The Manasara is a Sanskrit treatise covering architecture, town planning, sculpture and iconography, part of the wider body of Indian technical literature known as shilpa shastra, texts concerned with the crafts. It sets out procedures for choosing and preparing a building site, for laying out the vastu purusha mandala, the grid diagram that governs the orientation and proportion of a structure, and for the design of temples, houses and images according to fixed systems of measurement rather than individual improvisation.
The text is traditionally attributed to a sage called Manasara, though nothing reliable is known about a historical individual of that name, and scholars generally treat the attribution as a conventional device rather than evidence of single authorship; the text itself likely represents an accumulated and edited body of architectural knowledge rather than the product of one author working at one time. Its scope extends well beyond religious architecture to cover town planning, palace design, furniture and the iconometric proportions governing how deities should be sculpted, giving it the character of a comprehensive craft manual rather than a narrowly devotional text.
Because building according to these prescriptions was understood to have ritual and cosmological consequences, not only structural ones, the Manasara sits at the intersection of engineering knowledge and religious practice, treating correct proportion and orientation as necessary conditions for a structure to function properly as a sacred space.