Skip to main content

Web3.js Config Guide

Configuration parameters​

There is list of configuration params that can be set for modifying behavior of different functions in web3.js packages. Following is list of configuration options with details:

Global level Config​

There is option of modifying any of above-mentioned configuration parameter at global level when instantiating Web3, and it will be available to all packages.

import { Web3 } from 'web3';

const web3 = new Web3({
  provider: 'https://mainnet.infura.io/v3/YOURID',
  config: {
    defaultTransactionType: '0x0',
  },
});

//now default transaction type will be 0x0 so using following function in eth will send type 0x0 transaction

web3.eth
  .sendTransaction({
    from: '0x18532dF2Ab835d4E9D07a8b9B759bf5F8f890f49',
    to: '0xB2f70d8965e754cc07D343a9b5332876D3070155',
    value: 100,
    gasLimit: 21000,
  })
  .then((res) => console.log(res));

For Advance Users: Global level config can also be set using Web3Context object.

import { Web3, Web3Context } from 'web3';

const context = new Web3Context('http://127.0.0.1:7545');
context.setConfig({ defaultTransactionType: '0x0' });

const web3 = new Web3(context);

//it will not default to 0x0 type transactions
web3.eth.sendTransaction({
    from: '0x18532dF2Ab835d4E9D07a8b9B759bf5F8f890f49',
    to: '0x018e221145dE7cefAD09BD53F41c11A918Bf1Cb7',
    value: 100,
    gasLimit: 21000
}).then(res => console.log(res));

Package level config​

Setting config in Individual Package under Web3 instance​

Some configuration options that effects selected packages can be modified using setConfig(...) function.

import { Web3 } from 'web3';

const web3 = new Web3('https://mainnet.infura.io/v3/YOURID');

web3.eth.setConfig({ defaultTransactionType: '0x0'});

web3.eth
  .sendTransaction({
    from: '0x18532dF2Ab835d4E9D07a8b9B759bf5F8f890f49',
    to: '0xB2f70d8965e754cc07D343a9b5332876D3070155',
    value: 100,
    gasLimit: 21000,
  })
  .then((res) => console.log(res));

Setting config in Individually imported Packages​

If an individual package is being imported instead of whole web3.js, there is option of setting config params by passing config in constructors or by using setConfig(...) function:

For example if only web3Eth package is installed using:

npm i web3-eth

Configuration options can be set by passing in constructor:

setConfig in the constructor
import { Web3Eth } from 'web3-eth';

const web3EthObj = new Web3Eth({
  provider: 'http://127.0.0.1:7545',
  config: {
    defaultTransactionType: 0x0,
  },
});

web3EthObj
  .sendTransaction({
    from: '0x18532dF2Ab835d4E9D07a8b9B759bf5F8f890f49',
    to: '0x018e221145dE7cefAD09BD53F41c11A918Bf1Cb7',
    value: 100,
    gasLimit: 21000,
  })
  .then((res) => console.log(res));

Another way of setting config for individually imported package is by using setConfig(...) function.

setConfig function
import { Web3Eth } from 'web3-eth';

const web3EthObj = new Web3Eth('http://127.0.0.1:7545');

web3EthObj.setConfig({ defaultTransactionType: 0x0 });

web3EthObj
  .sendTransaction({
    from: '0x18532dF2Ab835d4E9D07a8b9B759bf5F8f890f49',
    to: '0x018e221145dE7cefAD09BD53F41c11A918Bf1Cb7',
    value: 100,
    gasLimit: 21000,
  })
  .then((res) => console.log(res));

Getting Current Config​

For getting list of current config params getContextObject().config can be used as :

getContextObject() in Web3 object
import { Web3 } from 'web3';

const web3 = new Web3('http://127.0.0.1:7545');

console.log(web3.getContextObject().config)
/* ↳
  handleRevert: false,
  defaultAccount: undefined,
  defaultBlock: 'latest',
  transactionBlockTimeout: 50,
  transactionConfirmationBlocks: 24,
  transactionPollingInterval: 1000,
  transactionPollingTimeout: 750000,
  transactionReceiptPollingInterval: undefined,
  transactionSendTimeout: 750000,
  transactionConfirmationPollingInterval: undefined,
  blockHeaderTimeout: 10,
  maxListenersWarningThreshold: 100,
  contractDataInputFill: 'input',
  defaultNetworkId: undefined,
  defaultChain: 'mainnet',
  defaultHardfork: 'london',
  defaultCommon: undefined,
  defaultTransactionType: '0x2',
  defaultMaxPriorityFeePerGas: '0x9502f900',
 ...
*/

For individually imported packages same approach can be used to get current config params.

getContextObject() in an imported package
import { Web3Eth } from 'web3';

const web3 = new Web3Eth('http://127.0.0.1:7545');

console.log(web3.getContextObject().config)
/* ↳
  handleRevert: false,
  defaultAccount: undefined,
  defaultBlock: 'latest',
  transactionBlockTimeout: 50,
  transactionConfirmationBlocks: 24,
  transactionPollingInterval: 1000,
  transactionPollingTimeout: 750000,
  ...
*/

Explanation of Configuration Parameters​

handleRevert​

The following methods will retrieve specific error types and error messages when handleRevert is set to true:

The error type will be one of the following:

For example, the error message could be TransactionRevertInstructionError('Returned error: invalid argument 0: json: cannot unmarshal invalid hex string into Go struct field TransactionArgs.data of type hexutil.Bytes'). The handleRevert option is only supported for sendTransaction and not for sendSignedTransaction for now.

The default value of handleRevert is false.

defaultAccount​

The defaultAccount option is used as the default from property, if no from property is specified for the following methods:

The default value of defaultAccount is undefined.

defaultBlock​

The following methods accept an optional blockNumber parameter, the defaultBlock option is used for these methods if no blockNumber parameter is provided.

If a blockNumber parameter is provided to one of the above function calls, it will override this option.

The default value of defaultBlock is "latest".

All available choices for defaultBlock:​

web3.defaultBlock = 20167235; // A block number
web3.defaultBlock = "earliest"; // The genesis block
web3.defaultBlock = "latest"; // The latest block (current head of the blockchain)
web3.defaultBlock = "pending"; // The block pending to be mined (including pending transactions)
web3.defaultBlock = "finalized"; // (For POS networks) The finalized block is one which has been accepted as canonical by greater than 2/3 of validators
web3.defaultBlock = "safe"; // (For POS networks) The safe head block is one which under normal network conditions, is expected to be included in the canonical chain. Under normal network conditions the safe head and the actual tip of the chain will be equivalent (with safe head trailing only by a few seconds). Safe heads will be less likely to be reorged than the proof of work network`s latest blocks.

transactionBlockTimeout​

This option defines the number of new blocks to wait for the first confirmation, otherwise the PromiEvent rejects with a timeout error.

The default value of transactionBlockTimeout is 50.

transactionConfirmationBlocks​

This defines the number of blocks required for a transaction to be considered confirmed. Different chains have varying security considerations and requirements for confirmation block numbers.

The default value of transactionConfirmationBlocks is 24.

transactionPollingInterval​

This option defines the number of seconds between Web3 calls for a receipt which confirms that a transaction was mined by the network. Modifying this value can reduce the wait time for confirmations or decrease the number of network requests. Setting the transactionPollingInterval would also set transactionReceiptPollingInterval and transactionConfirmationPollingInterval to the same value.

The default value of transactionPollingInterval is 1000 ms.

import { Web3 } from 'web3';

const web3 = new Web3('http://127.0.0.1:7545');

web3.transactionPollingInterval = 1000; // 1000 ms = 1 s

console.log(web3.getContextObject().config);
/* ↳
  ...
  transactionPollingInterval: 1000,
  transactionPollingTimeout: 750000,
  transactionReceiptPollingInterval: 1000,
  transactionSendTimeout: 750000,
  transactionConfirmationPollingInterval: 1000,
  ...
*/

transactionPollingTimeout​

This option defines the number of seconds Web3 will wait for a receipt which confirms that a transaction was mined by the network. It can be set based on the average transaction confirmation time on the network. Note: If the transactionPollingTimeout is exceeded, the transaction may still be pending.

The default value of transactionPollingTimeout is 750 seconds (12.5 minutes).

transactionReceiptPollingInterval​

This option defines the number of seconds between Web3 calls for a receipt which confirms that a transaction was mined by the network. Compared to transactionPollingInterval, it takes higher precedence. When this value is set, it will be read first.

The default value of transactionReceiptPollingInterval is undefined.

transactionSendTimeout​

The transactionSendTimeout option is used to specify how long to wait for the network to return the sent transaction result. Note: If the RPC call times out, the transaction may still be pending or even mined by the network. It is recommended that the pending transactions be checked in such a case.

The default value of transactionSendTimeout is 750 seconds (12.5 minutes).

transactionConfirmationPollingInterval​

The transactionConfirmationPollingInterval option is deprecated. Please use transactionReceiptPollingInterval or transactionPollingInterval instead.

blockHeaderTimeout​

After sending a transaction, Web3 will listen for the appearance of new blocks and proceed with subsequent operations based on the transaction results within them. This option defines the number of seconds Web3 should wait for the appearance of new blocks before reverting to polling to fetch the transaction receipt.

The default value of blockHeaderTimeout is 10 seconds.

maxListenersWarningThreshold​

The maxListenersWarningThreshold is used to set the maxListeners property in EventEmitter.

The default value of maxListenersWarningThreshold is 100.

contractDataInputFill​

The contractDataInputFill option allows users to specify whether the data or input property (or both properties) should be set to the hash of the method signature and encoded parameters. This will affect the contracts send, call and estimateGas methods.

The default value of contractDataInputFill is data.

All available choices for contractDataInputFill:​

'data'
'input'
'both'

defaultNetworkId​

Each network has its own network ID. The defaultNetworkId option allows users to set the default network ID. If this option is not set, Web3 will fetch the network ID with an RPC request.

The default value of defaultNetworkId is undefined.

defaultChain​

The defaultChain option is used to set the Common baseChain property. The value of this option should be consistent with defaultCommon.baseChain if both options are set.

The default value of defaultChain is mainnet.

All available choices for defaultChain:​

'goerli'
'kovan'
'mainnet'
'rinkeby'
'ropsten'
'sepolia'

defaultHardfork​

The defaultHardfork option is used to set the Common hardfork property. The value of this option should be consistent with defaultCommon.hardfork if both options are set.

The default value of defaultHardfork is london.

All available choices for defaultHardFork:​

'chainstart'
'frontier'
'homestead'
'dao'
'tangerineWhistle'
'spuriousDragon'
'byzantium'
'constantinople'
'petersburg'
'istanbul'
'muirGlacier'
'berlin'
'london'
'altair'
'arrowGlacier'
'grayGlacier'
'bellatrix'
'merge'
'capella'
'sharding'

defaultCommon​

The defaultCommon option is used to set the defaultCommon value for smart contract transactions. It should be consistent with the defaultHardfork and defaultChain options if they are set.

The default value of defaultCommon is undefined.

import { Web3, Hardfork } from 'web3';

const web3 = new Web3('http://127.0.0.1:7545');

web3.defaultHardfork = 'berlin'
web3.defaultChain = 'goerli'

web3.defaultCommon = {
    baseChain: 'goerli',
    hardfork: 'berlin' as Hardfork,
    customChain: {
        networkId: 1,
        chainId: 1,
    },
};

console.log(web3.getContextObject().config);

defaultTransactionType​

The defaultTransactionType option is used to set the transaction type. Transactions with type 0x0 are legacy transactions that use the transaction format that existed before typed transactions were introduced in EIP-2718. Transactions with type 0x1 are transactions introduced in EIP-2930. Transactions with type 0x2 are transactions introduced in EIP-1559, included in Ethereum's London fork.

The default value of defaultTransactionType is 0x02.

defaultMaxPriorityFeePerGas​

The defaultMaxPriorityFeePerGas option is used to set the defaultMaxPriorityFeePerGas value for EIP-1559 smart contract transactions (transaction type 0x2).

The default value of defaultMaxPriorityFeePerGas is 2500000000 (2.5gwei) in hexstring format.

defaultReturnFormat​

The defaultReturnFormat option allows users to specify the format in which certain types of data should be returned by default. It is a configuration parameter that can be set at the global level and affects how data is returned across the entire library.

import { Web3, FMT_NUMBER, FMT_BYTES } from 'web3';

web3.defaultReturnFormat = {
    number: FMT_NUMBER.BIGINT,
    bytes: FMT_BYTES.HEX,
};

All available choices for numeric data:​

export enum FMT_NUMBER {
    NUMBER = 'NUMBER_NUMBER',
    HEX = 'NUMBER_HEX',
    STR = 'NUMBER_STR',
    BIGINT = 'NUMBER_BIGINT',
};

All available choices for bytes data:​

export enum FMT_BYTES {
    HEX = 'BYTES_HEX',
    UINT8ARRAY = 'BYTES_UINT8ARRAY',
};