feat: expose quote preparation [APP-2659]

[derHowie]

Add EIP-7702 Batching Support

Overview

This PR introduces support for EIP-7702 transaction batching by adding new transaction preparation functions.

What's New

New Functions

• prepareFillQuote - Extracts transaction data from regular quotes without executing
• prepareFillCrosschainQuote - Extracts transaction data from crosschain quotes without executing
• BatchCall interface - Standardized format for transaction data ({ data, to, value })

Refactored Functions

• fillQuote - Now uses prepareFillQuote internally (reduced from ~100 to 13 lines)
• fillCrosschainQuote - Now uses prepareFillCrosschainQuote internally (reduced from ~15 to 10 lines)

Backward Compatibility

• Zero breaking changes to existing API
• All existing functions work exactly as before
• Maintains full feature parity

Usage Examples

Traditional Usage (unchanged)

const tx = await fillQuote(quote, options, wallet, permit, chainId, referrer);

New Batching Usage

// Prepare multiple transactions for batching
const swapCalldata = await prepareFillQuote(quote1, options, wallet, permit, chainId);

// Execute as batch with EIP-7702
await executeBatchedTransaction({
  calls: [approveCalldata, swapCalldata],
  walletClient,
  publicClient,
});

Safety & Testing

• Added proper type safety with null checks for optional fields
• Maintains all existing error handling and validation
• All transaction preparation logic identical between prepare and execute paths
• No changes to core swap logic or contract interactions

[linear[bot]]

APP-2659 Atomic Swaps [swaps SDK]