Pass - AWS Step Functions

Pass

A Pass state ("Type": "Pass") passes its input to its output, without performing work. Pass states are useful when constructing and debugging state machines.

You can also use a Pass state to transform JSON state input using filters, and then pass the transformed data to the next state in your workflows. For information about input transformation, see InputPath, Parameters and ResultSelector.

In addition to the common state fields, Pass states allow the following fields.

Result (Optional)

Refers to the output of a virtual task that is passed on to the next state. If you include the ResultPath field in your state machine definition, Result is placed as specified by ResultPath and passed on to the next state.

ResultPath (Optional)

Specifies where to place the output (relative to the input) of the virtual task specified in Result. The input is further filtered as specified by the OutputPath field (if present) before being used as the state's output. For more information, see Input and Output Processing.

Parameters (Optional)

Creates a collection of key-value pairs that will be passed as input. You can specify Parameters as a static value or select from the input using a path. For more information, see InputPath, Parameters and ResultSelector.

Pass State Example

Here is an example of a Pass state that injects some fixed data into the state machine, probably for testing purposes.

"No-op": { "Type": "Pass", "Result": { "x-datum": 0.381018, "y-datum": 622.2269926397355 }, "ResultPath": "$.coords", "End": true }

Suppose the input to this state is the following.

{ "georefOf": "Home" }

Then the output would be this.

{ "georefOf": "Home", "coords": { "x-datum": 0.381018, "y-datum": 622.2269926397355 } }