Decode ABI Parameters

DecodeAbiParameters (and DecodeAbiParametersInto, DecodeWithSelector) decode ABI-encoded bytes using a list of AbiParam definitions. They are standalone functions: no parsed ABI required.

Import

import (
  "encoding/hex"
  "github.com/ChefBingbong/viem-go/abi"
)

DecodeAbiParameters

Decode raw ABI-encoded bytes using AbiParam definitions. Returns a slice of decoded values in order.

import (
  "encoding/hex"
  "github.com/ChefBingbong/viem-go/abi"
)

params := []abi.AbiParam{
  {Name: "x", Type: "string"},
  {Name: "y", Type: "uint256"},
  {Name: "z", Type: "bool"},
}
data, _ := hex.DecodeString("...") // ABI-encoded bytes

values, err := abi.DecodeAbiParameters(params, data)
if err != nil {
  log.Fatal(err)
}
// values[0] string, values[1] *big.Int or int64, values[2] bool

• Signature: DecodeAbiParameters(params []AbiParam, data []byte) ([]any, error)
• Decoded types match ABI Types (address → common.Address, uint256 → *big.Int or int64, etc.).

DecodeAbiParametersInto

Decode into a provided struct or slice (pointer). Useful for typed results.

var out struct {
    X string
    Y *big.Int
    Z bool
}
err := abi.DecodeAbiParameters(params, data, &out)

• Signature: DecodeAbiParametersInto(params []AbiParam, data []byte, output any) error
• output must be a pointer to a struct (fields by position) or a slice.

DecodeWithSelector

Decode data that starts with a 4-byte selector: returns the selector and decoded parameters (data after the selector).

selector, values, err := abi.DecodeWithSelector(params, data)
// selector is [4]byte, values is []any from data[4:]

• Signature: DecodeWithSelector(params []AbiParam, data []byte) ([4]byte, []any, error)

Go notes

• For decoding function calldata or return data with a parsed ABI, use contract-level DecodeFunctionData and DecodeFunctionResult.

See also

• Encode Parameters — EncodeAbiParameters
• Parse ABI — get a parsed ABI for contract decoding
• Types — AbiParam and type mapping