> ## 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}. # List the subject vocabulary > The frozen 25-term vocabulary every page is tagged with, grouped into five scholarly buckets, with a scope note and the number of tagged pages for each term. ## OpenAPI ````yaml /api-reference/openapi.yaml get /subjects openapi: 3.1.0 info: title: Da-Vinci API version: 1.0.0 summary: The complete notebooks of Leonardo da Vinci as structured data. description: > The Da-Vinci API exposes the **Veni Vidi Da Vinci** library — 7,549 manuscript pages across 28 collections — as read-only structured data. Every page carries: - the original **e-Leo transcription** (Leonardo's Italian, where one exists) - the **Reader's Edition** layer: an editorial title and subtitle, subject tags from a frozen 25-term vocabulary, a plain-English summary, grounded highlights ("on this page") with evidence pointers, and a complete English translation (22,839 translated blocks) — written with AI from the e-Leo transcription and the page scan - public **high-resolution scans** in three sizes, served from a CDN ## Attribution The API is free to use. Anything you build with it must credit **venivididavinci.com** and link to the source page (`https://venivididavinci.com/codex/{slug}/{index}`). The Reader's Edition layer (titles, summaries, translations) is AI-generated editorial content — keep the provenance line "Reader's Edition — venivididavinci.com" wherever you reproduce it. Commercial licensing: contact us. ## Authentication & rate limits Anonymous requests work out of the box at a modest rate limit. Pass an API key in the `X-API-Key` header for higher limits; **Patron** keys (from the $40/yr membership) get the highest tier. Limits are returned on every response in `X-RateLimit-Limit`, `X-RateLimit-Remaining`, and `X-RateLimit-Reset` headers. | Tier | Limit | |---|---| | Anonymous | 60 requests / hour per IP | | Free key | 1,000 requests / day | | Patron key | 10,000 requests / day | ## Conventions - All responses are JSON, UTF-8. - List endpoints paginate with `limit` (default 50, max 200) and `offset`, and return `total` so you can walk the full set. - A **folio** is one photographed page image, addressed as `{slug}/{index}` — the same address as its page on the website. - Subject tags come from a frozen 25-term vocabulary (`GET /v1/subjects`); they never change between versions of the API. contact: name: Veni Vidi Da Vinci url: https://venivididavinci.com email: menachemberrebi@gmail.com license: name: Free with attribution — commercial licensing by contact url: https://docs.venivididavinci.com/attribution servers: - url: https://venivididavinci.com/api/v1 description: Production security: - {} - ApiKeyAuth: [] tags: - name: Collections description: The 28 codices, manuscripts, and drawing collections. - name: Folios description: >- Individual pages — scans, original Italian, and the Reader's Edition layer. - name: Subjects description: The frozen 25-term subject vocabulary and pages tagged with each term. - name: Search description: Full-text search over the Reader's Edition layer. paths: /subjects: get: tags: - Subjects summary: List the subject vocabulary description: > The frozen 25-term vocabulary every page is tagged with, grouped into five scholarly buckets, with a scope note and the number of tagged pages for each term. operationId: listSubjects responses: '200': description: All 25 subjects. content: application/json: schema: type: object required: - data properties: data: type: array items: $ref: '#/components/schemas/Subject' '429': $ref: '#/components/responses/RateLimited' components: schemas: Subject: type: object required: - id - label - bucket - bucketLabel - scope - pages properties: id: $ref: '#/components/schemas/SubjectId' label: type: string example: Physics & Mechanics bucket: type: string description: Coarse scholarly shelf this subject belongs to (one of five). example: physics-and-natural-world bucketLabel: type: string example: Physics & the Natural World scope: type: string description: What the term covers and what it deliberately excludes. pages: type: integer description: Number of pages tagged with this subject. SubjectId: type: string description: One of the 25 frozen subject terms. enum: - geometry - arithmetic-and-proportion - physics-and-mechanics - hydraulics - anatomy - geology - astronomy - optics-and-light - botany - flight - machines-and-devices - weapons-and-fortification - architecture - civil-engineering - painting-and-perspective - figure-studies - sculpture-and-casting - horses-and-animals - landscape - cartography - ornament-and-heraldry - lists-and-accounts - language-and-latin - personal-notes - fables-and-prose Error: type: object required: - error properties: error: type: object required: - code - message properties: code: type: string enum: - not_found - bad_request - rate_limited message: type: string responses: RateLimited: description: Rate limit exceeded — check `X-RateLimit-Reset`, or pass an API key. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: rate_limited message: >- Anonymous limit is 60 requests/hour. Pass an X-API-Key header for more. securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: Optional — raises your rate limit. Patron keys get the highest tier. ````