Books and libraries · by Library of Congress (US)

Library of Congress

The US national library's online collections of photos, maps, manuscripts, newspapers, recordings and books, with a keyless JSON API plus IIIF image, full-text and streaming services.

Any search page on loc.gov can be turned into structured data, so whole collections of historic photos or maps become something you can query and plot.

API, no keyDownloadCommercial: conditions

Open loc.gov ↗ agent.md

For your project

Official API: Official API · Free JSON/YAML API: 20 requests per minute (1-hour block if exceeded); Text and Image Services: 150/min; Streaming: 60/min; no paging past 100,000 items; recommended max 1,000 items per page.
“Specifically, it includes technical documentation of the Library's loc.gov JSON API, its sitemaps, and suite of microservices.” loc.gov/apis/
Key: Not needed
“The API is accessible to the public with no API key or authentication required. Rate limiting is strongly encouraged.” loc.gov/apis/json-and-yaml/working-within-limits/
Formats: JSON, YAML, IIIF, XML
Data download: Yes json, xml, jpg, tiff, pdf, txt
License: Varies per item (Library generally does not own rights; many items public domain) Each collection item; users must check copyright status themselves
Commercial use: Commercial use with conditions
“As a publicly supported institution, we generally do not own the rights to materials in our collections. You should determine for yourself whether or not an item is protected by copyright or in the public domain, and then satisfy any copyright or use restrictions when publishing or distributing materials from our collections.” loc.gov/legal/
Credit: Not stated
Embedding: Embedding unclear
Using the website: Free

Read on Library of Congress's own pages on Oct 23, 2026 · license or terms · API docs. Check the license page before you ship.

For your agent

Add fo=json to almost any loc.gov search or item URL; keep to 20 req/min, pause on 429 or CAPTCHA HTML, and narrow with facets instead of deep paging.
Stay at or below 20 requests/minute for the JSON API and back off on 429 or CAPTCHA pages.
Check each item's rights statement before reuse; the Library does not grant rights.
Do not page past 100,000 results; use facets or narrower queries.

Paste into your agent: Read https://agentgid.com/resources/library-of-congress/agent.md before using Library of Congress.

What you can build

A historic map or photo viewer for one US town using the JSON API and IIIF images
A 'then and now' app that pairs Library photos with today's street view links
A newspaper headline explorer built on the full-text Text Services

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Project Gutenberg It is one of the largest clean, proofread corpora of classic literature, and the whole catalog and text set can be downloaded in bulk. API, no keyDownloadCommercial: conditions Open Library Almost every page has a machine-readable twin: add .json to a work or author URL and you get the structured record behind it. API, no keyDownloadCommercial: conditions Internet Archive Behind every item is a folder of original files and metadata you can fetch directly, from old radio shows to scanned books and forgotten home movies. API, no keyDownloadCommercial: conditions Europeana One query can pull paintings, manuscripts, newspapers and sound recordings from institutions all over Europe, filtered to items that are free to reuse. APIDownloadCommercial: conditions Digital Public Library of America It stitches together small local archives and big institutions, so one search can surface a town historical society's photos next to national collections. License unclear archive.today It keeps frozen, script-free copies of pages that later change or vanish, so you can see what a page said on a given day. License unclear

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