In Sway and the FuelVM, bytes32 is used to represent hashes. It holds a 256-bit (32-bytes) value.
To generate a random bytes32 value, you can use the randomBytes function from the fuels module:
import { randomBytes, type Bytes } from 'fuels';
const bytes32: Bytes = randomBytes(32);
You can use the hexlify function to convert a byte array to a hex string, and the arrayify function to convert a hex string back to a byte array:
import type { Bytes } from 'fuels';
import { arrayify, hexlify, randomBytes } from 'fuels';
const randomBytes32: Bytes = randomBytes(32);
const bytes32String: string = hexlify(randomBytes32);
const bytes32: Bytes = arrayify(bytes32String); In Fuel, there is a special type called b256, which is similar to bytes32. Like bytes32, B256 is also used to represent hashes and holds a 256-bit value. You can learn more about working with B256 values in the B256 documentation .