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Overview

The cast() method executes the spell sequence that has been built using add(). It submits the transaction to the blockchain, executing all spells atomically in a single transaction.

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Syntax

await spells.cast()

// With optional parameters
await spells.cast(params)

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Parameters

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params
object
Optional parameters to configure the transaction

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Returns

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transaction
object
Transaction object containing the transaction hash and receipt

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Examples

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Basic Cast

Execute spells with default parameters: 
const spells = dsa.Spell()

spells.add({
  connector: "aave",
  method: "deposit",
  args: [
    "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
    "1000000000000000000", // 1 ETH
    0,
    0
  ]
})

const txHash = await spells.cast()
console.log('Transaction hash:', txHash)

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Cast with ETH Value

Send ETH along with the transaction: 
const spells = dsa.Spell()

spells.add({
  connector: "aave",
  method: "deposit",
  args: [
    "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
    "1000000000000000000",
    0,
    0
  ]
})

await spells.cast({
  value: "1000000000000000000" // Send 1 ETH with transaction
})

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Cast with Gas Configuration

Configure gas price for faster confirmation (Node.js): 
const spells = dsa.Spell()

spells
  .add({
    connector: "aave",
    method: "deposit",
    args: [
      "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
      "1000000000000000000",
      0,
      0
    ]
  })
  .add({
    connector: "aave",
    method: "borrow",
    args: [
      "0x6B175474E89094C44Da98b954EedeAC495271d0F",
      "100000000000000000000",
      0,
      0
    ]
  })

await spells.cast({
  gasPrice: web3.utils.toWei('50', 'gwei'),
  nonce: 42
})

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Cast with EIP-1559 Gas

Use EIP-1559 transaction format: 
await spells.cast({
  maxFeePerGas: web3.utils.toWei('100', 'gwei'),
  maxPriorityFeePerGas: web3.utils.toWei('2', 'gwei')
})

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Cast with Callbacks

Monitor transaction confirmation: 
await spells.cast({
  onReceipt: (receipt) => {
    console.log('Transaction confirmed!')
    console.log('Gas used:', receipt.gasUsed)
  },
  onConfirmation: (confirmationNumber, receipt) => {
    console.log(`Confirmation ${confirmationNumber}`)
    if (confirmationNumber === 3) {
      console.log('Transaction is highly secure now')
    }
  }
})

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Multi-Protocol Complex Transaction

const spells = dsa.Spell()

// Deposit 1 ETH to Aave
spells.add({
  connector: "aave",
  method: "deposit",
  args: [
    "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
    "1000000000000000000", // 1 ETH
    0,
    0
  ]
})

// Borrow 100 DAI from Aave
spells.add({
  connector: "aave",
  method: "borrow",
  args: [
    "0x6B175474E89094C44Da98b954EedeAC495271d0F",
    "100000000000000000000", // 100 DAI
    0,
    0
  ]
})

// Deposit borrowed DAI to Compound
spells.add({
  connector: "compound",
  method: "deposit",
  args: [
    "0x6B175474E89094C44Da98b954EedeAC495271d0F",
    "100000000000000000000", // 100 DAI
    0,
    0
  ]
})

// Execute with gas configuration and callbacks
const tx = await spells.cast({
  gasPrice: web3.utils.toWei('50', 'gwei'),
  value: "1000000000000000000",
  onReceipt: (receipt) => {
    console.log('All operations completed successfully!')
    console.log('Transaction hash:', receipt.transactionHash)
  }
})

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Behavior

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Empty Spell Sequence

If no spells have been added, cast() will log a message and return without executing: 
const spells = dsa.Spell()
await spells.cast()
// Logs: "No spells casted. Add spells with `.add(...)`."

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Atomic Execution

All spells in the sequence execute atomically. If any spell fails, the entire transaction reverts: 
spells
  .add({ /* spell 1 - succeeds */ })
  .add({ /* spell 2 - fails */ })
  .add({ /* spell 3 - never executes */ })

// Transaction reverts, no state changes occur

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Console Output

The cast() method logs configuration information: 
DSA config:
 version: 2
 chainId: 1
Casting spells to DSA(#52)...

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Error Handling

try {
  const spells = dsa.Spell()
  
  spells
    .add({
      connector: "aave",
      method: "deposit",
      args: [
        "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
        "1000000000000000000",
        0,
        0
      ]
    })
  
  const tx = await spells.cast()
  console.log('Success:', tx)
  
} catch (error) {
  if (error.message.includes('insufficient funds')) {
    console.error('Not enough balance in DSA')
  } else if (error.message.includes('gas')) {
    console.error('Gas estimation failed')
  } else {
    console.error('Transaction failed:', error)
  }
}

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Node.js vs Browser

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Browser Mode

In browser mode, cast() triggers the user’s Web3 wallet (like MetaMask) to confirm the transaction: 
// Browser - prompts user confirmation
const dsa = new DSA(web3)
await spells.cast()

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Node.js Mode

In Node.js mode, transactions are automatically signed with the provided private key: 
// Node.js - automatically signs and sends
const dsa = new DSA({
  web3: web3,
  mode: "node",
  privateKey: PRIVATE_KEY
})

await spells.cast({
  gasPrice: web3.utils.toWei('50', 'gwei'),
  gas: 500000,
  nonce: 42
})

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Best Practices

  1. Check Balances First: Ensure your DSA has sufficient balance before casting
  2. Estimate Gas: Use estimateCastGas() before casting to verify gas requirements
  3. Handle Errors: Always wrap cast() in try-catch blocks
  4. Monitor Confirmations: Use callbacks to track transaction status
  5. Set Appropriate Gas: In Node.js mode, always specify gas price and limit
  6. Test First: Test spell sequences on testnets before mainnet
  • estimateCastGas(): Estimate gas before casting
  • encodeCastABI(): Get transaction calldata without executing
  • encodeSpells(): Get encoded spell data

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See Also

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