It is intended to make data tamper-proof and to improve the security and reliability of different roles addresses. ### Data Publishing Publishing data to the blockchain happens through multi-nodes. Multi-nodes also ensure that those smart contracts that already store some data are secure and audited. Multi-node architecture can also adjust the frequency of data publishing based on the situation. For example, it can help you get accurate data during high price volatility. ### Data Monitoring The data on the KCC Oracle is kept up to date by an independent monitoring service that works 24 hours a day, seven days a week. It fetches prices from different data sources and compares them to published blockchain data. And the KCC Oracle support team will intervene if a significant deviation is detected. ## API Reference Oracle Aggregator periodically publishes valuable data to the Oracle network. The aggregator stores the aggregated data on a chain so that consumers can retrieve and use it in the same transaction. We recommend retrieving data sources through [`AggregatorV3Interface`](https://github.com/kcc-community/kcc-oracle/blob/main/contracts/interfaces/AggregatorV3Interface.sol) and proxy addresses. ### Functions
NameDescripition
decimalsThe number of decimals
descriptionThe description of trading pairs
getRoundDataGet data from a specific round
latestRoundDataGet data from the latest round
versionGet the version of the aggregator
#### decimals Get the number of decimals of the response ```solidity function decimals() external view returns (uint8); ``` **Return values** * RETURN: The number of decimals #### description Get the description of the aggregator ```solidity function description() external view returns (string memory); ``` **Return values** * RETURN: The description of trading pairs #### getRoundData Get the round data details for a given round ID ```solidity function getRoundData(uint80 _roundId) external view returns ( uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound ); ``` **Parameters** * \_roundId: The round ID **Return values** * roundId: The round ID * answer: The answer for this round * startedAt: Timestamp of when the round started * updatedAt: Timestamp of when the round was updated * answeredInRound: The round ID in which the answer was computed #### latestRoundData Get the price from the latest round ```solidity function latestRoundData() external view returns ( uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound ); ``` **Return values** * roundId: The round ID * answer: The price * startedAt: Timestamp of when the round started * updatedAt: Timestamp of when the round was updated * answeredInRound: The round ID of the round in which the answer was computed #### version Get the version of the aggregator ```solidity function version() external view returns (uint256); ``` **Return values** * RETURN: The version of the aggregator ## Contract Address **KCC Mainnet Feed addresses**
Pair (Base/Quote)Decimals DeviationHeartbeatData Feed Contract (Proxy Address)
BTC/USD80.2%2m0xFAce3f85602A8dc013217b61a97a9AFE7B2F276F
ETH/USD80.2%2m0x72E10386eBE0E3175f62BF3Edfc9A64aC3c5918a
KCS/USD80.2%20m0xAFC9c849b1a784955908d91EE43A3203fBC1f950
SKCS/USD80.2%20m0xdB4b34b3Fc38D828DFE5D9D34CcF0f5f15c09684
USDT/USD80.1%30m0x001c1a168ba2a36D01a99542740C375c51615161
USDC/USD80.1%30m0x1A165db46d431804B0082eb5BEbc307ffb97e31b
**KCC Testnet Feed addresses**
Pair (Base/Quote)Decimals DeviationHeartbeatData Feed Contract (Proxy Address)
BTC/USD80.2%2m0xBb3423a913a9a69aD7Dba09B62abdFDE4643BAe4
ETH/USD80.2%2m0x22337a9a305E081c0C801dd7B7b8eCF4966660bB
KCS/USD80.2%20m0xae3DB39196012a7bF6D38737192F260cdFE1E7Ec
SKCS/USD80.2%20m0xAAf1A426D4b5D57c55E67f6eCc2918c698D94359
USDT/USD80.1%30m0x2bE470B8BD3CF5655dcC666CDe37E3E4D6cf3168
USDC/USD80.1%30m0x91b66dAd926FaC824da9390D1aF6f68db391A5c0