Node inputs and outputs

Sharing payloads or results between nodes

Nodes in the Stream Designer Studio (SDS) can receive input data and produce output data. This data can be passed between nodes or accessed from the stream context using wildcards.

Wildcards are dynamic expressions that are resolved at runtime using values available in the stream execution context.

Using Wildcards in Node Inputs

To pass data delivered to a stream (for example from a webhook or cronjob), use a wildcard expression inside a node’s input field:

{{ payload.data }}

Wildcard Resolution Behavior

Wildcards are resolved at runtime according to the following rules:

• If the input field contains only the wildcard, the original data type is preserved. Example:

  {{ payload.data }}

  Result: The original object, number, or boolean is preserved.

• If the wildcard is part of a larger string, the value is automatically converted to a string. Example:

  File path: {{ payload.path }}

  Result: The wildcard value is inserted as text.

Accessing Outputs from Other Nodes

Each node produces outputs that can be used by other nodes in the stream.

To access the output of another node, use the following wildcard format:

{{ output.nodeId.OutputName }}

Where:

• nodeId is the unique ID of the node

• OutputName is the name of the output field

Example:

{{ output.64d3482f-3151-4615-ah29-1a8d2d1cf84b.StdOut }}

This expression retrieves the StdOut output from the specified node.

Using the Wildcard Catalog

The Stream Designer Studio provides a Wildcard Catalog, accessible from the left sidebar under Wildcards.

The Wildcard Catalog contains a list of available wildcards, organized by category.

Each wildcard includes:

• Wildcard expression

• Description of what the wildcard represents

• The data it provides

This allows you to easily discover and use valid wildcards without manually typing them.

Common wildcard categories include:

• Payload wildcards (data from triggers)

• Node output wildcards (data from other nodes)

• System wildcards (system-level values)

• Execution context wildcards

To use a wildcard:

1. Open the Wildcards panel in the left sidebar.

2. Browse or search for the desired wildcard.

3. Copy the wildcard expression.

4. Paste it into the node input field.