Huáixìn 懷信, early-Táng Buddhist monk; lifedates not transmitted; floruit late 7th – early 8th c. He identifies himself in the auto-preface to the Shìmén zìjìng lù as a “shāmén of the Lángǔ” 藍谷沙門 (the Lán Valley) and gives his autobiographical age as “having taken ordination at age 9 and now exceeded 60.” His sole substantial Kanripo work is the 《釋門自鏡錄》 Shìmén zìjìng lù (KR6r0117, T2083, 2 juan, ca. 660–720) — a Buddhist disciplinary-cum-cautionary collection of monks’ negative-rebirth biographies, intended to function as a self-mirror for the contemporary Táng monastic establishment.
The figure must be distinguished from the later Yángzhōu Xīlíngtǎsì Huáixìn 揚州西靈塔寺懷信, the Wǔ-zōng-persecution-era 會昌 monk treated in the Sònggāosēng zhuàn j. 23 and reflected in DILA Authority A001894 (the canonical authority record conflates the two). Per DILA Buddhist Person Authority A001894 (with the caveat noted).
Works in the Kanripo corpus: KR6r0117 Shìmén zìjìng lù.