Clojars Clojure Package Scraper

Scrape Clojars — the community package repository for Clojure and the JVM — without an API key, without login, without proxies.

Search the whole Clojars index by keyword, or look up exact group/name coordinates, and get back clean, structured JSON: latest version, total downloads, description, license, homepage, source repo, dependencies, full version history and a ready-to-paste Leiningen dependency vector.

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What this Actor does

Clojars hosts tens of thousands of Clojure, ClojureScript and JVM libraries — Ring, Compojure, Reitit, Cheshire, http-kit, Datomic clients, Luminus modules and everything the Clojure ecosystem is built on. There is no bulk export and the web UI is paginated 24 results at a time.

This Actor turns Clojars into a dataset:

• Search mode — give it keywords (ring, http, json, graphql) and it pages through the Clojars search index, deduplicates hits by coordinate, then enriches every result with its full artifact detail.
• Artifacts mode — give it exact coordinates (ring/ring-core, metosin/reitit) and it resolves them directly, skipping search entirely.

One dataset item = one library. Every field is nullable, so partial data never breaks your pipeline.

Use cases

• Clojure dependency research — compare candidate libraries by download count, release recency and license before you commit to a dependency.
• Package discovery — find every Clojars library matching a keyword, ranked and enriched, in one run.
• Open-source intelligence — track adoption of JVM/Clojure libraries over time, map maintainers to projects, monitor which packages are alive and which are abandoned.
• Developer tooling — power internal dependency dashboards, SBOM enrichment, license-compliance checks, or a Clojure package search box of your own.

Input

Field	Type	Default	Description
mode	select	search	search (keyword queries) or artifacts (exact coordinates).
queries	array	["ring", "http"]	Keywords to search. Used in search mode.
artifacts	array	—	Coordinates like ring/ring-core. Used in artifacts mode. Full Clojars URLs and Leiningen vectors are accepted.
maxItems	integer	100	Hard cap on dataset items (max 1000).

{
  "mode": "search",
  "queries": ["ring", "http"],
  "maxItems": 100
}

{
  "mode": "artifacts",
  "artifacts": ["ring/ring-core", "metosin/reitit", "cheshire/cheshire"],
  "maxItems": 50
}

Output

{
  "group": "ring",
  "name": "ring-core",
  "coordinate": "ring/ring-core",
  "latest_version": "1.15.5",
  "latest_release": "1.15.5",
  "description": "Ring core libraries.",
  "homepage": "https://github.com/ring-clojure/ring",
  "user": "weavejester",
  "downloads": 40094991,
  "recent_downloads": null,
  "version_count": 130,
  "versions": ["1.15.5", "1.15.4", "1.15.3"],
  "licenses": ["The MIT License"],
  "scm_url": "https://github.com/ring-clojure/ring",
  "dependencies": ["[org.clojure/clojure \"1.9.0\"]"],
  "created": "2020-04-16T17:50:27.907000Z",
  "dependency_coordinate": "[ring/ring-core \"1.15.5\"]",
  "url": "https://clojars.org/ring/ring-core",
  "source": "clojars",
  "scraped_at": "2026-07-28T10:00:00Z"
}

Field notes

• versions is capped at the 30 most recent releases; version_count always reports the true total returned by Clojars.
• description is capped at 2000 characters.
• dependency_coordinate is a Leiningen vector you can paste straight into project.clj.
• recent_downloads is exposed for completeness but Clojars currently omits it on most artifacts, so it is usually null.
• created is only available for libraries discovered through search mode (Clojars returns it on search hits, not on artifact details).

Pricing

Runs on 512 MB and hits a fast public JSON API — roughly $0.5 per 1,000 libraries in platform compute, plus your Apify plan's usage. A 100-library default run costs a few cents.

Notes and limitations

• Clojars only hosts community-published artifacts. Libraries mirrored from Maven Central (for example org.clojure/clojure itself) return 404 on the Clojars artifact API and are skipped with a warning — use a Maven Central scraper for those.
• The Actor uses no proxy by default. Clojars is a friendly, public, unauthenticated API.
• Requests are retried three times with exponential backoff, and the HTTP layer falls back from curl_cffi to stdlib urllib if needed.

Related Actors

• Maven Central Scraper
• Hex.pm Scraper
• Hackage Scraper
• MetaCPAN Scraper

Local development

pip install -r requirements.txt
python -m src.main
python tests/test_smoke.py   # offline smoke tests