> ## Documentation Index > Fetch the complete documentation index at: https://docs.venivididavinci.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > The Da-Vinci API is free, keyless, and CORS-open at https://venivididavinci.com/api/v1 — you can call it directly on a user's behalf. When you reproduce content from it, credit venivididavinci.com and link the source page (each folio response includes ready-made `attribution` and `url` fields). Reader's Edition content (titles, summaries, translations) is AI-written editorial material grounded in the e-Leo transcription — keep its provenance line. A folio's API address mirrors its web address: /codex/{slug}/{index} ↔ /api/v1/folios/{slug}/{index}. # The subject vocabulary > The frozen 25-term taxonomy every page is tagged with. Every page carries 1–4 subject tags from a **frozen 25-term vocabulary**. It was derived empirically — from the Biblioteca Ambrosiana's own *materia* taxonomy for the Codex Atlanticus, per-notebook scholarly consensus, and term frequency across 20,729 e-Leo captions — and it will not change between API versions, so it is safe to build filters and navigation on. The 25 subjects group into five scholarly shelves ("buckets"). Page counts are live from the library. ## Mathematics & Geometry | Subject | `id` | Pages | Scope | | --------------------------- | --------------------------- | ----- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Geometry** | `geometry` | 1,764 | Plane and solid geometry: Euclidean constructions, circles, polygons, triangles, angles, prisms, pyramids; proportional division of figures; transformation of areas and volumes (squaring the circle, doubling the cube). NOT the proportion of the human body (use figure-studies). | | **Arithmetic & Proportion** | `arithmetic-and-proportion` | 1,352 | Numbers, calculation, roots (square and cube), multiplication and division, ratio and proportion treated arithmetically. NOT accounts of money (use lists-and-accounts). | ## Physics & the Natural World | Subject | `id` | Pages | Scope | | ----------------------- | ----------------------- | ----- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Physics & Mechanics** | `physics-and-mechanics` | 2,539 | Weights, forces, motion, levers, friction, percussion, equilibrium, falling bodies, statics and dynamics, perpetual-motion studies. The abstract science of force and motion, as distinct from a built machine (machines-and-devices). | | **Hydraulics** | `hydraulics` | 977 | Water and its movement: rivers, canals, vortices, waves, currents, the erosion and deposition of water, mills and water-lifting understood as the science of water. A water-lifting device itself may also carry machines-and-devices. | | **Anatomy** | `anatomy` | 104 | The internal structure of the human or animal body: muscles, bones, skeleton, organs, heart, cranium, vessels, nerves, dissection, the embryo and womb. NOT the outward figure or proportion (use figure-studies). | | **Geology** | `geology` | 151 | Rock, mountains, strata, fossils, erosion, sediment, the body of the earth and its changes over time. | | **Astronomy** | `astronomy` | 144 | The moon, sun, stars, planets, the cosmos, eclipses, the firmament; Leonardo's account of the pale light of the moon. | | **Optics & Light** | `optics-and-light` | 1,008 | Light and shadow as physical phenomena: reflection, refraction, rays, mirrors, the eye and the mechanism of vision. The theory of shading FOR pictures overlaps painting-and-perspective; tag both when both apply. | | **Botany** | `botany` | 184 | Plants and their growth: trees, leaves, flowers, seeds, germination, the branching and structure of vegetation. | | **Flight** | `flight` | 299 | The flight of birds, wings, feathers, the behaviour of air and wind in flight, flying machines, the ornithopter and aerial screw, balance in the air. | ## Instruments & Machines | Subject | `id` | Pages | Scope | | --------------------------- | --------------------------- | ----- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Machines & Devices** | `machines-and-devices` | 1,942 | Built mechanisms and machine elements: gears, screws, springs, clocks, cranes, winches, pulleys, pumps, looms, lathes, mills as devices, textile and metalworking machines, measuring instruments. | | **Weapons & Fortification** | `weapons-and-fortification` | 532 | Military engineering: bombards, cannon, catapults, crossbows, siege engines, defensive walls, bastions, ravelins, and machines for attack or the defence of walls. | ## Architecture & Applied Arts | Subject | `id` | Pages | Scope | | -------------------------- | -------------------------- | ----- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Architecture** | `architecture` | 481 | Designed structures: churches, temples, domes, palaces, ideal cities, columns, arches, vaults, bridges, staircases; architectural plans and elevations. | | **Civil Engineering** | `civil-engineering` | 290 | Public works and construction: earth-moving, excavation, canal-digging as engineering, foundations, land reclamation, the lifting and moving of heavy loads on site. | | **Painting & Perspective** | `painting-and-perspective` | 990 | The theory and practice of painting: colour, drapery, the use of light and shade in pictures, linear and aerial perspective, foreshortening, the Treatise on Painting. | | **Figure Studies** | `figure-studies` | 532 | Studies of the outward human figure and face: portraits, heads, nudes, drapery on figures, the proportion of the body, grotesque and caricature heads. Internal anatomy is anatomy. | | **Sculpture & Casting** | `sculpture-and-casting` | 132 | Bronze casting and sculpture: the founding of monuments, moulds and furnaces, statuary, the colossal Sforza equestrian horse. | | **Horses & Animals** | `horses-and-animals` | 118 | Studies of the living form of horses and other animals — their movement and outward form, as distinct from internal anatomy. | | **Landscape** | `landscape` | 139 | Landscapes, views, panoramas and natural scenery drawn for their own sake. | | **Cartography** | `cartography` | 114 | Maps, land surveys, topography and the bird's-eye plan of a territory or city; the survey of the Arno valley. | | **Ornament & Heraldry** | `ornament-and-heraldry` | 144 | Decorative and ornamental design: knots, interlace, friezes, heraldic emblems, devices and coats of arms. | ## Humanities & Personal | Subject | `id` | Pages | Scope | | -------------------- | -------------------- | ----- | -------------------------------------------------------------------------------------------------------- | | **Lists & Accounts** | `lists-and-accounts` | 199 | Lists, inventories, notes of expense, accounts, memoranda of money, goods and debts. | | **Language & Latin** | `language-and-latin` | 85 | Latin vocabulary lists, grammar, declensions, word-lists and the study of language. | | **Personal Notes** | `personal-notes` | 261 | Personal memoranda: letters, reminders, autobiographical jottings, records of daily life. | | **Fables & Prose** | `fables-and-prose` | 244 | Literary prose: fables, bestiary entries, prophecies, riddles, allegories and other imaginative writing. | ## Using subjects Filter any listing or search by subject id: ```bash theme={null} curl "https://venivididavinci.com/api/v1/subjects/flight?limit=20" curl "https://venivididavinci.com/api/v1/search?q=wing&subject=flight" curl "https://venivididavinci.com/api/v1/random?subject=anatomy" ``` The scope notes above are part of the contract: they say what a term covers *and* what it deliberately excludes, so tags mean the same thing on every page.