Loop Node

The Loop node repeats the same actions for every item in a list. If you have 10 emails to process, it does the same thing 10 times - once for each email. Think of it like a factory assembly line: each item comes through, gets the same treatment, then moves on.

Loop node configuration form — Loop configuration — point at an array of items and name the per-iteration variable.

When to Use

Processing lists - Handle each email, each row in a spreadsheet, each file
Sending to multiple people - Send personalized emails to everyone on a list
Processing data - Do the same thing to every item
Collecting results - Gather what you learned from each item

Example: Process Email Attachments

Extract and analyze each attachment from an email:

Receive email with attachments

Use Event from App (Gmail) to trigger on emails with attachments.

Loop over attachments

Add a Loop node:

Iterable data: {{event_from_app_1.email.attachments}}

Process each attachment

Inside the loop:

Read File (current attachment)
Ask AI (analyze content)
Update Variable (append results)

After loop

Send summary of all analyzed attachments.

Workflow:

├── Event from App (Gmail with attachments)
├── Update Variable (results = [], initialize)
├── Loop (over attachments)
│   ├── Read File ({{loop_1.currentItem}})
│   ├── Ask AI (analyze: {{parse_file_1.content}})
│   └── Update Variable (results, append {{llm_1.response}})
└── External API (Slack: "Processed {{loop_1.completedCount}} files")

Example: Send Personalized Emails

Send individual emails to a list of recipients:

├── HTTP Request (get recipient list from CRM)
├── Loop (over {{http_request_1.body.contacts}})
│   ├── Ask AI (generate personalized message for {{loop_1.currentItem.name}})
│   └── External API (Gmail: send to {{loop_1.currentItem.email}})
└── Update Variable (log: sent {{loop_1.completedCount}} emails)

Accessing item properties:

Name: {{loop_1.currentItem.name}}
Email: {{loop_1.currentItem.email}}
Company: {{loop_1.currentItem.company}}

Example: Process Spreadsheet Rows

Handle each row from a Google Sheet:

├── External API (Google Sheets: get all rows)
├── Loop (over {{external_api_1.values}})
│   ├── Condition (row has email?)
│   │   ├── Met:
│   │   │   ├── Ask AI (classify lead)
│   │   │   └── External API (HubSpot: create/update contact)
│   │   └── Unmet: (skip row)
└── External API (Slack: "Processed {{loop_1.completedCount}} leads")

Collecting Results from Each Loop

If you want to remember what happened with each item:

Save Results as You Go

├── Update Variable (allResults = [], create empty list first)
├── Loop (over items)
│   ├── Ask AI (analyze the item)
│   └── Update Variable (allResults, add this result to the list)
└── Ask AI (summarize all the results)

This way, after the loop ends, you have a list of everything that happened.

Process Results with Code

# Get all the results we collected
results = input["set_variable_1"]["value"]

# Count successes and failures
successful = [r for r in results if r["success"]]
failed = [r for r in results if not r["success"]]

return {
    "total": len(results),
    "successful": len(successful),
    "failed": len(failed)
}

Loops Inside Loops

Sometimes you need to loop through a list that’s inside another list:

├── Loop (for each department)
│   └── Loop (for each employee in that department)
│       └── Send email to that employee

Be careful with loops inside loops - the numbers multiply! 10 departments with 50 employees each = 500 total emails.

Conditional Processing

Skip items that don’t meet criteria:

├── Loop (over items)
│   ├── Condition (should process?)
│   │   ├── Met: Process item
│   │   └── Unmet: (skip - no action)

The unmet branch doesn’t need to connect to anything.

Using Index and Position

First item handling:

├── Loop
│   ├── Condition ({{loop_1.isFirst}})
│   │   ├── Met: Send "Starting batch of {{loop_1.totalCount}} items"
│   │   └── Unmet: (continue)
│   └── Process item

Last item handling:

├── Loop
│   ├── Process item
│   ├── Condition ({{loop_1.isLast}})
│   │   ├── Met: Send "Completed all {{loop_1.totalCount}} items"
│   │   └── Unmet: (continue)

Using index for numbering:

Item {{loop_1.currentIndex + 1}} of {{loop_1.totalCount}}: {{loop_1.currentItem.name}}

Loop Completion

The nodes connected after the loop (not inside it) execute once after all iterations complete:

├── Loop (over 10 items)
│   └── [Executes 10 times]
└── After Loop [Executes 1 time after loop completes]

Error Handling

By default, if one iteration fails, the loop continues with remaining items. To handle errors:

├── Loop (over items)
│   ├── HTTP Request (call API)
│   ├── Condition (success?)
│   │   ├── Met: Update Variable (successes, append)
│   │   └── Unmet: Update Variable (failures, append)

Then after the loop, check failures and alert if needed.

How Long Will It Take?

Items are processed one at a time. If you have 100 items and each takes 3 seconds, that’s 5 minutes total.

If your loop is slow:

Some services let you send multiple items at once - check if yours does
Test with just a few items first before running the full list
Make sure your timeout is long enough

Tips

Create your results list before the loop starts. Use Update Variable to create an empty list [], then add to it inside the loop.

Use isFirst to send a “starting now” message, and isLast to send a “all done” message.

While building and testing, add a condition that only processes the first 3 items. Once everything works, remove that condition.

Settings

string

default:"Loop"

What to call this node (shown on the canvas).

string

default:"loop_1"

A short code to reference this node’s data.

string

required

The list to loop through. Examples:

{{http_request_1.body.items}} - items from a web request
{{event_from_app_1.email.attachments}} - files attached to an email
{{external_api_1.values}} - rows from a spreadsheet

Outputs

During each loop iteration:

any

The item being processed right now.

number

Which number item this is (starts at 0, so the first item is 0, second is 1, etc.).

boolean

True if this is the first item.

boolean

True if this is the last item.

number

How many items there are in total.

After the loop finishes:

number

How many items were processed.

Condition

Filter items within loops.

Update Variable

Accumulate results across iterations.

Overview

Triggers

Actions

Logic

Communication

When to Use

Example: Process Email Attachments

Example: Send Personalized Emails

Example: Process Spreadsheet Rows

Collecting Results from Each Loop

Save Results as You Go

Process Results with Code

Loops Inside Loops

Conditional Processing

Using Index and Position

Loop Completion

Error Handling

How Long Will It Take?

Tips

Settings

Outputs

Condition

Update Variable

​When to Use

​Example: Process Email Attachments

​Example: Send Personalized Emails

​Example: Process Spreadsheet Rows

​Collecting Results from Each Loop

​Save Results as You Go

​Process Results with Code

​Loops Inside Loops

​Conditional Processing

​Using Index and Position

​Loop Completion

​Error Handling

​How Long Will It Take?

​Tips

​Settings

​Outputs

​Related Nodes

Condition

Update Variable

When to Use

Example: Process Email Attachments

Example: Send Personalized Emails

Example: Process Spreadsheet Rows

Collecting Results from Each Loop

Save Results as You Go

Process Results with Code

Loops Inside Loops

Conditional Processing

Using Index and Position

Loop Completion

Error Handling

How Long Will It Take?

Tips

Settings

Outputs

Related Nodes