pyth-network_pyth-crosschain/apps/developer-hub/content/docs/entropy/whats-new-entropyv2.mdx

---
title: What's New in Entropy v2
description: New features and improvements in Entropy v2
icon: Sparkle
---

import { DynamicCodeBlock } from "fumadocs-ui/components/dynamic-codeblock";

## Key Improvements

Pyth Entropy v2 brings new features and improvements that make random number generation more flexible, efficient, and easier to integrate.

### 1. Multiple Request Variants

Entropy v2 provides multiple ways to request random numbers:

- **Basic Request**: Simplest implementation with default settings
- **Custom Gas Limit**: Specify gas limits for complex callbacks
- **Custom Provider**: Choose specific entropy providers
- **Full Control**: Specify all parameters (provider, gas limit, user random number)

Each of these request types is described in more detail with examples in [Request Callback Variants](request-callback-variants).

### 2. Improved Fee Structure

The new version offers more granular fee calculation:

<DynamicCodeBlock lang="solidity" code={`// Get fee for default provider and gas limit
uint256 basicFee = entropy.getFeeV2();

// Get fee for custom gas limit
uint256 customGasFee = entropy.getFeeV2(gasLimit);

// Get fee for specific provider and gas limit
uint256 providerFee = entropy.getFeeV2(provider, gasLimit);
`} />

### 3. Enhanced Callback Status

Entropy V2 introduces callback statuses, which allow users to track the status of their callbacks.

[Pyth Dev-Forum Announcement](https://dev-forum.pyth.network/t/announcing-entropy-v2/324#p-649-enhanced-callback-statuses-2) provides more details on enhanced callback statuses.

### 4. Entropy Debugger

Entropy V2 includes a public Entropy Explorer, that lets teams easily track the status of their callbacks and re-request them if they fail on-chain.

See [Entropy Explorer](https://entropy-debugger.pyth.network/) to search and debug your callbacks.

### 5. Gas Optimization

Improved contract efficiency reduces overall gas costs for entropy requests.

## Migration Guide

If you're upgrading from Entropy v1 to v2:

1. Update your imports to use [`IEntropyV2`](https://github.com/pyth-network/pyth-crosschain/blob/main/target_chains/ethereum/entropy_sdk/solidity/IEntropyV2.sol).
2. Replace `request()` calls with [`requestV2()`](https://github.com/pyth-network/pyth-crosschain/blob/f5402df8e44158c519496bcd2fac5d3afe856a0e/target_chains/ethereum/entropy_sdk/solidity/IEntropyV2.sol#L26)
3. Update fee calculation to use [`getFeeV2()`](https://github.com/pyth-network/pyth-crosschain/blob/f5402df8e44158c519496bcd2fac5d3afe856a0e/target_chains/ethereum/entropy_sdk/solidity/IEntropyV2.sol#L135)
4. Test thoroughly with the new interface

## Backward Compatibility

Entropy v2 maintains backward compatibility with v1 for existing applications. However, we recommend migrating to v2 for new applications to take advantage of the improved features.