The API is available at api.hearthstonejson.com/v1/
The files are all in JSON format, encoded in UTF-8 and categorized by build, then by locale.
The /v1/latest/ endpoint redirects (302) to whichever build is the latest one.
All files are automatically converted from the game files, made available in the hs-data repository.
Card objects
Example card:

{
	"id": "EX1_116",
	"dbfId": 559,
	"name": "Leeroy Jenkins",
	"text": "<b>Charge</b>. <b>Battlecry:</b> Summon two 1/1 Whelps for your opponent.",
	"flavor": "At least he has Angry Chicken.",
	"artist": "Gabe from Penny Arcade",
	"attack": 6,
	"cardClass": "NEUTRAL",
	"collectible": true,
	"cost": 5,
	"elite": true,
	"faction": "ALLIANCE",
	"health": 2,
	"mechanics": [
		"BATTLECRY",
		"CHARGE"
	],
	"rarity": "LEGENDARY",
	"set": "EXPERT1",
	"type": "MINION"
}Card art
See full card art and render documentation
Changelog
2018-06-27
The card art and render API is now officially available!
Patch 7.1.0.17720:
- playerClasshas been renamed- cardClass. Both properties are still available, but the former will be removed in an upcoming patch.
- The cardback API is no longer supported, as almost nobody was using it.
- Support for the dustproperty has been dropped as it is not reliable.
- New property: referencedTags. This works exactly likemechanics, except that it contains tags which are referenced rather than directly set on the card (for example: Mad Scientist referencesSECRET).
- TREASUREhas been renamed to- DISCOVER.
- New property: hideStats(boolean)
Patch 7.0.0.15590:
The game files have greatly changed for the Gadgetzan patch. Some of the data may have changed in unexpected ways.
- New property: multiClassGroup. Currently, this can beGRIMY_GOONS,JADE_LOTUSorKABAL.
- New property: classes. This is a list of classes, which is only included when the card is available for multiple classes. Note that theplayerClassis usuallyNEUTRALfor multi-class cards.
- New property: collectionText. Some cards, most notably Jade Golem cards, have multiple card texts: A generic one (for the collection) and a formatted version, with{}placeholders. ThecollectionTextproperty is the generic version of the description.
- The textInPlayproperty is no longer supported as it is no longer used.
Changes since legacy API
- Website:
    - New website style and theme!
- API now has its own subdomain and is served with HTTPS
- API is now versioned (/v1/)
- Separate output for each build. /v1/latest/ will always give you the latest build.
- Locales are now generated into their own directory
- Zip support has been removed in favour of server compression
 
- Cards:
    - CardSet separation has been removed as it was largely unused
- Tags are not localized anymore (mostly this just means uppercased)
- Created separate “collectible” set
- Added individual setandtargetingArrowTextproperties
- Added some more mechanics (forgetful, treasure…)
- Added entourageproperty
- Added playRequirementsproperty
- Added dustproperty
 
- Card backs:
    - Added more properties from the DBF
 
Support
HearthstoneJSON is a HearthSim project and is available on GitHub.