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This content applies to WaaS 1.0 only. We highly recommend that you upgrade to WaaS 2.0.
Delegate can call either execTransaction() or execTransactions() to send transactions. The following uses execTransaction() as an example, where the CallData struct is passed in as a parameter. 
struct CallData {
    uint256 flag; // 0x1 delegate call, 0x0 call.
    address to;
    uint256 value;
    bytes data; // calldata
    bytes hint;
    bytes extra; // for future support: signatures etc.
}
Each field in the struct is defined as follows:
  • flag: The call type. 0 indicates call and 1 indicates delegatecall. Note that each type of call comes with different access controls.
  • to: The target smart contract to be called.
  • value: The ETH amount of the transaction when the contract is called.
  • data: The calldata of a transaction (i.e., abi.encoded parameters of a contract call).
  • hint: When the hint field is set, the Authorizer will optimize the validation process by executing a fast path. This helps reduce gas consumption.
To generate a hint, you can execute an eth_call to the execTransaction() function with the hint field left unset. The TransactionResult returned from the call will contain the correct hint value. The above process can be achieved using Cobo Safe SDKs. The following uses Cobo Safe SDKs in Javascript as an example. 
const {CoboSafeAccount} = require("jscobosafe");
const {ethers} = require("ethers");
const ERC20_ABI = require("./ERC20.json");

require("dotenv").config();
const PRI_KEY = process.env.PRIV;
const COBO_SAFE_ADDRESS = process.env.COBOSAFE

const provider = new ethers.JsonRpcProvider("https://rpc.ankr.com/polygon")
const signer = new ethers.Wallet(PRI_KEY, provider);
const coboSafe = new CoboSafeAccount(COBO_SAFE_ADDRESS, signer)
const delegate = coboSafe.delegate;

const WMATIC_ADDRESS = "0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270";

async function main(){
    console.log("CoboSafe", coboSafe.address);
    console.log("Safe", await coboSafe.safe());
    console.log("Delegate", coboSafe.delegate);

    let tx;

    // Connect with the contract as other ethers.js signers do.
    const token = new ethers.Contract(WMATIC_ADDRESS, ERC20_ABI, coboSafe);

    console.log(await token.balanceOf(await coboSafe.safe()))
    tx = await token.transfer(delegate, 1);
    await tx.wait()
    console.log(await token.balanceOf(await coboSafe.safe()))
}

main().catch((error) => {
    console.error(error);
    process.exitCode = 1;
});
Cobo Safe offers SDKs in Python and Javascript.
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