Source Library

Check if a book already exists in Source Library before importing. Uses 4-tier matching: source fingerprint, title+author normalization, keyword search, and semantic similarity. Returns confidence level, matches with URLs, and a suggestion (safe to import / review matches / likely duplicate). Use this BEFORE every import to avoid duplicates.

Get a book's AI-generated summary, chapter list, index stats, edition metadata, DOI, page counts, and processing status. THIS IS THE RIGHT FIRST CALL whenever the user has named a specific author or work — the summary is typically a multi-paragraph orientation covering the book's argument, structure, and significance, often answering the question without any further searching. Pair with get_book_text to read selected chapters, or search_within_book to locate passages inside it.

READ A BOOK — start here. Preferred: use 'chapter' param to read one chapter at a time (includes page markers like [Page 42] for citation). Or use page ranges (from/to) for focused reading. Call get_book first to see the chapter list. TRUNCATION: the response always includes truncated: true/false. When truncated=true, the truncation_note field gives the exact next from/to values to call — this means content was cut short by a page-budget limit, NOT that the book ended. An AI agent MUST NOT infer end-of-book from pages_returned alone; always check truncated first. Budget limits apply to anonymous callers (~50 pages per 24h); sign in at sourcelibrary.org/auth/signin or get an API key at sourcelibrary.org/developers for higher limits.

Get the exact translated text of a single page for quoting. Returns the verbatim translation, original OCR text, and a formatted citation. ALWAYS use this tool before putting text in quotation marks — copy the exact text from the response, do not paraphrase or reconstruct from memory. The response headline is citation_link (the stable sourcelibrary.org/q/… shortlink) — present it to the user alongside the quote and its page number. Render as: > [exact translation text, verbatim] > — [Author], p. [N]. [citation_link]

Browse the catalog by metadata — filter by author/title fragment, language, category, or translation recency. Returns books with title, author, language, year, page counts, and translation progress. Use this to discover WHAT EXISTS by an author or in a tradition before searching content; for content matches (passages on a topic) use search_translations or search_concept.

Conceptual / semantic passage search across the whole library. Use when the modern term won't literally appear in historical texts — e.g. "distributed cognition" maps to passages about active intellect, art of memory, wax tablet metaphors; "social contract" maps to pre-Hobbesian discussions of consent and authority. Ranks passages by cosine similarity on Gemini embeddings, so paraphrases and conceptually adjacent phrasings match even when no keyword overlaps. ORIENTATION HINT: if the user named a specific author or work, prefer get_book first — semantic search is expensive and best reserved for cross-corpus discovery. Prefer search_translations for literal phrases or distinctive single terms; use search_concept when the concept matters more than the wording. Similarity calibration: 0.70+ strong match, 0.55–0.70 worth reading but verify, below 0.55 mostly conceptual drift.

Search the visual collection: 50,000+ illustrations extracted from book pages PLUS 23,000+ standalone artworks (paintings, frescoes, prints, sculptures from Met, Rijksmuseum, Wikimedia, NGA). Filter by type, subject, figure, symbol, year, book, or text query. Each result has a source field — gallery (illustration in a book) or artwork (standalone museum work). Use type=painting or type=fresco to find standalone works; type=woodcut, type=engraving, type=emblem etc. surface mostly book illustrations. The source parameter narrows the search: 'all' (default), 'gallery' (illustrations only), or 'artworks' (standalone works only).

Full-text search across Source Library's 22,000+ rare historical books. Searches titles, authors, translations, and OCR text. Returns matching books and page snippets with citation URLs. ORIENTATION HINT: when the user has named a specific author or work, call get_book directly (or list_books to find the ID first) — the AI-generated book summary is usually the right first answer and saves repeated passage hunting.

Search inside translated page text across the entire library. THE tool for sweeping across many books for evidence on a theme. Unlike search_library (which matches titles/authors), this searches inside the actual text. Returns passage snippets with page numbers, book info, and citation URLs. ORIENTATION HINT: if the user has named a specific author or work, prefer get_book first — every book has an AI-generated summary + chapter outline that is usually the right first read. Use search_translations when looking for evidence across multiple books. (Also available as 'search_passages'.)

Search inside a specific book's pages (OCR and translations). Returns matching pages with snippets and citation URLs. Use after finding a book to locate specific passages.

Share a research dossier back to the Source Library team — a title, an optional summary, and an ordered list of citations (the passages your thesis rests on). Each citation is a reference { book_id, page, note }, NOT copied text: the library re-renders the canonical quote from the reference, so links stay authoritative. Use this when the user has assembled a thesis backed by passages across one or more books and wants to contribute it back. Like submit_feedback, it goes to the team for review (not an instant public page).

Submit feedback, bug reports, feature requests, or comments to the Source Library team. Messages go directly to the maintainers.