User Operation

1. What are User Operations?

The available user operations are:

• Send Token (ERC-20)
• Send Native Coin (ETH, MATIC, etc.)
• Send NFT (ERC-721)
• Send NFT (ERC-1155)
• Sign Transaction
• Activate Account

2. How To Execute User Operation

The process for executing a user operation involves the following steps:

1. Request Operation Hash

   • Call the API to request a user operation hash
   • Available user operation types refer to API documentation
   • API returns:
     • Hash that needs to be signed
     • User operation ID for tracking

2. Sign the Hash

   • Owner must sign the operation hash using personalSign
   • The signing wallet must be the owner address of the account

3. Submit Operation

   • Submit to the API:
     • Original hash
     • User operation ID
     • Owner's signature

4. Monitor Operation Status

   • Check operation status periodically through the API
   • API will indicate when operation is complete
   • Transaction hash will be provided once confirmed

5. Important Notes

   • Account must be activated before executing operations
   • Only the owner address can sign operation hashes
   • Invalid signatures will cause operations to fail
   • Sufficient gas must be available in the gas tank

3. User Operation Status Life Cycle

The life cycle of a user operation is illustrated below:

Note: The orange highlighted events (expired, success, failed) will be sent to your webhook for real-time status updates.

Explanation:

• The process starts with generating a user operation hash.
• The operation enters a waiting_signature state, waiting for the owner's signature.
• If no signature is submitted before the time limit (validUntil), the operation expires.
• If a signature is submitted, the operation moves to on_process or failed.
• An operation in on_process will eventually result in either success or failed.

4. How to Sign a User Operation Hash

To authorize a user operation, the owner must sign the operation hash using their wallet. Below is an example using the Xellar SDK and ethers.js:

import * as ethers from "ethers";
import { Network, XellarSDK } from "../src";
 
const generatePersonalSignHash = (data: string) => {
  // Convert hex string to bytes
  const bytes = ethers.getBytes(data);
 
  // Create the Ethereum signed message prefix
  const prefix = `\x19Ethereum Signed Message:\n${bytes.length}`;
 
  // Calculate the keccak256 hash
  const resultHash = ethers.keccak256(
    ethers.concat([ethers.toUtf8Bytes(prefix), bytes])
  );
 
  return resultHash;
};
 
export async function activateAccount(accountId: string): Promise<void> {
  const xellar = new XellarSDK({
    clientSecret: process.env.XELLAR_CLIENT_SECRET!,
    appId: process.env.XELLAR_APP_ID!,
  });
 
  const { userOpId, hash } = await xellar.accountAbstraction.create.activate(
    accountId
  );
 
  const personalSignHash = generatePersonalSignHash(hash);
 
  const ownerSignature = await xellar.wallet.signHash({
    hash: personalSignHash,
    walletToken: "your wallet token",
    refreshToken: "your refresh token",
    network: Network.POLYGON, // adjust this
  });
 
  // Submit the signed user operation
  await xellar.accountAbstraction.submitUserOp({
    userOpId,
    hash,
    signature: ownerSignature.signature,
    isSponsored: true,
  });
}

Key Points:

• Always use the correct hash format for signing (see generatePersonalSignHash).
• The signature must be generated by the account owner's wallet.
• After signing, submit the signature and hash to the Xellar API/SDK to complete the user operation.