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

# EIP-7702

> Sign EIP-7702 authorizations to delegate EOA capabilities to smart contracts using the Express API.

## Overview

[EIP-7702](https://eips.ethereum.org/EIPS/eip-7702) introduces a new transaction type (Type-4) that allows Externally Owned Accounts (EOAs) to temporarily delegate to smart contract code. This enables account abstraction features like batched transactions, gas sponsorship, and session keys for regular wallets.

### Use cases

* Temporarily delegate an EOA to a smart contract implementation for advanced features
* Enable batched transactions through a delegated smart account
* Integrate with account abstraction infrastructure that leverages EIP-7702

### Compatibility

* Requires a network that supports EIP-7702 (e.g., Ethereum Mainnet, Sepolia, Arbitrum, Base, Optimism)
* Signing an authorization is gasless; gas is only required when the signed authorization is included in an on-chain transaction

## Sign an EIP-7702 Authorization

Send a `POST` request to `/v1/wallet/sign/eip7702` with the delegation parameters.

```bash cURL icon="square-terminal" theme={null}
curl -X POST 'https://tee.express.magiclabs.com/v1/wallet/sign/eip7702' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_JWT_TOKEN' \
  -H 'X-Magic-API-Key: YOUR_MAGIC_API_KEY' \
  -H 'X-OIDC-Provider-ID: YOUR_OIDC_PROVIDER_ID' \
  -H 'X-Magic-Chain: ETH' \
  -d '{
    "chain_id": 11155111,
    "address": "0x000000004F43C49e93C970E84001853a70923B03",
    "nonce": 0
  }'
```

### Request Parameters

<ParamField body="chain_id" type="integer" required>
  The chain ID for the authorization.
</ParamField>

<ParamField body="address" type="string" required>
  The smart contract implementation address to delegate to.
</ParamField>

<ParamField body="nonce" type="integer" required>
  The account nonce for the authorization.
</ParamField>

### Response Fields

**Response:**

```json theme={null}
{
  "r": "123456789012345678901234567890",
  "s": "987654321098765432109876543210",
  "y_parity": 1
}
```

<ResponseField name="r" type="string">
  The `r` component of the signature, returned as a decimal string.
</ResponseField>

<ResponseField name="s" type="string">
  The `s` component of the signature, returned as a decimal string.
</ResponseField>

<ResponseField name="y_parity" type="integer">
  The `y_parity` value of the signature (0 or 1).
</ResponseField>

<Warning>
  The `r` and `s` values are returned as **decimal strings**, not hex. You need to convert them to hex before using them with libraries like viem.
</Warning>

## Usage with viem

The response values need to be converted from decimal strings to hex to construct a `SignedAuthorization` object compatible with viem:

```typescript TypeScript icon="square-js" theme={null}
import type { Address, Hex, SignedAuthorization } from 'viem';

const decToHex = (dec: string): Hex =>
  `0x${BigInt(dec).toString(16).padStart(64, '0')}` as Hex;

const signEip7702Authorization = async (
  chainId: number,
  contractAddress: Address,
  nonce: number,
): Promise<SignedAuthorization<number>> => {
  const body = {
    chain_id: chainId,
    address: contractAddress,
    nonce,
  };

  const res = await fetch('https://tee.express.magiclabs.com/v1/wallet/sign/eip7702', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${YOUR_JWT_TOKEN}`,
      'X-Magic-API-Key': 'YOUR_MAGIC_API_KEY',
      'X-OIDC-Provider-ID': 'YOUR_OIDC_PROVIDER_ID',
      'X-Magic-Chain': 'ETH',
    },
    body: JSON.stringify(body),
  });

  const { r, s, y_parity } = await res.json();

  return {
    address: contractAddress,
    chainId,
    nonce,
    r: decToHex(r),
    s: decToHex(s),
    yParity: y_parity,
  } as SignedAuthorization<number>;
};
```

## Resources

* [EIP-7702 Specification](https://eips.ethereum.org/EIPS/eip-7702)
* [Wallet Operations](/server-wallets/express-api/wallet-operations)