diff --git a/apps/web/src/components/sidebar.test.tsx b/apps/web/src/components/sidebar.test.tsx
new file mode 100644
index 0000000..7527664
--- /dev/null
+++ b/apps/web/src/components/sidebar.test.tsx
@@ -0,0 +1,18 @@
+import { describe, expect, it } from "vitest";
+
+import { mtp } from "@tensamin/shared/data";
+import { onlineStatusOptions } from "./status-options";
+
+describe("sidebar status requests", () => {
+  it.each(onlineStatusOptions)("sends $label as $value", ({ value }) => {
+    expect(mtp.SetUserState.request.parse({ UserState: value })).toEqual({
+      UserState: value,
+    });
+  });
+
+  it("keeps status text on the profile operation", () => {
+    expect(mtp.ChangeUserData.request.parse({ Status: "At lunch" })).toEqual({
+      Status: "At lunch",
+    });
+  });
+});
diff --git a/apps/web/src/components/sidebar.tsx b/apps/web/src/components/sidebar.tsx
index 10baf34..7a7c58b 100644
--- a/apps/web/src/components/sidebar.tsx
+++ b/apps/web/src/components/sidebar.tsx
@@ -36,23 +36,19 @@ import { useShowMobileNavbar } from "@/routes/app/useShowMobileNavbar";
 import { Ellipsis, Check } from "lucide-react";
 import { useState } from "react";
 import type { User } from "@tensamin/user/context";
-import type z from "zod";
-import { mtp } from "@tensamin/shared/data";
+import { mtp, userPresencePreferenceSchema } from "@tensamin/shared/data";
 import { useMTP } from "@tensamin/mtp";
+import {
+  onlineStatusLabels,
+  onlineStatusOptions,
+  type OnlineStatus,
+} from "./status-options";
 
-type OnlineStatus = z.infer<typeof mtp.GetUserData.response.shape.OnlineStatus>;
-
-const onlineStatusLabels: Record<OnlineStatus, string> = {
-  user_online: "Online",
-  user_offline: "Offline",
-  user_dnd: "Do not disturb",
-  user_idle: "Idle",
-  user_wc: "Away",
-  user_borked: "Borked",
-  iota_offline: "Iota offline",
-  iota_online: "Iota online",
-  iota_borked: "Iota borked",
-};
+function accountPreference(status: User["OnlineStatus"]): OnlineStatus {
+  return userPresencePreferenceSchema.safeParse(status).success
+    ? (status as OnlineStatus)
+    : "user_online";
+}
 
 function StatusDialog({
   user,
@@ -87,7 +83,7 @@ function StatusDialog({
       onOpenChange={(nextOpen) => {
         if (!nextOpen) {
           setDraftStatus(user.Status ?? "");
-          setDraftOnlineStatus(user.OnlineStatus);
+          setDraftOnlineStatus(accountPreference(user.OnlineStatus));
           setErrorMessage("");
           setSaveSucceeded(false);
         }
@@ -126,10 +122,11 @@ function StatusDialog({
               </SelectValue>
             </SelectTrigger>
             <SelectContent className="p-1">
-              <SelectItem value="user_online">Online</SelectItem>
-              <SelectItem value="user_offline">Offline</SelectItem>
-              <SelectItem value="user_idle">Idle</SelectItem>
-              <SelectItem value="user_dnd">Do not disturb</SelectItem>
+              {onlineStatusOptions.map((option) => (
+                <SelectItem key={option.value} value={option.value}>
+                  {option.label}
+                </SelectItem>
+              ))}
             </SelectContent>
           </Select>
         </div>
@@ -140,12 +137,9 @@ function StatusDialog({
           <DialogClose render={<Button variant="destructive">Cancel</Button>} />
           <Button
             onClick={async () => {
-              const payload = {
-                ...(draftStatus && { status: draftStatus }),
-                OnlineStatus: draftOnlineStatus,
-              };
+              const payload = { UserState: draftOnlineStatus };
 
-              const validation = mtp.ChangeUserData.request.safeParse(payload);
+              const validation = mtp.SetUserState.request.safeParse(payload);
 
               if (!validation.success) {
                 setSaveSucceeded(false);
@@ -156,7 +150,17 @@ function StatusDialog({
               }
 
               try {
-                await send("ChangeUserData", validation.data);
+                await send("SetUserState", validation.data);
+                const profileValidation = mtp.ChangeUserData.request.safeParse({
+                  Status: draftStatus,
+                });
+                if (!profileValidation.success) {
+                  throw new Error(
+                    profileValidation.error.issues[0]?.message ??
+                      "Invalid status data",
+                  );
+                }
+                await send("ChangeUserData", profileValidation.data);
                 setSaveSucceeded(true);
                 setErrorMessage("");
               } catch (err) {
@@ -227,7 +231,9 @@ export default function Sidebar() {
                             <DropdownMenuItem
                               onClick={() => {
                                 setDraftStatus(user.Status ?? "");
-                                setDraftOnlineStatus(user.OnlineStatus);
+                                setDraftOnlineStatus(
+                                  accountPreference(user.OnlineStatus),
+                                );
                                 setStatusErrorMessage("");
                                 setStatusSaveSucceeded(false);
                                 setDialogOpen(true);
@@ -246,7 +252,9 @@ export default function Sidebar() {
                     onOpenChange={(nextOpen) => {
                       if (!nextOpen) {
                         setDraftStatus(user.Status ?? "");
-                        setDraftOnlineStatus(user.OnlineStatus);
+                        setDraftOnlineStatus(
+                          accountPreference(user.OnlineStatus),
+                        );
                         setStatusErrorMessage("");
                         setStatusSaveSucceeded(false);
                       }
diff --git a/apps/web/src/components/status-options.test.ts b/apps/web/src/components/status-options.test.ts
new file mode 100644
index 0000000..4a1d078
--- /dev/null
+++ b/apps/web/src/components/status-options.test.ts
@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+
+import { onlineStatusOptions } from "./status-options";
+
+describe("status options", () => {
+  it("uses the exact client protocol values", () => {
+    expect(onlineStatusOptions).toEqual([
+      { label: "Online", value: "user_online" },
+      { label: "Idle", value: "user_idle" },
+      { label: "Do not disturb", value: "user_dnd" },
+      { label: "Away", value: "user_wc" },
+      { label: "Offline", value: "user_invisible" },
+    ]);
+  });
+});
diff --git a/apps/web/src/components/status-options.ts b/apps/web/src/components/status-options.ts
new file mode 100644
index 0000000..58dfc2d
--- /dev/null
+++ b/apps/web/src/components/status-options.ts
@@ -0,0 +1,13 @@
+export const onlineStatusOptions = [
+  { label: "Online", value: "user_online" },
+  { label: "Idle", value: "user_idle" },
+  { label: "Do not disturb", value: "user_dnd" },
+  { label: "Away", value: "user_wc" },
+  { label: "Offline", value: "user_invisible" },
+] as const;
+
+export type OnlineStatus = (typeof onlineStatusOptions)[number]["value"];
+
+export const onlineStatusLabels = Object.fromEntries(
+  onlineStatusOptions.map((option) => [option.value, option.label]),
+) as Record<OnlineStatus, string>;
diff --git a/mtp-type-maps b/mtp-type-maps
index 11a1d79..486541b 160000
--- a/mtp-type-maps
+++ b/mtp-type-maps
@@ -1 +1 @@
-Subproject commit 11a1d79409857b734e948dd8c3e28e6ba721d15f
+Subproject commit 486541b9483356ff49ff3ec7016f87d3ecbeaa0e
diff --git a/package.json b/package.json
index e7a9815..686eec0 100644
--- a/package.json
+++ b/package.json
@@ -49,5 +49,9 @@
     "@methanium/ui": "https://git.methanium.net/methanium/ui/releases/download/0.0.2/methanium-ui.tgz",
     "mtp": "*",
     "sonner": "^2.0.7"
+  },
+  "overrides": {
+    "@methanium/ui": "https://git.methanium.net/methanium/ui/releases/download/0.0.22/methanium-ui.tgz",
+    "mtp": "https://git.methanium.net/methanium/mtp/releases/download/0.2.0-dev-a692bed/mtp-0.2.0.tgz"
   }
 }
diff --git a/packages/cache/src/sync.test.tsx b/packages/cache/src/sync.test.tsx
new file mode 100644
index 0000000..30ff1c4
--- /dev/null
+++ b/packages/cache/src/sync.test.tsx
@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+
+import { removeMissingContactSnapshots } from "./sync";
+
+describe("authoritative contact cache updates", () => {
+  it("removes missing users and keeps the latest authoritative set", () => {
+    const contacts = [{ UserId: 2 }, { UserId: 3 }, { UserId: 4 }];
+    expect(removeMissingContactSnapshots(contacts, [3, 99])).toEqual([
+      { UserId: 2 },
+      { UserId: 4 },
+    ]);
+  });
+
+  it("does not let a delayed state notification recreate a removed contact", () => {
+    const contacts = [{ UserId: 2 }];
+    const afterMissing = removeMissingContactSnapshots(contacts, [2]);
+    expect(removeMissingContactSnapshots(afterMissing, [])).toEqual([]);
+  });
+});
diff --git a/packages/cache/src/sync.tsx b/packages/cache/src/sync.tsx
index f90e80d..37076c1 100644
--- a/packages/cache/src/sync.tsx
+++ b/packages/cache/src/sync.tsx
@@ -12,6 +12,14 @@ function isError(message: ProtocolMessage) {
   return message.type.startsWith("Error");
 }
 
+export function removeMissingContactSnapshots<T extends { UserId: number }>(
+  contacts: T[],
+  missingUserIds: readonly number[],
+): T[] {
+  const missing = new Set(missingUserIds);
+  return contacts.filter((contact) => !missing.has(contact.UserId));
+}
+
 export default function CacheSync() {
   const { addInterceptor, contextReady, freshContacts, subscribePush } =
     useMTP();
@@ -37,6 +45,20 @@ export default function CacheSync() {
     [accountId],
   );
 
+  const removeMissingContacts = useCallback(
+    async (userIds: number[]) => {
+      if (userIds.length === 0) return;
+      const cache = secureCache();
+      const contacts = await cache.contacts.get();
+      if (!contacts) return;
+      const remaining = removeMissingContactSnapshots(contacts, userIds);
+      if (remaining.length === contacts.length) return;
+      await cache.contacts.replace(remaining);
+      await cache.conversations.replaceSelected(remaining);
+    },
+    [secureCache],
+  );
+
   const replaceMessage = useCallback(
     async (
       partnerId: number,
@@ -110,6 +132,15 @@ export default function CacheSync() {
       const request = (data ?? {}) as Record<string, unknown>;
       const result = response.data as Record<string, unknown>;
 
+      if (type === "GetStates" && Array.isArray(result.MissingUserIds)) {
+        await removeMissingContacts(
+          result.MissingUserIds.filter(
+            (userId): userId is number => typeof userId === "number",
+          ),
+        );
+        return;
+      }
+
       if (type === "GetUserData") {
         await createCache(String(accountId)).profiles.put(
           result as unknown as UserProfile,
@@ -196,7 +227,14 @@ export default function CacheSync() {
         return;
       }
     },
-    [accountId, insertMessage, removeMessage, replaceMessage, secureCache],
+    [
+      accountId,
+      insertMessage,
+      removeMissingContacts,
+      removeMessage,
+      replaceMessage,
+      secureCache,
+    ],
   );
 
   useEffect(() => {
@@ -210,6 +248,14 @@ export default function CacheSync() {
     async (message: ProtocolMessage) => {
       if (!accountId || isError(message)) return;
       const data = message.data as Record<string, unknown>;
+      if (message.type === "GetStates" && Array.isArray(data.MissingUserIds)) {
+        await removeMissingContacts(
+          data.MissingUserIds.filter(
+            (userId): userId is number => typeof userId === "number",
+          ),
+        );
+        return;
+      }
       if (message.type === "MessageLive") {
         await insertMessage(
           Number(data.SenderId),
@@ -263,7 +309,14 @@ export default function CacheSync() {
         await replaceMessage(partnerId, sendTime, { Reactions: reactions });
       }
     },
-    [accountId, insertMessage, removeMessage, replaceMessage, secureCache],
+    [
+      accountId,
+      insertMessage,
+      removeMessage,
+      removeMissingContacts,
+      replaceMessage,
+      secureCache,
+    ],
   );
 
   useEffect(() => {
diff --git a/packages/mtp/src/context.test.tsx b/packages/mtp/src/context.test.tsx
new file mode 100644
index 0000000..7f50aba
--- /dev/null
+++ b/packages/mtp/src/context.test.tsx
@@ -0,0 +1,21 @@
+import { describe, expect, it } from "vitest";
+
+import { isPushType, validateResponse } from "./context";
+
+describe("MTP protocol dispatch", () => {
+  it("preserves protocol errors for the request layer", () => {
+    const error = validateResponse("GetStates", {
+      id: 12,
+      type: "ErrorInternal",
+      data: { ErrorType: "temporary" },
+    });
+    expect(error.type).toBe("ErrorInternal");
+    expect(error.id).toBe(12);
+  });
+
+  it("recognizes initial and live presence pushes", () => {
+    expect(isPushType("GetStates")).toBe(true);
+    expect(isPushType("ClientChanged")).toBe(true);
+    expect(isPushType("UnknownMessage")).toBe(false);
+  });
+});
diff --git a/packages/mtp/src/context.tsx b/packages/mtp/src/context.tsx
index 69010a9..a86fa57 100644
--- a/packages/mtp/src/context.tsx
+++ b/packages/mtp/src/context.tsx
@@ -24,6 +24,7 @@ import {
   type MTP as Schemas,
 } from "@tensamin/shared/data";
 import { log } from "@tensamin/shared/log";
+import { ProtocolError } from "@tensamin/shared/errors";
 import { useStorage } from "@tensamin/storage/context";
 
 import { RECONNECT_RESET, RECONNECT_TRIES, RETRY_INTERVAL } from "./values";
@@ -62,9 +63,30 @@ const PUSH_TYPES = [
   "MessageDeleteLive",
   "MessageState",
   "CallInvite",
+  "GetStates",
+  "ClientChanged",
   "ErrorNoIota",
 ] as const;
 
+export function isPushType(type: string): boolean {
+  return (PUSH_TYPES as readonly string[]).includes(type);
+}
+
+function removeMissingContacts(
+  contacts: Contacts,
+  message: ProtocolMessage,
+): Contacts {
+  if (message.type !== "GetStates") return contacts;
+  const data = message.data as { MissingUserIds?: unknown };
+  if (!Array.isArray(data.MissingUserIds)) return contacts;
+  const missing = new Set(
+    data.MissingUserIds.filter(
+      (userId): userId is number => typeof userId === "number",
+    ),
+  );
+  return contacts.filter((contact) => !missing.has(contact.UserId));
+}
+
 export type MTPExchange = {
   type: keyof Schemas & string;
   data: unknown;
@@ -110,7 +132,7 @@ function getProtocolErrorDetails(error: unknown) {
 }
 
 // Zod schema validation
-function validateResponse<T extends keyof Schemas & string>(
+export function validateResponse<T extends keyof Schemas & string>(
   type: T,
   message: { id?: number; type: string; data: unknown },
 ): ProtocolMessage<T> {
@@ -142,15 +164,26 @@ function validateResponse<T extends keyof Schemas & string>(
 function useMessageHandlers() {
   const interceptorsRef = useRef(new Set<MTPInterceptor>());
   const pushHandlersRef = useRef(new Set<PushHandler>());
+  const lastInitialStateRef = useRef<ProtocolMessage | null>(null);
   const subscribePush = useCallback((handler: PushHandler) => {
     pushHandlersRef.current.add(handler);
+    const initialState = lastInitialStateRef.current;
+    if (initialState?.type === "GetStates") {
+      void Promise.resolve(handler(initialState)).catch(() => undefined);
+    }
     return () => pushHandlersRef.current.delete(handler);
   }, []);
   const addInterceptor = useCallback((interceptor: MTPInterceptor) => {
     interceptorsRef.current.add(interceptor);
     return () => interceptorsRef.current.delete(interceptor);
   }, []);
-  return { addInterceptor, interceptorsRef, pushHandlersRef, subscribePush };
+  return {
+    addInterceptor,
+    interceptorsRef,
+    lastInitialStateRef,
+    pushHandlersRef,
+    subscribePush,
+  };
 }
 
 function BrowserProvider(props: {
@@ -172,8 +205,13 @@ function BrowserProvider(props: {
   const clientRef = useRef<Awaited<ReturnType<typeof MTPClient.create>> | null>(
     null,
   );
-  const { addInterceptor, interceptorsRef, pushHandlersRef, subscribePush } =
-    useMessageHandlers();
+  const {
+    addInterceptor,
+    interceptorsRef,
+    lastInitialStateRef,
+    pushHandlersRef,
+    subscribePush,
+  } = useMessageHandlers();
 
   const connected = readyState === ConnectionState.Connected;
 
@@ -197,7 +235,20 @@ function BrowserProvider(props: {
         (data ?? {}) as Record<string, unknown>,
         options,
       );
-      return validateResponse(type, message);
+      const response = validateResponse(type, message);
+      setFreshContacts((contacts) => removeMissingContacts(contacts, response));
+      if (response.type.startsWith("Error")) {
+        const errorData = response.data as Record<string, unknown>;
+        throw new ProtocolError({
+          type: response.type,
+          requestId: response.id,
+          errorType:
+            typeof errorData.ErrorType === "string"
+              ? errorData.ErrorType
+              : undefined,
+        });
+      }
+      return response;
     },
     [],
   );
@@ -418,6 +469,9 @@ function BrowserProvider(props: {
               return;
             }
 
+            setFreshContacts((contacts) =>
+              removeMissingContacts(contacts, validated),
+            );
             for (const handler of [...pushHandlersRef.current]) {
               void Promise.resolve()
                 .then(() => handler(validated))
@@ -425,6 +479,9 @@ function BrowserProvider(props: {
                   log(1, "mtp", "red", "Push handler failed", error, { type });
                 });
             }
+            if (validated.type === "GetStates") {
+              lastInitialStateRef.current = validated;
+            }
           });
         }
         setReadyState(activeClient.state);
@@ -537,7 +594,13 @@ function BrowserProvider(props: {
       setIdentifying(false);
       sonnerToast.dismiss("mtp-connection-toast");
     };
-  }, [mtpUrl, props.blockConnection, load, pushHandlersRef]);
+  }, [
+    lastInitialStateRef,
+    mtpUrl,
+    props.blockConnection,
+    load,
+    pushHandlersRef,
+  ]);
 
   // No Iota check
   useEffect(() => {
@@ -644,8 +707,13 @@ function TauriProvider(props: {
   const [freshCommunities, setFreshCommunities] = useState<Communities>([]);
   const [freshCalls, setFreshCalls] = useState<Calls>([]);
   const generationRef = useRef(0);
-  const { addInterceptor, interceptorsRef, pushHandlersRef, subscribePush } =
-    useMessageHandlers();
+  const {
+    addInterceptor,
+    interceptorsRef,
+    lastInitialStateRef,
+    pushHandlersRef,
+    subscribePush,
+  } = useMessageHandlers();
   const subscriptionsRef = useRef(
     new Map<string, Set<(message: ProtocolMessage) => void>>(),
   );
@@ -686,7 +754,10 @@ function TauriProvider(props: {
         []) {
         handler(validated);
       }
-      if (!(PUSH_TYPES as readonly string[]).includes(validated.type)) return;
+      if (!isPushType(validated.type)) return;
+      setFreshContacts((contacts) =>
+        removeMissingContacts(contacts, validated),
+      );
       for (const handler of [...pushHandlersRef.current]) {
         void Promise.resolve(handler(validated)).catch((error) => {
           log(1, "mtp", "red", "Native MTP push handler failed", error, {
@@ -694,8 +765,11 @@ function TauriProvider(props: {
           });
         });
       }
+      if (validated.type === "GetStates") {
+        lastInitialStateRef.current = validated;
+      }
     },
-    [pushHandlersRef],
+    [lastInitialStateRef, pushHandlersRef],
   );
 
   useEffect(() => {
@@ -770,6 +844,20 @@ function TauriProvider(props: {
         id: options?.id,
       });
       const validated = validateResponse(type, response);
+      setFreshContacts((contacts) =>
+        removeMissingContacts(contacts, validated),
+      );
+      if (validated.type.startsWith("Error")) {
+        const errorData = validated.data as Record<string, unknown>;
+        throw new ProtocolError({
+          type: validated.type,
+          requestId: validated.id,
+          errorType:
+            typeof errorData.ErrorType === "string"
+              ? errorData.ErrorType
+              : undefined,
+        });
+      }
       for (const interceptor of interceptorsRef.current) {
         void Promise.resolve(
           interceptor({ type, data, response: validated as ProtocolMessage }),
diff --git a/packages/shared/package.json b/packages/shared/package.json
index 5bfb379..9c2b724 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -6,6 +6,7 @@
   "exports": {
     "./asyncQueue": "./src/asyncQueue.ts",
     "./code": "./src/code.ts",
+    "./errors": "./src/errors.ts",
     "./data": "./src/data.ts",
     "./desktopMedia": "./src/desktopMedia.tsx",
     "./log": "./src/log.tsx",
diff --git a/packages/shared/src/data.test.ts b/packages/shared/src/data.test.ts
new file mode 100644
index 0000000..7b1d679
--- /dev/null
+++ b/packages/shared/src/data.test.ts
@@ -0,0 +1,65 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  accountUserSchema,
+  mtp,
+  publicUserSchema,
+  userPresencePreferenceSchema,
+} from "./data";
+
+const profile = {
+  Display: "Alice",
+  IotaId: 1,
+  OmikronConnections: [],
+  PublicKey: "aGVsbG8=",
+  SubEnd: 0,
+  SubLevel: 0,
+  UserId: 1,
+  Username: "alice",
+};
+
+describe("presence protocol schemas", () => {
+  it.each([
+    "user_online",
+    "user_idle",
+    "user_dnd",
+    "user_wc",
+    "user_invisible",
+  ])("accepts writable preference %s", (state) => {
+    expect(userPresencePreferenceSchema.parse(state)).toBe(state);
+    expect(mtp.SetUserState.request.parse({ UserState: state })).toEqual({
+      UserState: state,
+    });
+  });
+
+  it("keeps invisible private to the account schema", () => {
+    expect(
+      accountUserSchema.parse({ ...profile, OnlineStatus: "user_invisible" })
+        .OnlineStatus,
+    ).toBe("user_invisible");
+    expect(
+      publicUserSchema.safeParse({ ...profile, OnlineStatus: "user_invisible" })
+        .success,
+    ).toBe(false);
+    expect(
+      publicUserSchema.parse({ ...profile, OnlineStatus: "user_offline" })
+        .OnlineStatus,
+    ).toBe("user_offline");
+  });
+
+  it("does not put state changes or lowercase status in ChangeUserData", () => {
+    const statePayload = mtp.ChangeUserData.request.safeParse({
+      OnlineStatus: "user_online",
+    });
+    expect(statePayload.success ? statePayload.data : undefined).toEqual({});
+    expect(mtp.ChangeUserData.request.parse({ Status: "At lunch" })).toEqual({
+      Status: "At lunch",
+    });
+    const lowercasePayload = mtp.ChangeUserData.request.safeParse({
+      status: "At lunch",
+    });
+    expect(
+      lowercasePayload.success ? lowercasePayload.data : undefined,
+    ).toEqual({});
+  });
+});
diff --git a/packages/shared/src/data.ts b/packages/shared/src/data.ts
index 8480258..9f16723 100644
--- a/packages/shared/src/data.ts
+++ b/packages/shared/src/data.ts
@@ -143,34 +143,71 @@ export type Contacts = z.infer<typeof authPayload.shape.Contacts>;
 export type Communities = z.infer<typeof authPayload.shape.Communities>;
 export type Calls = z.infer<typeof authPayload.shape.Calls>;
 
-
-
 // MTP
-const user = z.object({
+const userFields = {
   About: z.string().max(255).optional(),
   Avatar: z.string().optional(),
   Display: z.string().min(1).max(15),
   IotaId: z.number(),
   OmikronConnections: z.array(z.number()),
   OmikronId: z.number().optional(),
-  OnlineStatus: z.enum([
-    "user_offline",
-    "user_online",
-    "user_dnd",
-    "user_idle",
-    "user_wc",
-    "user_borked",
-    "iota_offline",
-    "iota_online",
-    "iota_borked",
-  ]),
   PublicKey: z.base64(),
   Status: z.string().max(15).optional(),
   SubEnd: z.number(),
   SubLevel: z.number(),
   UserId: z.number(),
   Username: z.string().min(1).max(15),
+};
+
+export const publicUserStateSchema = z.enum([
+  "user_online",
+  "user_idle",
+  "user_dnd",
+  "user_wc",
+  "user_offline",
+  "iota_offline",
+]);
+
+export const userPresencePreferenceSchema = z.enum([
+  "user_online",
+  "user_idle",
+  "user_dnd",
+  "user_wc",
+  "user_invisible",
+]);
+
+export const clientUserStateSchema = z.union([
+  publicUserStateSchema,
+  userPresencePreferenceSchema,
+]);
+
+export const publicUserSchema = z.object({
+  ...userFields,
+  OnlineStatus: z.enum([
+    "user_online",
+    "user_idle",
+    "user_dnd",
+    "user_wc",
+    "user_offline",
+    "iota_offline",
+    "user_borked",
+    "iota_online",
+    "iota_borked",
+  ]),
 });
+
+export const accountUserSchema = z.object({
+  ...userFields,
+  OnlineStatus: userPresencePreferenceSchema,
+});
+
+export const userSchema = z.union([publicUserSchema, accountUserSchema]);
+
+export const userStateEntrySchema = z.object({
+  UserId: z.number().int().positive(),
+  UserState: publicUserStateSchema,
+});
+
 export const mtp = {
   IdentificationResponse: {
     request: z.object({}).optional(),
@@ -201,10 +238,47 @@ export const mtp = {
       UserId: z.number().optional(),
       Username: z.string().optional(),
     }),
-    response: user,
+    response: userSchema,
+  },
+  GetStates: {
+    request: z.object({
+      SessionId: z.number().int().positive(),
+      UserIds: z.array(z.number().int().positive()),
+    }),
+    response: z.object({
+      SessionId: z.number().int().positive(),
+      // Keep valid entries when one entry in a server snapshot is malformed.
+      UserStates: z.array(userStateEntrySchema.nullable().catch(null)),
+      MissingUserIds: z.array(z.number().int().positive()).optional(),
+    }),
+  },
+  ClientChanged: {
+    request: z.object({}).optional(),
+    response: z.object({
+      SessionId: z.number().int().positive(),
+      UserId: z.number().int().positive(),
+      UserState: clientUserStateSchema,
+    }),
+  },
+  SetUserState: {
+    request: z.object({
+      UserState: userPresencePreferenceSchema,
+    }),
+    response: z.object({
+      UserState: userPresencePreferenceSchema,
+    }),
   },
   ChangeUserData: {
-    request: user.partial(),
+    request: z
+      .object({
+        About: userFields.About,
+        Avatar: userFields.Avatar,
+        Display: userFields.Display,
+        PublicKey: userFields.PublicKey,
+        Status: userFields.Status,
+        Username: userFields.Username,
+      })
+      .partial(),
     response: z.object({}),
   },
   MessageDelete: {
@@ -455,24 +529,24 @@ export interface Storage extends SettingsStorageDefaults {
   call_mute_range_end: number;
   theme_color: string;
   theme_palette: Record<
-  | "base00"
-  | "base01"
-  | "base02"
-  | "base03"
-  | "base04"
-  | "base05"
-  | "base06"
-  | "base07"
-  | "base08"
-  | "base09"
-  | "base0A"
-  | "base0B"
-  | "base0C"
-  | "base0D"
-  | "base0E"
-  | "base0F",
-  string
-> | null;
+    | "base00"
+    | "base01"
+    | "base02"
+    | "base03"
+    | "base04"
+    | "base05"
+    | "base06"
+    | "base07"
+    | "base08"
+    | "base09"
+    | "base0A"
+    | "base0B"
+    | "base0C"
+    | "base0D"
+    | "base0E"
+    | "base0F",
+    string
+  > | null;
   theme_primary_color: string;
   theme_polarity: "dark" | "light" | "system";
   theme_tint: "soft" | "hard" | "extreme";
@@ -585,7 +659,9 @@ export const storageDefaults: Storage = {
 
 // User Status
 export function getStatusColor(
-  status: z.infer<typeof mtp.GetUserData.response.shape.OnlineStatus>,
+  status:
+    | z.infer<typeof publicUserSchema.shape.OnlineStatus>
+    | z.infer<typeof userPresencePreferenceSchema>,
 ) {
   switch (status) {
     case "user_online":
diff --git a/packages/shared/src/errors.ts b/packages/shared/src/errors.ts
new file mode 100644
index 0000000..ab2d058
--- /dev/null
+++ b/packages/shared/src/errors.ts
@@ -0,0 +1,25 @@
+export class ProtocolError extends Error {
+  readonly type: string;
+  readonly id: number | undefined;
+  readonly communicationType: string;
+  readonly requestId: number | undefined;
+  readonly errorType: string | undefined;
+
+  constructor(options: {
+    type: string;
+    requestId?: number;
+    errorType?: string;
+  }) {
+    super(
+      options.errorType
+        ? `${options.type}: ${options.errorType}`
+        : options.type,
+    );
+    this.name = "ProtocolError";
+    this.type = options.type;
+    this.id = options.requestId;
+    this.communicationType = options.type;
+    this.requestId = options.requestId;
+    this.errorType = options.errorType;
+  }
+}
diff --git a/packages/user/src/context.test.tsx b/packages/user/src/context.test.tsx
new file mode 100644
index 0000000..e00e77e
--- /dev/null
+++ b/packages/user/src/context.test.tsx
@@ -0,0 +1,45 @@
+import { describe, expect, it } from "vitest";
+
+import { accountUserSchema, publicUserSchema } from "@tensamin/shared/data";
+import { mergeTransientPresence } from "./context";
+
+const profile = {
+  Display: "Alice",
+  IotaId: 1,
+  OmikronConnections: [],
+  PublicKey: "aGVsbG8=",
+  SubEnd: 0,
+  SubLevel: 0,
+  UserId: 7,
+  Username: "alice",
+};
+
+describe("transient presence overlay", () => {
+  it("keeps private invisible state on the account without persisting it", () => {
+    const account = accountUserSchema.parse({
+      ...profile,
+      OnlineStatus: "user_online",
+    });
+    const overlay = new Map([[7, "user_invisible" as const]]);
+
+    expect(mergeTransientPresence(account, overlay).OnlineStatus).toBe(
+      "user_invisible",
+    );
+    expect(publicUserSchema.safeParse(account).success).toBe(false);
+  });
+
+  it("merges public live state into a profile without changing durable fields", () => {
+    const contact = publicUserSchema.parse({
+      ...profile,
+      OnlineStatus: "user_online",
+    });
+    const overlay = new Map([[7, "user_offline" as const]]);
+    const merged = mergeTransientPresence(contact, overlay);
+
+    expect(merged).toMatchObject({
+      UserId: 7,
+      Username: "alice",
+      OnlineStatus: "user_offline",
+    });
+  });
+});
diff --git a/packages/user/src/context.tsx b/packages/user/src/context.tsx
index 390cba0..be741f4 100644
--- a/packages/user/src/context.tsx
+++ b/packages/user/src/context.tsx
@@ -7,15 +7,29 @@ import {
   useRef,
   useState,
 } from "react";
-import { useMTP } from "@tensamin/mtp";
+import { useMTP, type ProtocolMessage } from "@tensamin/mtp";
 
-import { mtp as schemas } from "@tensamin/shared/data";
+import {
+  clientUserStateSchema,
+  mtp as schemas,
+  publicUserStateSchema,
+  userStateEntrySchema,
+} from "@tensamin/shared/data";
 import type z from "zod";
 import { createCache } from "@tensamin/cache";
 import { useStorage } from "@tensamin/storage/context";
 import { useSession } from "@tensamin/storage/session";
 
 export type User = z.infer<typeof schemas.GetUserData.response>;
+type ClientUserState = z.infer<typeof clientUserStateSchema>;
+
+export function mergeTransientPresence<T extends { UserId: number }>(
+  user: T,
+  presence: ReadonlyMap<number, ClientUserState>,
+): T {
+  const state = presence.get(user.UserId);
+  return state === undefined ? user : ({ ...user, OnlineStatus: state } as T);
+}
 
 const USER_CACHE_MAX_AGE = 5 * 60 * 1000;
 
@@ -35,19 +49,105 @@ export default function UserProvider(props: { children: ReactNode }) {
   const storageRef = useRef<Record<number, User>>({});
   const pendingRef = useRef<Record<number, Promise<User> | undefined>>({});
   const checkedAtRef = useRef<Record<number, number>>({});
+  const presenceRef = useRef(new Map<number, ClientUserState>());
+  const durableProfileRef = useRef<Record<number, User>>({});
 
-  const { send } = useMTP();
+  const { send, subscribePush } = useMTP();
   const { load } = useStorage();
   const { contacts } = useSession();
   const [accountId, setAccountId] = useState<number | null>(null);
   const [cacheVersion, setCacheVersion] = useState(0);
+  const [sessionId, setSessionId] = useState<number | null>(null);
+  const contactsRef = useRef(contacts);
+  const initialStatesRef = useRef(
+    new Map<number, z.infer<typeof publicUserStateSchema>>(),
+  );
+
+  useEffect(() => {
+    contactsRef.current = contacts;
+  }, [contacts]);
+
+  const mergeUserPresence = useCallback((user: User): User => {
+    return mergeTransientPresence(user, presenceRef.current);
+  }, []);
+
+  const applyUserState = useCallback(
+    (userId: number, state: ClientUserState, privateState = false) => {
+      const known =
+        userId === accountId ||
+        contactsRef.current.some((contact) => contact.UserId === userId);
+      if (!known) return false;
+
+      if (state === "user_invisible" && userId !== accountId) return false;
+      if (userId === accountId && !privateState) return false;
+
+      presenceRef.current.set(userId, state);
+      const current = storageRef.current[userId];
+      if (current) storageRef.current[userId] = mergeUserPresence(current);
+      setCacheVersion((version) => version + 1);
+      return true;
+    },
+    [accountId, mergeUserPresence],
+  );
+
+  const removePresence = useCallback((userId: number) => {
+    presenceRef.current.delete(userId);
+    initialStatesRef.current.delete(userId);
+    delete checkedAtRef.current[userId];
+    setCacheVersion((version) => version + 1);
+  }, []);
+
+  const handleStatePush = useCallback(
+    async (message: ProtocolMessage) => {
+      if (!accountId || !sessionId) return;
+      const data = message.data as Record<string, unknown>;
+      if (message.type === "GetStates") {
+        if (Number(data.SessionId) !== sessionId) {
+          return;
+        }
+        if (Array.isArray(data.MissingUserIds)) {
+          for (const userId of data.MissingUserIds) {
+            if (typeof userId === "number") removePresence(userId);
+          }
+        }
+        if (!Array.isArray(data.UserStates)) return;
+        for (const entry of data.UserStates) {
+          const parsed = userStateEntrySchema.safeParse(entry);
+          if (!parsed.success) continue;
+          if (parsed.data.UserId === accountId) continue;
+          initialStatesRef.current.set(
+            parsed.data.UserId,
+            parsed.data.UserState,
+          );
+          if (applyUserState(parsed.data.UserId, parsed.data.UserState)) {
+            initialStatesRef.current.delete(parsed.data.UserId);
+          }
+        }
+        return;
+      }
+      if (message.type !== "ClientChanged") return;
+      if (Number(data.SessionId) !== sessionId) return;
+      const parsed = schemas.ClientChanged.response.safeParse(data);
+      if (!parsed.success) return;
+      applyUserState(parsed.data.UserId, parsed.data.UserState, true);
+    },
+    [accountId, applyUserState, removePresence, sessionId],
+  );
 
   useEffect(() => {
     void load("user_id").then((accountId) => {
       setAccountId(accountId);
     });
+    void load("session_id").then((value) => {
+      setSessionId(value);
+    });
   }, [load]);
 
+  useEffect(() => {
+    if (!accountId || !sessionId) return;
+    return subscribePush(handleStatePush);
+  }, [accountId, handleStatePush, sessionId, subscribePush]);
+
   /**
    * Executes get.
    * @param userId Parameter userId.
@@ -73,17 +173,20 @@ export default function UserProvider(props: { children: ReactNode }) {
           schemas.GetUserData.response.safeParse(cachedValue);
         const cached = cachedResult.success ? cachedResult.data : undefined;
         if (cached) {
-          storageRef.current[userId] = cached;
+          durableProfileRef.current[userId] = cached;
+          const merged = mergeUserPresence(cached);
+          storageRef.current[userId] = merged;
           const checkedAt = checkedAtRef.current[userId];
           if (!checkedAt || Date.now() - checkedAt < USER_CACHE_MAX_AGE) {
             checkedAtRef.current[userId] = Date.now();
-            return cached;
+            return merged;
           }
         }
         try {
           const userData = await send("GetUserData", { UserId: userId });
           if (userData.type === "ErrorNotFound" || userData.data.UserId === 0) {
             delete storageRef.current[userId];
+            delete durableProfileRef.current[userId];
             delete checkedAtRef.current[userId];
             await cache.profiles.delete(userId);
             throw new Error("GetUserData failed: user not found");
@@ -91,14 +194,15 @@ export default function UserProvider(props: { children: ReactNode }) {
           if (userData.type.startsWith("Error")) {
             throw new Error(`GetUserData failed: ${userData.type}`);
           }
-          const user = userData.data;
+          const user = mergeUserPresence(userData.data);
+          durableProfileRef.current[userId] = userData.data;
           storageRef.current[userId] = user;
           checkedAtRef.current[userId] = Date.now();
           return user;
         } catch (error) {
           if (cached && storageRef.current[userId]) {
             checkedAtRef.current[userId] = Date.now();
-            return cached;
+            return storageRef.current[userId];
           }
           throw error;
         }
@@ -112,23 +216,48 @@ export default function UserProvider(props: { children: ReactNode }) {
         delete pendingRef.current[userId];
       }
     },
-    [accountId, cacheVersion, send],
+    [accountId, cacheVersion, mergeUserPresence, send],
   );
 
   const update = useCallback(
     async (user: User) => {
-      await createCache(String(accountId ?? user.UserId)).profiles.put(user);
-      storageRef.current[user.UserId] = user;
+      const durableProfile = {
+        ...user,
+        OnlineStatus:
+          durableProfileRef.current[user.UserId]?.OnlineStatus ??
+          user.OnlineStatus,
+      } as User;
+      await createCache(String(accountId ?? user.UserId)).profiles.put(
+        durableProfile,
+      );
+      durableProfileRef.current[user.UserId] = durableProfile;
+      storageRef.current[user.UserId] = mergeUserPresence(durableProfile);
       checkedAtRef.current[user.UserId] = Date.now();
       setCacheVersion((version) => version + 1);
     },
-    [accountId],
+    [accountId, mergeUserPresence],
   );
 
   useEffect(() => {
     if (!accountId) return;
-    for (const contact of contacts) void get(contact.UserId);
-  }, [accountId, contacts, get]);
+    void (async () => {
+      const userIds = [
+        accountId,
+        ...contacts.map((contact) => contact.UserId),
+      ].filter((userId, index, all) => all.indexOf(userId) === index);
+      for (const userId of userIds) {
+        try {
+          await get(userId);
+          const state = initialStatesRef.current.get(userId);
+          if (state && applyUserState(userId, state)) {
+            initialStatesRef.current.delete(userId);
+          }
+        } catch {
+          // The normal user loading path reports profile failures to its caller.
+        }
+      }
+    })();
+  }, [accountId, applyUserState, contacts, get]);
 
   return (
     <UserContext.Provider value={{ get, update }}>