Giving the answer I would give if I was testing, and not the answer I know to be true. 

BUT - Given then error you’re receiving - It seems to need a nested directory, which I would infer to be an array of arrays….

Is there no way to parse each line-item as an array?

@Saastronomical I haven’t been able to find any documentation on how line-item fields in an action step are provided to the bundle, just how to create line items via the CLI or via the UI. But is bundle.inputData.lines an array? An array of objects? or what? By default it seems to thing it’s a string as it puts quotes around it (by default). 

To be clear, I am talking about an app on the Zapier platform, not just a zap. I need to know how to handle it inside the app to be able to “parse” or get it formatted correctly for the way the API wants to receive it. 

Yeah - I figured that you were creating an app - But the same logic, I think still applies.

You want to find a way to ensure that 

bundle.inputData.lines

is an array of objects, I think? 

Yes

Argh, so I figured out what the problem was, and that is that Freshbooks wanted the price of a line item in a nested directory… so Zapier was formatting everything correctly… I just had to replace the value in “unit_cost”:”45” with {“amount”,”45”} to make “unit_cost”:{“amount”:”45”}

I did this by looping through the bundle like so:

var linesVar = bundle.inputData.lines

for( var am in linesVar ){

    linesVar am].unit_cost = {"amount":linesVarVam].unit_cost}

}

and then I used the linesVar in place of bundle.inputDate.lines and Freshbooks accepted it and loved it!

Kinda fun to have solved this!