The Indian master named in the colophon to KR6r0010 部執異論 (T49 no. 2033) — Paramārtha’s Chén-dynasty Chinese translation of a Samayabheda doxographic treatise on the eighteen Buddhist schools. The name 天友 has been variously reconstructed as Sanskrit Devamitra and treated by some modern scholars as a separate Indian author parallel to 世友 (Vasumitra), and by others as an alternative epithet for Vasumitra himself (the graphs 世 “world” and 天 “heaven / deva” being functionally interchangeable in some Buddhist translation conventions). The historical question is unsettled; what is certain is that the work attributed to 天友 differs in important particulars from the Yìbù zōnglún lùn attributed to 世友 (KR6r0007).
No further biographical information is available.