Paths
In the Amazon States Language, a path is a string beginning with $
that
you can use to identify components within JSON text. Paths follow JsonPathInputPath
,
ResultPath
, and OutputPath
. For more information see Input and Output Processing in Step Functions.
You can also specify a JSON node of the input or the context object by using paths
within the Parameters
field of a state definition. See Pass Parameters to a Service API.
Reference Paths
A reference path is a path whose syntax is limited in such a way that it can identify only a single node in a JSON structure:
-
You can access object fields using only dot (
.
) and square bracket ([ ]
) notation. -
The operators
@ .. , : ? *
aren't supported. -
Functions such as
length()
aren't supported.
For example, if state input data contains the following values:
{
"foo": 123,
"bar": ["a", "b", "c"],
"car": {
"cdr": true
}
}
The following reference paths would return the following.
$.foo => 123
$.bar => ["a", "b", "c"]
$.car.cdr => true
Certain states use paths and reference paths to control the flow of a state machine or configure a state's settings or options.