View Functions
View functions not to modify the state of the contract's data. Common examples are "getter" functions – you might use this to receive a user's balance for example. - Ethereum.org
For example, ERC-20 contracts have a public view function called balanceOf
Copy function balanceOf ( address _owner ) public view returns ( uint256 balance)
Calling the view function balanceOf
and passing in the argument 0xAlice
will get the token balance of 0xAlice
View functions do not require a wallet.
Write Functions
Write functions modify the state of contract data.
For example, ERC-20 contracts have a public write function called transfer
Copy function transfer ( address _to , uint256 _value ) public returns ( bool success)
Calling the write function transfer
and passing in the argument 0xAlice
and 123
will transfer 123 tokens to 0xAlice.
Write functions require a wallet .
Events
Events let you communicate with your smart contract from your frontend or other subscribing applications. When a transaction is mined, smart contracts can emit events and write logs to the blockchain that the frontend can then process. - Ethereum.org
For example, ERC-20 contracts emit an event called Transfer
Copy event Transfer ( address indexed _from, address indexed _to, uint256 _value)
Every time an ERC-20 token gets transferred, web3hook listens to the _from
address, _to
address and _value
amount and sends this information to Zapier.
Contract Address
Contract address refers to the address hosting a collection of code on the Ethereum blockchain that executes functions - Etherscan
To get the contract address, visit a block explorer. For example, USDT is address 0xdac17f958d2ee523a2206206994597c13d831ec7
. This can be found here
ABI
The Contract Application Binary Interface (ABI) is the standard way to interact with contracts in the Ethereum ecosystem, both from outside the blockchain and for contract-to-contract interaction. - SolidityLang.org
Common ABIs:
ERC-20
Fungible tokens like USDC
Copy [ { "inputs": [ { "internalType": "string", "name": "name_", "type": "string" }, { "internalType": "string", "name": "symbol_", "type": "string" } ], "stateMutability": "nonpayable", "type": "constructor" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "spender", "type": "address" }, { "indexed": false, "internalType": "uint256", "name": "value", "type": "uint256" } ], "name": "Approval", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "from", "type": "address" }, { "indexed": true, "internalType": "address", "name": "to", "type": "address" }, { "indexed": false, "internalType": "uint256", "name": "value", "type": "uint256" } ], "name": "Transfer", "type": "event" }, { "inputs": [ { "internalType": "address", "name": "owner", "type": "address" }, { "internalType": "address", "name": "spender", "type": "address" } ], "name": "allowance", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "approve", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "account", "type": "address" } ], "name": "balanceOf", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "decimals", "outputs": [ { "internalType": "uint8", "name": "", "type": "uint8" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "subtractedValue", "type": "uint256" } ], "name": "decreaseAllowance", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "addedValue", "type": "uint256" } ], "name": "increaseAllowance", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "name", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "symbol", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "totalSupply", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "transfer", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "transferFrom", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" } ]
ERC-721
Non-fungible tokens (NFTs) like Bored Apes
Copy [ { "inputs": [ { "internalType": "string", "name": "name_", "type": "string" }, { "internalType": "string", "name": "symbol_", "type": "string" } ], "stateMutability": "nonpayable", "type": "constructor" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "approved", "type": "address" }, { "indexed": true, "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "Approval", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "operator", "type": "address" }, { "indexed": false, "internalType": "bool", "name": "approved", "type": "bool" } ], "name": "ApprovalForAll", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "from", "type": "address" }, { "indexed": true, "internalType": "address", "name": "to", "type": "address" }, { "indexed": true, "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "Transfer", "type": "event" }, { "inputs": [ { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "approve", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "owner", "type": "address" } ], "name": "balanceOf", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "getApproved", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "owner", "type": "address" }, { "internalType": "address", "name": "operator", "type": "address" } ], "name": "isApprovedForAll", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "name", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "ownerOf", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "safeTransferFrom", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" }, { "internalType": "bytes", "name": "data", "type": "bytes" } ], "name": "safeTransferFrom", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "operator", "type": "address" }, { "internalType": "bool", "name": "approved", "type": "bool" } ], "name": "setApprovalForAll", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "bytes4", "name": "interfaceId", "type": "bytes4" } ], "name": "supportsInterface", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "symbol", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "tokenURI", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "transferFrom", "outputs": [], "stateMutability": "nonpayable", "type": "function" } ]
To find other ABIs, visit a block explorer and view the source code. For example, USDT ABI can be found here:
OpenZepplin Defender
Wallets are used to handle sending transactions and writing functions .
Web3Hook does not handle your wallet keys. Instead, it relies on third party wallets.
OpenZepplin Defender Relay implements private relayers with support for testnets, mainnet, layer 2 and sidechains. Increase user security with embedded key vaults, API key management, and meta-transactions.
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