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RubyGems API

Free RubyGems API with no key: gem metadata, versions, download counts, dependencies, licence and source URLs. CORS enabled. Tested curl example.

No API key requiredCORS enabledHTTPSFree tier

Endpoint tested and returned HTTP 200 on 2026-08-19

What is the RubyGems API?

The RubyGems API is a free, key-free registry API returning metadata for any published Ruby gem — current version, download counts, dependencies, licences and source code URLs.

RubyGems exposes clean, flat JSON for every gem. Unlike some registries the response is immediately readable: name, version, downloads, authors, licences and dependencies all sit at the top level with no envelope to unwrap.

The split between `downloads` (all-time) and `version_downloads` (this version only) is useful for judging adoption of a recent release, which a single total cannot tell you.

Quick facts

Base URL
https://rubygems.org/api/v1
Authentication
No API key for reads. Publishing gems requires an API key.
Rate limit
About 10 requests per second; heavier consumers should use the published data dumps.
Pricing
Free.
CORS
Enabled — callable directly from browser JavaScript
Official docs
Read the docs

How to use the RubyGems API

Every request below was executed against the live API on 2026-08-19, and the response shown is the real body it returned — not an illustration.

1. Fetch metadata for a Ruby gem

GET https://rubygems.org/api/v1/gems/rails.json

curl
curl 'https://rubygems.org/api/v1/gems/rails.json'
JavaScript (fetch)
const res = await fetch("https://rubygems.org/api/v1/gems/rails.json");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);
Python (requests)
import requests

res = requests.get("https://rubygems.org/api/v1/gems/rails.json", timeout=20)
res.raise_for_status()
print(res.json())
Response — HTTP 200 (truncated)
{
  "name": "rails",
  "downloads": 777445565,
  "version": "8.1.3.1",
  "version_created_at": "2026-07-29T15:02:41.060Z",
  "version_downloads": 2902228,
  "platform": "ruby",
  "authors": "David Heinemeier Hansson",
  "info": "Ruby on Rails is a full-stack web framework optimized for programmer happiness and sustainable productivity. It encourages beautiful code by favoring convention over configuration.",
  "licenses": [
    "MIT"
  ],
  "metadata": {
    "changelog_uri": "https://github.com/rails/rails/releases/tag/v8.1.3.1",
    "bug_tracker_uri": "https://github.com/rails/rails/issues",
    "source_code_uri": "https://github.com/rails/rails/tree/v8.1.3.1",
    "mailing_list_uri": "https://discuss.rubyonrails.org/c/rubyonrails-talk",
    "documentation_uri": "https://api.rubyonrails.org/v8.1.3.1/",
    "rubygems_mfa_required": "true"
  },
  "yanked": false,
  "sha": "ccd11a36bfc171bf9c66d585d14c0ece91c0c9dde840aae60c0118d6f5c9c52a",
  "spec_sha": "5b60af49df6edf722925a85d144f1118abda22485a820da2c516e97cab8347b8",
  "project_uri": "https://rubygems.org/gems/rails",
  "gem_uri": "https://rubygems.org/gems/rails-8.1.3.1.gem",
  "homepage_uri": "https://rubyonrails.org",
  "wiki_uri": null,
  "documentation_uri": "https://api.rubyonrails.org/v8.1.3.1/",
  "mailing_list_uri": "https://discuss.rubyonrails.org/c/rubyonrails-talk",
  "source_code_uri": "https://github.com/rails/rails/tree/v8.1.3.1",
  "bug_tracker_uri": "https://github.com/rails/rails/issues",
  "changelog_uri": "https://github.com/rails/rails/releases/tag/v8.1.3.1",
  "funding_uri": null,
  "dependencies": {

Parameters

ParameterTypeRequiredDescription
gems/<name>.jsonpathRequiredGem name. rails
versions/<name>.jsonpathOptionalAll published versions of a gem. rails
search.json?query=pathOptionalSearch gems by keyword. http

Response fields

namestring
Gem name.
versionstring
Current released version.
downloadsinteger
All-time download count.
version_downloadsinteger
Downloads of the current version only.
authorsstring
Gem authors as a single string.
licensesarray
Licence identifiers.
source_code_uri / homepage_uristring
Repository and homepage links, often null.
dependenciesobject
Runtime and development dependencies.

What you can build with the RubyGems API

  • Display the current version of a gem in documentation or a badge
  • Check whether a dependency has a newer release
  • Audit gem licences for compliance
  • Compare adoption between gems using download counts

Common errors and how to fix them

404

Gem name not found.

Fix: Gem names are case-sensitive and use hyphens or underscores exactly as published.

null source_code_uri

Not every gem declares its repository.

Fix: Fall back to homepage_uri, then to the RubyGems page itself.

RubyGems API — frequently asked questions

Is the RubyGems API free?

Yes, reads require no API key. An API key is only needed to publish or yank gems.

How do I get the latest version of a gem?

Request /api/v1/gems/<name>.json and read the `version` field, which always reflects the current release.

What is the difference between downloads and version_downloads?

`downloads` is all-time across every version; `version_downloads` counts only the current version, which is a better signal of whether a recent release has been adopted.

Can I see a gem's dependencies?

Yes, the `dependencies` object separates runtime from development dependencies, each with version requirements.

Tools that pair with this API

JSON Formatter

Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.

JSON Validator

Free online JSON validator: validate JSON and find syntax errors with the exact line and column. See root type, key counts and depth — instant and 100% private.

RubyGems is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 2026-08-19; always check the official documentation before relying on this API in production, as terms and limits can change.