Data and logging actions / Action reference
Extract JSON values
Manual / Actions / Data and logging
Select text, number, and boolean values from one JSON source.
Read Shared action rules for disabling this action, outputs, error routing, and recovery.
Configuration and behavior
| Parameter | Notes |
|---|---|
| Source * | One upstream value holding a JSON object, array, or JSON text - ${trigger.payload} or ${steps.http_request.body}, unmodified. |
| Assignments * | Managed by the editor. Simple browses the value this step received during the latest Test and lets you click scalar values. Advanced takes an exact path (customer.name, items[0].id, ["odd key"]), an expected type (Text / Number / Boolean), and a name. |
The source variable must be available on every path to this step. A variable assigned on only one incoming branch does not satisfy this rule. Assign it before branching, or set it on every incoming branch. Relay 0.68.0 enforces this check for existing workflows too. A workflow that lacks the source on one path can stop running after an upgrade until you correct its assignments.
Each assignment becomes ${vars.<slug>}. Paths locate exactly one scalar value; there are no wildcards, slices, or filters (chapter 8.7). If any assignment fails - path absent, value is null, an object, or an array, or the type does not match - nothing is set and the step fails.