Utilities
This crate provides miscellaneous components and libraries containing utility functions to handle common tasks.
Core
use openzeppelin_utils;Module containing core utilities of the library.
Members
Inner modules
Inner modules
cryptography module
module
#deployments module
module
#math module
module
#contract_clock module
module
#serde module
module
#use openzeppelin_utils::cryptography;Module containing utilities related to cryptography.
Members
Inner modules
Inner modules
nonces module
module
#snip12 module
module
#use openzeppelin_utils::deployments;Module containing utility functions for calculating contract addresses through deploy_syscall and the Universal Deployer Contract (UDC).
Members
Structs
Functions
calculate_contract_address_from_deploy_syscall(salt, class_hash, constructor_calldata, deployer_address)compute_hash_on_elements(data)calculate_contract_address_from_udc(salt, class_hash, constructor_calldata, deployer_info)
Structs
DeployerInfo(caller_address: ContractAddress, udc_address: ContractAddress)
struct
#Struct containing arguments necessary in utils::calculate_contract_address_from_udc for origin-dependent deployment calculations.
Functions
calculate_contract_address_from_deploy_syscall(salt: felt252, class_hash: ClassHash, constructor_calldata: Span<felt252>, deployer_address: ContractAddress) → ContractAddress
function
#Returns the contract address when passing the given arguments to deploy_syscall.
compute_hash_on_elements(data: Span<felt252>) → felt252
function
#Creates a Pedersen hash chain with the elements of data and returns the finalized hash.
calculate_contract_address_from_udc(salt: felt252, class_hash: ClassHash, constructor_calldata: Span<felt252>, deployer_info: Option<DeployerInfo>) → ContractAddress
function
#Returns the calculated contract address for UDC deployments.
Origin-independent deployments (deployed from zero) should pass Option::None as deployer_info.
Origin-dependent deployments hash salt with caller_address (member of DeployerInfo) and pass the hashed salt to the inner deploy_syscall as the contract_address_salt argument.
use openzeppelin_utils::math;Module containing math utilities.
Members
Functions
Functions
average(a: T, b: T) → T
function
#Returns the average of two unsigned integers. The result is rounded down.
T is a generic value matching different numeric implementations.
use openzeppelin_utils::contract_clock;Module providing a trait for the EIP-6372 standard along with default clock implementations based on either block number or block timestamp.
Traits
Implementations
use openzeppelin_utils::contract_clock::ERC6372Clock;A trait for the EIP-6372 standard that allows flexible internal clock implementation — based on block timestamp, block number, or a custom logic.
Functions
Functions
clock() → u64
external
#Returns the current timepoint determined by the contract's operational mode, intended for use in time-sensitive logic.
Requirements:
- This function MUST always be non-decreasing.
CLOCK_MODE() → ByteArray
external
#Returns a description of the clock the contract is operating in.
Requirements:
- The output MUST be formatted like a URL query string, decodable in standard JavaScript.
Implementations
ERC6372BlockNumberClock impl
impl
#Implementation of the ERC6372Clock trait that uses the block number as its clock reference.
ERC6372TimestampClock impl
impl
#Implementation of the ERC6372Clock trait that uses the block timestamp as its clock reference.
use openzeppelin_utils::serde;Module containing utilities related to serialization and deserialization of Cairo data structures.
Members
Traits
Traits
SerializedAppend trait
trait
#Importing this trait allows the ability to append a serialized representation of a Cairo data structure already implementing the Serde trait to a felt252 buffer.
Usage example:
use openzeppelin_utils::serde::SerializedAppend;
use starknet::ContractAddress;
fn to_calldata(recipient: ContractAddress, amount: u256) -> Array<felt252> {
let mut calldata = array![];
calldata.append_serde(recipient);
calldata.append_serde(amount);
calldata
}Note that the append_serde method is automatically available for arrays of felts, and it accepts any data structure that implements the Serde trait.
Cryptography
use openzeppelin_utils::cryptography::nonces::NoncesComponent;This component provides a simple mechanism for handling incremental nonces for a set of addresses. It is commonly used to prevent replay attacks when contracts accept signatures as input.
Embeddable Implementations
NoncesImpl
Internal Implementations
InternalImpl
Embeddable functions
nonces(self: @ContractState, owner: ContractAddress) → felt252
external
#Returns the next unused nonce for an owner.
Internal functions
use_nonce(ref self: ComponentState, owner: ContractAddress) → felt252
internal
#Consumes a nonce, returns the current value, and increments nonce.
For each account, the nonce has an initial value of 0, can only be incremented by one, and cannot be decremented or reset. This guarantees that the nonce never overflows.
use_checked_nonce(ref self: ComponentState, owner: ContractAddress, nonce: felt252) → felt252
internal
#Same as use_nonce but checking that nonce is the next valid one for owner.
use openzeppelin_utils::snip12;Supports on-chain generation of message hashes compliant with SNIP12.
For a full walkthrough on how to use this module, see the SNIP12 and Typed Messages guide.