Hathitrust Lookup

hathitrust-lookup — HathiTrust catalog lookup

Resolve identifiers to HathiTrust catalog records using the ht-lookup CLI, a thin client over the HathiTrust Bibliographic API. For each record it prints the title, identifiers, publish dates, and the list of digitized items (volumes) — each with its HathiTrust id (htid), reading-room URL, and US access status (Full view vs Limited (search-only)).

ht-lookup oclc 424023
ht-lookup isbn 9780030110405 lccn 62009520     # batch, up to 20 ids
ht-lookup --json --full recordnumber 000578050  # raw JSON incl. MARC-XML

Scope — read this first

This is identifier lookup, not keyword/full-text search. HathiTrust does not expose its catalog free-text search as an open API (the search pages sit behind a bot challenge), and the page-content Data API was retired in July 2024. So you cannot script "find books about X" here.

To go from a title/author to an identifier: have the user search the catalog in a browser at , then pass back the OCLC number or record number. Citations, library catalog entries, and MARC records usually already carry an OCLC/LCCN/ISBN you can feed straight in.

For bulk text mining (the "research datasets" that replaced the old API), point the user to the HathiTrust Research Center (Extracted Features dataset, Data Capsules) — out of scope for this skill.

Install

Check command -v ht-lookup first. If missing, download the release binary (the repo is public — no token needed):

mkdir -p ~/.local/bin
curl -fsSL -o ~/.local/bin/ht-lookup \
  "https://github.com/LouLouLibs/claude-skills/releases/latest/download/ht-lookup-$(uname -s | tr '[:upper:]' '[:lower:]')-$(uname -m)"
chmod +x ~/.local/bin/ht-lookup

Assets: ht-lookup-linux-x86_64 (static musl — runs on any Linux, including NixOS microVM guests) and ht-lookup-darwin-arm64. Runtime requirement: curl on PATH (HTTPS is delegated to it).

Usage

ht-lookup [--full] [--json]   [  ...]

| | | |---|---| | idtype | one of oclc, lccn, issn, isbn, htid, recordnumber | | --full | request full MARC records (adds MARC-XML; pair with --json) | | --json | print the raw API JSON instead of the formatted view |

Up to 20 identifiers per call (the API's batch limit). Mixed id types in one call are fine.

Reading the output

Infinite series (1962)
  record:  https://catalog.hathitrust.org/Record/000578050
  oclc:    424023
  lccn:    62009520
  items (2):
    [Limited (search-only)] mdp.39015025315527  University of Michigan
        https://babel.hathitrust.org/cgi/pt?id=mdp.39015025315527

• [Full view] — the full text is readable online at the item URL.
• [Limited (search-only)] — in-copyright; only page-level search is

public. The item URL still opens the (limited) viewer.

• For serials/multi-volume sets each item is tagged with its enumeration in

brackets, e.g. [v.2 1881]. These records can list many items — use --json and pipe through jq to filter, e.g. only Full-view volumes:

``bash ht-lookup --json oclc 6412936 \ | jq -r '.[].items[] | select(.usRightsString | startswith("Full")) | .htid' ``

Notes

• No API key or authentication is needed; the API is public and unauthenticated.
• An unknown identifier prints : no record found and still exits 0.
• HT_API_BASE overrides the API base URL (used by the test harness).

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: LouLouLibs
• Source: LouLouLibs/claude-skills
• License: MIT

Install and usage instructions live in the source repository linked above.