generated: '2026-07-20'
method: searched
source: https://docs.joinplayroom.com/api-reference/js
summary: >-
  Cross-cutting semantics for the Playroom Kit client SDK (not a REST API).
  State is a synchronized key/value store; multiplayer logic runs peer-side with
  an elected host; cross-client calls use RPCs.
authentication:
  style: gameId application identifier (see authentication/playroom-authentication.yml)
state_model:
  global_state:
    setter: setState(key, value, reliable)
    getter: getState(key)
    reset: resetStates() / resetPlayersStates()
    react_hook: useMultiplayerState(key, default)
    reliability: >-
      setState accepts a reliable flag; unreliable updates are lower-latency for
      high-frequency values (e.g. positions), reliable ensures delivery/order.
  player_state:
    accessor: myPlayer() / PlayerState
    react_hooks: [usePlayerState, usePlayersState, usePlayersList]
    persistence: >-
      Player state can be preserved across leave/rejoin (since v0.0.94) and
      persisted per the persistence feature.
host_model:
  election: one client is the authoritative host
  checks: isHost() / useIsHost()
  transfer: transferHost()
  guidance: >-
    Run authoritative game logic behind isHost() so it executes once; other
    clients receive results via synced state.
rpc:
  register: RPC.register(name, handler)
  call: RPC.call(name, data, mode)
  purpose: request/response and broadcast calls between connected players.
lifecycle_hooks:
  join: onPlayerJoin(callback)
  disconnect: onDisconnect(callback)
  async_helpers: [waitForState, waitForPlayerState]
matchmaking:
  api: startMatchmaking(MatchmakingOptions)
  rooms: getRoomCode() returns the 4-letter room code
idempotency:
  supported: false
  note: >-
    No idempotency-key contract; state is last-write-wins on a key, and RPCs are
    fire-and-forward. No Idempotency pointer is emitted.
versioning:
  ref: lifecycle/playroom-lifecycle.yml
errors:
  ref: errors/playroom-error-codes.yml
rate_limiting:
  model: >-
    Usage is metered by Monthly Active Users (MAU) rather than per-request rate
    limits; see billing (Pricing).