Loops

The Loop node repeats a sequence of steps. Three loop types are supported: forEach, while, and times.

Loop types

forEach

Iterates over a collection. The collection can be a literal array or an expression referencing an upstream step's output.

Field	Description	Example
Collection	JavaScript expression evaluating to an array	fetch_orders.results
Item variable	Name for each item inside the loop	order

Generated code:

const process_orders = await step.do('Process Orders', async () => {
  let _output
  let _loop_i = 0
  for (const order of fetch_orders.results) {
    const send_confirmation = await step.do(`Send Confirmation [${_loop_i}]`, async () => {
      await fetch('https://api.resend.com/emails', {
        method: 'POST',
        body: JSON.stringify({ to: order.email, subject: 'Order confirmed' }),
      })
    })
    _loop_i++
  }
  return _output
})

INFO

Step names inside a loop are automatically suffixed with [0], [1], etc. to keep each iteration's step name unique. Cloudflare Workflows requires unique step names within an instance.

while

Repeats while a condition is true.

Field	Description	Example
Condition	JavaScript expression	poll_status.status !== "complete"

Generated code:

const poll_loop = await step.do('Poll Until Complete', async () => {
  let _output
  let _loop_i = 0
  while (poll_status.status !== 'complete') {
    const check = await step.do(`Check Status [${_loop_i}]`, async () => {
      // check status
    })
    _loop_i++
  }
  return _output
})

WARNING

A while loop with a condition that never becomes false will run indefinitely. Always ensure the loop body mutates state that the condition depends on, or set a maximum iteration count using a counter inside a Step node.

times

Repeats a fixed number of times.

Field	Description	Example
Count	Number of iterations	5

Generated code:

const retry_loop = await step.do('Retry 3 Times', async () => {
  let _output
  for (let _loop_i = 0; _loop_i < 3; _loop_i++) {
    const attempt = await step.do(`Attempt [${_loop_i}]`, async () => {
      // attempt logic
    })
  }
  return _output
})

Returning a value from a loop

Assign to the _output variable inside any step in the loop body. The last value assigned to _output becomes the loop node's return value, which is then accessible to downstream steps.

// Inside a Step node in the loop body:
_output = { processedCount: _loop_i + 1, lastItem: order }

Break node

The Break node exits the innermost loop immediately. Place it inside a Branch node within the loop body to conditionally stop iteration.

// Generated from a Branch + Break inside a loop:
if (check.status === 'complete') {
  break
}

TIP

Use Break inside a while loop when you need to exit based on a complex condition computed inside the loop body, rather than in the loop condition expression itself.