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What is EIP-7702?

EIP-7702 allows Externally Owned Accounts (EOAs) to delegate their execution logic to smart contracts. When an EOA signs an authorization, it temporarily gains smart account capabilities without changing its address.

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Supported Operations

EIP-7702 accounts work with all OneBalance transaction types:
  • Swaps: Cross-chain token exchanges with automatic bridging
  • Transfers: Send assets across chains to any address
  • Contract Calls: Execute smart contract functions with call data
All operations benefit from gas abstraction and single-transaction UX.

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Key Concept: Delegation vs Deployment

EIP-7702 Accounts (Delegation):
  • EOA signs authorization to delegate to smart contract implementation
  • Address remains unchanged - no migration needed
  • Delegation happens when first transaction is needed
ERC-4337 Accounts (Deployment):
  • New smart contract deployed with predicted address
  • Requires address migration from existing EOA
  • Deployment happens when account is created

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Integration Flow

OneBalance implements EIP-7702 through a clear process:
1

Prepare Quote

Call prepare-call-quote to analyze your requirements and get delegation objects if needed
2

Sign Delegations

Sign any delegation objects using viem’s signAuthorization method
3

Get Quote

Submit signed delegations to call-quote to get the executable quote
4

Execute

Execute the quote using execute-quote to perform the cross-chain operation
OneBalance handles delegation automatically. If your EOA is already delegated on a chain, no additional signing is required.

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How EIP-7702 Works

When you configure an EIP-7702 account with OneBalance:
  1. Account Configuration: Set deploymentType: "EIP7702" and use your EOA address for both signerAddress and accountAddress
  2. Smart Contract Implementation: OneBalance uses Kernel 3.3 as the delegation target
  3. Automatic Delegation: When needed, OneBalance generates authorization objects for you to sign
  4. Execution: Your EOA temporarily gains smart account capabilities during the transaction

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Example: Account Configuration

const account = {
  type: "kernel-v3.3-ecdsa",
  deploymentType: "EIP7702",
  signerAddress: "0x5Cb2369421F8a00Ef556d662D6E97C1419B1d37c", // Your EOA
  accountAddress: "0x5Cb2369421F8a00Ef556d662D6E97C1419B1d37c" // Same address
};
When delegation is needed:
  • Source chain: Always required for spending operations (swaps, transfers, contract calls)
  • Destination chain: Only required for contract calls (not for swaps or transfers)

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When to Use EIP-7702

Choose EIP-7702 when you want to preserve existing EOA addresses:
  • Existing EOA users: No address migration needed
  • Embedded wallets: Upgrade EOAs to smart account capabilities
  • Address preservation: Keep on-chain history and familiar addresses
Choose ERC-4337 when you need:
  • Resource Locks (requires managed key infrastructure)
  • Custom account implementations beyond Kernel v3.3
EIP-7702 uses the same ERC-4337 infrastructure (bundlers, paymasters, UserOps) but extends it to work with existing EOA addresses. Learn more about Account Types.

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Current Limitations

OneBalance’s EIP-7702 implementation works for most scenarios but has one constraint: Multi-Input Limitation: When you have assets on more than 1 source chain different from the destination chain, you’ll need to use a manual delegation workaround.
Example AssetsDestinationResult
USDC on OptimismArbitrum✅ Single transaction
USDC on Optimism + ArbitrumArbitrum✅ Single transaction
USDC on Optimism + BaseArbitrum⚠️ Needs workaround

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Cross-Chain Funding with Solana

EIP-7702 accounts can be funded using Solana assets for cost efficiency and expanded liquidity access:

Solana + EIP-7702

Fund EIP-7702 contract calls using SOL or USDC from Solana

Solana Examples

Complete working examples of cross-chain contract execution
Using Solana funding with EIP-7702 enables atomic operations: SOL → USDC swap → bridge → delegation → contract execution.

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Next Steps

Getting Started

Build your first EIP-7702 swap with delegation

Troubleshooting

Handle multi-input limitations and edge cases
All existing OneBalance API endpoints work with EIP-7702. Just update your account configuration to use type: "kernel-v3.3-ecdsa" and deploymentType: "EIP7702".