Pyth Price Feed Data Demo

Pre-requisities

1. Install node.js, refer https://nodejs.org/en/download/package-manager. Once installed, check the version.

node --version

2. Install foundry, refer here - https://book.getfoundry.sh/getting-started/installation. Check for forge and cast

Build

$ forge build

Test

$ forge test

Format

$ forge fmt

Deploy the smart contract on Sepolia public testnet

export SEPOLIA_RPC_URL=https://rpc.sepolia.org
export PYTH_ETH_SEPOLIA_ADDRESS=0xDd24F84d36BF92C65F92307595335bdFab5Bbd21
export ETH_USD_ID=0xff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace
export PRIVATE_KEY=0x

forge create src/PriceFeed.sol:PriceFeed --private-key $PRIVATE_KEY --rpc-url $SEPOLIA_RPC_URL --constructor-args $PYTH_ETH_SEPOLIA_ADDRESS $ETH_USD_ID

# Copy the Deployed to address
export DEPLOYMENT_ADDRESS=<<Adress of the PriceFeed contract>>

Interact with smart contract functions

cast call $DEPLOYMENT_ADDRESS "getEthUsdPrice()" --rpc-url $SEPOLIA_RPC_URL --trace

Get price update from Hermes API

curl -s "https://hermes.pyth.network/v2/updates/price/latest?&ids[]=$ETH_USD_ID" | jq -r ".binary.data[0]" > price_update.txt

Call Update and Get EthUSDPrice

noglob cast send --private-key $PRIVATE_KEY --rpc-url $SEPOLIA_RPC_URL --value 0.0005ether $DEPLOYMENT_ADDRESS "UpdateAndGetEthUsdPrice(bytes[])" [0x$(cat price_update.txt)] 

cast call $DEPLOYMENT_ADDRESS "getEthUsdPrice()" --rpc-url $SEPOLIA_RPC_URL

cast --to-dec  <<Result>>

Exercise for you

To write tests for the smart contract in test folder. To get started, check out https://book.getfoundry.sh/forge/tests

Help

$ forge --help
$ cast --help