Chester Zoo claims a first world captive breeding of the Sunbeam Snake (Xenopeltis unicolor), though I have seen a report of an unconfirmed earlier breeding in Thailand. The original pair were presented by HM Customs and they bred on several occasions.
This species only produced young every two years and they were not a good exhibition species, being fossorial in nature. The group was eventually exported to Cotswold Wildlife Park, I think.