> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/mezo-org/documentation/llms.txt
> Use this file to discover all available pages before exploring further.

# Set Up Developer Environment

> Configure your development environment to build and deploy on Mezo using Hardhat or Foundry.

Configure your Hardhat or Foundry development environment for Mezo to start building and deploying smart contracts.

## Before You Begin

Before you can deploy applications, you will need an Ethereum wallet with BTC to pay for gas fees.

<Card title="Connect Your Wallet" icon="wallet" href="/getting-started/connect-wallet">
  Learn how to connect your wallet to Mezo
</Card>

<Note>
  For advanced chain configuration and network parameters, see the [Chains Configuration Guide](/developers/reference/chains).
</Note>

## Testnet Configuration

### Network Details

| Parameter      | Value                                                     |
| -------------- | --------------------------------------------------------- |
| Network Name   | Mezo Testnet                                              |
| Chain ID       | `31611`                                                   |
| Currency       | BTC (18 decimals)                                         |
| Block Explorer | [explorer.test.mezo.org](https://explorer.test.mezo.org/) |

### RPC Endpoints

| Protocol | URL                          |
| -------- | ---------------------------- |
| HTTPS    | `https://rpc.test.mezo.org`  |
| WSS      | `wss://rpc-ws.test.mezo.org` |

### Get Testnet BTC

To pay for gas fees on the Testnet, you will need Testnet BTC.

<Steps>
  <Step title="Visit the Mezo Faucet">
    Obtain Testnet BTC from the official [Mezo Faucet](https://faucet.test.mezo.org/).

    <Note>The faucet is protected by a CAPTCHA to prevent abuse.</Note>
  </Step>

  <Step title="Setup Your Wallet">
    Ensure you have a browser wallet installed that supports Ethereum (EVM), such as MetaMask.
  </Step>
</Steps>

### Hardhat Configuration

<Steps>
  <Step title="Install Hardhat">
    If you are new to Hardhat, use the [Hardhat Quick Start](https://hardhat.org/hardhat-runner/docs/getting-started#quick-start) guide to learn how to install and initialize your project.
  </Step>

  <Step title="Configure Network">
    To configure Hardhat for Mezo Testnet, modify your `hardhat.config.js` (or `.ts`) file:

    ```javascript hardhat.config.js theme={null}
    module.exports = {
      defaultNetwork: "mezotestnet",
      networks: {
        mezotestnet: {
          url: "https://rpc.test.mezo.org",
          chainId: 31611,
          accounts: ["YOUR_PRIVATE_WALLET_KEY"] // Use environment variables for security
        }
      },
      solidity: {
        version: "0.8.28",
        settings: {
          evmVersion: "london",
          optimizer: {
            enabled: true,
            runs: 200
          }
        }
      },
    };
    ```

    <Warning>
      Always use environment variables to store private keys. Never commit private keys to version control.
    </Warning>
  </Step>
</Steps>

### Foundry Configuration

<Steps>
  <Step title="Install Foundry">
    If you are new to Foundry, use the [Foundry Getting Started](https://book.getfoundry.sh/getting-started/installation) guide to learn how to install and initialize your project.
  </Step>

  <Step title="Configure Network">
    To configure a Foundry project for Mezo Testnet, set the following in your `foundry.toml`:

    ```toml foundry.toml theme={null}
    [profile.default]
    chain_id = 31611
    eth_rpc_url = "https://rpc.test.mezo.org"
    evm_version = 'london'
    ```
  </Step>
</Steps>

## Mainnet Configuration

### Network Details

| Parameter      | Value                                           |
| -------------- | ----------------------------------------------- |
| Network Name   | Mezo Mainnet                                    |
| Chain ID       | `31612`                                         |
| Currency       | BTC (18 decimals)                               |
| Block Explorer | [explorer.mezo.org](https://explorer.mezo.org/) |

### RPC Providers

<Note>
  For production deployments, it is recommended to use a dedicated RPC provider for higher rate limits and stability.
</Note>

| Provider         | HTTPS                                            | WSS                                            |
| ---------------- | ------------------------------------------------ | ---------------------------------------------- |
| Boar             | `https://rpc-http.mezo.boar.network`             | `wss://rpc-ws.mezo.boar.network`               |
| Imperator        | `https://rpc_evm-mezo.imperator.co`              | `wss://ws_evm-mezo.imperator.co`               |
| Validation Cloud | `https://mainnet.mezo.public.validationcloud.io` | `wss://mainnet.mezo.public.validationcloud.io` |
| dRPC NodeCloud   | `https://mezo.drpc.org`                          | `wss://mezo.drpc.org`                          |

### Hardhat Configuration

To configure Hardhat for Mezo Mainnet, modify your `hardhat.config.js` (or `.ts`) file:

```javascript hardhat.config.js theme={null}
module.exports = {
  defaultNetwork: "mezomainnet",
  networks: {
    mezomainnet: {
      url: "https://rpc-http.mezo.boar.network",
      chainId: 31612,
      accounts: ["YOUR_PRIVATE_WALLET_KEY"] // Use environment variables for security
    }
  },
  solidity: {
    version: "0.8.28",
    settings: {
      evmVersion: "london",
      optimizer: {
        enabled: true,
        runs: 200
      }
    }
  },
};
```

<Warning>
  Always use environment variables to store private keys. Never commit private keys to version control.
</Warning>

### Foundry Configuration

To configure a Foundry project for Mezo Mainnet, set the following in your `foundry.toml`:

```toml foundry.toml theme={null}
[profile.default]
chain_id = 31612
eth_rpc_url = "https://rpc-http.mezo.boar.network"
evm_version = 'london'
```

## Multi-Network Configuration

For projects that need to support both Testnet and Mainnet, you can configure multiple networks:

<CodeGroup>
  ```javascript hardhat.config.js theme={null}
  module.exports = {
    networks: {
      mezotestnet: {
        url: "https://rpc.test.mezo.org",
        chainId: 31611,
        accounts: [process.env.TESTNET_PRIVATE_KEY]
      },
      mezomainnet: {
        url: "https://rpc-http.mezo.boar.network",
        chainId: 31612,
        accounts: [process.env.MAINNET_PRIVATE_KEY]
      }
    },
    solidity: {
      version: "0.8.28",
      settings: {
        evmVersion: "london",
        optimizer: {
          enabled: true,
          runs: 200
        }
      }
    },
  };
  ```

  ```toml foundry.toml theme={null}
  [profile.testnet]
  chain_id = 31611
  eth_rpc_url = "https://rpc.test.mezo.org"
  evm_version = 'london'

  [profile.mainnet]
  chain_id = 31612
  eth_rpc_url = "https://rpc-http.mezo.boar.network"
  evm_version = 'london'
  ```
</CodeGroup>

## Next Steps

<CardGroup cols={2}>
  <Card title="Deploy Contracts" icon="rocket">
    Start deploying your smart contracts to Mezo using your configured environment
  </Card>

  <Card title="Mezo Passport" icon="wallet" href="/developers/getting-started/mezo-passport">
    Integrate wallet support for both Bitcoin and EVM wallets
  </Card>

  <Card title="MUSD Integration" icon="dollar-sign" href="/musd/overview">
    Integrate MUSD stablecoin into your dApp
  </Card>

  <Card title="dApp Requirements" icon="list-check" href="/developers/developers/getting-started/dapp-requirements">
    Review requirements for featuring in Mezo Market
  </Card>
</CardGroup>