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

# Deploy with Hardhat

> Deploy a contract to BOT Chain testnet with Hardhat Ignition and find it on BOTScan.

In this guide you deploy a contract to BOT Chain testnet with Hardhat Ignition, then read it back from a script.

<Tip>
  Everything on this page uses **testnet** (chain 968). Get free test tokens from the [faucet](https://faucet.botchain.ai/basic).
</Tip>

## What you'll build

An Ignition module that deploys `Counter`, a record of the deployment in your project, and a script that reads the deployed contract.

## Prerequisites

* A Hardhat 3 project set up for BOT Chain, including the fee hook. Follow [Set up Hardhat](/guides/environment/hardhat) first.
* `BOT_PRIVATE_KEY` set in the Hardhat keystore or your terminal, for a wallet with at least 0.01 tBOT.
* `contracts/Counter.sol` from the setup guide.

## Steps

<Steps>
  <Step title="Write an Ignition module">
    An Ignition module describes what to deploy. Ignition works out the order and keeps a journal, so a failed deploy can resume where it stopped.

    ```ts ignition/modules/Counter.ts theme={"dark"}
    import { buildModule } from "@nomicfoundation/hardhat-ignition/modules";

    export default buildModule("CounterModule", (m) => {
      const counter = m.contract("Counter");
      return { counter };
    });
    ```

    If your contract takes constructor arguments, pass them as an array: `m.contract("Greeter", ["Hello"])`.
  </Step>

  <Step title="Deploy to testnet">
    ```bash theme={"dark"}
    npx hardhat ignition deploy ignition/modules/Counter.ts --network botTestnet
    ```

    Ignition asks you to confirm the network. Type `y`. When it finishes you'll see output like:

    ```text Output theme={"dark"}
    [ CounterModule ] successfully deployed 🚀

    Deployed Addresses

    CounterModule#Counter - 0x24E48d0fcf9B5500EE3DD77f96d095Db090a9F58
    ```

    Your address will be different. Ignition also saves it in `ignition/deployments/chain-968/deployed_addresses.json`.
  </Step>

  <Step title="Read the contract from a script">
    ```ts scripts/read-counter.ts theme={"dark"}
    import { network } from "hardhat";

    const counterAddress = process.env.COUNTER_ADDRESS;
    if (!counterAddress) throw new Error("Set COUNTER_ADDRESS to your Counter address");

    const { viem } = await network.getOrCreate();
    const counter = await viem.getContractAt("Counter", counterAddress as `0x${string}`);
    console.log(`count is ${await counter.read.count()}`);
    ```

    ```bash theme={"dark"}
    COUNTER_ADDRESS=0xYOUR_COUNTER npx hardhat run scripts/read-counter.ts --network botTestnet
    ```

    You should see `count is 0`.
  </Step>
</Steps>

## Verify it worked

* Run `npx hardhat ignition status chain-968`. It prints `Deployment chain-968 (chainId: 968) was successful` and the address.
* Open `https://scan.bohr.life/address/YOUR_ADDRESS`. BOTScan shows the contract and the deploy transaction.

Next, [verify the source](/guides/deploy/verify/hardhat) so others can read it on BOTScan.

## Deploy to mainnet

<Warning>
  Mainnet deploys cost real BOT and can't be undone. Test on testnet first and use a separate key for mainnet.
</Warning>

Use the same module with the mainnet network:

```bash theme={"dark"}
npx hardhat ignition deploy ignition/modules/Counter.ts --network botMainnet
```

Ignition stores mainnet deployments in `ignition/deployments/chain-677`.

## Troubleshooting

<AccordionGroup>
  <Accordion title="transaction underpriced: effective gas tip 0, minimum needed 20000000000">
    Ignition sent a fee of 0 because BOT Chain's base fee is 0. Add the fee hook from [Set up Hardhat](/guides/environment/hardhat), then deploy again.
  </Accordion>

  <Accordion title="Ignition says a previous run failed or a transaction is pending">
    Ignition resumes from its journal. If the earlier run failed before anything was sent (for example, an RPC error), delete `ignition/deployments/chain-968` and deploy again. Don't delete it if a contract was deployed, or Ignition will deploy a second copy.
  </Accordion>

  <Accordion title="insufficient funds for gas">
    Your wallet needs tBOT. Check the address with the script in [Set up Hardhat](/guides/environment/hardhat) and claim from a faucet.
  </Accordion>

  <Accordion title="An RPC call returns 502">
    The public RPC sometimes drops a request. Run the same deploy command again; Ignition picks up where it stopped.
  </Accordion>
</AccordionGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="Verify with Hardhat" icon="badge-check" href="/guides/deploy/verify/hardhat">
    Publish your source on BOTScan.
  </Card>

  <Card title="Set up wagmi" icon="settings" href="/guides/frontend/wagmi-setup">
    Call your contract from a web app.
  </Card>
</CardGroup>


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