# Account State > Account state and in-memory event store patterns in Amethyst. Use when working with `Account.kt` (per-user state objects — `kind3FollowList`, `nip65RelayList`, `muteList`, `bookmarkState`, each exposing a `.flow` StateFlow), `LocalCache` (the object-level event store backed by `LargeCache`), `User`/`Note` model classes, or any ViewModel that reads user-specific state. Covers how account events cascade from relay arrival to UI state, how to add a new account-scoped setting, and when to read from `LocalCache` vs subscribe to a StateFlow. - Skill: `vitorpamplona/account-state` (Agent Skill, multi-file: 3 files) - Install (CLI): `npx skillmds@latest add vitorpamplona/account-state` - Raw SKILL.md: https://api.skillmd.com/api/skills/vitorpamplona/account-state/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: vitorpamplona (https://skillmd.com/u/vitorpamplona) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/vitorpamplona/account-state --- # Account & Local Cache State The backbone of Amethyst's client state: one `Account` per signed-in user, plus the singleton `LocalCache` that holds every `Note` and `User` the client has seen. ## When to Use This Skill - Working on `amethyst/src/main/java/com/vitorpamplona/amethyst/model/Account.kt` - Working on `amethyst/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt` - Adding a new account-scoped setting (mutes, bookmarks, custom relay lists, private lists) - Reading/writing user metadata (`User`) or note state (`Note`) - Deciding whether to query `LocalCache` vs subscribe to an `Account` StateFlow ## Mental Model ``` Relay frame ──► LocalCache.insertOrUpdateNote() ──► LocalCacheFlow emits change │ ▼ Account state objects pin the relevant addressable notes │ ▼ State-object `.flow` updates (kind3FollowList, nip65RelayList, muteList, …) │ ▼ ViewModels collect │ ▼ Composables render ``` `LocalCache` is the event store. `Account` is the *derived* per-user view (follow list, relays, mutes, emojis, bookmarks, etc.). UI listens to the `.flow` of `Account`'s state objects, not directly to `LocalCache`, except for note-level rendering. ## Key Files ### `Account.kt` (singleton-per-session) - `class Account(...)` — holds 50+ **state objects**, one per feature, each wired to a specific Nostr kind: - `kind3FollowList = Kind3FollowListState(...)` ← NIP-02 ContactList (kind 3) - `nip65RelayList = Nip65RelayListState(...)` ← NIP-65 RelayList (kind 10002), plus siblings `dmRelayList`, `searchRelayList`, `blockedRelayList`, `trustedRelayList`, `proxyRelayList`, `broadcastRelayList`, `indexerRelayList`, … - `muteList = MuteListState(...)` ← NIP-51 MuteList (kind 10000) - `bookmarkState = BookmarkListState(...)` ← NIP-51 Bookmarks (kind 10003), plus `labeledBookmarkLists`, `pinState`, `interestSets`, `peopleLists`, `followLists`, `hashtagList`, `geohashList`, `communityList`, `emoji`, `blossomServers`, … - Derived/merged views: `hiddenUsers`, `allFollows`, `homeRelays`, `outboxRelays`, `dmRelays`, `notificationRelays`, `trustedRelays`, and the `live*FollowListsPerRelay` outbox loaders. - **The pattern:** each `XState` class pins its addressable note via `cache.getOrCreateAddressableNote(address)` (a long-term reference so GC/eviction can't drop it), exposes `val flow: StateFlow<…>` derived from the note's metadata flow (decrypted through a per-feature `DecryptionCache`, with backup fallback from `AccountSettings`, `stateIn(scope, Eagerly, …)`), and offers suspend mutation helpers (e.g. `MuteListState.hideUser(pubkey)`) that build the updated signed event. Consumers read `account.muteList.flow`, never a raw `MutableStateFlow` on `Account`. - Encrypted lists pair the state object with a `DecryptionCache` sibling (`muteListDecryptionCache`, `peopleListDecryptionCache`, …) so NIP-44 decryption results are cached per event. - UI reads via `collectAsStateWithLifecycle` on Android and `collectAsState` on Desktop. - Sibling files per feature live alongside: `AccountSettings.kt`, `AccountSyncedSettings.kt`, plus per-NIP state classes under `model/nip02FollowLists/`, `model/nip51Lists/`, `model/nip65RelayList/`, etc. ### `LocalCache.kt` - `object LocalCache : ILocalCache, ICacheProvider` — the singleton event store. - Primary structures (all `LargeCache` — see `nostr-expert/references/large-cache.md`): - `notes: LargeCache` — every seen event (regular + addressable + replaceable) keyed by id or d-address. - `users: LargeCache` — every seen pubkey, lazily populated. - `addressables: LargeCache` — secondary index for `kind:pubkey:d-tag` lookups. - `channels`, `deletionIndex`, `hashtagIndex`, … - `LocalCacheFlow` emits coarse-grained "something changed, recheck" signals. Fine-grained reactivity lives in `Account`'s per-kind StateFlows. - Eviction is driven by `MemoryTrimmingService` (android service) under pressure. ### Model classes - `User.kt` — mutable profile holder. Contains metadata, follow/follower counts, relay lists, liveset of notes authored. - `Note.kt` — mutable note holder. Contains the underlying `Event`, replies, reactions, zaps. Mutation via `addReply`, `addReaction`, `addZap`, emitted on `Note.flowSet` flows. - `Constants.kt` — DEFAULT_RELAYS, magic kinds/limits not covered by quartz. ## Adding a New Account-Scoped Setting Typical recipe: 1. If the setting is persisted as a Nostr event, pick the right kind (e.g. NIP-51 list, NIP-78 app-specific data, NIP-65 relay list). 2. Add a model folder under `amethyst/.../model/nipXX…/` with an `XState` class modeled on an existing one (`MuteListState` for an encrypted list, `BookmarkListState` for a plain one): - Pin the addressable note: `val xNote = cache.getOrCreateAddressableNote(XEvent.createAddress(signer.pubKey))`. - Expose `val flow: StateFlow<…>` mapped from `xNote.flow().metadata.stateFlow`, decrypting through a per-feature `DecryptionCache` if the list is private, with backup fallback from `AccountSettings`, then `stateIn(scope, Eagerly, default)`. - Add suspend mutation helpers that build the updated event via the quartz event class (`XEvent.add/remove/create`) and return it signed. 3. In `Account.kt`, instantiate the state object (and its `DecryptionCache` sibling if encrypted) as a `val`. Publishing the returned event goes through `Account`'s send path; the relay subscription side is the relayClient pattern (see `relay-client` skill). 4. Add UI that `collect`s `account.x.flow`. Settings screens live in `amethyst/.../ui/screen/loggedIn/settings/`. ## `LocalCache` vs `Account` Flow — Which to Read? - **Are you rendering a specific note / user you hold an id for?** → `LocalCache.getOrCreateNote(id)` + collect `note.flowSet.metadata`. - **Are you rendering "my follows", "my mutes", "my relays"?** → `account..flow` (e.g. `account.kind3FollowList.flow`, `account.muteList.flow`, `account.nip65RelayList.flow`). - **Are you rendering a feed?** → Use a `FeedFilter` + `FeedViewModel` (see `feed-patterns` skill). Don't scan `LocalCache` in a composable. ## Gotchas - **`LocalCache` is a singleton across accounts.** Switching accounts doesn't wipe it — `Account` re-derives its flows from the same cache. - **Don't store Flows inside `Note` / `User`** expecting them to survive eviction. Eviction drops the whole object. - **State-object mutation helpers return a signed event — publishing it is the caller's job.** A locally updated list without a publish means other clients won't see it. - **`Note` is mutable** — treat instances as identity-based (same id → same Note). Use `.flowSet` when you need reactive state. - **`MemoryTrimmingService` can evict aggressively** on Android under pressure. Don't assume a previously-seen note is still resident. ## References - `references/account-state-flow.md` — catalog of major `Account` state objects and their source kinds. - `references/local-cache.md` — `LocalCache` internals, insertion path, indexes. - Complements: `nostr-expert` (event parsing), `relay-client` (subscription wiring), `feed-patterns` (how feeds consume this state), `auth-signers` (how mutation signs events).