| name | lcu-api |
| description | League of Legends LCU (League Client Update) API reference. Use when working with LCU endpoints, champ select, skin selection, gameflow phases, ownership checks, lobby, matchmaking, store, collections, or any fetch/PATCH calls to the local client API. |
| allowed-tools | Read, Grep, Glob |
| argument-hint | ["endpoint or topic"] |
LCU API Reference
Complete reference for the League Client Update (LCU) local REST API. All schemas validated against the official swagger definition (dysolix/hasagi-types).
The LCU API is a local HTTPS REST API exposed by the League of Legends client on 127.0.0.1 with a random port. In CEF plugin context, use relative paths: fetch('/lol-champ-select/v1/session').
Supporting Files
- all-endpoints.md — Every LCU endpoint grouped by plugin (~1700 lines, 90+ plugins)
- schemas.md — All schema/type definitions with fields and types (~950 schemas)
- endpoints.md — Detailed docs for commonly used endpoints with example JSON
Use Read or Grep on these files to find specific endpoint or schema details.
Swagger Source
https://raw.githubusercontent.com/dysolix/hasagi-types/main/swagger.json
Key Conventions
- Skin IDs: Base/default skin =
championId * 1000. Example: Ahri (103) → base skin 103000.
- PATCH body field: Skin selection uses
selectedSkinId (NOT skinId). Confirmed across all schema variants.
- Ownership check:
s.ownership.owned === true for purchased. s.ownership.rental.rented === true for rented/boosted.
- Local player in session:
session.myTeam.find(p => p.cellId === session.localPlayerCellId)
- WebSocket events:
context.socket.observe(path, callback) where callback receives { eventType, uri, data }.
- Gameflow phases (lifecycle order):
None → Lobby → Matchmaking → ReadyCheck → ChampSelect → GameStart → InProgress → WaitingForStats → PreEndOfGame → EndOfGame
Plugin Index
Major LCU plugins and what they cover:
| Plugin prefix | Domain |
|---|
lol-champ-select | Champion select session, picks, bans, skin selection, swaps |
lol-champ-select-legacy | Legacy champ select (same structure, older endpoints) |
lol-champions | Champion/skin inventories, ownership data |
lol-game-data | Static game data (champion info, skin lists, items) |
lol-summoner | Current summoner info, profile |
lol-gameflow | Game lifecycle phases and session |
lol-matchmaking | Queue, ready check, search |
lol-lobby | Lobby management, invites, party |
lol-lobby-team-builder | Team builder / draft lobby |
lol-collections | Player collections (ward skins, spells, etc.) |
lol-catalog | Store catalog, items, bundles |
lol-store | Store operations, purchases |
lol-inventory | Player inventory (skins, champions, etc.) |
lol-loot | Hextech crafting, loot |
lol-chat | Chat, friends, conversations |
lol-ranked | Ranked stats, tiers, LP |
lol-perks | Runes/perks pages |
lol-loadouts | Item sets, loadouts |
lol-cosmetics | TFT cosmetics (companions, arenas, etc.) |
lol-clash | Clash tournaments |
lol-challenges | Challenges system |
lol-champion-mastery | Mastery points and levels |
lol-end-of-game | Post-game stats |
lol-event-hub | Events, passes, reward tracks |
lol-active-boosts | Active XP/skin boosts |
lol-patch | Client patching status |
lol-player-behavior | Honor, restrictions, reform cards |
lol-pre-end-of-game | Pre-end-of-game sequence |
lol-replays | Replay downloads and playback |
lol-settings | Client settings |
lol-suggested-players | Suggested players to play with |
lol-tft | TFT-specific endpoints |
Critical Schemas (Quick Ref)
PATCH /lol-champ-select/v1/session/my-selection body
Schema: TeamBuilderDirect-ChampSelectMySelection
{
"selectedSkinId": 0,
"spell1Id": 0,
"spell2Id": 0
}
Champ select player (in session.myTeam[])
Schema: TeamBuilderDirect-ChampSelectPlayerSelection
Key fields: cellId (int64), championId (int32), selectedSkinId (int32), summonerId (uint64), assignedPosition (string), spell1Id, spell2Id, gameName, tagLine, puuid
Skin object (from inventories endpoint)
Schema: LolChampionsCollectionsChampionSkin
Key fields: id (int32), championId (int32), name (string), isBase (boolean), ownership → { owned, rental: { rented } }, chromas[], splashPath, tilePath
Ownership
Schema: LolChampionsCollectionsOwnership
Fields: owned (boolean), loyaltyReward (boolean), xboxGPReward (boolean), rental → { rented, endDate, purchaseDate, winCountRemaining, gameId }
Summoner
Schema: LolSummonerSummoner
Key fields: summonerId (uint64), accountId (uint64), puuid (string), gameName (string), tagLine (string), displayName, summonerLevel, profileIconId
Gameflow phase
Schema: LolGameflowGameflowPhase (enum string)
Values: None, Lobby, Matchmaking, CheckedIntoTournament, ReadyCheck, ChampSelect, GameStart, FailedToLaunch, InProgress, Reconnect, WaitingForStats, PreEndOfGame, EndOfGame, TerminatedInError
