decodeAbi #

Decodes ABI encoded data using the ABI specification, given a set of ABI parameters (inputs/outputs) and the encoded ABI data.

The decodeAbi function is used by the other contract decoding utilities (ie. decodeFunctionData, decodeEventTopics, etc).

Install #

import { decodeAbi } from 'viem'

Usage #

The decodeAbi function accepts:

• a set of parameters (params), in the shape of the inputs or outputs attribute of an ABI event/function.
• the ABI encoded data (data) that correspond to the given params.

import { decodeAbi } from 'viem'

const values = decodeAbi({
  data: '0x0000000000000000000000000000000000000000000000000000000000010f2c',
  params: [{ internalType: 'uint32', name: 'x', type: 'uint32' }],
})
// [69420]

Return Value #

The decoded data. Type is inferred from the ABI.

Parameters #

data #

• Type: Hex

The ABI encoded data.

const values = decodeAbi({
  data: '0x0000000000000000000000000000000000000000000000000000000000010f2c', 
  params: [{ internalType: 'uint32', name: 'x', type: 'uint32' }],
})

params #

• Type: AbiParameter[]

The set of ABI parameters to decode against data, in the shape of the inputs or outputs attribute of an ABI event/function.

These parameters must include valid ABI types.

const values = decodeAbi({
  data: '0x0000000000000000000000000000000000000000000000000000000000010f2c',
  params: [{ internalType: 'uint32', name: 'x', type: 'uint32' }], 
})

More Examples #

Simple struct #

import { abi } from './abi'

const values = decodeAbi({
  data: '0x00000000000000000000000000000000000000000000000000000000000001a40000000000000000000000000000000000000000000000000000000000000001000000000000000000000000a5cc3c03994db5b0d9a5eedd10cabab0813678ac',
  params: abi[0].outputs
})
// { x: 420n, y: true, z: '0xa5cc3c03994DB5b0d9A5eEdD10CabaB0813678AC' }

export const abi = [
  {
    name: 'staticStruct',
    outputs: [
      {
        components: [
          {
            internalType: 'uint256',
            name: 'x',
            type: 'uint256',
          },
          {
            internalType: 'bool',
            name: 'y',
            type: 'bool',
          },
          {
            internalType: 'address',
            name: 'z',
            type: 'address',
          },
        ],
        internalType: 'struct Example.Foo',
        name: 'foo',
        type: 'tuple',
      },
    ],
  }
] as const

contract Example {
  struct Foo {
    uint256 x;
    bool y;
    address z;
  }

  function staticStruct(...) returns (Foo calldata foo) { 
    ... 
    return foo;
  }
}