I have a class with an InvocableMethod which takes a set of InvocableVariable's

Such that I can call the Apex class from Process Builder.


I would like one of the fields to appear as a dropdown list of options when configuring within Process Builder.


I have tried setting the InvocableVariable type as a custom class:

global class TestType { 

    public final String VALUE_ONE = 'one';
    public final String VALUE_TWO = 'two';


And I have tried setting the InvocableVariable type as an Enum:

public enum Season 

Both give me an error of:

InvocableVariable fields do not support type of XXX

How do I define the InvocableVariable such that I can pick from a set of options?

3 Answers 3


It's not possible.

The invocable variable can’t be one of the following:

  • A type such as an interface, class, or enum.

  • A non-member variable such as a static or local variable.

  • A property. A final variable. Protected or private.

The data type of the invocable variable must be one of the following:

  • A primitive data type or a list of a primitive data type – the generic Object type is not supported.

  • An sObject type or a list of an sObject type – the generic sObject type is not supported.



So, one option would be to define (or reuse an existing) Sobject Foo__c with a custom picklist field that has the value set you care about.

Seasons__c type picklist with values SPRING, ...

Then have the invocable method support a list of Foo__c as the argument. This will provide the dropdown values you need.

  • @Robs -- Have the PB invoke a Visual Flow that in turn calls the invocableApex using custom Sobject Foo__c. VisualFlow supports choosing from existing picklist values in the Assignment operation
    – cropredy
    Jul 9, 2018 at 19:23

@Robs i am not sure if you manage to find best possible solution.

I use to do like this, so at least user know possible values for the parameter.

    @InvocableVariable(label='Season' description='Type one of these WINTER, SPRING, SUMMER, FALL' required=true)
    public String season;

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