How to create a stripe session with httr

Question

I'm trying to create a stripe session in shiny to inititate a payment process. (Stripe docs)

I have this curl post request:

curl https://api.stripe.com/v1/checkout/sessions \
  -u sk_test_XXX: \
  -d success_url="https://example.com/success" \
  -d cancel_url="https://example.com/cancel" \
  -d payment_method_types[]=card \
  -d line_items[][name]=T-shirt

Trying a similar command (incl subscriptions for line_items) in R with httr always throws an error.
So far, I tried this:

httr::POST(
  url = "https://api.stripe.com/v1/checkout/sessions",
  config = httr::add_headers(
    Authorization = paste("Bearer", Sys.getenv("stripe_key"))
  ),
  body = list(
    success_url = "https://example.com/success",
    cancel_url = "https://example.com/cancel",
    payment_method_types = "card",
    subscription_data = list(
      items = list(plan = "plan_XX"),
      trial_period_days = 7
    )
  ),
  encode = "form"
)

Which exits with error

Error in vapply(elements, encode, character(1)) : 
  values must be length 1,
 but FUN(X[[6]]) result is length 2

The issue seems to be due to parameters card and subscription_data. At least subscription_data needs to be of type dictionary. How to handle this with httr?

Answer 1

I solved the issue by setting the body parameters as close as possible to the original curl command

httr::POST(
  url = "https://api.stripe.com/v1/checkout/sessions",
  config = httr::add_headers(
    Authorization = paste("Bearer", Sys.getenv("stripe_key"))
  ),
  body = list(
    `success_url` = "https://example.com/success",
    `cancel_url` = "https://example.com/cancel",
    `payment_method_types[]` = "card",
    `subscription_data[items][][plan` = "plan_XX"
  ),
  encode = "form"
)