Lambda Input

Lambda Input is the starting point of a lambda workflow: it lists the values the workflow accepts from whoever calls it.

What it does

A lambda workflow is a reusable sub-workflow that other workflows call, like a function. It has no trigger. Instead it starts at Lambda Input and ends at Lambda Output.

Each entry you add under Inputs has a name, a type and an optional default value. When the workflow is called, Lambda Input takes the value the caller sent for each name. If the caller sent nothing for a name, it uses the default. If there is still no value, the run stops with an error.

The inputs you declare here also become the settings of the Lambda Workflow node that calls this workflow, so callers see one field per input.

When to use it

• You are building a lambda workflow (choose Lambda when you create a blank workflow). It needs exactly one Lambda Input.
• You want a reusable step, such as “clean up a contact” or “post a report”, that takes a few named values.

For a workflow that starts on its own (a shortcut, a schedule, a page event), use a trigger such as When Started instead.

Inputs and settings

Setting	Type	What it does
Inputs REQ(required)	Field list	The inputs for the lambda workflow.

Give inputs short, clear names such as email or pageUrl: they become the field labels callers see and the field names you read later with {{ $input.email }}.

A default value is used both when a caller leaves the field empty and when you test the lambda workflow on its own from the canvas, so set realistic defaults to make testing easy.

Outputs

• Output

The output is one item with exactly the inputs you declared, for example { "email": "ana@example.com", "pageUrl": "https://example.com" }. Connect the first step of your lambda workflow to it and read the values with {{ $input.email }}, or from later steps with {{ $('Lambda Input').email }}.

Dependencies and credentials

None. This node needs no connection and has no slots for other nodes.

Example workflow

A reusable “Summarize a page” lambda workflow:

1. Create a blank workflow, choose Lambda, and add Lambda Input with one input url (default https://example.com).
2. Add Http Request with the URL {{ $input.url }}.
3. Add a summarizing step, then Lambda Output with an output summary set to that step’s result.
4. In another workflow, open the node list, go to the Customs tab, and add the workflow from My Lambda Workflows. Its node shows a url field.

Common issues

• “Input url is required”. The caller sent no value for that input and it has no default. Fill the field on the calling node or set a default value. A value of 0, false or empty text also counts as missing, so pass those as text (for example "0") or set a non-empty default.
• There is no Test Workflow button on the canvas. A lambda workflow can only be tested once it has both a Lambda Input and a Lambda Output. Use the Add Lambda Input or Add Lambda Output button in the top right.
• A later step reads an empty value. The name in the expression must match the input name exactly, including capital letters.

Related nodes

• Lambda Output: the values the lambda workflow returns.
• Lambda Workflow: call this workflow from another one.
• Workflow as Tool: let an AI agent call it.