npm package: @openzeppelin/hardhat-defender
Description: Hardhat plugin to propose smart contract upgrades on OpenZeppelin Defender
Latest version: 2.0.0
Deprecated: @openzeppelin/hardhat-defender is deprecated. This functionality is now included as part of @openzeppelin/hardhat-upgrades

# OpenZeppelin Hardhat Defender

[![Docs](https://img.shields.io/badge/docs-%F0%9F%93%84-blue)](https://docs.openzeppelin.com/upgrades-plugins/hardhat-upgrades)
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**Hardhat plugin for integrating upgrades and deployment verifications with OpenZeppelin Defender.** This package adds functions to your Hardhat scripts so you can propose upgrades for your contracts and approve them via [Defender Admin](https://docs.openzeppelin.com/defender/admin) (depends on `@openzeppelin/hardhat-upgrades` and `ethers.js`) and verify deployments.

## Why?

Use this package to manage upgrades for mainnet contracts using Hardhat scripts, and then approve them by a multisig through Defender Admin.

You can use `@openzeppelin/hardhat-upgrades` to deploy your upgradeable contracts via [`deployProxy`](https://docs.openzeppelin.com/upgrades-plugins/1.x/api-hardhat-upgrades#deploy-proxy), and then transfer the admin powers to a multi-signature wallet via [`transferProxyAdminOwnership`](https://docs.openzeppelin.com/upgrades-plugins/1.x/api-hardhat-upgrades#admin-transfer-proxy-admin-ownership) for additional security. 

When you want to upgrade, use `proposeUpgrade` to prepare the upgrade, and create a new upgrade proposal in Defender Admin. The multisig admins can then [review the upgrade in Defender](https://docs.openzeppelin.com/defender/admin#upgrades), and sign their approval.

![Approve an Upgrade in Defender Admin](./assets/approve-upgrade.png)

You can also verify the deployment on Defender, which checks that the compilation artifact matches the deployed code, so reviewers can check that the new implementation matches the source code.

![Review bytecode verification](./assets/verified-deploy.png)

## Installation

```
npm install --save-dev @openzeppelin/hardhat-defender
npm install --save-dev @nomiclabs/hardhat-ethers ethers # peer dependencies
```

Register the plugin in your [`hardhat.config.js`](https://hardhat.org/config/):

```js
// Javascript
require('@openzeppelin/hardhat-defender');

// Typescript
import '@openzeppelin/hardhat-defender';
```

And add your Defender _Team API key_ to the exported configuration in [`hardhat.config.js`](https://hardhat.org/config/):

```js
module.exports = {
  defender: {
    apiKey: process.env.API_KEY,
    apiSecret: process.env.API_SECRET,
  }
}
```

## Upgrades

You can use this plugin in a [Hardhat script](https://hardhat.org/guides/scripts.html) to propose an upgrade for a contract previously deployed with [`deployProxy`](https://docs.openzeppelin.com/upgrades-plugins/1.x/api-hardhat-upgrades#deploy-proxy):

```js
// scripts/propose-upgrade.js
const { defender } = require("hardhat");

async function main() {
  const BoxV2 = await ethers.getContractFactory("BoxV2");
  const proposal = await defender.proposeUpgrade(BOX_ADDRESS, BoxV2);
  console.log("Upgrade proposal created at:", proposal.url);
}

main();
```

This will automatically check that the `Box` contract deployed at `BOX_ADDRESS` can be safely upgraded to `BoxV2`, deploy the `BoxV2` implementation contract, and create a new upgrade proposal in Defender Admin.

Note that `proposeUpgrade` will only deploy the implementation contract, but **will not change anything in your proxy contract**. Any changes must be approved by the upgrade admin(s), who can do so either via Defender or manually.

## Verification

You can upload the compilation artifact for a contract to Defender, along with its deployment address. Defender will check that the code on chain matches the artifact, and display a verification notice on the application.

```js
// scripts/verify-deploy.js
const { defender } = require('hardhat');

async function main() {
  const verification = await defender.verifyDeployment(BOX_ADDRESS, 'Box', MY_REPO_URL);
  console.log(`Verified artifact with hash`, verification.providedSha256);
}

main();
```

Alternatively, you can also upload the compilation artifact to a public URL and then have Defender retrieve the artifact from that location for verification, through the `verifyDeploymentWithUploadedArtifact` function. You can get the artifact to upload for a specific contract using `getDeploymentArtifact`, or an artifact that contains the build info for all your contracts using `getDeploymentBuildInfo`. You can also get the hash of the artifact for a given contract using `getBytecodeDigest` to check for matches against a pre existing verification on Defender.

## Learn more

* Refer to the [API documentation](https://docs.openzeppelin.com/upgrades-plugins/api-hardhat-upgrades).
* Also see the [main documentation](https://docs.openzeppelin.com/upgrades-plugins) for more info.
* And check the [Defender Admin documentation](https://docs.openzeppelin.com/defender/admin) to learn more about managing your contracts with Defender.