move labeler cache to mmkv, make moderation config sync

The per-account labeler cache was the only async dependency in
configureModerationForAccount. MMKV-backed sync reads let session
setup apply labelers in the same tick. No AsyncStorage backfill: the
cache is rewritten on every preferences fetch.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/state/queries/preferences/index.ts

@@ -21,7 +21,7 @@ import {
 } from '#/state/queries/preferences/types'
 import {createQueryKey} from '#/state/queries/util'
 import {useAgent} from '#/state/session'
-import {saveLabelers} from '#/state/session/agent-config'
+import {saveLabelers} from '#/state/session/moderation'
 import {useAgeAssurance} from '#/ageAssurance'
 import {makeAgeRestrictedModerationPrefs} from '#/ageAssurance/util'
 import {useAnalytics} from '#/analytics'
@@ -53,7 +53,7 @@ export function usePreferencesQuery() {
         const res = await agent.getPreferences()
 
         // save to local storage to ensure there are labels on initial requests
-        void saveLabelers(
+        saveLabelers(
           agent.did,
           res.moderationPrefs.labelers.map(l => l.did),
         )

src/state/session/agent-config.ts

@@ -1,12 +0,0 @@
-import AsyncStorage from '@react-native-async-storage/async-storage'
-
-const PREFIX = 'agent-labelers'
-
-export async function saveLabelers(did: string, value: string[]) {
-  await AsyncStorage.setItem(`${PREFIX}:${did}`, JSON.stringify(value))
-}
-
-export async function readLabelers(did: string): Promise<string[] | undefined> {
-  const rawData = await AsyncStorage.getItem(`${PREFIX}:${did}`)
-  return rawData ? JSON.parse(rawData) : undefined
-}

src/state/session/agent.ts

@@ -64,7 +64,7 @@ export async function createAgentAndResume(
   const gates = features.refresh({
     strategy: 'prefer-low-latency',
   })
-  const moderation = configureModerationForAccount(agent, storedAccount)
+  configureModerationForAccount(agent, storedAccount)
   const prevSession: AtpSessionData = sessionAccountToSession(storedAccount)
   if (isSessionExpired(storedAccount)) {
     await networkRetry(1, () => agent.resumeSession(prevSession))
@@ -78,7 +78,7 @@ export async function createAgentAndResume(
   agent.configureProxy(BLUESKY_PROXY_HEADER.get())
 
   return agent.prepare({
-    resolvers: [gates, moderation, aa],
+    resolvers: [gates, aa],
     onSessionChange,
   })
 }
@@ -111,13 +111,13 @@ export async function createAgentAndLogin(
 
   const account = agentToSessionAccountOrThrow(agent)
   const gates = features.refresh({strategy: 'prefer-fresh-gates'})
-  const moderation = configureModerationForAccount(agent, account)
+  configureModerationForAccount(agent, account)
   const aa = prefetchAgeAssuranceServerData({agent})
 
   agent.configureProxy(BLUESKY_PROXY_HEADER.get())
 
   return agent.prepare({
-    resolvers: [gates, moderation, aa],
+    resolvers: [gates, aa],
     onSessionChange,
   })
 }
@@ -159,7 +159,7 @@ export async function createAgentAndCreateAccount(
   })
   const account = agentToSessionAccountOrThrow(agent)
   const gates = features.refresh({strategy: 'prefer-fresh-gates'})
-  const moderation = configureModerationForAccount(agent, account)
+  configureModerationForAccount(agent, account)
 
   const createdAt = new Date().toISOString()
   const birthdate = birthDate.toISOString()
@@ -277,7 +277,7 @@ export async function createAgentAndCreateAccount(
   agent.configureProxy(BLUESKY_PROXY_HEADER.get())
 
   return agent.prepare({
-    resolvers: [gates, moderation, aa],
+    resolvers: [gates, aa],
     onSessionChange,
   })
 }

src/state/session/moderation.ts

@@ -1,10 +1,31 @@
 import {AtpAgent, BSKY_LABELER_DID} from '@atproto/api'
 
 import {IS_TEST_USER} from '#/lib/constants'
+import {account as accountStorage} from '#/storage'
 import {configureAdditionalModerationAuthorities} from './additional-moderation-authorities'
-import {readLabelers} from './agent-config'
 import {type SessionAccount} from './types'
 
+/**
+ * Cache an account's subscribed labeler DIDs. Called on every preferences
+ * fetch, so the cache is eventually consistent with the server.
+ */
+export function saveLabelers(did: string, value: string[]) {
+  accountStorage.set([did, 'labelers'], value)
+}
+
+/**
+ * Read the cached labeler DIDs for an account, or `undefined` if none have
+ * been cached yet (first session on this device) or the entry is unreadable.
+ */
+export function readLabelers(did: string): string[] | undefined {
+  try {
+    return accountStorage.get([did, 'labelers'])
+  } catch {
+    /* a corrupt entry fails JSON.parse inside Storage.get; treat as no cache */
+    return undefined
+  }
+}
+
 export function configureModerationForGuest() {
   // This global mutation is *only* OK because this code is only relevant for testing.
   // Don't add any other global behavior here!
@@ -12,7 +33,12 @@ export function configureModerationForGuest() {
   configureAdditionalModerationAuthorities()
 }
 
-export async function configureModerationForAccount(
+/**
+ * Configure global app labelers and the account's cached labeler
+ * subscriptions. Fully synchronous so session setup can apply labeler headers
+ * in the same tick, before any request goes out.
+ */
+export function configureModerationForAccount(
   agent: AtpAgent,
   account: SessionAccount,
 ) {
@@ -20,11 +46,12 @@ export async function configureModerationForAccount(
   // Don't add any other global behavior here!
   switchToBskyAppLabeler()
   if (IS_TEST_USER(account.handle)) {
-    await trySwitchToTestAppLabeler(agent)
+    // Test accounts may briefly use the production authority while this resolves.
+    void trySwitchToTestAppLabeler(agent)
   }
 
   // The code below is actually relevant to production (and isn't global).
-  const labelerDids = await readLabelers(account.did).catch(_ => {})
+  const labelerDids = readLabelers(account.did)
   if (labelerDids) {
     agent.configureLabelersHeader(
       labelerDids.filter(did => did !== BSKY_LABELER_DID),
@@ -41,6 +68,7 @@ function switchToBskyAppLabeler() {
   AtpAgent.configure({appLabelers: [BSKY_LABELER_DID]})
 }
 
+/** Resolve and install the test environment's moderation authority. */
 async function trySwitchToTestAppLabeler(agent: AtpAgent) {
   const did = (
     await agent

src/storage/schema.ts

@@ -108,4 +108,15 @@ export type Account = {
    * account after a switch, until that account's preferences loaded.
    */
   isBetaUser?: boolean
+
+  /**
+   * The account's subscribed labeler DIDs, cached from preferences so the
+   * `atproto-accept-labelers` header can be configured synchronously at
+   * session start, before preferences load. Eventually consistent: rewritten
+   * on every preferences fetch (see `saveLabelers` in
+   * `#/state/session/moderation`). Until the first fetch lands there is
+   * simply no cache entry and initial requests go out without per-account
+   * labeler headers.
+   */
+  labelers?: string[]
 }