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Automatic enrichment

Paper and book results are filled in from more sources than the one that answered the call. Enrichment runs in two phases:

  • Phase 0 (primary): OpenAlex (open-access status, affiliations, funders, concepts) and CrossRef (publisher, page ranges, container titles).
  • Phase 1 (secondary): Open Library (book metadata for papers with an ISBN) and Google Books (preview links, excerpts, snippets).

Books cited as papers

When get_paper, get_citations, get_references or get_citation_graph returns a paper whose externalIds.ISBN is present and not empty, Open Library metadata is fetched and attached to the record as book_metadata:

Field Description
publisher Publisher name
edition Edition string (such as "2nd ed.")
isbn_13 ISBN-13
cover_url Cover image URL (from Open Library covers)
openlibrary_work_id Open Library work ID (such as OL17953442W)
description Work description, if available
subjects List of subject strings
page_count Page count, if known
authors List of author names, resolved from Open Library work metadata

Other sources

CrossRef adds publisher metadata, page ranges and container titles to a paper result that has a DOI. Google Books adds google_books_url and snippet to a book record that has an ISBN.

When a source doesn't answer

Enrichment is best effort. If a source is unreachable or has no data, the record comes back without that layer. At most 10 enrichment requests run at once in each phase.