Alchemy SDKSDK V2 Methods

waitForTransaction - SDK

Returns a promise which will not resolve until specified transaction hash is mined. If confirmations is 0, this method is non-blocking, and if the transaction has not been mined returns null . Otherwise, this method will block until the transaction has confirmed blocks mined on top of the block in w…

Returns a promise which will not resolve until specified transaction hash is mined.

If confirmations is 0, this method is non-blocking, and if the transaction has not been mined returns null. Otherwise, this method will block until the transaction has confirmed blocks mined on top of the block in which it was mined.

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Description

Returns a promise which will not resolve until the specified transaction hash is mined.

If confirmations is 0, this method is non-blocking, and if the transaction has not been mined returns null. Otherwise, this method will block until the transaction has confirmed blocks mined on top of the block in which it was mined.

Parameters

NameTypeDescription
transactionHashstringThe hash of the transaction to wait for.
confirmationsnumberOptional The number of blocks to wait for.
timeoutnumberOptional The maximum time to wait for the transaction to confirm.

Response

PropertyTypeDescription
Promise<TransactionReceipt \ null>objectReturns the transaction status.

TransactionReceipt response object parameters

PropertyTypeDescription
tostring20 Bytes - address of the receiver. null when its a contract creation transaction
fromstring20 Bytes - address of the sender.
contractAddressstring20 Bytes - The contract address created, if the transaction was a contract creation, otherwise null.
transactionIndexnumber`Integer of the transactions index position log was created from. null when its pending log.
root?string32 bytes of post-transaction stateroot (pre Byzantium).
gasUsednumber | stringThe amount of gas used by this specific transaction alone
logsBloomstring256 Bytes - Bloom filter for light clients to quickly retrieve related logs.
blockHashstring32 Bytes - hash of the block where this log was in. null when its pending. null when its pending log.
transactionHashstring32 Bytes - hash of the transaction
logsarrayArray of log objects, which this transaction generated.
blockNumbernumberThe block number where this log was in. null when its pending. null when its pending log.
confirmationsnumberDescribes the number of confirmations.
cummulativeGasUsednumber | stringThe total amount of gas used when this transaction was executed in the block.
effectiveGasPricenumber | stringEffective gas price used.
byzantiumbooleanspecifies true or falsle.
typenumberDescribes the type.
status?numberEither 1 (success) or 0 (failure)

Example Request and Response

Prerequisite: You will need to install the Alchemy SDK before making requests with it.

The commands for installing it using npm or yarn are given below:

$npm install alchemy-sdk

Request

index.js
1// Imports the Alchemy SDK
2const { Alchemy, Network, Wallet, Utils } = require("alchemy-sdk");
3
4// Configures the Alchemy SDK
5const config = {
6    apiKey: "alchemy-replit", // Replace with your API key
7    network: Network.ETH_MAINNET, // Replace with your network
8};
9
10// Creates an Alchemy object instance with the config to use for making requests
11const alchemy = new Alchemy(config);
12
13const main = async () => {
14    // define the transaction hash
15    const txHash = "0x88df016429689c079f3b2f6ad39fa052532c56795b733da78a91ebe6a713944b";
16
17    //Call the method
18    const response = await alchemy.transact.waitForTransaction(txHash)
19
20    //Logging the response to the console
21    console.log(response)
22}
23
24main();

Response

shell
${
>  to: '0xF02c1c8e6114b1Dbe8937a39260b5b0a374432bB',
>  from: '0xa7d9ddBE1f17865597fBD27EC712455208B6B76d',
>  contractAddress: null,
>  transactionIndex: 65,
>  gasUsed: BigNumber { _hex: '0x53a0', _isBigNumber: true },
>  logsBloom: '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
>  blockHash: '0x1d59ff54b1eb26b013ce3cb5fc9dab3705b415a67127a003c3e61eb445bb8df2',
>  transactionHash: '0x88df016429689c079f3b2f6ad39fa052532c56795b733da78a91ebe6a713944b',
>  logs: [],
>  blockNumber: 6139707,
>  confirmations: 10641165,
>  cumulativeGasUsed: BigNumber { _hex: '0x20ec2d', _isBigNumber: true },
>  effectiveGasPrice: BigNumber { _hex: '0x04a817c800', _isBigNumber: true },
>  status: 1,
>  type: 0,
>  byzantium: true
>}

Use Cases

Here are some potential use cases for the waitForTransaction method:

  • Ensuring transaction execution: When sending a transaction to the Ethereum network, there is no guarantee that the transaction will be executed immediately. waitForTransaction can be used to ensure that the transaction is mined and executed before moving on to the next step in the program.

  • Waiting for contract deployment: When deploying a new smart contract to the Ethereum network, it may take some time for the contract to be deployed and ready for use. waitForTransaction can be used to wait for the contract deployment transaction to be confirmed before interacting with the contract.

  • Checking transaction status: waitForTransaction can be used to check the status of a transaction and ensure that it was successfully mined and confirmed by the network. This is useful for ensuring that funds were successfully transferred, or for verifying that a contract function was executed as expected.