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

# Migration Guide - v0.9.0

> Guide for migrating from transaction-based APIs to UserOperation APIs

# ZeroDev v0.9.0 Migration Guide

Version 0.9.0 introduces a unified UserOperation API that replaces the previous transaction-based APIs. The new API supports both single and batch transactions with a consistent interface.

## Breaking Changes

The following functions have been removed:

* `estimateTransactionGas` → Use `estimateUserOperationGas`
* `canSponsorTransaction` → Use `canSponsorUserOperation`
* `prepareUserOperationWithKernelClient` → Use `sendUserOperation`

## New Features

* **Batch Transaction Support**: Execute multiple operations atomically in a single UserOperation
* **Unified API**: Consistent interface for single and batch transactions
* **Better Error Handling**: More granular error types and messages

## Migration Examples

### Checking Sponsorship

**Before (v0.8.x):**

```javascript theme={"system"}
import { canSponsorTransaction } from "@dynamic-labs-sdk/zerodev";

const canSponsor = await canSponsorTransaction({
  walletAccount,
  transaction: {
    to: recipientAddress,
    value: parseEther("0.01"),
    data: "0x",
  },
});
```

**After (v0.9.0):**

```javascript theme={"system"}
import { canSponsorUserOperation } from "@dynamic-labs-sdk/zerodev";

const canSponsor = await canSponsorUserOperation({
  walletAccount,
  calls: [
    {
      to: recipientAddress,
      value: parseEther("0.01"),
      data: "0x",
    },
  ],
});
```

**Key Changes:**

* Renamed from `canSponsorTransaction` to `canSponsorUserOperation`
* `transaction` parameter → `calls` (array)
* Single transaction now wrapped in an array

### Estimating Gas

**Before (v0.8.x):**

```javascript theme={"system"}
import { estimateTransactionGas } from "@dynamic-labs-sdk/zerodev";

const gasEstimate = await estimateTransactionGas({
  walletAccount,
  transaction: {
    to: recipientAddress,
    value: parseEther("0.01"),
    data: "0x",
  },
});
```

**After (v0.9.0):**

```javascript theme={"system"}
import { estimateUserOperationGas } from "@dynamic-labs-sdk/zerodev";

const gasEstimate = await estimateUserOperationGas({
  walletAccount,
  calls: [
    {
      to: recipientAddress,
      value: parseEther("0.01"),
      data: "0x",
    },
  ],
});
```

**Key Changes:**

* Renamed from `estimateTransactionGas` to `estimateUserOperationGas`
* `transaction` parameter → `calls` (array)
* Single transaction now wrapped in an array

### Sending Transactions

**Before (v0.8.x):**

```javascript theme={"system"}
// No direct equivalent - you had to use prepareUserOperationWithKernelClient
// and manually send the operation
```

**After (v0.9.0):**

```javascript theme={"system"}
import { sendUserOperation } from "@dynamic-labs-sdk/zerodev";

const receipt = await sendUserOperation({
  walletAccount,
  calls: [
    {
      to: recipientAddress,
      value: parseEther("0.01"),
      data: "0x",
    },
  ],
});

console.log("Transaction successful:", receipt.userOpHash);
```

**Key Changes:**

* New unified `sendUserOperation` function
* Simplifies the send flow - no need for manual kernel client preparation
* Returns complete receipt with `userOpHash` and `success` status

## Batch Transaction Support

The new API's main advantage is native batch transaction support:

```javascript theme={"system"}
import { sendUserOperation } from "@dynamic-labs-sdk/zerodev";

// Send multiple transactions atomically
const receipt = await sendUserOperation({
  walletAccount,
  calls: [
    { to: "0xRecipient1...", value: parseEther("0.1") },
    { to: "0xRecipient2...", value: parseEther("0.2") },
    { to: "0xRecipient3...", value: parseEther("0.3") },
  ],
});
```

**Benefits:**

* **Atomicity**: All operations succeed or all fail together
* **Cost Efficiency**: Single validation per batch reduces gas fees
* **Better UX**: Users approve once for multiple operations
* **Composability**: Enable complex multi-step workflows (e.g., approve + swap)

## Migration Checklist

* [ ] Replace `canSponsorTransaction` with `canSponsorUserOperation`
* [ ] Replace `estimateTransactionGas` with `estimateUserOperationGas`
* [ ] Replace manual UserOperation preparation with `sendUserOperation`
* [ ] Update `transaction` parameter to `calls` array
* [ ] Wrap single transactions in an array: `calls: [transaction]`
* [ ] Update error handling for new error types
* [ ] Test all transaction flows thoroughly
* [ ] Consider using batch transactions for multi-step workflows

## Related Documentation

* [sendUserOperation](/docs/javascript/reference/zerodev/send-user-operation)
* [canSponsorUserOperation](/docs/javascript/reference/zerodev/can-sponsor-user-operation)
* [estimateUserOperationGas](/docs/javascript/reference/zerodev/estimate-user-operation-gas)