API to get Ethereum Smart Contract Events

By admin Product Tutorial October 5, 2020

As we know Ethereum blockchain only output events and transactions. Therefore, events provide very important insights into smart contract activities.

However, extracting, storing, and indexing these events can be troublesome for many developers.

Therefore, we provide Blockchain GraphQL APIs to get events data for any Ethereum smart contract.

In this article, we will see how to get smart contract events from famous Ethereum protocols using Bitquery GraphQL API.

Table of Contents

Tether denylist and destroying funds for denylisted users

Tether (USDT) stablecoin smart contract has a mechanism to embargo addresses and destroyed funds of those addresses by simply subtracting the balance from the total supply.

Every time Tether bans a user, it will emit an “AddBlackList” event. Using the following query you can get these events.

{
  ethereum {
    smartContractEvents(options: {desc: "block.height", limit: 10},
      smartContractEvent: {is: "AddedBlackList"},
      smartContractAddress: 
      {is: "0xdac17f958d2ee523a2206206994597c13d831ec7"}) {
      block {
        height
        timestamp {
          iso8601
          unixtime
        }
      }
      arguments {
        value
        argument
      }
    }
  }
}

If you also want to know about the destroyed USDT funds of embargoed users. You can track the “DestroyedBlackFunds” event.

{
  ethereum {
    smartContractEvents(options: {desc: "block.height", limit: 10},
      smartContractEvent: {is: "DestroyedBlackFunds"},
      smartContractAddress: 
      {is: "0xdac17f958d2ee523a2206206994597c13d831ec7"}) {
      block {
        height
        timestamp {
          iso8601
          unixtime
        }
      }
      arguments {
        value
        argument
      }
    }
  }
}

Tracking ENS registrations

If you want to know the newly registered ENS domains, you can track the “NameRegistered” event of the ENS Base Registrar smart contract by using the query below.

{
  ethereum {
    smartContractEvents(options: {desc: "block.height", limit: 10},
      smartContractEvent: {is: "NameRegistered"},
      smartContractAddress: 
      {is: "0x57f1887a8bf19b14fc0df6fd9b2acc9af147ea85"}) {
      block {
        height
        timestamp {
          iso8601
          unixtime
        }
      }
      arguments {
        value
        argument
      }
    }
  }
}

Tracking Aave Flash loans

Interested in flash loans? use the following query to get the latest FlashLoan events emitted by the Aave’s Lending pool smart contract.

{
  ethereum {
    smartContractEvents(options: {desc: "block.height", limit: 10},
      smartContractEvent: {is: "FlashLoan"},
      smartContractAddress: 
      {is: "0x398eC7346DcD622eDc5ae82352F02bE94C62d119"}) {
      block {
        height
        timestamp {
          iso8601
          unixtime
        }
      }
      eventIndex
      arguments {
        value
        argument
      }
    }
  }
}

Uniswap’s newly created Pools/Pools

Want to know about newly created Uniswap pools/pairs? Use the query below to track the “PairCreated” event emitted by the Uniswap Factory smart contract.

{
  ethereum {
    smartContractEvents(options: {desc: "block.height", limit: 10},
      smartContractEvent: {is: "PairCreated"},
      smartContractAddress: 
      {is: "0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f"}) {
      block {
        height
        timestamp {
          iso8601
          unixtime
        }
      }
      eventIndex
      arguments {
        value
        argument
      }
    }
  }
}

If you have any questions, you can ask them on our Telegram channel. Also, let us know if you are looking for blockchain data APIs.

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