Flow control

Flow-control nodes shape the path through your workflow. They don't transform data; they decide what runs next, and when.

If

What: Routes each item to a true or false port based on one or more conditions.

Ports: in input; out true, false.

Configuration:

Operators: equal, notEqual, greaterThan, lessThan, greaterThanOrEqual, lessThanOrEqual, contains, notContains, startsWith, notStartsWith, endsWith, notEndsWith, regex, isEmpty, isNotEmpty, isNull, isNotNull, isTrue, isFalse. See Operators for how each one compares values.

Example: "Is the order amount over 1000?"

value1:   {{ $trigger.payload.amount }}
operator: greaterThan
value2:   1000

Connect true to a high-value-order branch; connect false to the normal path.

A misconfigured condition (an unknown operator, a non-numeric value for greaterThan, an invalid regex) fails the node. It does not quietly route to false.

Switch

What: Multi-way branching. Routes each item to a named port chosen by rules.

Ports: in input; out one port per rule, plus default (no match) and error (the rule could not be evaluated, for example a missing field).

Configuration:

Value mode is what the Settings tab edits. Each row compares a field with a value using the If operators, and names the port. Add Routing Rule names new ports output1, output2 and so on, shown on the canvas as Route 1, Route 2.

mode: value
rules:
  - { value1: eventType, operator: equal,      value2: order.created, output: orders }
  - { value1: eventType, operator: startsWith, value2: refund.,       output: refunds }

Other modes are edited in the node's JSON tab:

Known limitations:

• Expression mode reads a separate expressions list of {condition, output}. A condition written as a $ expression, such as {{ $input.isVip }}, arrives as the text "true" and never matches. Name a field of the current item without $ instead, for example {{ isVip }}, and compute the flag first in a Set or Code node.
• In expression and multi mode the ports drawn on the canvas do not always match the ports the node sends to. Prefer value mode, or chain If nodes.

Loop

What: Iterates over a list, an object, a numeric range, batches or pages. The loop port feeds the body once per element; done fires after the last one.

Ports: in input; out loop, done, error.

Configuration:

Pattern:

The loop port feeds the body once per item, and the last body node connects back into the Loop. The done port fires after the last item.

Inside the body: read the current element as {{ $input.item }} (or your outputFieldName) and its position as {{ $input._loopIteration.current }}. _loopIteration also has total, index, isFirst and isLast. Wire the last body node back into the Loop.

When you add a Loop, the editor places a Replace Me card in the body. Swap it for the node you need.

While

What: Repeats the connected body while its conditions hold, up to a maximum number of passes. The first pass always runs.

Ports: in input; out loop, done, error.

Configuration:

Use when: Polling until a job finishes, paging through an API until there are no more results.

Merge

What: Waits for its inputs and combines them into one stream.

Ports: in input1, input2 (more input* ports are accepted); out output.

Configuration:

Use when: Joining results from parallel branches. With waitForAll on and strategy: first, the next node runs once after both branches finish.

Split

What: Sends an identical copy of the input down every connected branch, in parallel.

Ports: in input; out branch_0, branch_1.

A plain output connection already fans out to every node connected to it, so you rarely need Split.

Approval

What: Pauses the run until a person approves or rejects. The run waits for input and the request appears in Approvals.

Ports: in input; out approved, rejected. Connect the branch you want for each decision.

Configuration:

Notes:

• Anyone with access to the run can decide in Approvals, not only the listed approvers.
• The first decision wins. One approve or reject resumes the run.
• There is no automatic timeout. The run waits until someone decides or someone stops it. The node shows a timeout port, but nothing is sent to it today.
• Data from before the pause is still available to expressions after the run resumes.

See Approval basics for the full guide.

Workflow Control

What: Control operations in one node: delay, retry, parallel, conditional, gate, throttle and batch.

Ports: in input; out output. The conditional operation also sends to true and false.

Configuration: operation (required), plus a delay, retry or throttle object for those operations.

Delay

What: Waits a number of milliseconds, then passes the data on. In the palette it sits under Developer Tools.

Ports: in input; out output.

Configuration: duration in milliseconds (default 1000), passThrough (default on).

Use when: Staggering calls to a rate-limited API, or waiting for an external system to catch up.

Error Handling

What: Error-handling operations: catch, recovery, circuit_breaker, validate and sanitize. In the palette it sits under Developer Tools.

Ports: in input; out output. The catch operation also sends to success and error; validate also sends to valid and invalid.

Configuration: operation (required), includeStackTrace (default off), plus a recovery or circuitBreaker object for those operations.

For most workflows, the per-node Settings dialog (retry, fallback value, continue anyway) and a connected error port are simpler. See Settings every node has.

Tips & gotchas

• If vs Switch: If is binary; Switch handles many cases. For three or more branches, Switch in value mode is cleaner.
• Loops survive pauses. An approval inside a loop gates every iteration, and the run resumes where it stopped.
• Nested loops start fresh for each pass of the outer loop.
• A failing body node stops the loop. Its failure goes to the Loop's error port.
• There is no workflow-wide time limit. A long Delay or a slow node only times out if you set a Timeout in its Settings.

Related

• Triggers
• Sub-workflows
• Approvals
• Retries & error handling

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