diff --git a/src/components/activity-notifications/SubscribeProfileDialog.tsx b/src/components/activity-notifications/SubscribeProfileDialog.tsx
index 8a6b8314cd..6731cb3038 100644
--- a/src/components/activity-notifications/SubscribeProfileDialog.tsx
+++ b/src/components/activity-notifications/SubscribeProfileDialog.tsx
@@ -2,10 +2,10 @@ import {useMemo, useState} from 'react'
 import {View} from 'react-native'
 import {
   type AppBskyNotificationDefs,
-  type AppBskyNotificationListActivitySubscriptions,
   type ModerationOpts,
   type Un$Typed,
 } from '@atproto/api'
+import {type DidString} from '@atproto/syntax'
 import {msg} from '@lingui/core/macro'
 import {useLingui} from '@lingui/react'
 import {Trans} from '@lingui/react/macro'
@@ -20,7 +20,7 @@ import {cleanError} from '#/lib/strings/errors'
 import {sanitizeHandle} from '#/lib/strings/handles'
 import {updateProfileShadow} from '#/state/cache/profile-shadow'
 import {RQKEY_getActivitySubscriptions} from '#/state/queries/activity-subscriptions'
-import {useAgent} from '#/state/session'
+import {useAppviewClient} from '#/state/session'
 import {atoms as a, platform, useTheme, web} from '#/alf'
 import {Admonition} from '#/components/Admonition'
 import {
@@ -37,6 +37,7 @@ import * as Toast from '#/components/Toast'
 import {Text} from '#/components/Typography'
 import {useAnalytics} from '#/analytics'
 import {IS_WEB} from '#/env'
+import {app} from '#/lexicons'
 import type * as bsky from '#/types/bsky'
 
 export function SubscribeProfileDialog({
@@ -74,7 +75,7 @@ function DialogInner({
   const ax = useAnalytics()
   const {_} = useLingui()
   const t = useTheme()
-  const agent = useAgent()
+  const client = useAppviewClient()
   const control = Dialog.useDialogContext()
   const queryClient = useQueryClient()
   const initialState = parseActivitySubscription(
@@ -122,8 +123,9 @@ function DialogInner({
     mutationFn: async (
       activitySubscription: Un$Typed<AppBskyNotificationDefs.ActivitySubscription>,
     ) => {
-      await agent.app.bsky.notification.putActivitySubscription({
-        subject: profile.did,
+      await client.call(app.bsky.notification.putActivitySubscription, {
+        // the profile view carries an already-resolved did
+        subject: profile.did as DidString,
         activitySubscription,
       })
     },
@@ -148,7 +150,7 @@ function DialogInner({
           queryClient.setQueryData(
             RQKEY_getActivitySubscriptions,
             (
-              old?: InfiniteData<AppBskyNotificationListActivitySubscriptions.OutputSchema>,
+              old?: InfiniteData<app.bsky.notification.listActivitySubscriptions.$OutputBody>,
             ) => {
               if (!old) return old
               return {
diff --git a/src/state/cache/thread-mutes.tsx b/src/state/cache/thread-mutes.tsx
index f0d9911348..17f6be9f34 100644
--- a/src/state/cache/thread-mutes.tsx
+++ b/src/state/cache/thread-mutes.tsx
@@ -5,9 +5,11 @@ import {
   useEffect,
   useState,
 } from 'react'
+import {type AtUriString} from '@atproto/syntax'
 
 import * as persisted from '#/state/persisted'
-import {useAgent, useSession} from '../session'
+import {app} from '#/lexicons'
+import {useAppviewClient, useSession} from '../session'
 
 type StateContext = Map<string, boolean>
 type SetStateContext = (uri: string, value: boolean) => void
@@ -56,7 +58,7 @@ export function useSetThreadMute() {
 }
 
 function useMigrateMutes(setThreadMute: SetStateContext) {
-  const agent = useAgent()
+  const client = useAppviewClient()
   const {currentAccount} = useSession()
 
   useEffect(() => {
@@ -87,8 +89,11 @@ function useMigrateMutes(setThreadMute: SetStateContext) {
 
           setThreadMute(root, true)
 
-          await agent.api.app.bsky.graph
-            .muteThread({root})
+          await client
+            .call(app.bsky.graph.muteThread, {
+              // the persisted list only ever holds post at-uris
+              root: root as AtUriString,
+            })
             // not a big deal if this fails, since the post might have been deleted
             .catch(console.error)
         }
@@ -100,5 +105,5 @@ function useMigrateMutes(setThreadMute: SetStateContext) {
         cancelled = true
       }
     }
-  }, [agent, currentAccount, setThreadMute])
+  }, [client, currentAccount, setThreadMute])
 }
diff --git a/src/state/queries/activity-subscriptions.ts b/src/state/queries/activity-subscriptions.ts
index 30964fe7d6..e6dcbd8829 100644
--- a/src/state/queries/activity-subscriptions.ts
+++ b/src/state/queries/activity-subscriptions.ts
@@ -1,7 +1,6 @@
 import {
   type AppBskyActorDefs,
   type AppBskyNotificationDeclaration,
-  type AppBskyNotificationListActivitySubscriptions,
 } from '@atproto/api'
 import {t} from '@lingui/core/macro'
 import {
@@ -13,23 +12,23 @@ import {
   useQueryClient,
 } from '@tanstack/react-query'
 
-import {useAgent, useSession} from '#/state/session'
+import {useAgent, useAppviewClient, useSession} from '#/state/session'
 import * as Toast from '#/components/Toast'
+import {app} from '#/lexicons'
 
 export const RQKEY_getActivitySubscriptions = ['activity-subscriptions']
 export const RQKEY_getNotificationDeclaration = ['notification-declaration']
 
 export function useActivitySubscriptionsQuery() {
-  const agent = useAgent()
+  const client = useAppviewClient()
 
   return useInfiniteQuery({
     queryKey: RQKEY_getActivitySubscriptions,
     queryFn: async ({pageParam}) => {
-      const response =
-        await agent.app.bsky.notification.listActivitySubscriptions({
-          cursor: pageParam,
-        })
-      return response.data
+      return await client.call(
+        app.bsky.notification.listActivitySubscriptions,
+        {cursor: pageParam},
+      )
     },
     initialPageParam: undefined as string | undefined,
     getNextPageParam: prev => prev.cursor,
@@ -111,7 +110,7 @@ export function* findAllProfilesInQueryData(
   did: string,
 ): Generator<AppBskyActorDefs.ProfileView, void> {
   const queryDatas = queryClient.getQueriesData<
-    InfiniteData<AppBskyNotificationListActivitySubscriptions.OutputSchema>
+    InfiniteData<app.bsky.notification.listActivitySubscriptions.$OutputBody>
   >({
     queryKey: RQKEY_getActivitySubscriptions,
   })
diff --git a/src/state/queries/notifications/feed.ts b/src/state/queries/notifications/feed.ts
index cc24d3d0fc..51740e8d50 100644
--- a/src/state/queries/notifications/feed.ts
+++ b/src/state/queries/notifications/feed.ts
@@ -33,7 +33,7 @@ import {
 
 import {useModerationOpts} from '#/state/preferences/moderation-opts'
 import {STALE} from '#/state/queries'
-import {useAgent} from '#/state/session'
+import {useAppviewClient} from '#/state/session'
 import {useThreadgateHiddenReplyUris} from '#/state/threadgate-hidden-replies'
 import type * as bsky from '#/types/bsky'
 import {
@@ -60,7 +60,7 @@ export function useNotificationFeedQuery(opts: {
   enabled?: boolean
   filter: 'all' | 'mentions'
 }) {
-  const agent = useAgent()
+  const client = useAppviewClient()
   const queryClient = useQueryClient()
   const moderationOpts = useModerationOpts()
   const unreads = useUnreadNotificationsApi()
@@ -106,7 +106,7 @@ export function useNotificationFeedQuery(opts: {
           ]
         }
         const {page: fetchedPage} = await fetchPage({
-          agent,
+          client,
           limit: PAGE_SIZE,
           cursor: pageParam,
           queryClient,
diff --git a/src/state/queries/notifications/settings.ts b/src/state/queries/notifications/settings.ts
index 86e8a6c7f1..2cadb519dc 100644
--- a/src/state/queries/notifications/settings.ts
+++ b/src/state/queries/notifications/settings.ts
@@ -10,10 +10,10 @@ import {
   useQueryClient,
 } from '@tanstack/react-query'
 
-import {DM_SERVICE_HEADERS} from '#/lib/constants'
 import {logger} from '#/logger'
-import {useAgent} from '#/state/session'
+import {useAppviewClient, useChatClient} from '#/state/session'
 import * as Toast from '#/components/Toast'
+import {app, chat} from '#/lexicons'
 
 const RQKEY_ROOT = 'notification-settings'
 const RQKEY_APP = [RQKEY_ROOT, 'app']
@@ -67,13 +67,13 @@ type ChatNotificationSettingsUpdate =
 export function useNotificationSettingsQuery({
   enabled,
 }: {enabled?: boolean} = {}) {
-  const agent = useAgent()
+  const client = useAppviewClient()
 
   return useQuery({
     queryKey: RQKEY_APP,
     queryFn: async (): Promise<AppNotificationSettingsPreferences> => {
-      const res = await agent.app.bsky.notification.getPreferences()
-      return appPreferencesWithoutChat(res.data.preferences)
+      const data = await client.call(app.bsky.notification.getPreferences)
+      return appPreferencesWithoutChat(data.preferences)
     },
     enabled,
   })
@@ -82,21 +82,24 @@ export function useNotificationSettingsQuery({
 export function useChatNotificationSettingsQuery({
   enabled,
 }: {enabled?: boolean} = {}) {
-  const agent = useAgent()
+  const client = useChatClient()
 
   return useQuery({
     queryKey: RQKEY_CHAT,
     queryFn: async (): Promise<ChatNotificationSettingsPreferences> => {
-      const res = await agent.chat.bsky.notification.getPreferences(undefined, {
-        headers: DM_SERVICE_HEADERS,
-      })
-      return chatPreferencesForSettings(res.data.preferences)
+      const data = await client.call(chat.bsky.notification.getPreferences)
+      return chatPreferencesForSettings(data.preferences)
     },
     enabled,
   })
 }
 export function useNotificationSettingsUpdateMutation() {
-  const agent = useAgent()
+  /*
+   * App preferences live on the appview and chat preferences on the chat
+   * service, so a combined update fans out over both clients.
+   */
+  const appviewClient = useAppviewClient()
+  const chatClient = useChatClient()
   const queryClient = useQueryClient()
 
   return useMutation({
@@ -104,13 +107,13 @@ export function useNotificationSettingsUpdateMutation() {
       const {appUpdate, chatUpdate} = splitNotificationSettingsUpdate(update)
       await Promise.all([
         hasUpdates(appUpdate)
-          ? agent.app.bsky.notification.putPreferencesV2(appUpdate)
+          ? appviewClient.call(
+              app.bsky.notification.putPreferencesV2,
+              appUpdate,
+            )
           : undefined,
         hasUpdates(chatUpdate)
-          ? agent.chat.bsky.notification.putPreferences(chatUpdate, {
-              headers: DM_SERVICE_HEADERS,
-              encoding: 'application/json',
-            })
+          ? chatClient.call(chat.bsky.notification.putPreferences, chatUpdate)
           : undefined,
       ])
     },
diff --git a/src/state/queries/notifications/unread.tsx b/src/state/queries/notifications/unread.tsx
index bf7505f91b..e905b29ac6 100644
--- a/src/state/queries/notifications/unread.tsx
+++ b/src/state/queries/notifications/unread.tsx
@@ -11,6 +11,7 @@ import {
   useState,
 } from 'react'
 import {AppState} from 'react-native'
+import {type ISODatetimeString} from '@atproto/syntax'
 import {useQueryClient} from '@tanstack/react-query'
 import {EventEmitter} from 'eventemitter3'
 
@@ -18,7 +19,8 @@ import BroadcastChannel from '#/lib/broadcast'
 import {resetBadgeCount} from '#/lib/notifications/notifications'
 import {useModerationOpts} from '#/state/preferences/moderation-opts'
 import {truncateAndInvalidate} from '#/state/queries/util'
-import {useAgent, useSession} from '#/state/session'
+import {useAppviewClient, useSession} from '#/state/session'
+import {app} from '#/lexicons'
 import {RQKEY as RQKEY_NOTIFS} from './feed'
 import {type CachedFeedPage, type FeedPage} from './types'
 import {fetchPage} from './util'
@@ -52,7 +54,7 @@ apiContext.displayName = 'NotificationsUnreadApiContext'
 
 export function Provider({children}: React.PropsWithChildren<{}>) {
   const {hasSession} = useSession()
-  const agent = useAgent()
+  const client = useAppviewClient()
   const queryClient = useQueryClient()
   const moderationOpts = useModerationOpts()
 
@@ -120,9 +122,10 @@ export function Provider({children}: React.PropsWithChildren<{}>) {
     return {
       async markAllRead() {
         // update server
-        await agent.updateSeenNotifications(
-          cacheRef.current.syncedAt.toISOString(),
-        )
+        await client.call(app.bsky.notification.updateSeen, {
+          // toISOString always emits the Z-suffixed form the format requires
+          seenAt: cacheRef.current.syncedAt.toISOString() as ISODatetimeString,
+        })
 
         // update & broadcast
         setNumUnread('')
@@ -135,7 +138,7 @@ export function Provider({children}: React.PropsWithChildren<{}>) {
         isPoll,
       }: {invalidate?: boolean; isPoll?: boolean} = {}) {
         try {
-          if (!agent.session) return
+          if (!hasSession) return
           if (AppState.currentState !== 'active') {
             return
           }
@@ -156,7 +159,7 @@ export function Provider({children}: React.PropsWithChildren<{}>) {
 
           // count
           const {page, indexedAt: lastIndexed} = await fetchPage({
-            agent,
+            client,
             cursor: undefined,
             limit: 40,
             queryClient,
@@ -207,7 +210,7 @@ export function Provider({children}: React.PropsWithChildren<{}>) {
         }
       },
     }
-  }, [setNumUnread, queryClient, moderationOpts, agent])
+  }, [setNumUnread, queryClient, moderationOpts, client, hasSession])
   checkUnreadRef.current = api.checkUnread
 
   return (
diff --git a/src/state/queries/notifications/util.ts b/src/state/queries/notifications/util.ts
index e5d1d81885..4606507700 100644
--- a/src/state/queries/notifications/util.ts
+++ b/src/state/queries/notifications/util.ts
@@ -6,15 +6,17 @@ import {
   type AppBskyGraphDefs,
   AppBskyGraphStarterpack,
   type AppBskyNotificationListNotifications,
-  type AtpAgent,
   hasMutedWord,
   moderateNotification,
   type ModerationOpts,
 } from '@atproto/api'
+import {type Client} from '@atproto/lex'
+import {type AtUriString} from '@atproto/syntax'
 import {type QueryClient} from '@tanstack/react-query'
 import chunk from 'lodash.chunk'
 
 import {labelIsHideableOffense} from '#/lib/moderation'
+import {app} from '#/lexicons'
 import * as bsky from '#/types/bsky'
 import {precacheProfile} from '../profile'
 import {
@@ -38,7 +40,7 @@ const MS_2DAY = MS_1HR * 48
 // =
 
 export async function fetchPage({
-  agent,
+  client,
   cursor,
   limit,
   queryClient,
@@ -46,7 +48,7 @@ export async function fetchPage({
   fetchAdditionalData,
   reasons,
 }: {
-  agent: AtpAgent
+  client: Client
   cursor: string | undefined
   limit: number
   queryClient: QueryClient
@@ -57,16 +59,16 @@ export async function fetchPage({
   page: FeedPage
   indexedAt: string | undefined
 }> {
-  const res = await agent.listNotifications({
+  const data = await client.call(app.bsky.notification.listNotifications, {
     limit,
     cursor,
     reasons,
   })
 
-  const indexedAt = res.data.notifications[0]?.indexedAt
+  const indexedAt = data.notifications[0]?.indexedAt
 
   // filter out notifs by mod rules
-  const notifs = res.data.notifications.filter(
+  const notifs = data.notifications.filter(
     notif => !shouldFilterNotif(notif, moderationOpts),
   )
 
@@ -76,7 +78,7 @@ export async function fetchPage({
   // we fetch subjects of notifications (usually posts) now instead of lazily
   // in the UI to avoid relayouts
   if (fetchAdditionalData) {
-    const subjects = await fetchSubjects(agent, notifsGrouped)
+    const subjects = await fetchSubjects(client, notifsGrouped)
     for (const notif of notifsGrouped) {
       if (notif.subjectUri) {
         if (
@@ -96,17 +98,17 @@ export async function fetchPage({
     }
   }
 
-  let seenAt = res.data.seenAt ? new Date(res.data.seenAt) : new Date()
+  let seenAt = data.seenAt ? new Date(data.seenAt) : new Date()
   if (Number.isNaN(seenAt.getTime())) {
     seenAt = new Date()
   }
 
   return {
     page: {
-      cursor: res.data.cursor,
+      cursor: data.cursor,
       seenAt,
       items: notifsGrouped,
-      priority: res.data.priority ?? false,
+      priority: data.priority ?? false,
     },
     indexedAt,
   }
@@ -207,7 +209,7 @@ export function groupNotifications(
 }
 
 async function fetchSubjects(
-  agent: AtpAgent,
+  client: Client,
   groupedNotifs: FeedNotification[],
 ): Promise<{
   posts: Map<string, AppBskyFeedDefs.PostView>
@@ -224,18 +226,22 @@ async function fetchSubjects(
       packUris.add(notif.notification.reasonSubject)
     }
   }
-  const postUriChunks = chunk(Array.from(postUris), 25)
-  const packUriChunks = chunk(Array.from(packUris), 25)
+  /*
+   * Both uri sets are collected from notification fields the server already
+   * validated as at-uris, so the branded cast reflects what the values are.
+   */
+  const postUriChunks = chunk(Array.from(postUris) as AtUriString[], 25)
+  const packUriChunks = chunk(Array.from(packUris) as AtUriString[], 25)
   const postsChunks = await Promise.all(
     postUriChunks.map(uris =>
-      agent.app.bsky.feed.getPosts({uris}).then(res => res.data.posts),
+      client.call(app.bsky.feed.getPosts, {uris}).then(data => data.posts),
     ),
   )
   const packsChunks = await Promise.all(
     packUriChunks.map(uris =>
-      agent.app.bsky.graph
-        .getStarterPacks({uris})
-        .then(res => res.data.starterPacks),
+      client
+        .call(app.bsky.graph.getStarterPacks, {uris})
+        .then(data => data.starterPacks),
     ),
   )
   const postsMap = new Map<string, AppBskyFeedDefs.PostView>()
diff --git a/src/view/com/notifications/NotificationFeedItem.tsx b/src/view/com/notifications/NotificationFeedItem.tsx
index c11cb8049b..2afb3a0f43 100644
--- a/src/view/com/notifications/NotificationFeedItem.tsx
+++ b/src/view/com/notifications/NotificationFeedItem.tsx
@@ -21,12 +21,13 @@ import {
   type ModerationOpts,
 } from '@atproto/api'
 import {TID} from '@atproto/common-web'
+import {type DidString} from '@atproto/syntax'
 import {plural} from '@lingui/core/macro'
 import {Plural, Trans, useLingui} from '@lingui/react/macro'
 import {useNavigation} from '@react-navigation/native'
 import {useQueryClient} from '@tanstack/react-query'
 
-import {DM_SERVICE_HEADERS, MAX_POST_LINES} from '#/lib/constants'
+import {MAX_POST_LINES} from '#/lib/constants'
 import {useAnimatedValue} from '#/lib/hooks/useAnimatedValue'
 import {makeProfileLink} from '#/lib/routes/links'
 import {type NavigationProp} from '#/lib/routes/types'
@@ -38,7 +39,7 @@ import {useProfileShadow} from '#/state/cache/profile-shadow'
 import {type FeedNotification} from '#/state/queries/notifications/feed'
 import {useProfileFollowMutationQueue} from '#/state/queries/profile'
 import {unstableCacheProfileView} from '#/state/queries/unstable-profile-cache'
-import {useAgent, useSession} from '#/state/session'
+import {useChatClient, useSession} from '#/state/session'
 import {FeedSourceCard} from '#/view/com/feeds/FeedSourceCard'
 import {Post} from '#/view/com/post/Post'
 import {formatCount} from '#/view/com/util/numeric/format'
@@ -73,6 +74,7 @@ import * as Toast from '#/components/Toast'
 import {Text} from '#/components/Typography'
 import {useAnalytics} from '#/analytics'
 import {IS_WEB} from '#/env'
+import {chat} from '#/lexicons'
 import * as bsky from '#/types/bsky'
 
 const MAX_AUTHORS = 5
@@ -911,21 +913,21 @@ function FollowBackButton({profile}: {profile: AppBskyActorDefs.ProfileView}) {
 
 function SayHelloBtn({profile}: {profile: AppBskyActorDefs.ProfileView}) {
   const {t: l} = useLingui()
-  const agent = useAgent()
+  const client = useChatClient()
+  const {currentAccount} = useSession()
   const navigation = useNavigation<NavigationProp>()
   const [isLoading, setIsLoading] = useState(false)
 
   const onPress = async () => {
     try {
       setIsLoading(true)
-      const res = await agent.api.chat.bsky.convo.getConvoForMembers(
-        {
-          members: [profile.did, agent.session!.did],
-        },
-        {headers: DM_SERVICE_HEADERS},
-      )
+      const data = await client.call(chat.bsky.convo.getConvoForMembers, {
+        // both dids are already resolved - one from the profile view, one from
+        // the active session
+        members: [profile.did, currentAccount!.did] as DidString[],
+      })
       navigation.navigate('MessagesConversation', {
-        conversation: res.data.convo.id,
+        conversation: data.convo.id,
       })
     } catch (e) {
       logger.error('Failed to get conversation', {safeMessage: e})