> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qu.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Verifying Contract on Quaiscan

> A guide to verifying your smart contracts on Quaiscan.

## Introduction

This article shows how to verify a smart contract on Quai Network's block explorer [Quaiscan](https://quaiscan.io/).

## Prerequisites

To deploy contracts and verify them on Quaiscan we'll need a few dependencies. Here's an overview of all the main dependencies we'll be using.

|                                                                                               |                                                                              |
| --------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------- |
| [**NodeJS**](https://nodejs.org/en/download/)                                                 | Javascript runtime environment. Use the LTS version.                         |
| [**hardhat-example**](https://github.com/dominant-strategies/hardhat-example)                 | A Hardhat project with sample contracts and deploy scripts for Quai Network. |
| [**hardhat-deploy-metadata**](https://github.com/dominant-strategies/hardhat-deploy-metadata) | A plugin for hardhat that uploads contract metadata to IPFS                  |
| [**Quais.js**](https://www.npmjs.com/package/quais)                                           | A JavaScript library for interacting with Quai Network.                      |

## Walkthrough

Today we’re going to be verifying a smart contract on Quaiscan, Quai Network's block explorer.

This guide follows the [Deploy with Solidity](https://docs.qu.ai/guides/development/solidity) guide, so make sure you're familiar with that and the [hardhat-example](https://github.com/dominant-strategies/hardhat-example) repo before beginning.

### Deploy a Smart Contract

Following the [Deploy with Solidity](https://docs.qu.ai/guides/development/solidity) guide, deploy a smart contract complete with IPFS metadata.

When using the [hardhat-example](https://github.com/dominant-strategies/hardhat-example) repo the command should be `npx hardhat run scripts/deployERC20.js` which produces output similar to the following:

```
File added with CID: QmPCoBa1bCFmRoTD7GuexJqBAy7pqg8J4b8B48q5DgxUEV
Original IPFS hash found in bytecode: QmPCoBa1bCFmRoTD7GuexJqBAy7pqg8J4b8B48q5DgxUEV
Metadata JSON for ERC20 saved to /../hardhat-example/Solidity/metadata/ERC20_metadata.json
Transaction broadcasted:  0x0032004cc6a910b8733ad9502caa315beb74f3409bee2b481116bddfb9c8880d
Contract deployed to:  0x0015dFe3280783CD9b126D8E0ccc728B6490b2b2
```

In the above output you'll see that the contract's metadata was uploaded to `ipfs.qu.ai` with the following hash: `QmPCoBa1bCFmRoTD7GuexJqBAy7pqg8J4b8B48q5DgxUEV`

Your hash **will be different**. Make sure you capture it as we'll need it in the next step.

### Download the IPFS metadata

When using the [hardhat-deploy-metadata](https://github.com/dominant-strategies/hardhat-deploy-metadata) plugin, the IPFS metadata is stored in the project under the `metadata` folder, but isn't formatted properly for Quaiscan.

We'll need to download the proper format from IPFS to upload into Quaiscan and verify our contract.

Run the following command using **your IPFS hash** when you deployed your contract to download the metadata and save it as `ipfsMeta.json`.

```
curl https://ipfs.qu.ai/ipfs/[YOUR IPFS METADATA HASH] > ipfsMeta.json
```

### Verify Smart Contract on Quaiscan

Now that we have a deployed smart contract and the IPFS metadata in proper JSON formatting, we can verify our smart contract on Quaiscan.

Open your browser and visit the [Verify Contract](https://quaiscan.io/contract-verification?shard=) page on Quaiscan.

<Frame>
  <img src="https://mintcdn.com/dominantstrategies/BvvhftC0HW11EtQX/images/Guides/VerifyContract/verifyDialogue.png?fit=max&auto=format&n=BvvhftC0HW11EtQX&q=85&s=1ef41896cb7f9930fbc2e76f359bf95e" width="1325" height="637" data-path="images/Guides/VerifyContract/verifyDialogue.png" />
</Frame>

Using this page fill in all the details of your contract exactly as it's been written.

You'll need the correct contract address and license indicated by the `SPX-License-Identifier` in your contract's code.

Select **Solidity (Standard JSON input)** as the Verification Method and the correct version of the Solidity Compiler used to compile your contract.

Finally upload `ipfsMeta.json` and click **Verify & Publish** to verify your smart contract.

<Frame>
  <img src="https://mintcdn.com/dominantstrategies/BvvhftC0HW11EtQX/images/Guides/VerifyContract/verifyDialogueFilled.png?fit=max&auto=format&n=BvvhftC0HW11EtQX&q=85&s=4423d26ebdb85950bcee929d2b8a4e3f" width="1358" height="1074" data-path="images/Guides/VerifyContract/verifyDialogueFilled.png" />
</Frame>

Once successful you can visit your contract's page on Quaiscan to interact with it directly and see it's verification status.

<Frame>
  <img src="https://mintcdn.com/dominantstrategies/BvvhftC0HW11EtQX/images/Guides/VerifyContract/verifiedContract.png?fit=max&auto=format&n=BvvhftC0HW11EtQX&q=85&s=433fad0a1a8bbb4f92321bdcb8815891" width="2133" height="1161" data-path="images/Guides/VerifyContract/verifiedContract.png" />
</Frame>

Congratulations! You have just verified your smart contract on Quaiscan!