Stripe recurring payments for 3DS source - stripe-payments

Question

I want to use Stripe to charge cards recurrently every 30 days with amounts that oscilate.
From the docs I got that if there is a possibility that the card requires 3DS we should use Sources so I switched to sources ;)
From the source object stripe.js retrieves I look at three_d_secure param to decide whether to create a source object that requires 3DS or a normal card charging.
The flow:
With JS I get the source object that has three_d_secure set to either optional or required.
When it's set to optional after I retrieve the source with: source = Stripe::Source.retrieve(source_id) it looks like this:
"status": "chargeable",
"type": "card",
"usage": "reusable",
"card":{"exp_month":12,"exp_year":2032,"brand":"Visa",...
I attach it to a customer and charge it. I guess usage: reusable means that I can charge the card again later...
When three_d_secure=='required' I create a new source calling this:
source = Stripe::Source.create({
amount: amount,
currency: currency,
type: 'three_d_secure',
three_d_secure: {
card: source_id, #src_xcvxcvxcvc
},
redirect: {
return_url: return_url
},
})
I redirect the user to the URL Stripe provides, user enters his 3DS PIN and gets back to my return_url. When Stripe redirects the user back to my return_url I retrieve the source again and get something like this:
"status": "chargeable",
"type": "three_d_secure",
"usage": "single_use",
"three_d_secure": {"card":"src_1B1JzQHopXUl9h9Iwk05JV1z","authenticated":true,"customer":null}
I would expect that after passing the 3DS the source becomes reusable and chargeable until the date of expiry or so :|
My questions are:
1 Why is the 3DS source single_use? Is this like this only in sanbox environment or with the card I am using to test?
2 Can a 3DS protected card be charged again at all?
3 What's the correct approach to attach to customer sources (3DS or normal) that can be charged again and again?
Thank you!

Answer 1

Because it is a source payment token, not a source card token. It expires on a due date or when is consumed. You can use reusable token to create single_use tokens. reusable one represents a card source token
Yes if a 3ds is optional or not_supported, no if required. If required then every payement needs to fulfill a 3ds.
Steps:
Create an src_card_token for a card or use saved one (reusable)
Create an customer object with an src from src_card_token
Create an src_payment_token for a customer using one of his saved cards (as token)
fullfil a 3ds redirect process if required.
create a charge