query-event

query-event

This example shows how to query smart contract event data using the quais SDK. It is comprised of a single example script that queries the Transfer event of a QRC20 token contract for a single address.

Dependencies

• Node.js - JavaScript runtime
• quais - Quai JavaScript SDK

Usage

To install dependencies, navigate to this directory (quais-by-example/query-event) and run:

npm install

Use nodejs to run the example script:

node index.js

Example Breakdown

The index.js script takes in a contract address, event to query for, and event filter params. To run the script, you'll need to edit the contractAddress, eventName, and eventFilterParams variables. In the example script, we query the Transfer event of a QRC20 token contract that involve the address: 0x1077b8213a19e34c790da18a0a7ce723b074344d.

const rpcURL = 'https://rpc.cyprus1.colosseum.quaiscan.io' // cyprus 1 rpc url
const contractAddress = '0x0dcb6cc8516568104758705b8320924cdca5bd44' // cyprus 1 qrc20 contract

// event to query for
const filterFrom = QRC20.filters.Transfer('0x1077b8213a19e34c790da18a0a7ce723b074344d') // filter for transfers from this address

Ensure that the rpcURL you provide is for the same chain that the contractAddress and queried address are on. Once you've done that, you can run the script with:

node index.js

This script will output the event data that matches your filter params in JSON format.