ext-sponsored-transfer

;; title: ext-sponsored-transfer
;; version:
;; summary:
;; description:

(define-constant err-invalid-payload (err u500))

(define-public (call (payload (buff 2048)))
  (let ((details (unwrap!
      (from-consensus-buff? {
        amount: uint,
        to: principal,
        fees: uint,
      }
        payload
      )
      err-invalid-payload
    )))
    (try! (stx-transfer? (get amount details) tx-sender (get to details)))
    (match tx-sponsor?
      spnsr (try! (stx-transfer? (get fees details) tx-sender spnsr))
      true
    )
    (ok true)
  )
)