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p15-chainlink-data-feeds

README.md

Chainlink Data Feed and Feed Registry

This project demonstrates how to get price feeds for different currencies using Chainlink Data Feed and Chainlink Feed Registry. We will learn how to use both of these either in a smart contract or in a DApp.

Steps for Data Feed

  1. Install dependencies using
yarn
  1. Create a .env in the project directory and write the following environment variables. AGGREGATOR environment variable is for BTC / USD price feed on Rinkeby Network.
MNEMONIC = REPLACE_WITH_YOUR_MNEMONIC
RINKEBY_RPC = https://rinkeby.infura.io/v3/YOUR_INFURA_PROJECT_ID

# Aggregator address for BTC / USD feed on Rinkeby network.
# See for details: https://docs.chain.link/docs/ethereum-addresses/#Rinkeby%20Testnet
AGGREGATOR = 0xECe365B379E1dD183B20fc5f022230C044d51404
  1. Deploy the smart contract contracts/DataFeedConsumer.sol using the script in scripts/deployDataFeedConsumer.ts. Make sure you have some Rinkeby test ETH in your account you are using to deploy the contract.
npx hardhat run scripts/deployDataFeedConsumer.ts --network rinkeby

After deployment, save the address of the deployed DataFeedConsumer in .env file.

DATA_FEED_CONSUMER = 0xB674c51096a21d3E36c12F2c76Ba4b9bd306C4b9
  1. To get the latest BTC / USD price feed through the DataFeedConsumer smart contract, run the script in scripts/withDataFeedSolidity.ts.
npx hardhat run scripts/withDataFeedSolidity.ts --network rinkeby
  1. To get the latest BTC / USD price feed through Ethers library, run the script in scripts/withDataFeedJavaScript.ts. This is how you will use Chainlink Data Feed in a DApp using Ethers.
npx hardhat run scripts/withDataFeedJavaScript.ts --network rinkeby

Steps for Feed Registry

  1. Install dependencies if you haven't already.
yarn
  1. In .env file, write the following environment variables. FEED_REGISTRY environment variable is for Feed Registry on Kovan Network.
MNEMONIC = REPLACE_WITH_YOUR_MNEMONIC
KOVAN_RPC = https://kovan.infura.io/v3/YOUR_INFURA_PROJECT_ID

# Feed Registry contract address for Kovan network.
# See for details: https://docs.chain.link/docs/feed-registry/#contract-addresses
FEED_REGISTRY = 0xAa7F6f7f507457a1EE157fE97F6c7DB2BEec5cD0
  1. Deploy the smart contract contracts/FeedRegistryConsumer.sol using the script in scripts/deployFeedRegistryConsumer.ts. Make sure you have some Kovan test ETH in your account you are using to deploy the contract.
npx hardhat run scripts/deployFeedRegistryConsumer.ts --network kovan

After deployment, save the address of the deployed FeedRegistryConsumer in .env file.

FEED_REGISTRY_CONSUMER = 0xf756e9C157c44AFdabfDfe975Ca49944c5281a1D
  1. To get the latest ETH / USD price feed through the FeedRegistryConsumer smart contract, run the script in scripts/withFeedRegistrySolidity.ts.
npx hardhat run scripts/withFeedRegistrySolidity.ts --network kovan
  1. To get the latest ETH / USD price feed through Ethers library, run the script in scripts/withFeedRegistryJavaScript.ts. This is how you will use Chainlink Feed Registry in a DApp using Ethers.
npx hardhat run scripts/withFeedRegistryJavaScript.ts --network kovan

Deployed Contracts

  1. EACAggregatorProxy Contract | Rinkeby
  2. DataFeedConsumer Contract | Rinkeby
  3. FeedRegistry | Kovan
  4. FeedRegistryConsumer Contract | Kovan