openlibrary — Book Metadata from Open Library

Query Open Library's 50M+ record catalog over its public HTTP API: search works and authors, walk the edition/work/author graph by ISBN or OLID, enumerate editions, and read community ratings. No API key exists; everything here is a keyless GET.

Setup

Nothing to authenticate: the public Open Library API requires no API key for reads. There is no token, no registration step, no lazy-auth dance.

# Optional etiquette: identified User-Agent gets ~3x rate budget (~3 req/s vs ~1)
export OL_EMAIL="you@example.com"

Requires Python 3.8+ and requests only. --help and --dry-run work with no environment at all. Write endpoints exist upstream but require an authenticated Internet Archive session and are effectively internal — treat this surface as read-only.

Three hosts matter and they serve different things:

Host	Serves
openlibrary.org	metadata JSON: search, records, ratings
covers.openlibrary.org	cover images + author photos (separate service)
archive.org	scan content / bulk dumps (redirect targets)

Essential Commands

find books — search

openlibrary search --query "dune"                       # relevance order
openlibrary search --query "dune" --sort editions       # most editions first
openlibrary search --query "dune" --sort new            # newest first
openlibrary search --query "foundation" --lang fr       # prefer French editions
openlibrary search --query "dune" --limit 5 --offset 10 # paginate
openlibrary search --query "dune" --json                # machine-readable

Results carry title, authors, first_publish_year, edition count, and the work key (/works/OL…W) that feeds the other commands. The CLI validates --sort choices client-side because an unknown sort value makes the server return a plain-text HTTP 500.

find people who write — author search

openlibrary search-authors --query "asimov"             # name candidates
openlibrary search-authors --query "le guin" --limit 5
openlibrary search-authors --query "asimov" --json      # includes top_work, work_count

Author docs arrive with bare keys (OL23919A), unlike book search's path keys.

inspect records — author / work

openlibrary author OL23919A                # bio, dates, photo URL
openlibrary work OL1168083W                # description, subjects, cover URL
openlibrary work OL1168083W --json         # full record

Keys may be passed bare (OL23919A) or as paths (/authors/OL23919A) — the CLI normalizes both.

resolve an ISBN

openlibrary isbn 9780451524935             # ISBN-10 or ISBN-13
openlibrary isbn 9780451524935 --json      # + resolved edition_key, work_keys, cover_url

Upstream, /isbn/<isbn>.json answers a 302 redirect to the canonical edition JSON (/books/<OL…M>.json). The CLI follows it and reports which edition matched via edition_key. If the edition record lacks author names (some ship authors:null), the CLI recovers them from the linked work.

list every edition of a work

openlibrary editions OL81699W                          # publisher/date/ISBN per edition
openlibrary editions OL81699W --limit 50 --offset 50   # page through large sets
openlibrary editions OL81699W --json                   # + next_offset when more exist

Backs onto /works/<key>/editions.json; next_offset is computed from the server's prebuilt next-page link.

read the room — community signals

openlibrary ratings OL45804W               # average rating + shelf counts
openlibrary ratings OL45804W --json        # full distribution + bookshelves

Joins /works/<key>/ratings.json (summary.average, per-star counts) with /works/<key>/bookshelves.json (want_to_read, currently_reading, already_read).

Global Flags

Position-independent; put them before or after the subcommand:

openlibrary --json search --query "dune"     # machine output anywhere
openlibrary --dry-run isbn 9780451524935     # preview the exact URL, no network
openlibrary --quiet search --query "dune"    # suppress diagnostics

Flag	Effect
--json	One JSON object on stdout instead of human text
--dry-run	Print the planned request as JSON without executing it
--quiet	Suppress non-essential output
--verbose	Verbose logging

Multi-Step Pipeline Recipes

ISBN → edition → work → author bio

The canonical walk across all three key types:

openlibrary isbn 9780451524935 --json | jq -r '.work_keys[0]'   # OL1168083W
openlibrary work OL1168083W --json | jq -r '.authors[0]'        # bare OL…A key
openlibrary author OL118077A                                    # bio, dates

The CLI keeps this pipeline type-safe: every command that emits an authors field under --json (isbn, work) uses the same shape — an array of bare OL…A keys — while human output renders comma-separated labels instead. Each hop uses a different key suffix (M → W → A); see Known Gotchas before hand-assembling these URLs yourself.

Rank a series by community love

for w in $(openlibrary search --query 'series:dune' --limit 8 --json | jq -r '.results[].key'); do
  openlibrary ratings "${w##*/}" --json \
    | jq -c '{work: .key, avg: .average, rated: .ratings_count,
              want_to_read: .bookshelves.want_to_read}'
done

Find readable ebooks, then their print editions

openlibrary search --query 'title:"moby dick"' --sort editions --json \
  | jq '.results[] | select(.has_fulltext) | {title, key}'
openlibrary editions OL81699W --json | jq '.editions[] | {key, isbn_13}'

Using --json with jq

openlibrary search --query "voracious" --json | jq '.results[] | {title, first_publish_year}'
openlibrary search-authors --query "butler" --json | jq '.results[0] | {name, key, top_work}'
openlibrary isbn 9780451524935 --json | jq -r '.cover_url'          # covers host URL
openlibrary editions OL81699W --json | jq '[.editions[].publish_date]'
openlibrary ratings OL45804W --json | jq '.rating_distribution'

Known Gotchas

• ISBN endpoints answer 302, not JSON — /isbn/<isbn>.json, /lccn/*.json, /oclc/*.json redirect to /books/<OL…M>.json. Clients must follow redirects (curl -L; requests does by default) or they parse an HTML redirect page. Direct /books/<OLID>.json calls return 200 immediately.
• Merged keys return redirect stubs inside HTTP 200 — Open Library is a wiki; when duplicate works merge, the old key keeps answering 200 with {"type":{"key":"/type/redirect"},"location":"/works/<master>"} instead of a 3xx. Detect the stub type in success responses and re-fetch. The bundled CLI does this automatically (and appends .json to stub locations, since extension-less URLs redirect to HTML pages).
• Key types are encoded in the suffix — OL…M = edition (/books/), OL…W = work (/works/), OL…A = author (/authors/). Works link to authors double-nested (authors[].author.key); editions nest flat (authors[].key) — or ship authors:null entirely, recovering names from the linked work. Requesting a key under the wrong collection yields a 301 reroute.
• Search empties are not errors — malformed queries parse loosely and come back HTTP 200 with numFound:0; conversely a bad sort= enum is a plain-text HTTP 500 and non-integer limit is a FastAPI 422. Branch on bodies, not just status codes.
• availability needs ia — in raw /search.json calls, requesting fields=availability silently returns nothing unless ia is also requested.
• Covers live on another host — image URLs are always covers.openlibrary.org/b/id/<cover_id>-{S,M,L}.jpg (or /b/isbn/..., /a/id/... for author photos). Missing covers return a blank placeholder with HTTP 200 unless you add ?default=false; non-ID/non-OLID lookups cap at 100 req/IP per 5 min then 403; cover URLs often 302 into archive.org zip shards.
• Rate limits are policy, not headers — no Retry-After/X-Rate-Limit headers exist. Anonymous ≈1 req/s; a User-Agent: App (email) (set OL_EMAIL) raises it to ≈3 req/s. Batch with one search rather than hundreds of lookups; bulk belongs in monthly dumps.
• Text fields nest {type,value} objects — older records wrap bio, description, notes as {"type":"/type/text","value":"..."} while newer ones use plain strings. Handle both; the CLI unwraps centrally.
• OLID ≠ long-term identity — deleted keys can be reassigned to unrelated books, and merged-away keys become redirect stubs. Pair OLIDs with title/ISBN in any cache.
• .json placement matters for slugged URLs — append .json to the bare key (/authors/OL23919A.json), never after a slug path.

When to use

• Any question about books, authors, or works Open Library's public catalog can answer
• Resolving ISBNs/OLID keys to canonical records and walking edition/work/author graphs
• Finding readable or borrowable scans, cover images, community ratings/shelf counts

When not to use

Do not use this skill for local library-catalog administration — Koha/Evergreen ILS configuration, MARC batch processing, patron management — or for licensed commercial data feeds (ISBNdb, Google Books), citation formatting, or managing your own Open Library reading account/lists (that requires site login this skill deliberately does not handle). For movie/TV metadata use tmdb instead.

Reference Files

File	Topic	Read when
references/api-overview-and-key-graph.md	Access model, rate-limit etiquette, OLID M/W/A key graph, cross-collection 301s, merge-stub handling, {type,value} text wrapping	Assembling record URLs by hand, handling merges/wrong-key errors, or planning request pacing
references/search-api-guide.md	/search.json parameters, sort keys, field scopes (title:, isbn:, …), fields= projection incl. the availability/ia interaction, /search/authors.json, /subjects/<name>.json, inside-book search, error model	Building precise queries, paginating deep result sets, or debugging empty results
references/books-isbn-and-covers.md	Identifier endpoints and their 302 resolution, raw records vs legacy /api/books view models, editions listing, ratings/bookshelves shapes, covers-host URL rules and limits	Working with ISBNs/LCCNs/OCLCs, enumerating editions, or fetching images
references/recipes-and-gotchas.md	End-to-end curl/jq pipelines (ISBN→work→author chain, ebook discovery, cover assembly, disambiguation) plus a symptom-indexed gotcha table	Wiring multi-step workflows or diagnosing an unexpected response

Available Scripts

Script	Purpose	Invocation
scripts/openlibrary	The CLI this skill drives: search, search-authors, author, work, isbn, editions, ratings — all with --json/--dry-run, automatic 302 + merge-stub resolution, {type,value} unwrapping, covers-host URL assembly, and client-side sort validation. Run it for every book-metadata question above.	scripts/openlibrary search --query "dune" --json
scripts/test_openlibrary.py	Offline pytest/unittest suite covering help, argument errors, dry-run plans, mocked-client logic (redirect stubs, author fallback, editions paging), plus two env-guarded live probes (OPENLIBRARY_LIVE_TESTS=1). Zero egress otherwise.	.venv/bin/python3 -m pytest -p no:cacheprovider --strict-markers scripts/test_openlibrary.py

Prerequisites

• Python 3.8+ with requests (stdlib otherwise); invoke as python3 scripts/openlibrary ... if not executable directly
• No credentials of any kind; optional OL_EMAIL for rate-limit etiquette
• jq recommended for --json post-processing