Card

One record per card as a game piece; reprints share one record.

A card is the game piece: its rules, cost and stats. Reprints share one record. Gameplay data lives here and applies to every printing of the card.

Where it appears

registry.json → cards[]
cards/{codex_id}.json, which adds printings, name_history and card_history
index/cards.json, a subset of the fields

Fields

Every field is present on every record; a value that does not apply is null, never missing. Types are from the release's schema; the schema itself is the contract.

Field	Type	Meaning
`codex_id`	codex ID, C plus six digits	The card's permanent ID.
`name`	string	The current name. Earlier names are in name_history.
`type`	string or null	Observed values: Artifact, Aura, Avatar, Magic, Minion, Site.
`category`	string or null	Coarser grouping: Spell (Minion, Magic, Artifact, Aura), Site, Avatar, Token.
`rarity`	string or null	The rarity printed on the card. Observed values: Ordinary, Exceptional, Elite, Unique; null on Avatars and some tokens.
`slot`	string or null	The rarity slot the card is distributed in. Agrees with rarity except for Avatars (no printed rarity) and tokens.
`subtypes`	array of string	In upstream's order, e.g. ["Beast", "Spirit"].
`elements`	array of string	In upstream's order. ["None"] means colourless (Artifacts, Avatars, most Sites).
`keywords`	array of string	Ability keywords the card carries (Airborne, Genesis, Spellcaster, ...), as upstream tags them.
`umbrellas`	array of string	Cross-subtype groupings rules text refers to (Evil, Knight, Royalty).
`cost`	integer or null	Mana cost. null for Sites and Avatars, and for X costs.
`attack`	integer or null	Printed attack; null when the card has none.
`defense`	integer or null	Printed defense; null when the card has none.
`power`	integer or null	Derived: Sorcery's power - equal to attack when attack equals defense, otherwise floor((attack + defense) / 2); null when either is null. Published so every consumer computes the same number.
`life`	integer or null	Only Avatars have a life value.
`thr_air`	integer, 0 or more	Air threshold: the number of Air the card needs in play to be cast. 0 when none.
`thr_earth`	integer, 0 or more	Earth threshold. 0 when none.
`thr_fire`	integer, 0 or more	Fire threshold. 0 when none.
`thr_water`	integer, 0 or more	Water threshold. 0 when none.
`rules_text`	string	Current text the card plays by, applying to every printing. Canonicalised: \n line endings, no trailing whitespace, one line per ability. Changes are recorded in rules_history.
`back`	face object: the gameplay fields of a card (see Card) or null	The back face of a double-faced card; null for every other card. The card's own fields are its front.
`errata`	boolean	Registry-owned: true once any gameplay field of the card (type, elements, cost, attack, defense, life, thresholds, rules_text, back) has changed since it was printed. Seeded from the old upstream UPDATED: marker; set whenever a sync observes such a change (see card_history); corrected only through data/overrides.json. Rarity, slot, subtypes, keywords and umbrellas are classification, so a change to them is not errata.
`set_codes`	array of set code: three digits, or three letters for the registry's own	Derived, sorted: the sets this card appears in. For products and finishes, follow printing_ids.
`printing_ids`	array of printing ID, P plus six digits	Derived, sorted, and it only ever grows.
`default_printing_id`	printing ID, P plus six digits or null	Derived: the representative printing, by a fixed rule so every consumer picks the same one - not retired, showing the card's current face (printed_as_current) over older values, Booster over other products, Standard over other finishes, most recently released, lowest id. A reprint that changed the card's stats therefore becomes the default even when it is a promo; otherwise a promo never outranks a Booster printing. A registry maintainer can pin a different printing through data/overrides.json, with a reason. null only for a card with no printings.
`api_url`	string	Derived: this card's JSON object on api.kairosarchive.net, under the moving major alias (/v3/ always redirects to the newest verified v3.x release), so the address leads to the current record from any copy.
`kairos_url`	string	Derived: this card's page on kairosarchive.net.
`image_urls`	object: small, normal, large, original or null	Derived: the image of the card's default_printing_id (its front face), null while that printing has no image.
`image_status`	"missing", "lowres" or "ok"	Derived: the default printing's image_status.
`origin`	"api" or "manual"	—
`manual`	object: source, recorded, confirmed_at, withdrawn or null	—
`notes`	array of object: text, source, recorded	What the registry knows about this card that the official API does not say, oldest first. Empty for most records.

Example

Card · from release v3.4.0

{
  "codex_id": "C000139",
  "name": "Askelon Phoenix",
  "type": "Minion",
  "category": "Spell",
  "rarity": "Elite",
  "slot": "Elite",
  "subtypes": [
    "Beast"
  ],
  "elements": [
    "Fire"
  ],
  "keywords": [
    "Airborne"
  ],
  "umbrellas": [],
  "cost": 5,
  "attack": 4,
  "defense": 4,
  "power": 4,
  "life": null,
  "thr_air": 0,
  "thr_earth": 0,
  "thr_fire": 2,
  "thr_water": 0,
  "rules_text": "Airborne\nIf Askelon Phoenix would take fire damage, it gains +1 power this turn instead.",
  "back": null,
  "errata": true,
  "set_codes": [
    "001",
    "002"
  ],
  "printing_ids": [
    "P000569",
    "P000570",
    "P000571",
    "P000572"
  ],
  "default_printing_id": "P000571",
  "api_url": "https://api.kairosarchive.net/v3/cards/C000139.json",
  "kairos_url": "https://kairosarchive.net/cards/C000139",
  "image_urls": {
    "small": "https://api.kairosarchive.net/images/P000571.806b0ecb6963.small.webp",
    "normal": "https://api.kairosarchive.net/images/P000571.806b0ecb6963.normal.webp",
    "large": "https://api.kairosarchive.net/images/P000571.806b0ecb6963.large.webp",
    "original": "https://api.kairosarchive.net/images/P000571.806b0ecb6963.original.png"
  },
  "image_status": "lowres",
  "origin": "api",
  "manual": null,
  "notes": []
}

Reference: registry API contract and published object definitions. Report a data or documentation issue.