Bring Crossref
to LangChain

The "is-referenced-by-count" is the number of times other works cite this DOI. The "references-count" is how many references this work cites. Quick way to assess a paper's impact. Get citation count for a DOI

Use the funder ID from search_funders (e.g. "100000002" for NIH). Essential for understanding research funding landscapes and tracking funded output. Get works funded by a specific funding organization

Returns title, publisher, subjects, total DOI count, current and backfile counts, metadata coverage percentages, and quality flags. Get journal details by ISSN

Can be filtered with an optional text query. Useful for browsing a journal's publication history or searching within a specific journal. Get articles published in a specific journal

Returns name, DOI prefix, total/current/backfile DOI counts, metadata coverage scores, and quality flags. Get publisher details with output metrics

Returns all cited references with their DOIs (when available), authors, titles, journals, and years. Essential for bibliography analysis, finding source material, and understanding a paper's intellectual foundations. Get full reference list (bibliography) for a DOI

Returns title, authors, journal, publisher, publication date, volume, issue, pages, citation count, reference count, subject areas, and license information. The definitive tool for getting structured metadata from any DOI. Resolve a DOI to full bibliographic metadata

Use institution names like "Stanford University", "MIT", "Harvard Medical School". Can be combined with a topic query. Search works by institutional affiliation

ORCID is the universal researcher identifier. Format: "0000-0002-1825-0097". Essential for finding the complete publication record of a researcher across all journals and publishers. Find works by ORCID author identifier

Examples: "National Institutes of Health", "National Science Foundation", "European Research Council", "Wellcome Trust". Search funding organizations worldwide

Returns journal titles, ISSNs, publishers, subject areas, total DOI counts, and metadata coverage scores. Use this to find journal identifiers and evaluate journal metrics. Search academic journals by title or ISSN

This covers preprints from bioRxiv, medRxiv, SSRN, ChemRxiv, and other preprint servers that register DOIs with CrossRef. Search registered preprints across all servers

Returns publisher names, DOI prefixes, and total DOI counts. Search academic publishers

Default is last 7 days. Use this to monitor the latest publications across all journals and publishers. Find the most recently registered DOIs

Supports full-text query, filters, sorting, and pagination. Filter syntax: "from-pub-date:2024-01-01", "type:journal-article", "has-orcid:true", "has-references:true", "is-update:false". Sort options: "relevance", "published", "indexed", "is-referenced-by-count". Search 150M+ DOI-registered academic works

Returns whether the DOI exists in CrossRef, along with basic metadata (title, type, publisher) if valid. Useful for quality-checking reference lists and citation data. Check if a DOI is valid and registered