The first English-language translation (with rich historical introduction and extensive annotation) of a key group of Indian Buddhist tantric texts that have had profound influence on the Tibetan Buddhist tradition. The Seven Siddhi Texts is a key collection of Indian Buddhist tantric exegetical treatises that have shaped the interpretation of unexcelled yoga tantra and Mahamudra (Great Seal) practice in Tibet from the eighth century CE to the present. The scholar-yogi authors of these seven texts--drawing upon their scriptural knowledge and personal insight--clarify the intended meanings underlying cryptic, seemingly antinomian passages in root tantras such as the Esoteric Community Tantra ( Guhyasamaja-tantra ) pertaining to sex, violence, and magical powers, which have proved controversial for many traditional and modern scholars. These seven treatises come from the famed mahasiddha (great adept) tradition, which often defied the rigid social, religious, and gender norms of premodern India in quest of nondual wisdom. The translator's introduction places the collection in its Indian sociohistorical context, traces its reception in Tibetan Mahamudra practice lineages, and addresses modern misinterpretations. As a window into the earliest Indian Buddhist tantric communities, the Seven Siddhi Texts is a treasure for both practitioners and scholars of these increasingly popular subjects.