M3 reminders: notes.remind_at + Reminders view

- Migration 0010: notes.remind_at (nullable tz). PATCH accepts remind_at
  (ISO set / null clear); GET /api/notes/reminders (soonest first, non-trashed);
  serialize includes remind_at.
- Frontend: datetime util (local<->ISO, format, overdue); notes store setReminder;
  editor datetime-local picker + clear; card reminder chip (overdue = red);
  sidebar Reminders entry + /reminders view.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

alembic/versions/0010_note_reminder.py

@@ -0,0 +1,21 @@
+"""notes.remind_at
+
+Revision ID: 0010
+Revises: 0009
+Create Date: 2026-07-20
+"""
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0010"
+down_revision = "0009"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("notes", sa.Column("remind_at", sa.DateTime(timezone=True), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("notes", "remind_at")

frontend/src/components/AppShell.vue

@@ -130,6 +130,13 @@ async function signOut() {
           <RouterLink to="/trash" class="nav-link" :class="route.name === 'trash' ? 'nav-link-active' : ''">
             <Icon name="trash" /> Trash
           </RouterLink>
+          <RouterLink
+            to="/reminders"
+            class="nav-link"
+            :class="route.name === 'reminders' ? 'nav-link-active' : ''"
+          >
+            <Icon name="bell" /> Reminders
+          </RouterLink>
         </nav>
       </aside>
 

frontend/src/components/Icon.vue

@@ -17,6 +17,7 @@ const paths: Record<string, string> = {
   checkbox: '<rect width="18" height="18" x="3" y="3" rx="2"/><path d="m9 12 2 2 4-4"/>',
   image: '<rect width="18" height="18" x="3" y="3" rx="2"/><circle cx="9" cy="9" r="2"/><path d="m21 15-3.086-3.086a2 2 0 0 0-2.828 0L6 21"/>',
   graph: '<circle cx="18" cy="5" r="3"/><circle cx="6" cy="12" r="3"/><circle cx="18" cy="19" r="3"/><line x1="8.59" x2="15.42" y1="13.51" y2="17.49"/><line x1="15.41" x2="8.59" y1="6.51" y2="10.49"/>',
+  bell: '<path d="M10.268 21a2 2 0 0 0 3.464 0"/><path d="M3.262 15.326A1 1 0 0 0 4 17h16a1 1 0 0 0 .74-1.673C19.41 13.956 18 12.499 18 8A6 6 0 0 0 6 8c0 4.499-1.411 5.956-2.738 7.326"/>',
 };
 </script>
 

frontend/src/components/NoteCard.vue

@@ -5,6 +5,7 @@ import type { Note } from "../stores/notes";
 import Icon from "./Icon.vue";
 import LinkedText from "./LinkedText.vue";
 import NoteChecklist from "./NoteChecklist.vue";
+import { formatReminder, isOverdue } from "../notes/datetime";
 
 defineProps<{ note: Note; reorderable?: boolean }>();
 const emit = defineEmits<{
@@ -79,6 +80,31 @@ function cardClass(color: NoteColor): string {
       >
     </div>
 
+    <div v-if="note.remind_at" class="mt-2">
+      <span
+        class="inline-flex items-center gap-1 rounded-full px-2 py-0.5 text-xs"
+        :class="
+          isOverdue(note.remind_at)
+            ? 'bg-red-100 text-red-700 dark:bg-red-950/50 dark:text-red-300'
+            : 'bg-black/5 text-neutral-600 dark:bg-white/10 dark:text-neutral-300'
+        "
+      >
+        <svg
+          class="h-3 w-3"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          stroke-width="2"
+          stroke-linecap="round"
+          stroke-linejoin="round"
+        >
+          <circle cx="12" cy="12" r="10" />
+          <polyline points="12 6 12 12 16 14" />
+        </svg>
+        {{ formatReminder(note.remind_at) }}
+      </span>
+    </div>
+
     <div
       class="mt-2 flex items-center justify-end gap-0.5 opacity-0 transition focus-within:opacity-100 group-hover:opacity-100"
     >

frontend/src/components/NoteEditor.vue

@@ -7,6 +7,7 @@ import ColorPicker from "./ColorPicker.vue";
 import Icon from "./Icon.vue";
 import LabelPicker from "./LabelPicker.vue";
 import NoteChecklist from "./NoteChecklist.vue";
+import { fromLocalInput, toLocalInput } from "../notes/datetime";
 import type { Note, NoteLabel } from "../stores/notes";
 import type { NoteColor } from "../notes/colors";
 
@@ -86,6 +87,12 @@ async function openLink(link: { title: string; id: string | null }) {
   emit("navigate", created.id);
 }
 
+const reminderLocal = computed(() => toLocalInput(liveNote.value.remind_at));
+
+function onReminderChange(e: Event) {
+  void notes.setReminder(props.note.id, fromLocalInput((e.target as HTMLInputElement).value));
+}
+
 async function onLabelsChange(next: NoteLabel[]) {
   labelList.value = next;
   await notes.setLabels(
@@ -226,6 +233,24 @@ async function act(fn: () => Promise<void>) {
           </span>
         </div>
 
+        <div class="flex items-center gap-2 pt-1">
+          <Icon name="bell" class="text-neutral-400" />
+          <input
+            type="datetime-local"
+            :value="reminderLocal"
+            class="rounded-md border border-neutral-300 bg-white px-2 py-1 text-xs text-neutral-700 outline-none focus-visible:ring-2 focus-visible:ring-brand dark:border-neutral-700 dark:bg-neutral-800 dark:text-neutral-200"
+            @change="onReminderChange"
+          />
+          <button
+            v-if="liveNote.remind_at"
+            type="button"
+            class="text-xs text-neutral-400 hover:text-neutral-700 dark:hover:text-neutral-200"
+            @click="notes.setReminder(note.id, null)"
+          >
+            Clear
+          </button>
+        </div>
+
         <div
           v-if="outgoingLinks.length || backlinks.length"
           class="flex flex-col gap-2 border-t border-neutral-100 pt-2 dark:border-neutral-800"

frontend/src/notes/datetime.ts

@@ -0,0 +1,28 @@
+// Reminder datetime helpers. Reminders are stored as ISO UTC; the editor's
+// <input type="datetime-local"> works in local time.
+
+export function toLocalInput(iso: string | null): string {
+  if (!iso) return "";
+  const d = new Date(iso);
+  const pad = (n: number) => String(n).padStart(2, "0");
+  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}T${pad(d.getHours())}:${pad(d.getMinutes())}`;
+}
+
+export function fromLocalInput(local: string): string | null {
+  if (!local) return null;
+  return new Date(local).toISOString();
+}
+
+export function formatReminder(iso: string | null): string {
+  if (!iso) return "";
+  return new Date(iso).toLocaleString(undefined, {
+    month: "short",
+    day: "numeric",
+    hour: "numeric",
+    minute: "2-digit",
+  });
+}
+
+export function isOverdue(iso: string | null): boolean {
+  return !!iso && new Date(iso).getTime() < Date.now();
+}

frontend/src/router/index.ts

@@ -17,6 +17,7 @@ const router = createRouter({
         { path: "label/:id", name: "label", component: () => import("../views/BoardView.vue") },
         { path: "search", name: "search", component: () => import("../views/SearchView.vue") },
         { path: "graph", name: "graph", component: () => import("../views/GraphView.vue") },
+        { path: "reminders", name: "reminders", component: () => import("../views/RemindersView.vue") },
       ],
     },
     {

frontend/src/stores/notes.ts

@@ -34,6 +34,7 @@ export interface Note {
   pinned: boolean;
   archived: boolean;
   trashed: boolean;
+  remind_at: string | null;
   labels: NoteLabel[];
   items: ChecklistItem[];
   attachments: Attachment[];
@@ -95,7 +96,7 @@ export const useNotesStore = defineStore("notes", () => {
 
   async function mutate(
     id: string,
-    changes: Partial<Pick<Note, "title" | "body" | "color" | "kind" | "pinned" | "archived">>,
+    changes: Partial<Pick<Note, "title" | "body" | "color" | "kind" | "pinned" | "archived" | "remind_at">>,
   ): Promise<void> {
     reconcile(await api.patch<Note>(`/api/notes/${id}`, changes));
   }
@@ -104,6 +105,7 @@ export const useNotesStore = defineStore("notes", () => {
   const setArchived = (id: string, archived: boolean) => mutate(id, { archived });
   const setColor = (id: string, color: NoteColor) => mutate(id, { color });
   const setKind = (id: string, kind: NoteKind) => mutate(id, { kind });
+  const setReminder = (id: string, remindAt: string | null) => mutate(id, { remind_at: remindAt });
   const saveEdit = (id: string, changes: { title: string; body: string; color: NoteColor }) => mutate(id, changes);
 
   async function setLabels(id: string, labelIds: string[]): Promise<void> {
@@ -192,6 +194,7 @@ export const useNotesStore = defineStore("notes", () => {
     setArchived,
     setColor,
     setKind,
+    setReminder,
     saveEdit,
     setLabels,
     addItem,

frontend/src/views/RemindersView.vue

@@ -0,0 +1,57 @@
+<script setup lang="ts">
+import { onMounted, ref } from "vue";
+import { api } from "../api/client";
+import { useNotesStore, type Note } from "../stores/notes";
+import NoteCard from "../components/NoteCard.vue";
+import NoteEditor from "../components/NoteEditor.vue";
+
+const notes = useNotesStore();
+const items = ref<Note[]>([]);
+const loading = ref(true);
+const editing = ref<Note | null>(null);
+
+async function load() {
+  loading.value = true;
+  try {
+    const res = await api.get<{ notes: Note[] }>("/api/notes/reminders");
+    items.value = res.notes;
+  } finally {
+    loading.value = false;
+  }
+}
+
+function openEditor(n: Note) {
+  editing.value = n;
+}
+async function closeEditor() {
+  editing.value = null;
+  await load();
+}
+async function onNavigate(id: string) {
+  const found = items.value.find((n) => n.id === id) ?? notes.items.find((n) => n.id === id);
+  editing.value = found ?? (await notes.fetchOne(id));
+}
+
+onMounted(load);
+</script>
+
+<template>
+  <div class="mx-auto w-full max-w-6xl px-4 py-6">
+    <h1 class="mb-4 text-lg font-semibold">Reminders</h1>
+
+    <div v-if="loading" class="py-24 text-center text-sm text-neutral-400">Loading…</div>
+
+    <div v-else-if="items.length === 0" class="py-24 text-center">
+      <h2 class="text-lg font-semibold text-neutral-700 dark:text-neutral-200">No reminders</h2>
+      <p class="mt-1 text-sm text-neutral-400">Set a reminder on a note (in its editor) to see it here.</p>
+    </div>
+
+    <div v-else class="columns-1 gap-4 sm:columns-2 lg:columns-3 xl:columns-4">
+      <NoteCard v-for="n in items" :key="n.id" :note="n" @open="openEditor" />
+    </div>
+
+    <template v-if="editing">
+      <NoteEditor :note="editing" @close="closeEditor" @navigate="onNavigate" />
+    </template>
+  </div>
+</template>

src/thoughtsync/models/note.py

@@ -48,6 +48,8 @@ class Note(Base):
     archived: Mapped[bool] = mapped_column(Boolean(), nullable=False, server_default=func.false())
     # Soft delete: non-null => in Trash. Restore sets it back to null.
     deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    # Optional reminder time (surfaced in the Reminders view; no push in M3).
+    remind_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
@@ -64,6 +66,7 @@ class Note(Base):
             "pinned": self.pinned,
             "archived": self.archived,
             "trashed": self.deleted_at is not None,
+            "remind_at": self.remind_at.isoformat() if self.remind_at else None,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
         }

src/thoughtsync/notes.py

@@ -198,6 +198,23 @@ async def search_notes():
         return jsonify({"notes": await _serialize_notes(db, notes)})
 
 
+@bp.get("/reminders")
+@login_required
+async def list_reminders():
+    async with session_scope() as db:
+        stmt = (
+            select(Note)
+            .where(
+                visible_to_user("note", Note.owner_id, Note.id, g.user_id),
+                Note.deleted_at.is_(None),
+                Note.remind_at.is_not(None),
+            )
+            .order_by(Note.remind_at.asc())
+        )
+        notes = (await db.scalars(stmt)).all()
+        return jsonify({"notes": await _serialize_notes(db, notes)})
+
+
 @bp.get("/titles")
 @login_required
 async def list_titles():
@@ -343,6 +360,15 @@ async def update_note(note_id: str):
             note.pinned = bool(data["pinned"])
         if "archived" in data:
             note.archived = bool(data["archived"])
+        if "remind_at" in data:
+            raw = data["remind_at"]
+            if raw in (None, ""):
+                note.remind_at = None
+            else:
+                try:
+                    note.remind_at = datetime.fromisoformat(str(raw).replace("Z", "+00:00"))
+                except ValueError:
+                    return jsonify({"error": "invalid remind_at"}), 400
         if "body" in data:
             await _rewrite_links(db, note)
         await db.commit()

tests/test_notes.py

@@ -96,3 +96,9 @@ async def test_graph_requires_auth(app):
     client = app.test_client()
     resp = await client.get("/api/graph")
     assert resp.status_code == 401
+
+
+async def test_reminders_requires_auth(app):
+    client = app.test_client()
+    resp = await client.get("/api/notes/reminders")
+    assert resp.status_code == 401