CTAN API

Base URL

https://ctan.org/json/2.0

Authentication

No key or account. Please use a mirror for bulk downloads rather than hammering the main site.

Rate limit

Not published. Package metadata changes rarely, so cache per package id.

Pricing

Free.

CORS

Not enabled — call it from your server

Official docs

Read the docs

Every request below was executed against the live API on 21 Aug 2026, and the response shown is the real body it returned — not an illustration.

curl 'https://ctan.org/json/2.0/pkg/graphicx'

const res = await fetch("https://ctan.org/json/2.0/pkg/graphicx");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get("https://ctan.org/json/2.0/pkg/graphicx", timeout=20)
res.raise_for_status()
print(res.json())

{
  "id": "graphicx",
  "name": "graphicx",
  "aliases": [],
  "caption": "Enhanced support for graphics",
  "authors": [
    {
      "id": "latex",
      "active": true
    },
    {
      "id": "carlisle",
      "active": true
    }
  ],
  "copyright": [
    {
      "owner": "David Carlisle, Sebastian Rahtz",
      "year": "1994"
    },
    {
      "owner": "David Carlisle, LaTeX3 Project",
      "year": "1995-2021"
    }
  ],
  "license": "lppl1.3c",
  "version": {
    "number": "1.2e",
    "date": "2026-05-17"
  },
  "descriptions": [
    {
      "language": null,
      "text": "<p>\n      The package builds upon the <ref refid=\"graphics\">graphics</ref>\n      package, providing a key-value interface for optional arguments\n      to the <tt>\\includegraphics</tt> command. This interface provides\n      facilities that go far beyond what the\n      <ref refid=\"graphics\">graphics</ref> package offers on its own.\n    </p>\n  <p>\n      For extended documentation, see\n      <ref refid=\"epslatex\">epslatex</ref>.\n    </p>\n  <p>\n      The package is part of the\n      <ref refid=\"latex-graphics\">latex-graphics</ref> bundle,\n      which is one of the collections in the\n      <ref refid=\"required\">LaTeX <q>required</q>\n    </ref>\n      set of packages.\n    </p>"
    }
  ],
  "documentation": [
    {
      "language": "en",
      "details": "Guide to graphics in LaTeX (English)",
      "href": "ctan:/macros/latex/required/graphics/grfguide.pdf"
    },
    {
      "language": "it",
      "details": "Guide to graphics in LaTeX (Italian)",
      "href": "ctan:/inf

id / namestring

Package identifier and display name. The id is what you pass to other endpoints.

captionstring

One-line description, safe to display as-is. This is the plain-text field; `descriptions` is not.

authorsarray

Author references as `{id, active}`. Only the id is present, so resolve it against the author endpoint to get a name.

copyrightarray

Copyright statements as `{owner, year}` pairs. `year` is a string and may be a range such as `1995-2021`.

licensestring

Licence key in CTAN's own vocabulary, such as `lppl1.3c`. Not an SPDX identifier.

versionobject

`number` and `date` of the current release. The date is an ISO date string.

descriptionsarray

Long descriptions in CTAN's XML-flavoured markup, including `<ref refid="...">` cross-references. Transform before rendering; do not print raw.

documentationarray

Documentation links as `{language, details, href}`. Hrefs often use a `ctan:/` pseudo-scheme that must be resolved against a mirror.

• Build a searchable LaTeX package browser or documentation portal
• Check the licence of every package a thesis template depends on
• Resolve `\usepackage` names to authors and documentation links inside an editor plugin
• Detect unmaintained packages by inspecting version dates and author `active` flags
• Construct a dependency or cross-reference graph from the `refid` links in descriptions

If CTAN does not fit, these developer & testing apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.