diff --git a/desktop/src/features/sidebar/lib/channelSectionsHelpers.test.mjs b/desktop/src/features/sidebar/lib/channelSectionsHelpers.test.mjs
new file mode 100644
index 000000000..97362adf2
--- /dev/null
+++ b/desktop/src/features/sidebar/lib/channelSectionsHelpers.test.mjs
@@ -0,0 +1,79 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { swapSectionOrder } from "./channelSectionsHelpers.ts";
+
+function makeStore(sections, assignments = {}) {
+  return { version: 1, sections, assignments };
+}
+
+function makeSection(id, name, order) {
+  return { id, name, order };
+}
+
+test("move up succeeds: middle section swaps order with the one above", () => {
+  const store = makeStore([
+    makeSection("a", "A", 0),
+    makeSection("b", "B", 1),
+    makeSection("c", "C", 2),
+  ]);
+  const result = swapSectionOrder(store, "b", "up");
+  assert.notEqual(result, null);
+  const byId = Object.fromEntries(result.sections.map((s) => [s.id, s.order]));
+  assert.equal(byId["b"], 0);
+  assert.equal(byId["a"], 1);
+  assert.equal(byId["c"], 2);
+});
+
+test("move down succeeds: middle section swaps order with the one below", () => {
+  const store = makeStore([
+    makeSection("a", "A", 0),
+    makeSection("b", "B", 1),
+    makeSection("c", "C", 2),
+  ]);
+  const result = swapSectionOrder(store, "b", "down");
+  assert.notEqual(result, null);
+  const byId = Object.fromEntries(result.sections.map((s) => [s.id, s.order]));
+  assert.equal(byId["b"], 2);
+  assert.equal(byId["c"], 1);
+  assert.equal(byId["a"], 0);
+});
+
+test("move up at top boundary returns null", () => {
+  const store = makeStore([makeSection("a", "A", 0), makeSection("b", "B", 1)]);
+  assert.equal(swapSectionOrder(store, "a", "up"), null);
+});
+
+test("move down at bottom boundary returns null", () => {
+  const store = makeStore([makeSection("a", "A", 0), makeSection("b", "B", 1)]);
+  assert.equal(swapSectionOrder(store, "b", "down"), null);
+});
+
+test("non-existent section returns null", () => {
+  const store = makeStore([makeSection("a", "A", 0)]);
+  assert.equal(swapSectionOrder(store, "z", "up"), null);
+});
+
+test("single section move up returns null", () => {
+  const store = makeStore([makeSection("a", "A", 0)]);
+  assert.equal(swapSectionOrder(store, "a", "up"), null);
+});
+
+test("single section move down returns null", () => {
+  const store = makeStore([makeSection("a", "A", 0)]);
+  assert.equal(swapSectionOrder(store, "a", "down"), null);
+});
+
+test("non-contiguous orders: swap uses actual order values not indices", () => {
+  const store = makeStore([
+    makeSection("a", "A", 0),
+    makeSection("b", "B", 5),
+    makeSection("c", "C", 10),
+  ]);
+  const result = swapSectionOrder(store, "b", "up");
+  assert.notEqual(result, null);
+  const byId = Object.fromEntries(result.sections.map((s) => [s.id, s.order]));
+  assert.equal(byId["b"], 0);
+  assert.equal(byId["a"], 5);
+  assert.equal(byId["c"], 10);
+});
diff --git a/desktop/src/features/sidebar/lib/channelSectionsHelpers.ts b/desktop/src/features/sidebar/lib/channelSectionsHelpers.ts
new file mode 100644
index 000000000..fe41cfee6
--- /dev/null
+++ b/desktop/src/features/sidebar/lib/channelSectionsHelpers.ts
@@ -0,0 +1,21 @@
+import type { ChannelSectionStore } from "./channelSectionsStorage";
+
+export function swapSectionOrder(
+  prev: ChannelSectionStore,
+  sectionId: string,
+  direction: "up" | "down",
+): ChannelSectionStore | null {
+  const target = prev.sections.find((s) => s.id === sectionId);
+  if (!target) return null;
+  const sorted = prev.sections.slice().sort((a, b) => a.order - b.order);
+  const idx = sorted.findIndex((s) => s.id === sectionId);
+  const neighborIdx = direction === "up" ? idx - 1 : idx + 1;
+  if (neighborIdx < 0 || neighborIdx >= sorted.length) return null;
+  const neighbor = sorted[neighborIdx];
+  const sections = prev.sections.map((s) => {
+    if (s.id === target.id) return { ...s, order: neighbor.order };
+    if (s.id === neighbor.id) return { ...s, order: target.order };
+    return s;
+  });
+  return { ...prev, sections };
+}
diff --git a/desktop/src/features/sidebar/lib/channelSectionsStorage.test.mjs b/desktop/src/features/sidebar/lib/channelSectionsStorage.test.mjs
new file mode 100644
index 000000000..390e255d4
--- /dev/null
+++ b/desktop/src/features/sidebar/lib/channelSectionsStorage.test.mjs
@@ -0,0 +1,204 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  DEFAULT_STORE,
+  parseChannelSectionPayload,
+  readChannelSectionsStore,
+  storageKey,
+  stripOrphanedAssignments,
+  writeChannelSectionsStore,
+} from "./channelSectionsStorage.ts";
+
+if (typeof globalThis.window === "undefined") {
+  const storage = new Map();
+  globalThis.window = {
+    localStorage: {
+      getItem: (key) => storage.get(key) ?? null,
+      setItem: (key, value) => storage.set(key, value),
+      removeItem: (key) => storage.delete(key),
+    },
+  };
+}
+
+function makeStore(overrides = {}) {
+  return {
+    version: 1,
+    sections: overrides.sections ?? [{ id: "s1", name: "Test", order: 0 }],
+    assignments: overrides.assignments ?? {},
+    ...overrides,
+  };
+}
+
+function makeSection(overrides = {}) {
+  return { id: "s1", name: "Test", order: 0, ...overrides };
+}
+
+test("parseChannelSectionPayload: valid complete payload returns correct store", () => {
+  const payload = {
+    version: 1,
+    sections: [{ id: "s1", name: "Work", order: 0 }],
+    assignments: { chan1: "s1" },
+  };
+  const result = parseChannelSectionPayload(payload);
+  assert.deepEqual(result, {
+    version: 1,
+    sections: [{ id: "s1", name: "Work", order: 0 }],
+    assignments: { chan1: "s1" },
+  });
+});
+
+test("parseChannelSectionPayload: null input returns null", () => {
+  assert.equal(parseChannelSectionPayload(null), null);
+});
+
+test("parseChannelSectionPayload: non-object input returns null", () => {
+  assert.equal(parseChannelSectionPayload("string"), null);
+  assert.equal(parseChannelSectionPayload(42), null);
+  assert.equal(parseChannelSectionPayload(true), null);
+});
+
+test("parseChannelSectionPayload: missing sections returns empty sections array", () => {
+  const result = parseChannelSectionPayload({ assignments: {} });
+  assert.deepEqual(result?.sections, []);
+});
+
+test("parseChannelSectionPayload: malformed section entries are filtered out", () => {
+  const payload = {
+    sections: [
+      { id: 123, name: "Bad ID", order: 0 },
+      { id: "s1", name: 456, order: 0 },
+      { id: "s2", name: "Good", order: "not-a-number" },
+      null,
+      "string-entry",
+    ],
+    assignments: {},
+  };
+  const result = parseChannelSectionPayload(payload);
+  assert.deepEqual(result?.sections, []);
+});
+
+test("parseChannelSectionPayload: valid sections with some invalid ones filters correctly", () => {
+  const payload = {
+    sections: [
+      { id: "s1", name: "Valid", order: 0 },
+      { id: 99, name: "Bad ID", order: 1 },
+      { id: "s2", name: "Also Valid", order: 2 },
+    ],
+    assignments: {},
+  };
+  const result = parseChannelSectionPayload(payload);
+  assert.deepEqual(result?.sections, [
+    { id: "s1", name: "Valid", order: 0 },
+    { id: "s2", name: "Also Valid", order: 2 },
+  ]);
+});
+
+test("parseChannelSectionPayload: missing assignments returns empty assignments object", () => {
+  const result = parseChannelSectionPayload({ sections: [] });
+  assert.deepEqual(result?.assignments, {});
+});
+
+test("parseChannelSectionPayload: assignments with non-string values are filtered out", () => {
+  const payload = {
+    sections: [{ id: "s1", name: "Test", order: 0 }],
+    assignments: { chan1: "s1", chan2: 42, chan3: null, chan4: true },
+  };
+  const result = parseChannelSectionPayload(payload);
+  assert.deepEqual(result?.assignments, { chan1: "s1" });
+});
+
+test("parseChannelSectionPayload: orphaned assignments are stripped", () => {
+  const payload = {
+    sections: [{ id: "s1", name: "Exists", order: 0 }],
+    assignments: { chan1: "s1", chan2: "missing-section" },
+  };
+  const result = parseChannelSectionPayload(payload);
+  assert.deepEqual(result?.assignments, { chan1: "s1" });
+});
+
+test("stripOrphanedAssignments: store with no orphans returns same reference", () => {
+  const store = makeStore({
+    sections: [makeSection({ id: "s1" })],
+    assignments: { chan1: "s1" },
+  });
+  assert.equal(stripOrphanedAssignments(store), store);
+});
+
+test("stripOrphanedAssignments: store with orphaned assignments returns new object without them", () => {
+  const store = makeStore({
+    sections: [makeSection({ id: "s1" })],
+    assignments: { chan1: "s1", chan2: "ghost" },
+  });
+  const result = stripOrphanedAssignments(store);
+  assert.notEqual(result, store);
+  assert.deepEqual(result.assignments, { chan1: "s1" });
+});
+
+test("stripOrphanedAssignments: store with all valid assignments returns same reference", () => {
+  const store = makeStore({
+    sections: [
+      makeSection({ id: "s1" }),
+      makeSection({ id: "s2", name: "B", order: 1 }),
+    ],
+    assignments: { chan1: "s1", chan2: "s2" },
+  });
+  assert.equal(stripOrphanedAssignments(store), store);
+});
+
+test("stripOrphanedAssignments: empty store returns same reference", () => {
+  const store = makeStore({ sections: [], assignments: {} });
+  assert.equal(stripOrphanedAssignments(store), store);
+});
+
+test("writeChannelSectionsStore + readChannelSectionsStore: write then read returns same data", () => {
+  const pubkey = "pk-roundtrip";
+  const store = makeStore({
+    sections: [makeSection({ id: "s1", name: "Work", order: 0 })],
+    assignments: { chan1: "s1" },
+  });
+  const written = writeChannelSectionsStore(pubkey, store);
+  assert.equal(written, true);
+  const result = readChannelSectionsStore(pubkey);
+  assert.deepEqual(result, store);
+});
+
+test("readChannelSectionsStore: non-existent key returns DEFAULT_STORE", () => {
+  const result = readChannelSectionsStore("pk-does-not-exist-xyz");
+  assert.deepEqual(result, DEFAULT_STORE);
+});
+
+test("readChannelSectionsStore: corrupt JSON returns DEFAULT_STORE", () => {
+  const pubkey = "pk-corrupt";
+  window.localStorage.setItem(storageKey(pubkey), "not-valid-json{{{");
+  const result = readChannelSectionsStore(pubkey);
+  assert.deepEqual(result, DEFAULT_STORE);
+});
+
+test("readChannelSectionsStore: object with wrong version returns DEFAULT_STORE", () => {
+  const pubkey = "pk-wrong-version";
+  window.localStorage.setItem(
+    storageKey(pubkey),
+    JSON.stringify({ version: 2, sections: [], assignments: {} }),
+  );
+  const result = readChannelSectionsStore(pubkey);
+  assert.deepEqual(result, DEFAULT_STORE);
+});
+
+test("writeChannelSectionsStore: returns false when setItem throws", () => {
+  const pubkey = "pk-throws";
+  const original = window.localStorage.setItem;
+  window.localStorage.setItem = () => {
+    throw new Error("storage full");
+  };
+  try {
+    const result = writeChannelSectionsStore(pubkey, makeStore());
+    assert.equal(result, false);
+  } finally {
+    window.localStorage.setItem = original;
+  }
+});
+
+test("storageKey: returns expected format with pubkey", () => {
+  assert.equal(storageKey("abc123"), "sprout-channel-sections.v1:abc123");
+});
diff --git a/desktop/src/features/sidebar/lib/channelSectionsSync.ts b/desktop/src/features/sidebar/lib/channelSectionsSync.ts
new file mode 100644
index 000000000..52008f77d
--- /dev/null
+++ b/desktop/src/features/sidebar/lib/channelSectionsSync.ts
@@ -0,0 +1,146 @@
+import { relayClient } from "@/shared/api/relayClient";
+import {
+  nip44DecryptFromSelf,
+  nip44EncryptToSelf,
+  signRelayEvent,
+} from "@/shared/api/tauri";
+import type { RelayEvent } from "@/shared/api/types";
+import { KIND_CHANNEL_SECTIONS } from "@/shared/constants/kinds";
+import {
+  parseChannelSectionPayload,
+  type ChannelSectionStore,
+} from "./channelSectionsStorage";
+
+const D_TAG = "channel-sections";
+const DEBOUNCE_MS = 2_000;
+
+export type RemoteSections = {
+  store: ChannelSectionStore;
+  createdAt: number;
+  eventId: string;
+};
+
+let debounceTimer: number | null = null;
+let lastRemoteCreatedAt = 0;
+let pendingStore: ChannelSectionStore | null = null;
+
+async function decryptAndParse(
+  event: RelayEvent,
+): Promise<RemoteSections | null> {
+  try {
+    const plaintext = await nip44DecryptFromSelf(event.content);
+    const store = parseChannelSectionPayload(JSON.parse(plaintext));
+    if (!store) return null;
+    return { store, createdAt: event.created_at, eventId: event.id };
+  } catch {
+    return null;
+  }
+}
+
+export async function fetchRemoteSections(
+  pubkey: string,
+): Promise<RemoteSections | null> {
+  try {
+    const events = await relayClient.fetchEvents({
+      kinds: [KIND_CHANNEL_SECTIONS],
+      authors: [pubkey],
+      "#d": [D_TAG],
+      limit: 1,
+    });
+    if (events.length === 0) return null;
+    if (events[0].pubkey !== pubkey) return null;
+    const result = await decryptAndParse(events[0]);
+    if (result) {
+      lastRemoteCreatedAt = Math.max(lastRemoteCreatedAt, result.createdAt);
+    }
+    return result;
+  } catch {
+    return null;
+  }
+}
+
+export function cancelPendingPublish(): void {
+  if (debounceTimer !== null) {
+    window.clearTimeout(debounceTimer);
+    debounceTimer = null;
+  }
+}
+
+export function getPendingStore(): ChannelSectionStore | null {
+  return pendingStore;
+}
+
+export function publishSections(store: ChannelSectionStore): void {
+  pendingStore = store;
+  if (debounceTimer !== null) {
+    window.clearTimeout(debounceTimer);
+  }
+  debounceTimer = window.setTimeout(() => {
+    debounceTimer = null;
+    void doPublish(store);
+  }, DEBOUNCE_MS);
+}
+
+async function doPublish(store: ChannelSectionStore): Promise<void> {
+  try {
+    const payload = {
+      sections: store.sections,
+      assignments: store.assignments,
+    };
+    const ciphertext = await nip44EncryptToSelf(JSON.stringify(payload));
+    const createdAt = Math.max(
+      Math.floor(Date.now() / 1_000),
+      lastRemoteCreatedAt + 1,
+    );
+    const event = await signRelayEvent({
+      kind: KIND_CHANNEL_SECTIONS,
+      content: ciphertext,
+      createdAt,
+      tags: [
+        ["d", D_TAG],
+        ["t", D_TAG], // relay discoverability; not used in our filters
+      ],
+    });
+    await relayClient.publishEvent(
+      event,
+      "Timed out publishing channel sections.",
+      "Failed to publish channel sections.",
+    );
+    lastRemoteCreatedAt = Math.max(lastRemoteCreatedAt, event.created_at);
+    pendingStore = null;
+  } catch (error) {
+    console.warn("[channelSectionsSync] publish failed:", error);
+  }
+}
+
+export async function subscribeToSections(
+  pubkey: string,
+  onUpdate: (remote: RemoteSections) => void,
+): Promise<() => Promise<void>> {
+  return relayClient.subscribeLive(
+    {
+      kinds: [KIND_CHANNEL_SECTIONS],
+      authors: [pubkey],
+      "#d": [D_TAG],
+      limit: 0,
+    },
+    (event: RelayEvent) => {
+      if (event.pubkey !== pubkey) return;
+      void decryptAndParse(event).then((result) => {
+        if (result) {
+          lastRemoteCreatedAt = Math.max(lastRemoteCreatedAt, result.createdAt);
+          onUpdate(result);
+        }
+      });
+    },
+  );
+}
+
+export function resetSyncState(): void {
+  if (debounceTimer !== null) {
+    window.clearTimeout(debounceTimer);
+    debounceTimer = null;
+  }
+  lastRemoteCreatedAt = 0;
+  pendingStore = null;
+}
diff --git a/desktop/src/features/sidebar/lib/useChannelSections.ts b/desktop/src/features/sidebar/lib/useChannelSections.ts
index 2052299b0..090b7e285 100644
--- a/desktop/src/features/sidebar/lib/useChannelSections.ts
+++ b/desktop/src/features/sidebar/lib/useChannelSections.ts
@@ -1,11 +1,22 @@
 import * as React from "react";
 
+import { relayClient } from "@/shared/api/relayClient";
 import {
   DEFAULT_STORE,
   readChannelSectionsStore,
   storageKey,
   writeChannelSectionsStore,
 } from "./channelSectionsStorage";
+import {
+  cancelPendingPublish,
+  fetchRemoteSections,
+  getPendingStore,
+  publishSections,
+  resetSyncState,
+  subscribeToSections,
+} from "./channelSectionsSync";
+import type { RemoteSections } from "./channelSectionsSync";
+import { swapSectionOrder } from "./channelSectionsHelpers";
 
 export type { ChannelSection } from "./channelSectionsStorage";
 
@@ -33,12 +44,22 @@ export function useChannelSections(pubkey: string | undefined): {
     return readChannelSectionsStore(pubkey);
   });
 
+  const lastAppliedRemoteTs = React.useRef(0);
+  const lastAppliedEventId = React.useRef("");
+
   React.useEffect(() => {
     if (!pubkey) {
       setStore(DEFAULT_STORE);
+      lastAppliedRemoteTs.current = 0;
+      lastAppliedEventId.current = "";
       return;
     }
     setStore(readChannelSectionsStore(pubkey));
+    lastAppliedRemoteTs.current = 0;
+    lastAppliedEventId.current = "";
+    return () => {
+      resetSyncState();
+    };
   }, [pubkey]);
 
   React.useEffect(() => {
@@ -58,6 +79,87 @@ export function useChannelSections(pubkey: string | undefined): {
     };
   }, [pubkey]);
 
+  const applyRemote = React.useCallback(
+    (
+      remote: RemoteSections,
+    ): ((prev: ChannelSectionStore) => ChannelSectionStore) => {
+      return (prev) => {
+        if (remote.createdAt < lastAppliedRemoteTs.current) return prev;
+        if (
+          remote.createdAt === lastAppliedRemoteTs.current &&
+          remote.eventId >= lastAppliedEventId.current
+        )
+          return prev;
+        lastAppliedRemoteTs.current = remote.createdAt;
+        lastAppliedEventId.current = remote.eventId;
+        cancelPendingPublish();
+        if (!writeChannelSectionsStore(pubkey!, remote.store)) return prev;
+        return remote.store;
+      };
+    },
+    [pubkey],
+  );
+
+  React.useEffect(() => {
+    if (!pubkey) return;
+    let cancelled = false;
+    void fetchRemoteSections(pubkey).then((remote) => {
+      if (cancelled) return;
+      if (remote) {
+        setStore(applyRemote(remote));
+      } else {
+        const local = readChannelSectionsStore(pubkey);
+        if (local.sections.length > 0) {
+          publishSections(local);
+        }
+      }
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, [pubkey, applyRemote]);
+
+  React.useEffect(() => {
+    if (!pubkey) return;
+    let unsub: (() => Promise<void>) | null = null;
+    let cancelled = false;
+    void subscribeToSections(pubkey, (remote) => {
+      if (cancelled) return;
+      setStore(applyRemote(remote));
+    }).then((dispose) => {
+      if (cancelled) {
+        void dispose();
+      } else {
+        unsub = dispose;
+      }
+    });
+    return () => {
+      cancelled = true;
+      if (unsub) void unsub();
+    };
+  }, [pubkey, applyRemote]);
+
+  React.useEffect(() => {
+    if (!pubkey) return;
+    let cancelled = false;
+    const unsub = relayClient.subscribeToReconnects(() => {
+      void fetchRemoteSections(pubkey).then((remote) => {
+        if (cancelled) return;
+        if (remote) {
+          setStore(applyRemote(remote));
+        }
+        const pending = getPendingStore();
+        if (pending) {
+          publishSections(pending);
+        }
+      });
+    });
+    return () => {
+      cancelled = true;
+      unsub();
+    };
+  }, [pubkey, applyRemote]);
+
   const sections = React.useMemo<ChannelSection[]>(
     () => store.sections.slice().sort((a, b) => a.order - b.order),
     [store.sections],
@@ -65,31 +167,27 @@ export function useChannelSections(pubkey: string | undefined): {
 
   const createSection = React.useCallback(
     (name: string): ChannelSection | null => {
-      if (!pubkey) {
-        return null;
-      }
-      let created: ChannelSection | null = null;
-      setStore((prev) => {
-        const maxOrder =
-          prev.sections.length > 0
-            ? Math.max(...prev.sections.map((s) => s.order))
-            : -1;
-        const section: ChannelSection = {
-          id: crypto.randomUUID(),
-          name,
-          order: maxOrder + 1,
-        };
+      if (!pubkey) return null;
+      const prev = readChannelSectionsStore(pubkey);
+      const maxOrder =
+        prev.sections.length > 0
+          ? Math.max(...prev.sections.map((s) => s.order))
+          : -1;
+      const section: ChannelSection = {
+        id: crypto.randomUUID(),
+        name,
+        order: maxOrder + 1,
+      };
+      setStore((current) => {
         const next: ChannelSectionStore = {
-          ...prev,
-          sections: [...prev.sections, section],
+          ...current,
+          sections: [...current.sections, section],
         };
-        if (!writeChannelSectionsStore(pubkey, next)) {
-          return prev;
-        }
-        created = section;
+        if (!writeChannelSectionsStore(pubkey, next)) return current;
+        publishSections(next);
         return next;
       });
-      return created;
+      return section;
     },
     [pubkey],
   );
@@ -109,6 +207,7 @@ export function useChannelSections(pubkey: string | undefined): {
         if (!writeChannelSectionsStore(pubkey, next)) {
           return prev;
         }
+        publishSections(next);
         return next;
       });
     },
@@ -135,6 +234,7 @@ export function useChannelSections(pubkey: string | undefined): {
         if (!writeChannelSectionsStore(pubkey, next)) {
           return prev;
         }
+        publishSections(next);
         return next;
       });
     },
@@ -143,33 +243,11 @@ export function useChannelSections(pubkey: string | undefined): {
 
   const moveSectionUp = React.useCallback(
     (sectionId: string) => {
-      if (!pubkey) {
-        return;
-      }
+      if (!pubkey) return;
       setStore((prev) => {
-        const target = prev.sections.find((s) => s.id === sectionId);
-        if (!target) {
-          return prev;
-        }
-        const sorted = prev.sections.slice().sort((a, b) => a.order - b.order);
-        const idx = sorted.findIndex((s) => s.id === sectionId);
-        if (idx <= 0) {
-          return prev;
-        }
-        const neighbor = sorted[idx - 1];
-        const sections = prev.sections.map((s) => {
-          if (s.id === target.id) {
-            return { ...s, order: neighbor.order };
-          }
-          if (s.id === neighbor.id) {
-            return { ...s, order: target.order };
-          }
-          return s;
-        });
-        const next: ChannelSectionStore = { ...prev, sections };
-        if (!writeChannelSectionsStore(pubkey, next)) {
-          return prev;
-        }
+        const next = swapSectionOrder(prev, sectionId, "up");
+        if (!next || !writeChannelSectionsStore(pubkey, next)) return prev;
+        publishSections(next);
         return next;
       });
     },
@@ -178,33 +256,11 @@ export function useChannelSections(pubkey: string | undefined): {
 
   const moveSectionDown = React.useCallback(
     (sectionId: string) => {
-      if (!pubkey) {
-        return;
-      }
+      if (!pubkey) return;
       setStore((prev) => {
-        const target = prev.sections.find((s) => s.id === sectionId);
-        if (!target) {
-          return prev;
-        }
-        const sorted = prev.sections.slice().sort((a, b) => a.order - b.order);
-        const idx = sorted.findIndex((s) => s.id === sectionId);
-        if (idx < 0 || idx >= sorted.length - 1) {
-          return prev;
-        }
-        const neighbor = sorted[idx + 1];
-        const sections = prev.sections.map((s) => {
-          if (s.id === target.id) {
-            return { ...s, order: neighbor.order };
-          }
-          if (s.id === neighbor.id) {
-            return { ...s, order: target.order };
-          }
-          return s;
-        });
-        const next: ChannelSectionStore = { ...prev, sections };
-        if (!writeChannelSectionsStore(pubkey, next)) {
-          return prev;
-        }
+        const next = swapSectionOrder(prev, sectionId, "down");
+        if (!next || !writeChannelSectionsStore(pubkey, next)) return prev;
+        publishSections(next);
         return next;
       });
     },
@@ -240,6 +296,7 @@ export function useChannelSections(pubkey: string | undefined): {
         if (!writeChannelSectionsStore(pubkey, next)) {
           return prev;
         }
+        publishSections(next);
         return next;
       });
     },
@@ -258,6 +315,7 @@ export function useChannelSections(pubkey: string | undefined): {
         if (!writeChannelSectionsStore(pubkey, next)) {
           return prev;
         }
+        publishSections(next);
         return next;
       });
     },
diff --git a/desktop/src/features/workspaces/useWorkspaceInit.ts b/desktop/src/features/workspaces/useWorkspaceInit.ts
index 8da3e949d..335ed8147 100644
--- a/desktop/src/features/workspaces/useWorkspaceInit.ts
+++ b/desktop/src/features/workspaces/useWorkspaceInit.ts
@@ -10,6 +10,7 @@ import { resetMediaCaches } from "@/shared/lib/mediaUrl";
 import { clearSearchHitEventCache } from "@/app/navigation/searchHitEventCache";
 import { clearAllDrafts } from "@/features/messages/lib/useDrafts";
 import { resetAgentObserverStore } from "@/features/agents/observerRelayStore";
+import { resetSyncState } from "@/features/sidebar/lib/channelSectionsSync";
 
 import { initFirstWorkspace } from "./workspaceStorage";
 import type { Workspace } from "./types";
@@ -26,6 +27,7 @@ function resetWorkspaceState(): void {
   resetMediaCaches();
   clearSearchHitEventCache();
   clearAllDrafts();
+  resetSyncState();
 }
 
 type WorkspaceInitResult =
diff --git a/desktop/src/shared/constants/kinds.ts b/desktop/src/shared/constants/kinds.ts
index 73028596f..bed88adad 100644
--- a/desktop/src/shared/constants/kinds.ts
+++ b/desktop/src/shared/constants/kinds.ts
@@ -16,7 +16,10 @@ export const KIND_FORUM_POST = 45001;
 export const KIND_FORUM_COMMENT = 45003;
 export const KIND_APPROVAL_REQUEST = 46010;
 export const KIND_TYPING_INDICATOR = 20002;
+// NIP-78 application-specific data. Both use kind 30078; the relay
+// differentiates them by d-tag ("read-state:<slotId>" vs "channel-sections").
 export const KIND_READ_STATE = 30078;
+export const KIND_CHANNEL_SECTIONS = 30078;
 export const KIND_USER_STATUS = 30315;
 export const KIND_AGENT_OBSERVER_FRAME = 24200;
 export const KIND_REPO_ANNOUNCEMENT = 30617;