Hackage Haskell Package Scraper

Scrape Haskell package metadata from Hackage (hackage.haskell.org) — the central package archive for the Haskell ecosystem. Extract package synopses, descriptions, authors, licenses, categories, build dependencies, and more. No API key required.

What does it do?

• Search packages by name or keyword — find all Haskell packages matching "parser", "aeson", "lens", etc.
• Fetch by name — retrieve full metadata for specific known packages including version history and cabal file details

Input

Field	Type	Description
mode	select	searchPackages or getByName
searchQuery	string	Keyword to filter packages (for searchPackages mode)
packageNames	array	Exact package names to fetch (for getByName mode)
maxItems	integer	Max results (1–1000, default 50)

Example inputs

Search for JSON-related packages:

{
  "mode": "searchPackages",
  "searchQuery": "json",
  "maxItems": 20
}

Fetch specific packages:

{
  "mode": "getByName",
  "packageNames": ["aeson", "parsec", "megaparsec", "text"],
  "maxItems": 10
}

Output

Each record contains:

Field	Description
packageName	Hackage package name
version	Latest stable version
synopsis	Short one-line description
description	Full package description (trimmed to 1000 chars)
author	Package author(s)
maintainer	Current maintainer with email
license	License type (e.g. BSD-3-Clause, MIT)
homepage	Project homepage URL
bugReports	Issue tracker URL
category	Hackage category tags
buildDepends	Build dependencies (list of package names)
deprecated	Whether this package is deprecated
hackageUrl	Hackage package page URL
sourceUrl	Same as hackageUrl
recordType	Always "package"
scrapedAt	ISO 8601 timestamp

Example output record

{
  "packageName": "aeson",
  "version": "2.2.3.0",
  "synopsis": "Fast JSON parsing and encoding",
  "description": "A JSON parsing and encoding library optimized for ease of use and high performance...",
  "author": "Bryan O'Sullivan",
  "maintainer": "Adam Bergmark <adam@bergmark.nl>",
  "license": "BSD-3-Clause",
  "homepage": "https://github.com/haskell/aeson",
  "bugReports": "https://github.com/haskell/aeson/issues",
  "category": "Text, Web, JSON",
  "buildDepends": ["base", "bytestring", "containers", "text", "time"],
  "deprecated": false,
  "hackageUrl": "https://hackage.haskell.org/package/aeson",
  "sourceUrl": "https://hackage.haskell.org/package/aeson",
  "recordType": "package",
  "scrapedAt": "2025-01-01T00:00:00+00:00"
}

FAQs

Do I need an API key? No. Hackage provides a fully public REST API with no authentication required.

How are packages found? The actor uses Hackage's /packages/search.json?terms=<query> endpoint to find relevant packages, then fetches each package's .cabal file for detailed metadata.

What is a cabal file? A .cabal file is the Haskell package manifest — it contains all metadata about a Haskell package including dependencies, licensing, and description.

What does deprecated mean? A package marked deprecated: true has been superseded by another package. The actor still scrapes its metadata but flags it clearly.

Can I search by category? The searchQuery field matches against package names in search results. Use queries like "parser", "web", "database", "crypto" to find packages in those domains.

How many packages are on Hackage? Hackage hosts over 15,000 Haskell packages. The searchPackages mode returns the most relevant matches for your query.