OpenZeppelin Hardhat Upgrades API

Both deployProxy and upgradeProxy functions will return instances of ethers.js contracts, and require ethers.js contract factories as arguments. For beacons, deployBeacon and upgradeBeacon will both return an upgradable beacon instance that can be used with a beacon proxy. All deploy and upgrade functions validate that the implementation contract is upgrade-safe, and will fail otherwise.

Common Options

The following options are common to some functions.

kind: ("uups" | "transparent" | "beacon") The kind of proxy to deploy, upgrade or import, or the kind of proxy that the implementation will be used with. deployProxy() and upgradeProxy() only support the values "uups" | "transparent". Defaults to "transparent". See Transparent vs UUPS.
unsafeAllow: (ValidationError[]) Selectively disable one or more validation errors:
- "external-library-linking": Allows a deployment with external libraries linked to the implementation contract. (External libraries are otherwise not yet supported.)
- "struct-definition", "enum-definition": Used to be necessary to deploy a contract with structs or enums. No longer necessary.
- "state-variable-assignment": Allows assigning state variables in a contract even though they will be stored in the implementation.
- "state-variable-immutable": Allows use of immutable variables, which are not unsafe
- "constructor": Allows defining a constructor. See constructorArgs.
- "delegatecall", "selfdestruct": Allow the use of these operations. Incorrect use of this option can put funds at risk of permanent loss. See Can I safely use delegatecall and selfdestruct?
- "missing-public-upgradeto": Allow UUPS implementations that do not contain a public upgradeTo function. Enabling this option is likely to cause a revert due to the built-in UUPS safety mechanism.
unsafeAllowRenames: (boolean) Configure storage layout check to allow variable renaming.
unsafeSkipStorageCheck: (boolean) upgrades the proxy or beacon without first checking for storage layout compatibility errors. This is a dangerous option meant to be used as a last resort.
constructorArgs: (unknown[]) Provide arguments for the constructor of the implementation contract. Note that these are different from initializer arguments, and will be used in the deployment of the implementation contract itself. Can be used to initialize immutable variables.
timeout: (number) Timeout in milliseconds to wait for the transaction confirmation when deploying an implementation contract or proxy admin contract. Defaults to 60000. Use 0 to wait indefinitely.
pollingInterval: (number) Polling interval in milliseconds between checks for the transaction confirmation when deploying an implementation contract or proxy admin contract. Defaults to 5000.
redeployImplementation: ("always" | "never" | "onchange") Determines whether the implementation contract will be redeployed. Defaults to "onchange".
- If set to "always", the implementation contract is always redeployed even if it was previously deployed with the same bytecode. This can be used with the salt option when deploying a proxy through OpenZeppelin Platform to ensure that the implementation contract is deployed with the same salt as the proxy.
- If set to "never", the implementation contract is never redeployed. If the implementation contract was not previously deployed or is not found in the network file, an error will be thrown.
- If set to "onchange", the implementation contract is redeployed only if the bytecode has changed from previous deployments.
usePlatformDeploy: (boolean) Deploy contracts using the OpenZeppelin Platform instead of ethers.js. See Using with OpenZeppelin Platform. Note: OpenZeppelin Platform is in beta and functionality related to Platform is subject to change.
verifySourceCode: (boolean) When using Platform, whether to verify source code on block explorers. Defaults to true.
walletId: (string) When using Platform, the ID of the wallet to use for the deployment. Defaults to the wallet configured for your deployment environment on Platform.
salt: (string) When using Platform, deployments are performed using the CREATE2 opcode. Use this option to provide the salt for the deployment. Defaults to a random salt.

Note that the options unsafeAllow can also be specified in a more granular way directly in the source code if using Solidity >=0.8.2. See How can I disable some of the checks?

The following options have been deprecated.

unsafeAllowLinkedLibraries: Equivalent to including "external-library-linking" in unsafeAllow.
unsafeAllowCustomTypes: Equivalent to including "struct-definition" and "enum-definition" in unsafeAllow. No longer necessary.
useDeployedImplementation: (boolean) Equivalent to setting redeployImplementation to "never".

deployProxy

async function deployProxy(
  Contract: ethers.ContractFactory,
  args: unknown[] = [],
  opts?: {
    initializer?: string | false,
    unsafeAllow?: ValidationError[],
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    kind?: 'uups' | 'transparent',
    usePlatformDeploy?: boolean,
  },
): Promise<ethers.Contract>

Creates a UUPS or Transparent proxy given an ethers contract factory to use as implementation, and returns a contract instance with the proxy address and the implementation interface. If args is set, will call an initializer function initialize with the supplied args during proxy deployment.

If you call deployProxy several times for the same implementation contract, several proxies will be deployed, but only one implementation contract will be used.

Parameters:

Contract - an ethers contract factory to use as the implementation.
args - arguments for the initializer function.
opts - an object with options:
- initializer: set a different initializer function to call (see Specifying Fragments), or specify false to disable initialization.
- additional options as described in Common Options.

Returns:

a contract instance with the proxy address and the implementation interface.

upgradeProxy

async function upgradeProxy(
  proxy: string | ethers.Contract,
  Contract: ethers.ContractFactory,
  opts?: {
    call?: string | { fn: string; args?: unknown[] },
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    kind?: 'uups' | 'transparent',
  },
): Promise<ethers.Contract>

Upgrades a UUPS or Transparent proxy at a specified address to a new implementation contract, and returns a contract instance with the proxy address and the new implementation interface.

Parameters:

proxy - the proxy address or proxy contract instance.
Contract - an ethers contract factory to use as the new implementation.
opts - an object with options:
- call: enables the execution of an arbitrary function call during the upgrade process. This call is described using a function name, signature, or selector (see Specifying Fragments), and optional arguments. It is batched into the upgrade transaction, making it safe to call migration initializing functions.
- additional options as described in Common Options.

Returns:

a contract instance with the proxy address and the new implementation interface.

deployBeacon

async function deployBeacon(
  Contract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
  },
): Promise<ethers.Contract>

Creates an upgradable beacon given an ethers contract factory to use as implementation, and returns the beacon contract instance.

Parameters:

Contract - an ethers contract factory to use as the implementation.
opts - an object with options:
- additional options as described in Common Options.

Returns:

the beacon contract instance.

Since:

@openzeppelin/hardhat-upgrades@1.13.0

upgradeBeacon

async function upgradeBeacon(
  beacon: string | ethers.Contract,
  Contract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
  },
): Promise<ethers.Contract>

Upgrades an upgradable beacon at a specified address to a new implementation contract, and returns the beacon contract instance.

Parameters:

beacon - the beacon address or beacon contract instance.
Contract - an ethers contract factory to use as the new implementation.
opts - an object with options:
- additional options as described in Common Options.

Returns:

the beacon contract instance.

Since:

@openzeppelin/hardhat-upgrades@1.13.0

deployBeaconProxy

async function deployBeaconProxy(
  beacon: string | ethers.Contract,
  attachTo: ethers.ContractFactory,
  args: unknown[] = [],
  opts?: {
    initializer?: string | false,
    usePlatformDeploy?: boolean,
  },
): Promise<ethers.Contract>

Creates a Beacon proxy given an existing beacon contract address and an ethers contract factory corresponding to the beacon’s current implementation contract, and returns a contract instance with the beacon proxy address and the implementation interface. If args is set, will call an initializer function initialize with the supplied args during proxy deployment.

Parameters:

beacon - the beacon address or beacon contract instance.
attachTo - an ethers contract factory corresponding to the beacon’s current implementation contract.
args - arguments for the initializer function.
opts - an object with options:
- initializer: set a different initializer function to call (see Specifying Fragments), or specify false to disable initialization.
- additional options as described in Common Options.

Returns:

a contract instance with the beacon proxy address and the implementation interface.

Since:

@openzeppelin/hardhat-upgrades@1.13.0

forceImport

async function forceImport(
  address: string,
  deployedImpl: ethers.ContractFactory,
  opts?: {
    kind?: 'uups' | 'transparent' | 'beacon',
  },
): Promise<ethers.Contract>

Forces the import of an existing proxy, beacon, or implementation contract deployment to be used with this plugin. Provide the address of an existing proxy, beacon or implementation, along with the ethers contract factory of the implementation contract that was deployed.

When importing a proxy or beacon, the deployedImpl argument must be the contract factory of the current implementation contract version that is being used, not the version that you are planning to upgrade to.

Use this function to recreate a lost network file by importing previous deployments, or to register proxies or beacons for upgrading even if they were not originally deployed by this plugin. Supported for UUPS, Transparent, and Beacon proxies, as well as beacons and implementation contracts.

Parameters:

address - the address of an existing proxy, beacon or implementation.
deployedImpl - the ethers contract factory of the implementation contract that was deployed.
opts - an object with options:
- kind: ("uups" | "transparent" | "beacon") forces a proxy to be treated as a UUPS, Transparent, or Beacon proxy. If not provided, the proxy kind will be automatically detected.

Returns:

a contract instance representing the imported proxy, beacon or implementation.

Since

@openzeppelin/hardhat-upgrades@1.15.0

validateImplementation

async function validateImplementation(
  Contract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    kind?: 'uups' | 'transparent' | 'beacon',
  },
): Promise<void>

Validates an implementation contract without deploying it.

Parameters:

Contract - the ethers contract factory of the implementation contract.
opts - an object with options:
- additional options as described in Common Options.

Since:

@openzeppelin/hardhat-upgrades@1.20.0

deployImplementation

async function deployImplementation(
  Contract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    getTxResponse?: boolean,
    kind?: 'uups' | 'transparent' | 'beacon',
    usePlatformDeploy?: boolean,
  },
): Promise<string | ethers.providers.TransactionResponse>

Validates and deploys an implementation contract, and returns its address.

Parameters:

Contract - an ethers contract factory to use as the implementation.
opts - an object with options:
- getTxResponse: if set to true, causes this function to return an ethers transaction response corresponding to the deployment of the new implementation contract instead of its address. Note that if the new implementation contract was originally imported as a result of forceImport, only the address will be returned.
- additional options as described in Common Options.

Returns:

the address or an ethers transaction response corresponding to the deployment of the implementation contract.

Since:

@openzeppelin/hardhat-upgrades@1.20.0

validateUpgrade

async function validateUpgrade(
  referenceAddressOrContract: string | ethers.ContractFactory,
  newContract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    kind?: 'uups' | 'transparent' | 'beacon',
  },
): Promise<void>

Validates a new implementation contract without deploying it and without actually upgrading to it. Compares the current implementation contract to the new implementation contract to check for storage layout compatibility errors. If referenceAddressOrContract is the current implementation address, the kind option is required.

Parameters:

referenceAddressOrContract - a proxy or beacon address that uses the current implementation, or an address or ethers contract factory corresponding to the current implementation.
newContract - the new implementation contract.
opts - an object with options:
- additional options as described in Common Options.

Since:

@openzeppelin/hardhat-upgrades@1.20.0

Examples:

Validate upgrading an existing proxy to a new contract (replace PROXY_ADDRESS with the address of your proxy):

const { ethers, upgrades } = require('hardhat');

const BoxV2 = await ethers.getContractFactory('BoxV2');
await upgrades.validateUpgrade(PROXY_ADDRESS, BoxV2);

Validate upgrading between two contract implementations:

const { ethers, upgrades } = require('hardhat');

const Box = await ethers.getContractFactory('Box');
const BoxV2 = await ethers.getContractFactory('BoxV2');
await upgrades.validateUpgrade(Box, BoxV2);

prepareUpgrade

async function prepareUpgrade(
  referenceAddressOrContract: string | ethers.Contract,
  Contract: ethers.ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    getTxResponse?: boolean,
    kind?: 'uups' | 'transparent' | 'beacon',
    usePlatformDeploy?: boolean,
  },
): Promise<string | ethers.providers.TransactionResponse>

Validates and deploys a new implementation contract, and returns its address. If referenceAddressOrContract is the current implementation address, the kind option is required. Use this method to prepare an upgrade to be run from an admin address you do not control directly or cannot use from Hardhat.

Parameters:

referenceAddressOrContract - the proxy or beacon or implementation address or contract instance.
Contract - the new implementation contract.
opts - an object with options:
- getTxResponse: if set to true, causes this function to return an ethers transaction response corresponding to the deployment of the new implementation contract instead of its address. Note that if the new implementation contract was originally imported as a result of forceImport, only the address will be returned.
- additional options as described in Common Options.

Returns:

the address or an ethers transaction response corresponding to the deployment of the new implementation contract.

platform.deployContract

async function deployContract(
  Contract: ethers.ContractFactory,
  args: unknown[] = [],
  opts?: {
    unsafeAllowDeployContract?: boolean,
    pollingInterval?: number,
  },
): Promise<ethers.Contract>

Note: OpenZeppelin Platform is in beta and this function is subject to change.

Deploys a non-upgradeable contract using the OpenZeppelin Platform, and returns a contract instance. Throws an error if the contract looks like an implementation contract.

Do not use this function to deploy implementations of upgradeable contracts, because upgrade safety validations are not performed with this function. For implementation contracts, use deployImplementation instead.

Parameters:

Contract - an ethers contract factory to use as the contract to deploy.
opts - an object with options:
- unsafeAllowDeployContract: if set to true, allows the contract to be deployed even if it looks like an implementation contract. Defaults to false.
- pollingInterval: polling interval in milliseconds between checks for the transaction confirmation when calling .deployed() on the resulting contract instance. Defaults to 5000.

Returns:

the contract instance.

Since:

@openzeppelin/hardhat-upgrades@1.25.0

platform.proposeUpgrade

async function proposeUpgrade(
  proxyAddress: string,
  ImplFactory: ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    kind?: 'uups' | 'transparent' | 'beacon',
    usePlatformDeploy?: boolean,
    approvalProcessId?: string,
  },
): Promise<{
    proposalId: string,
    url: string,
    txResponse?: ethers.providers.TransactionResponse,
  }>

Note: OpenZeppelin Platform is in beta and this function is subject to change.

Similar to prepareUpgrade. This method validates and deploys the new implementation contract, but also creates an upgrade proposal through the OpenZeppelin Platform, for review and approval by the upgrade administrators. Supported for UUPS or Transparent proxies. Not currently supported for beacon proxies or beacons. For beacons, use prepareUpgrade along with a transaction proposal on Platform to upgrade the beacon to the deployed implementation.

Parameters:

proxyAddress - the proxy address.
ImplFactory - the new implementation contract.
opts - an object with options:
- approvalProcessId: The ID of the upgrade approval process. Defaults to the upgrade approval process configured for your deployment environment on Platform.
- additional options as described in Common Options.

Returns:

an object with the Platform proposal ID, the URL of the proposal in Safe App if applicable, and the ethers transaction response corresponding to the deployment of the new implementation contract. Note that if the new implementation contract was originally imported as a result of forceImport, the ethers transaction response will be undefined.

Since:

@openzeppelin/hardhat-upgrades@1.26.0

platform.getDefaultApprovalProcess

async function getDefaultApprovalProcess(
): Promise<{
    approvalProcessId: string,
    address?: string,
  }>

Note: OpenZeppelin Platform is in beta and this function is subject to change.

Gets the default upgrade approval process configured for your deployment environment on Platform. For example, this is useful for determining the default multisig wallet that you can use in your scripts to assign as the owner of your proxy.

Returns:

an object with the default upgrade approval process ID and the associated address, such as a multisig or governor contract address.

Since:

@openzeppelin/hardhat-upgrades@1.26.0

defender.proposeUpgrade

async function proposeUpgrade(
  proxyAddress: string,
  ImplFactory: ContractFactory,
  opts?: {
    unsafeAllow?: ValidationError[],
    unsafeAllowRenames?: boolean,
    unsafeSkipStorageCheck?: boolean,
    constructorArgs?: unknown[],
    timeout?: number,
    pollingInterval?: number,
    redeployImplementation?: 'always' | 'never' | 'onchange',
    kind?: 'uups' | 'transparent' | 'beacon',
    title?: string,
    description?: string,
    multisig?: string,
    proxyAdmin?: string,
  },
): Promise<{
    url: string,
    txResponse?: ethers.providers.TransactionResponse,
  }>

This method requires the @openzeppelin/hardhat-defender package, as well as configuring a Defender Team API Key.

Similar to prepareUpgrade. This method validates and deploys the new implementation contract, but also creates an upgrade proposal in Defender Admin, for review and approval by the upgrade administrators. Supported for UUPS or Transparent proxies. Not currently supported for beacon proxies or beacons. For beacons, use prepareUpgrade along with a custom action in Defender Admin to upgrade the beacon to the deployed implementation.

Parameters:

proxyAddress - the proxy address.
ImplFactory - the new implementation contract.
opts - an object with options:
- title: title of the upgrade proposal as seen in Defender Admin, defaults to Upgrade to 0x12345678 (using the first 8 digits of the new implementation address)
- description: description of the upgrade proposal as seen in Defender Admin, defaults to the full implementation address.
- multisig: address of the multisignature wallet contract with the rights to execute the upgrade. This is autodetected in Transparent proxies, but required for UUPS proxies (read more here). Both Gnosis Safe and Gnosis MultisigWallet multisigs are supported.
- proxyAdmin: address of the ProxyAdmin contract that manages the proxy, if exists. This is autodetected in Transparent proxies, but required for UUPS proxies (read more here), though UUPS proxies typically do not require the usage of a ProxyAdmin.
- additional options as described in Common Options.

Returns:

an object with the URL of the Defender proposal, and the ethers transaction response corresponding to the deployment of the new implementation contract. Note that if the new implementation contract was originally imported as a result of forceImport, the ethers transaction response will be undefined.

deployProxyAdmin

async function deployProxyAdmin(
  signer?: ethers.Signer,
  opts?: {
    timeout?: number,
    pollingInterval?: number,
  },
): Promise<string>

Deploys a proxy admin contract and returns its address if one was not already deployed on the current network, or just returns the address of the proxy admin if one was already deployed. Note that this plugin currently only supports using one proxy admin per network.

Parameters:

signer - the signer to use for deployment.
opts - an object with options:
- additional options as described in Common Options.

Returns:

the address of the proxy admin.

Since:

@openzeppelin/hardhat-upgrades@1.20.0

admin.changeProxyAdmin

async function changeProxyAdmin(
  proxyAddress: string,
  newAdmin: string,
  signer?: ethers.Signer,
): Promise<void>

Changes the admin for a specific proxy.

Parameters:

proxyAddress - the address of the proxy to change.
newAdmin - the new admin address.
signer - the signer to use for the transaction.

admin.transferProxyAdminOwnership

async function transferProxyAdminOwnership(
  newAdmin: string,
  signer?: ethers.Signer,
): Promise<void>

Changes the owner of the proxy admin contract, which is the default admin for upgrade rights over all proxies.

Parameters:

newAdmin - the new admin address.
signer - the signer to use for the transaction.

erc1967

async function erc1967.getImplementationAddress(proxyAddress: string): Promise<string>;
async function erc1967.getBeaconAddress(proxyAddress: string): Promise<string>;
async function erc1967.getAdminAddress(proxyAddress: string): Promise<string>;

Functions in this module provide access to the ERC1967 variables of a proxy contract.

Parameters:

proxyAddress - the proxy address.

Returns:

the implementation, beacon, or admin address depending on the function called.

beacon

async function beacon.getImplementationAddress(beaconAddress: string): Promise<string>;

This module provides a convenience function to get the implementation address from a beacon contract.

Parameters:

beaconAddress - the beacon address.

Returns:

the implementation address.

Since:

@openzeppelin/hardhat-upgrades@1.13.0

silenceWarnings

function silenceWarnings()

This function is useful for tests, but its use in production deployment scripts is discouraged.

Silences all subsequent warnings about the use of unsafe flags. Prints a last warning before doing so.

verify

Extends hardhat-etherscan's verify task to completely verify a proxy on Etherscan. This supports verifying proxy contracts that were deployed by the Hardhat Upgrades or Truffle Upgrades plugin.

The arguments are the same as for hardhat-etherscan’s verify task. If the provided address is a proxy, this task will verify the proxy’s implementation contract, the proxy itself and any proxy-related contracts, as well as link the proxy to the implementation contract’s ABI on Etherscan. If the provided address is not a proxy, the regular verify task from hardhat-etherscan will be run on the address instead.

The following contracts will be verified when you run this task on your proxy address:

Your implementation contract
ERC1967Proxy or TransparentUpgradeableProxy or BeaconProxy (for UUPS, transparent, or beacon proxies, respectively)
ProxyAdmin (with transparent proxies)
UpgradeableBeacon (with beacon proxies)

Since:

@openzeppelin/hardhat-upgrades@1.18.0

Usage:

To use this task, ensure you have hardhat-etherscan installed:

npm install --save-dev @nomiclabs/hardhat-etherscan

Then import the @nomiclabs/hardhat-etherscan plugin along with the @openzeppelin/hardhat-upgrades plugin in your Hardhat configuration. For example, if you are using JavaScript, import the plugins in hardhat.config.js:

require("@nomiclabs/hardhat-etherscan");
require("@openzeppelin/hardhat-upgrades");

Or if you are using TypeScript, import the plugins in hardhat.config.ts:

import "@nomiclabs/hardhat-etherscan";
import "@openzeppelin/hardhat-upgrades";

Finally, follow hardhat-etherscan’s usage documentation to configure your Etherscan API key and run the verify task from the command line with the proxy address:

npx hardhat verify --network mainnet PROXY_ADDRESS

or programmatically using the verify:verify subtask:

await hre.run("verify:verify", {
  address: PROXY_ADDRESS,
});

Note that you do not need to include constructor arguments when verifying if your implementation contract only uses initializers. However, if your implementation contract has an actual constructor with arguments (such as to set immutable variables), then include constructor arguments according to the usage information for the task or subtask.