Batch Transactions

EVMcrispr can bundle multiple operations into a single atomic transaction. This guide covers how batching works and when to use it.

Basic Batching

Wrap commands in batch to combine them into one transaction:

batch (
  exec @token(DAI) "approve(address,uint256)" 0xRouter... @token.amount(DAI 1000)
  exec 0xRouter... "swap(address,uint256)" @token(DAI) @token.amount(DAI 1000)
)

Both the approve and swap happen atomically — if either fails, both revert.

When to Use Batch

• Approve + action: Approve a token and use it in the same tx
• Multi-step operations: Multiple related state changes that should be atomic
• Gas efficiency: Save gas by avoiding multiple transaction submissions
• Safety: Ensure all-or-nothing execution of related operations

Event Captures on Batches

You can capture events emitted during the entire batch:

batch (
  exec $wxdai "deposit()" --value 0.001e18
  exec $wxdai "withdraw(uint)" 0.001e18
) -> Deposit(address indexed, uint) [_ $amount]

Nested Batching

Batches can contain control flow and other constructs:

batch (
  for $addr of $recipients (
    exec @token(DAI) "transfer(address,uint256)" $addr @token.amount(DAI 100)
  )
)

Without Batch

By default, each exec command produces a separate transaction. Without batch, a script like:

exec @token(DAI) "approve(address,uint256)" 0xRouter... @token.amount(DAI 1000)
exec 0xRouter... "swap(address,uint256)" @token(DAI) @token.amount(DAI 1000)

would submit two separate transactions — the second could fail independently of the first.