# Calibur Account Quickstart

Calibur turns your EOA into a smart account via EIP-7702 delegation. After delegation, the address stays the same but gains batching, gas sponsorship, and key management capabilities including passkey authentication.

This guide demonstrates how to upgrade your EOA to a Calibur smart account and batch two NFT mints in a single sponsored transaction.

## Prerequisites[​](#prerequisites "Direct link to Prerequisites")

* Sepolia Bundler and Paymaster endpoints from the [Dashboard](https://dashboard.candide.dev)
* Node and a package manager (yarn or npm)

Here's the [complete code](https://github.com/candidelabs/abstractionkit-examples/blob/main/eip-7702/calibur-account/01-upgrade-eoa.ts) for you to reference if you prefer to run directly.

## Step 1: Get setup[​](#step-1-get-setup "Direct link to Step 1: Get setup")

1. Create a new directory for your project:

```
mkdir candide-calibur-quickstart
cd candide-calibur-quickstart
npx tsc --init
```

2. Install dependencies

```
npm i typescript --save-dev
npm i abstractionkit@0.2.39 dotenv
```

3. Configure Environment Variables

* Create a `.env` file and add the following environment variables with your own values

.env

```
CHAIN_ID=11155111
JSON_RPC_NODE_PROVIDER=https://ethereum-sepolia-rpc.publicnode.com
BUNDLER_URL=https://api.candide.dev/public/v3/sepolia
PAYMASTER_URL=https://api.candide.dev/public/v3/sepolia
PRIVATE_KEY=your_eoa_private_key_here
```

4. Create an empty file and a function to run your script

index.ts

```
async function main(): Promise<void> {
  // Rest of the code will go here...
}

main();
```

## Step 2: Initialize Account and Paymaster[​](#step-2-initialize-account-and-paymaster "Direct link to Step 2: Initialize Account and Paymaster")

Initialize the [Calibur7702Account](https://docs.candide.dev/wallet/abstractionkit/calibur-account.md) using your EOA address. The account address stays the same after delegation.

index.ts

```
import { Calibur7702Account, CandidePaymaster } from "abstractionkit";

const chainId = BigInt(process.env.CHAIN_ID as string);
const bundlerUrl = process.env.BUNDLER_URL as string;
const paymasterUrl = process.env.PAYMASTER_URL as string;
const nodeUrl = process.env.JSON_RPC_NODE_PROVIDER as string;
const privateKey = process.env.PRIVATE_KEY as string;

// Derive the EOA public address from the private key
import { Wallet } from "ethers";
const eoaWallet = new Wallet(privateKey);
const eoaAddress = eoaWallet.address;

// The account address is your EOA address. After delegation, it becomes
// a smart account while keeping the same address.
const smartAccount = new Calibur7702Account(eoaAddress);

console.log("Smart account address: " + smartAccount.accountAddress);

// Check if the EOA is already delegated to Calibur
const alreadyDelegated = await smartAccount.isDelegated(nodeUrl);

// CandidePaymaster sponsors gas so the EOA doesn't need native tokens.
const paymaster = new CandidePaymaster(paymasterUrl);
```

Run the code to verify the account address:

Terminal

```
npx ts-node index.ts
```

Details

Result example

Smart account address: 0x32afdcfa1e3bfe70d03ecb55b5c8045c26515c9d

## Step 3: Build Transactions[​](#step-3-build-transactions "Direct link to Step 3: Build Transactions")

Batch two NFT mints into a single UserOperation to demonstrate the smart account's batching capability.

index.ts

```
import {
  getFunctionSelector,
  createCallData,
  MetaTransaction,
} from "abstractionkit";

const nftContractAddress = "0x9a7af758aE5d7B6aAE84fe4C5Ba67c041dFE5336";
const mintFunctionSelector = getFunctionSelector('mint(address)');
const mintCallData = createCallData(
    mintFunctionSelector,
    ["address"],
    [eoaAddress],
);

const mintNft1: MetaTransaction = { to: nftContractAddress, value: 0n, data: mintCallData };
const mintNft2: MetaTransaction = { to: nftContractAddress, value: 0n, data: mintCallData };
```

## Step 4: Create UserOperation with EIP-7702 Delegation[​](#step-4-create-useroperation-with-eip-7702-delegation "Direct link to Step 4: Create UserOperation with EIP-7702 Delegation")

Call `createUserOperation` to build the unsigned UserOperation. Pass `eip7702Auth` on the first delegation. If the EOA is already delegated, skip the authorization by passing `undefined`.

index.ts

```
import { calculateUserOperationMaxGasCost } from "abstractionkit";

// eip7702Auth tells the bundler to include a delegation authorization
// in the transaction. Only needed for the first UserOperation.
let userOperation = await smartAccount.createUserOperation(
    [mintNft1, mintNft2],
    nodeUrl,
    bundlerUrl,
    {
        eip7702Auth: alreadyDelegated ? undefined : { chainId },
    },
);

const cost = calculateUserOperationMaxGasCost(userOperation);
console.log("This UserOperation may cost up to: " + cost + " wei");
```

## Step 5: Sign the Delegation Authorization[​](#step-5-sign-the-delegation-authorization "Direct link to Step 5: Sign the Delegation Authorization")

Sign the `eip7702Auth` tuple to authorize the Calibur singleton at your EOA address. This is only required during the first upgrade transaction.

index.ts

```
import { createAndSignEip7702DelegationAuthorization } from "abstractionkit";

// Option A: Pass private key string directly
if (!alreadyDelegated) {
    userOperation.eip7702Auth = createAndSignEip7702DelegationAuthorization(
        BigInt(userOperation.eip7702Auth.chainId),
        userOperation.eip7702Auth.address,
        BigInt(userOperation.eip7702Auth.nonce),
        privateKey,
    );
}

// Option B: Use a viem signer callback (private key never leaves the client)
// import { privateKeyToAccount } from "viem/accounts";
// const viemAccount = privateKeyToAccount(privateKey as `0x${string}`);
// if (!alreadyDelegated) {
//     userOperation.eip7702Auth = await createAndSignEip7702DelegationAuthorization(
//         BigInt(userOperation.eip7702Auth.chainId),
//         userOperation.eip7702Auth.address,
//         BigInt(userOperation.eip7702Auth.nonce),
//         async (hash) => viemAccount.sign({ hash: hash as `0x${string}` }),
//     );
// }
```

## Step 6: Sponsor Gas[​](#step-6-sponsor-gas "Direct link to Step 6: Sponsor Gas")

Optionally [sponsor gas](https://docs.candide.dev/wallet/guides/send-gasless-eip-7702.md) for your user. In ERC-4337 v0.8, paymaster data is included in the UserOperation hash, so it must be set before signing.

index.ts

```
let [sponsoredUserOperation] = await paymaster.createSponsorPaymasterUserOperation(
    userOperation,
    bundlerUrl,
);
userOperation = sponsoredUserOperation;
```

## Step 7: Sign the UserOperation[​](#step-7-sign-the-useroperation "Direct link to Step 7: Sign the UserOperation")

Sign the UserOperation with the EOA's root key.

index.ts

```
// Option A: Pass private key string
userOperation.signature = smartAccount.signUserOperation(
    userOperation,
    privateKey,
    chainId,
);

// Option B: Use a viem signer callback
// userOperation.signature = await smartAccount.signUserOperationWithSigner(
//     userOperation,
//     async (hash) => viemAccount.sign({ hash: hash as `0x${string}` }),
//     chainId,
// );
```

## Step 8: Send and Wait for Inclusion[​](#step-8-send-and-wait-for-inclusion "Direct link to Step 8: Send and Wait for Inclusion")

Send the UserOperation to the bundler and wait for on-chain inclusion.

index.ts

```
console.log("Sending sponsored UserOperation...");
const response = await smartAccount.sendUserOperation(userOperation, bundlerUrl);
console.log("UserOp hash:", response.userOperationHash);

const receipt = await response.included();

if (receipt.success) {
    if (!alreadyDelegated) {
        console.log("EOA upgraded to Calibur smart account!");
    }
    console.log("Minted 2 NFTs in a single batched UserOperation!");
    console.log("Gas was sponsored by CandidePaymaster.");
    console.log("Transaction:", receipt.receipt.transactionHash);
} else {
    console.log("UserOperation execution failed");
    console.log(receipt);
}
```

Run the script:

Terminal

```
npx ts-node index.ts
```

Result

```
Sending sponsored UserOperation...
UserOp hash: 0x89a5111d40c4ca45977a28419a08ca33e496a88e973bc995ec6a5a28da564cb5
EOA upgraded to Calibur smart account!
Minted 2 NFTs in a single batched UserOperation!
Gas was sponsored by CandidePaymaster.
Transaction: 0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a
```

You can look up the hash on explorers that support user operations like [Blockscout](https://www.blockscout.com/).

## Full Example[​](#full-example "Direct link to Full Example")

01-upgrade-eoa.ts

```
loading...
```

[See full example on GitHub](https://github.com/candidelabs/abstractionkit-examples/blob/main/eip-7702/calibur-account/01-upgrade-eoa.ts)

## Next Steps[​](#next-steps "Direct link to Next Steps")

* Explore the [Calibur SDK reference](https://docs.candide.dev/wallet/abstractionkit/calibur-account.md) for the full API
* Add passkey authentication: [02-passkeys.ts](https://github.com/candidelabs/abstractionkit-examples/blob/main/eip-7702/calibur-account/02-passkeys.ts)
* Manage keys and permissions: [03-manage-keys.ts](https://github.com/candidelabs/abstractionkit-examples/blob/main/eip-7702/calibur-account/03-manage-keys.ts)