Endpoints

All endpoints are GET (plus HEAD/OPTIONS), return JSON, and live under https://meta-api.leaguetoolkit.dev/v1. A trailing slash is tolerated on any route. Errors come back as JSON too - 404 responses include a hint and a pointer back to /v1. Class names and domain ids are exact and case-sensitive; hashes are accepted in any spelling (see Names and hashes).

Discovery

Endpoint	Returns
`/v1`	API metadata: the dataset window (first and latest tracked patch/build), class and patch counts, hash format, the PBE `preview` if there is one, and a map of every endpoint. Start here.
`/v1/openapi`	The OpenAPI 3.1 document describing every endpoint and schema - point a Swagger or Redoc viewer at it.

Classes

Endpoint	Returns
`/v1/classes`	The full class list: `{ count, classes: [name, …] }`. Unnamed classes appear as canonical hashes.
`/v1/classes?domain={id}`	The same list narrowed to the classes placed in one domain. Ids come from `/v1/categories`; an unknown id is a `404`.
`/v1/classes/{name-or-hash}`	One class: hash, `interface`/`value` flags, `kind`, `category`, bases, lifetime, ancestor/descendant trees, and its own properties with types, defaults, and history.
`/v1/classes/{name-or-hash}?inherited=1`	The same class in the precomputed flattened view: properties from all ancestors merged in, each stamped with a `from` field.
`/v1/categories`	The domains classes are grouped into, in display order: `{ count, domains: [{ id, title, description, unreleased, counts }] }`.

Class shape

curl https://meta-api.leaguetoolkit.dev/v1/classes/VfxEmitterDefinitionData

{
  "name": "VfxEmitterDefinitionData",
  "hash": "0x09cde442",
  "interface": false,
  "value": true,
  "kind": "value",
  "category": { "domain": "vfx", "via": "prefix", "family": "VfxEmitterDefinitionData" },
  "bases": [],
  "since": null,
  "removedIn": null,
  "properties": [
    {
      "name": "primitive",
      "hash": "0x007b14f6",
      "ft": "Pointer",
      "kt": null,
      "vt": null,
      "kh": "0x60c24094",
      "khName": null,
      "khKind": "class",
      "defaultValue": "{}"
    }
  ],
  "ancestorLevels": [],
  "descendantTree": []
}

Property type fields are the tuple the wiki renders: ft (field type), kt / vt (aux key/value types for containers and maps, null when not applicable), and the link target resolved three ways:

kh - the canonical hash of the referenced type, or null when the property links nothing.
khName - the resolved name, or null when unknown.
khKind - what the hash is: "class" (fetchable via /v1/classes/{kh}), "external" (an engine type outside the dumped class set), or "unknown".

Properties whose type changed over time carry a history array of the same tuple with since/until patch bounds.

Dataset window: tracking begins at the dataset.firstPatch reported by /v1 (currently patch 13.15). since: null means already present when tracking began, not “has always existed”; since: "14.1" means the class or property first appeared in that patch.

Inheritance: by default properties lists only the class’s own properties, with the full ancestry in ancestorLevels (nearest level first) and subclasses in descendantTree. With ?inherited=1, properties from all ancestors are merged in (the nearest definition wins on a name conflict) and every property gains a from field naming the class that defines it.

Category: every class sits in exactly one domain. category.domain is an id from /v1/categories, category.via is the rule that placed the class (pin, seed, prefix, usage, shared, or none), and category.family is the root of its primary base chain. A class used from several domains has the domain shared and lists them in usedByDomains; a class no rule claims has the domain uncategorized. kind is the two flags as one value: interface, value, or class. Placement is derived at build time, so it can change between dataset generations without the class changing.

PBE preview

Every response is live data unless the request says otherwise. While PBE is on a patch that live has not reached, the API also describes the newest PBE build, compared with the latest live build. /v1 reports it as preview:

{ "channel": "pbe", "patch": "16.21", "build": 8255794, "base": 8230722, "basePatch": "16.19", "classes": 236 }

preview is null if PBE and live are on the same patch. base is the live build that the PBE build is compared with, and classes counts the classes whose PBE response differs from the live one.

Endpoint	Returns
`/v1/classes/{name-or-hash}?channel=pbe`	The class as of the PBE build, in the same shape. A class that PBE adds has `since` set to the PBE patch; one that PBE removes has `removedIn` set to it. A class that PBE leaves alone returns the live response. Combines with `inherited=1`.
`/v1/classes?channel=pbe`	The class list with the PBE-only classes included.
`/v1/changelog/pbe`	What the PBE build changes against `base`, in the shape of a patch changelog, plus a `preview` object. A `404` if there is no preview.
`/v1/db/pbe`	The raw PBE overlay: the entries of `/v1/db` that differ as of the PBE build. Always present; `build` is `null` if there is no preview.

/v1/versions, /v1/hashes and /v1/changelog carry the same preview object, or null. In /v1/hashes it also lists the hashes that exist on PBE only. The PBE build is never part of the versions array, and its number can be lower than the number of a live build: order builds by channel, not by number.

A PBE build is replaced by the next one and is not promoted as is, so treat a PBE response as a preview of the next patch, not as a release. Without a preview, channel=pbe returns the live response. Any other channel value than live or pbe is a 400.

Lookup tables

Endpoint	Returns
`/v1/hashes`	Canonical hash → resolved name for every class (`null` = unnamed) and external type. Use it to translate hashes and names in bulk.
`/v1/index`	Class name → absolute wiki page URL, for linking back to the site.
`/v1/versions`	The full patch ↔ build-number map, for translating the raw `build` numbers that appear in changelog entries and `/v1/db`.

Changelogs

Endpoint	Returns
`/v1/changelog`	Patch index, newest first, with per-patch change counts.
`/v1/changelog/{slug}`	Full changelog for one patch: classes and properties added, removed, or changed. The slug is the patch with a hyphen - `16-13` for patch 16.13.

Bulk download

Endpoint	Returns
`/v1/db`	The complete raw meta database in one download (~3.5 MB, ~700 KB compressed). Unpadded hashes, per-build revisions. Live builds only. Prefer the per-class endpoints unless you genuinely need everything.

Documentation

The endpoints above serve structural facts extracted from the game. Documentation endpoints add the community-written prose on top - fetch the facts for a class, then merge the prose in by property name.

Endpoint	Returns
`/v1/docs`	Which classes have written documentation: `{ count, classes: [name, …] }`.
`/v1/docs/{name-or-hash}`	The prose for one class: `{ name, class: {…}, properties: { propName: {…} } }`, where each entry holds `description`, `notes`, and `examples`.
`/v1/docs/all`	Every documented class’s prose in one download - for tools bundling a documentation snapshot.

curl https://meta-api.leaguetoolkit.dev/v1/docs/AbilityObject

{
  "name": "AbilityObject",
  "class": null,
  "properties": {
    "AbilityTraits": {
      "description": "Gameplay-behavior tags for the ability…",
      "notes": ["Stored as a 4-byte (`U32`) bitmask."]
    }
  }
}

Prose also updates on a different cadence than facts: facts change only when a game patch is ingested, while prose changes whenever a documentation PR is merged. Note that /v1/docs* is the only surface serving licensed human-authored content - see Licensing if you redistribute it.