The feathery object exposes the Context API to your rule's logic. Using this object, you can perform actions such as setting a field value, navigating to a step, setting custom errors and more. Full reference.
Accessing Form Fields
Note: Field globals are only available in logic rules running inside Feathery, not in SDK call-backs running outside of Feathery.
feathery.fields["1st_name"].value ="first name";
// Another example
feathery.fields["last name"].value ="last name";
Each method of accessing the field will result in a Field object being returned. You can read more about the available methods and properties on the Field object here.
Rule are run synchronously in that a rule must complete before feathery runs other rules or continues with form processing. However, network requests made by rules may be either done from within the browser or on the server. In either case, the network request is asynchronous. If you want that network request to complete before continuing, you must await the request call. See an example of awaiting a network request here.