Library of Congress API Skill

Search and retrieve items from LOC's digitized collections — books, photos, maps, manuscripts, newspapers, audio, and more.

Critical: Things Claude Won't Know Without This Skill

This API covers digitized collections, NOT the full library catalog

The loc.gov JSON API searches LOC's digitized and online collections — not the full OPAC. By default, only digitized items are returned. Add all=true to include non-digitized catalog records.

Search romanized forms, not Chinese script

LOC catalog records for East Asian books are mostly romanized (pinyin for newer records, Wade-Giles in many older ones; Korean in McCune-Reischauer). Searching in Chinese script finds only the few records that carry the vernacular, and it was slow in one report (timeouts). For example, books with all=true (October 2026):