diff --git a/CHANGELOG.md b/CHANGELOG.md
index d663d7389..b2407e5d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 ## [Unreleased]
 
+## [1.13.0] — 2026-06-05 — your own mood tags
+
+### Added
+
+- **Make the mood-tag list your own.** You can now create your own custom mood tags, give each a label and an icon, and hide any of the built-in tags you don't use — so the tag picker shows exactly the set that fits you. Custom tags work everywhere a built-in tag does: logging, history, and the analysis. Custom tag names are encrypted at rest like the rest of your personal content. Deleting a custom tag keeps it on your past entries by default; a separate purge removes it from history too.
+
 ## [1.12.12] — 2026-06-05 — the period retrospective is never empty
 
 ### Added
diff --git a/docs/api/openapi.yaml b/docs/api/openapi.yaml
index f52dc9819..c2a5a4fca 100644
--- a/docs/api/openapi.yaml
+++ b/docs/api/openapi.yaml
@@ -1,7 +1,7 @@
 openapi: 3.1.0
 info:
   title: HealthLog API
-  version: 1.12.12
+  version: 1.13.0
   description: >-
     Self-hosted personal-health-tracking PWA — public API surface for the iOS native client and external ingest.
 
diff --git a/messages/de.json b/messages/de.json
index d87fc7340..c252373ab 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -531,7 +531,8 @@
       "social": "Soziales",
       "work": "Arbeit",
       "hobbies": "Hobbys",
-      "factors": "Faktoren"
+      "factors": "Faktoren",
+      "custom": "Eigene"
     },
     "tag": {
       "happy": "glücklich",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Geteilt aus HealthLog — einem selbst gehosteten Gesundheits-Tracker."
   }
-}
+}
\ No newline at end of file
diff --git a/messages/en.json b/messages/en.json
index 34cd6f238..de823f4ee 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -531,7 +531,8 @@
       "social": "Social",
       "work": "Work",
       "hobbies": "Hobbies",
-      "factors": "Factors"
+      "factors": "Factors",
+      "custom": "Custom"
     },
     "tag": {
       "happy": "happy",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Shared from HealthLog — a self-hosted personal health tracker."
   }
-}
+}
\ No newline at end of file
diff --git a/messages/es.json b/messages/es.json
index f77e0498f..3d49d0d69 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -531,7 +531,8 @@
       "social": "Social",
       "work": "Trabajo",
       "hobbies": "Aficiones",
-      "factors": "Factores"
+      "factors": "Factores",
+      "custom": "Personalizadas"
     },
     "tag": {
       "happy": "feliz",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Compartido desde HealthLog — un registro de salud autoalojado."
   }
-}
+}
\ No newline at end of file
diff --git a/messages/fr.json b/messages/fr.json
index 5cbdafd73..bb058fce4 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -531,7 +531,8 @@
       "social": "Social",
       "work": "Travail",
       "hobbies": "Loisirs",
-      "factors": "Facteurs"
+      "factors": "Facteurs",
+      "custom": "Personnalisées"
     },
     "tag": {
       "happy": "heureux",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Partagé depuis HealthLog — un suivi de santé auto-hébergé."
   }
-}
+}
\ No newline at end of file
diff --git a/messages/it.json b/messages/it.json
index 71b82ecfa..b061550b9 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -531,7 +531,8 @@
       "social": "Sociale",
       "work": "Lavoro",
       "hobbies": "Hobby",
-      "factors": "Fattori"
+      "factors": "Fattori",
+      "custom": "Personalizzate"
     },
     "tag": {
       "happy": "felice",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Condiviso da HealthLog — un tracker della salute self-hosted."
   }
-}
+}
\ No newline at end of file
diff --git a/messages/pl.json b/messages/pl.json
index 368af74df..a20339a0f 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -531,7 +531,8 @@
       "social": "Społeczne",
       "work": "Praca",
       "hobbies": "Hobby",
-      "factors": "Czynniki"
+      "factors": "Czynniki",
+      "custom": "Własne"
     },
     "tag": {
       "happy": "szczęśliwy",
@@ -4813,4 +4814,4 @@
     },
     "footer": "Udostępnione z HealthLog — samodzielnie hostowanego trackera zdrowia."
   }
-}
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index f9cb44cf5..76e9523e4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "healthlog",
-  "version": "1.12.12",
+  "version": "1.13.0",
   "description": "Self-hosted personal-health-tracking PWA with Withings integration, AI insights, and doctor-report PDF export.",
   "license": "AGPL-3.0-only",
   "homepage": "https://healthlog.dev",
diff --git a/prisma/migrations/0127_v1130_custom_mood_tags/migration.sql b/prisma/migrations/0127_v1130_custom_mood_tags/migration.sql
new file mode 100644
index 000000000..0c35dbde3
--- /dev/null
+++ b/prisma/migrations/0127_v1130_custom_mood_tags/migration.sql
@@ -0,0 +1,52 @@
+-- v1.13.0 — per-user custom mood tags + per-user catalogue hide.
+--
+-- Additive, non-destructive:
+--   1. `mood_tags` gains `user_id` (NULL = global catalogue, set = a user's
+--      custom tag carrying a `custom:<cuid>` key) and `label_encrypted`
+--      (AES-256-GCM ciphertext of a custom tag's free-text label; NULL for
+--      catalogue rows, which resolve `label_key` against the locale).
+--   2. New `mood_tag_hidden` join: a per-user hide of a CATALOGUE tag.
+--   3. Seed the global `custom` category every user's custom tags hang under.
+--
+-- Idempotent: ADD COLUMN IF NOT EXISTS, CREATE TABLE IF NOT EXISTS, and the
+-- category seed upserts by `key` (deterministic id `mtc_custom`).
+
+-- ─── 1. mood_tags: owner + encrypted custom label ────────────────────
+ALTER TABLE "mood_tags" ADD COLUMN IF NOT EXISTS "user_id" TEXT;
+ALTER TABLE "mood_tags" ADD COLUMN IF NOT EXISTS "label_encrypted" TEXT;
+
+DO $$ BEGIN
+  ALTER TABLE "mood_tags"
+    ADD CONSTRAINT "mood_tags_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;
+
+CREATE INDEX IF NOT EXISTS "mood_tags_user_id_idx" ON "mood_tags"("user_id");
+
+-- ─── 2. mood_tag_hidden: per-user catalogue hide ─────────────────────
+CREATE TABLE IF NOT EXISTS "mood_tag_hidden" (
+  "user_id"     TEXT NOT NULL,
+  "mood_tag_id" TEXT NOT NULL,
+  "created_at"  TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  CONSTRAINT "mood_tag_hidden_pkey" PRIMARY KEY ("user_id", "mood_tag_id")
+);
+CREATE INDEX IF NOT EXISTS "mood_tag_hidden_mood_tag_id_idx" ON "mood_tag_hidden"("mood_tag_id");
+
+DO $$ BEGIN
+  ALTER TABLE "mood_tag_hidden"
+    ADD CONSTRAINT "mood_tag_hidden_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;
+DO $$ BEGIN
+  ALTER TABLE "mood_tag_hidden"
+    ADD CONSTRAINT "mood_tag_hidden_mood_tag_id_fkey"
+    FOREIGN KEY ("mood_tag_id") REFERENCES "mood_tags"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+EXCEPTION WHEN duplicate_object THEN NULL; END $$;
+
+-- ─── 3. Seed the global `custom` category ────────────────────────────
+INSERT INTO "mood_tag_categories"
+  ("id", "key", "label_key", "icon", "sort_order", "is_active")
+VALUES ('mtc_custom', 'custom', 'mood.tagCategory.custom', 'Tag', 100, true)
+ON CONFLICT ("key") DO UPDATE SET
+  "label_key" = EXCLUDED."label_key", "icon" = EXCLUDED."icon",
+  "sort_order" = EXCLUDED."sort_order", "is_active" = EXCLUDED."is_active";
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index 0fd25f1a6..52d1e7cbe 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -378,6 +378,8 @@ model User {
   fitbitConnection       FitbitConnection?
   fitbitOAuthStates      FitbitOAuthState[]
   moodEntries            MoodEntry[]
+  moodTagsCustom         MoodTag[]             @relation("UserMoodTags")
+  moodTagsHidden         MoodTagHidden[]
   notificationChannels   NotificationChannel[]
   pushSubscriptions      PushSubscription[]
   dataBackups            DataBackup[]
@@ -2131,13 +2133,42 @@ model MoodTag {
   /// analytics layer flips the sign so "up" always reads as "better".
   inverse  Boolean @default(false) @map("inverse")
 
+  /// v1.13.0 — owner of a per-user custom tag. NULL = the global catalogue
+  /// (every row seeded by migration; resolves `labelKey` against the locale).
+  /// Set = a user's own custom tag, carrying a `custom:<cuid>` key and a
+  /// free-text label held in `labelEncrypted`.
+  userId         String? @map("user_id")
+  /// v1.13.0 — AES-256-GCM ciphertext of a custom tag's free-text label
+  /// (user prose, possibly health-adjacent — e.g. "Migräne", "Therapie").
+  /// NULL for catalogue rows. Decrypted server-side for the effective read.
+  labelEncrypted String? @map("label_encrypted")
+
   category MoodTagCategory    @relation(fields: [categoryId], references: [id], onDelete: Cascade)
+  user     User?              @relation("UserMoodTags", fields: [userId], references: [id], onDelete: Cascade)
   links    MoodEntryTagLink[]
+  hiddenBy MoodTagHidden[]
 
   @@index([categoryId, sortOrder])
+  @@index([userId])
   @@map("mood_tags")
 }
 
+/// v1.13.0 — per-user hide of a CATALOGUE tag. Present = hidden from that
+/// user's effective picker; absent = visible. A custom tag is hidden by
+/// flipping its own `MoodTag.isActive` instead, never via this table.
+model MoodTagHidden {
+  userId    String   @map("user_id")
+  moodTagId String   @map("mood_tag_id")
+  createdAt DateTime @default(now()) @map("created_at")
+
+  user    User    @relation(fields: [userId], references: [id], onDelete: Cascade)
+  moodTag MoodTag @relation(fields: [moodTagId], references: [id], onDelete: Cascade)
+
+  @@id([userId, moodTagId])
+  @@index([moodTagId])
+  @@map("mood_tag_hidden")
+}
+
 // Join: which structured tags a mood entry carries. Composite PK keeps
 // the pairing unique; cascade on both sides so deleting an entry (or a
 // catalog tag) cleans up its links. Distinct from the flat `tags` JSON
diff --git a/src/app/api/mood/tags/[key]/hidden/route.ts b/src/app/api/mood/tags/[key]/hidden/route.ts
new file mode 100644
index 000000000..f1929bea5
--- /dev/null
+++ b/src/app/api/mood/tags/[key]/hidden/route.ts
@@ -0,0 +1,63 @@
+import { NextRequest } from "next/server";
+
+import { prisma } from "@/lib/db";
+import { apiSuccess, apiError, returnAllZodIssues } from "@/lib/api-response";
+import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { annotate } from "@/lib/logging/context";
+import { hideCatalogueTagSchema, isCustomTagKey } from "@/lib/mood/custom-tags";
+
+export const dynamic = "force-dynamic";
+
+type RouteParams = { params: Promise<{ key: string }> };
+
+/**
+ * v1.13.0 — hide / show a CATALOGUE tag for the calling user.
+ *
+ * `PUT /api/mood/tags/:key/hidden` — body `{ hidden: boolean }`. Inserts /
+ * removes a `mood_tag_hidden` row so the effective `GET /api/mood/tags` omits
+ * the tag for this user without touching the global catalogue. Custom tags
+ * are not hidden this way — flip their own `isActive` via the custom PATCH.
+ */
+export const PUT = apiHandler(
+  async (request: NextRequest, { params }: RouteParams) => {
+    const { user } = await requireAuth();
+    const { key } = await params;
+    if (isCustomTagKey(key)) {
+      return apiError(
+        "Custom tags are hidden via their isActive flag, not this route",
+        400,
+      );
+    }
+
+    const parsed = hideCatalogueTagSchema.safeParse(await request.json());
+    if (!parsed.success) return returnAllZodIssues(parsed.error, 422);
+
+    // Resolve against the catalogue (user_id NULL) only.
+    const tag = await prisma.moodTag.findFirst({
+      where: { key, userId: null },
+      select: { id: true },
+    });
+    if (!tag) return apiError("Catalogue tag not found", 404);
+
+    if (parsed.data.hidden) {
+      await prisma.moodTagHidden.upsert({
+        where: {
+          userId_moodTagId: { userId: user.id, moodTagId: tag.id },
+        },
+        create: { userId: user.id, moodTagId: tag.id },
+        update: {},
+      });
+    } else {
+      await prisma.moodTagHidden.deleteMany({
+        where: { userId: user.id, moodTagId: tag.id },
+      });
+    }
+
+    annotate({
+      action: { name: "mood.tag.hidden.set" },
+      meta: { hidden: parsed.data.hidden },
+    });
+
+    return apiSuccess({ key, hidden: parsed.data.hidden });
+  },
+);
diff --git a/src/app/api/mood/tags/__tests__/custom-crud.test.ts b/src/app/api/mood/tags/__tests__/custom-crud.test.ts
new file mode 100644
index 000000000..161ff255e
--- /dev/null
+++ b/src/app/api/mood/tags/__tests__/custom-crud.test.ts
@@ -0,0 +1,131 @@
+/**
+ * v1.13.0 — custom mood-tag CRUD route guards: create cap, ownership 404 on
+ * edit/delete, soft-delete vs purge, and the custom-key rejection on the
+ * catalogue-hide route.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { NextRequest } from "next/server";
+
+const db = vi.hoisted(() => ({
+  moodTag: {
+    count: vi.fn(),
+    create: vi.fn(),
+    findFirst: vi.fn(),
+    update: vi.fn(),
+    delete: vi.fn(),
+  },
+  moodTagHidden: { upsert: vi.fn(), deleteMany: vi.fn() },
+}));
+
+vi.mock("@/lib/db", () => ({ prisma: db }));
+vi.mock("@/lib/crypto", () => ({
+  encrypt: (s: string) => `enc:${s}`,
+  decrypt: (s: string) => s.replace(/^enc:/, ""),
+}));
+vi.mock("@/lib/auth/session", () => ({ getSession: vi.fn() }));
+vi.mock("@/lib/auth/audit", () => ({ auditLog: vi.fn().mockResolvedValue(undefined) }));
+vi.mock("@/lib/logging/transports", () => ({ emitIfSampled: vi.fn() }));
+vi.mock("@/lib/db-compat", () => ({ ensureDbCompatibility: vi.fn().mockResolvedValue(undefined) }));
+vi.mock("next/headers", () => ({
+  headers: vi.fn(async () => ({ get: () => null })),
+  cookies: vi.fn(async () => ({ get: () => undefined, set: () => {}, delete: () => {} })),
+}));
+
+import { POST } from "../custom/route";
+import { PATCH, DELETE } from "../custom/[key]/route";
+import { PUT } from "../[key]/hidden/route";
+import { getSession } from "@/lib/auth/session";
+
+const SESSION_OK = {
+  session: { id: "s1", expiresAt: new Date(Date.now() + 3_600_000) },
+  user: { id: "user-1", username: "t", role: "USER" as const },
+};
+
+function jsonReq(url: string, method: string, body: unknown) {
+  return new NextRequest(url, {
+    method,
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+});
+
+describe("POST /api/mood/tags/custom", () => {
+  it("creates a custom tag and returns it (custom:true, decrypted label)", async () => {
+    db.moodTag.count.mockResolvedValue(3);
+    db.moodTag.create.mockResolvedValue({
+      key: "custom:abc", icon: "Heart", kind: "BINARY", scaleMin: 1, scaleMax: 5, inverse: false,
+    });
+    const res = await POST(jsonReq("http://localhost/api/mood/tags/custom", "POST", { label: "Date night", icon: "Heart" }));
+    expect(res.status).toBe(201);
+    const body = (await res.json()) as { data: { custom: boolean; label: string; labelKey: null; key: string } };
+    expect(body.data).toMatchObject({ custom: true, label: "Date night", labelKey: null, key: "custom:abc" });
+    // Label is stored encrypted, never plaintext.
+    expect(db.moodTag.create.mock.calls[0][0].data.labelEncrypted).toBe("enc:Date night");
+  });
+
+  it("rejects over the per-user cap with 422", async () => {
+    db.moodTag.count.mockResolvedValue(50);
+    const res = await POST(jsonReq("http://localhost/api/mood/tags/custom", "POST", { label: "X" }));
+    expect(res.status).toBe(422);
+    expect(db.moodTag.create).not.toHaveBeenCalled();
+  });
+});
+
+describe("PATCH/DELETE /api/mood/tags/custom/:key", () => {
+  const params = (key: string) => ({ params: Promise.resolve({ key }) });
+
+  it("404s when the key is not the caller's own custom tag", async () => {
+    db.moodTag.findFirst.mockResolvedValue(null);
+    const res = await PATCH(
+      jsonReq("http://localhost/api/mood/tags/custom/custom:x", "PATCH", { isActive: false }),
+      params("custom:x"),
+    );
+    expect(res.status).toBe(404);
+  });
+
+  it("404s a non-custom key without touching the DB", async () => {
+    const res = await DELETE(new NextRequest("http://localhost/api/mood/tags/custom/happy"), params("happy"));
+    expect(res.status).toBe(404);
+    expect(db.moodTag.findFirst).not.toHaveBeenCalled();
+  });
+
+  it("soft-deactivates by default and hard-deletes on ?purge=true", async () => {
+    db.moodTag.findFirst.mockResolvedValue({ id: "id1" });
+    const soft = await DELETE(new NextRequest("http://localhost/api/mood/tags/custom/custom:abc"), params("custom:abc"));
+    expect(soft.status).toBe(200);
+    expect(db.moodTag.update).toHaveBeenCalledWith({ where: { id: "id1" }, data: { isActive: false } });
+    expect(db.moodTag.delete).not.toHaveBeenCalled();
+
+    vi.clearAllMocks();
+    vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+    db.moodTag.findFirst.mockResolvedValue({ id: "id1" });
+    const purge = await DELETE(new NextRequest("http://localhost/api/mood/tags/custom/custom:abc?purge=true"), params("custom:abc"));
+    expect(purge.status).toBe(200);
+    expect(db.moodTag.delete).toHaveBeenCalledWith({ where: { id: "id1" } });
+  });
+});
+
+describe("PUT /api/mood/tags/:key/hidden", () => {
+  it("rejects a custom key with 400 (custom tags hide via isActive)", async () => {
+    const res = await PUT(
+      jsonReq("http://localhost/api/mood/tags/custom:abc/hidden", "PUT", { hidden: true }),
+      { params: Promise.resolve({ key: "custom:abc" }) },
+    );
+    expect(res.status).toBe(400);
+  });
+
+  it("upserts a hide row for a catalogue tag", async () => {
+    db.moodTag.findFirst.mockResolvedValue({ id: "t_sad" });
+    const res = await PUT(
+      jsonReq("http://localhost/api/mood/tags/sad/hidden", "PUT", { hidden: true }),
+      { params: Promise.resolve({ key: "sad" }) },
+    );
+    expect(res.status).toBe(200);
+    expect(db.moodTagHidden.upsert).toHaveBeenCalled();
+  });
+});
diff --git a/src/app/api/mood/tags/__tests__/route.test.ts b/src/app/api/mood/tags/__tests__/route.test.ts
index a890bca48..6e300d3c2 100644
--- a/src/app/api/mood/tags/__tests__/route.test.ts
+++ b/src/app/api/mood/tags/__tests__/route.test.ts
@@ -1,18 +1,31 @@
 /**
- * v1.12.0 — `GET /api/mood/tags` must expose the rated-factor metadata
- * (`kind` / `scaleMin` / `scaleMax` / `inverse`) so the client can branch
- * between binary toggle chips and rated segmented controls.
+ * v1.12.0 / v1.13.0 — `GET /api/mood/tags` exposes the rated-factor metadata
+ * (`kind` / `scaleMin` / `scaleMax` / `inverse`) AND the v1.13.0 effective
+ * per-user set: own custom tags merged in (label decrypted, `custom: true`),
+ * hidden catalogue tags omitted by default and surfaced under
+ * `?include=hidden`.
  */
 import { beforeEach, describe, expect, it, vi } from "vitest";
+import { NextRequest } from "next/server";
 
 const categoryFindMany = vi.fn();
+const tagFindMany = vi.fn();
+const hiddenFindMany = vi.fn();
 
 vi.mock("@/lib/db", () => ({
   prisma: {
     moodTagCategory: { findMany: (...a: unknown[]) => categoryFindMany(...a) },
+    moodTag: { findMany: (...a: unknown[]) => tagFindMany(...a) },
+    moodTagHidden: { findMany: (...a: unknown[]) => hiddenFindMany(...a) },
   },
 }));
 
+// Identity-ish crypto so the decrypted custom label is asserted in plaintext.
+vi.mock("@/lib/crypto", () => ({
+  encrypt: (s: string) => `enc:${s}`,
+  decrypt: (s: string) => s.replace(/^enc:/, ""),
+}));
+
 vi.mock("@/lib/auth/session", () => ({ getSession: vi.fn() }));
 vi.mock("@/lib/auth/audit", () => ({
   auditLog: vi.fn().mockResolvedValue(undefined),
@@ -38,77 +51,89 @@ const SESSION_OK = {
   user: { id: "user-1", username: "tester", role: "USER" as const },
 };
 
+const CATEGORIES = [
+  { id: "c1", key: "feelings", labelKey: "mood.tagCategory.feelings", icon: "Smile" },
+  { id: "mtc_custom", key: "custom", labelKey: "mood.tagCategory.custom", icon: "Tag" },
+];
+
+const TAGS = [
+  { id: "t_happy", categoryId: "c1", key: "happy", labelKey: "mood.tag.happy", icon: "Smile", kind: "BINARY", scaleMin: 1, scaleMax: 5, inverse: false, userId: null, labelEncrypted: null },
+  { id: "t_sad", categoryId: "c1", key: "sad", labelKey: "mood.tag.sad", icon: "Frown", kind: "BINARY", scaleMin: 1, scaleMax: 5, inverse: false, userId: null, labelEncrypted: null },
+  { id: "t_custom", categoryId: "mtc_custom", key: "custom:abc", labelKey: "custom:abc", icon: "Heart", kind: "BINARY", scaleMin: 1, scaleMax: 5, inverse: false, userId: "user-1", labelEncrypted: "enc:Migräne" },
+];
+
+interface TagOut {
+  key: string;
+  labelKey: string | null;
+  label: string | null;
+  custom: boolean;
+  kind: string;
+  scaleMin: number;
+  scaleMax: number;
+  inverse: boolean;
+  hidden?: boolean;
+}
+interface Body {
+  data: { categories: Array<{ key: string; tags: TagOut[] }> };
+}
+
+function req(url = "http://localhost/api/mood/tags") {
+  return new NextRequest(url);
+}
+
 beforeEach(() => {
   vi.clearAllMocks();
   vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+  categoryFindMany.mockResolvedValue(CATEGORIES);
+  tagFindMany.mockResolvedValue(TAGS);
+  hiddenFindMany.mockResolvedValue([{ moodTagId: "t_sad" }]);
 });
 
-describe("GET /api/mood/tags — rated-factor catalog metadata (v1.12.0)", () => {
-  it("selects + emits kind / scaleMin / scaleMax / inverse per tag", async () => {
-    categoryFindMany.mockResolvedValue([
-      {
-        key: "factors",
-        labelKey: "mood.tagCategory.factors",
-        icon: "SlidersHorizontal",
-        tags: [
-          {
-            key: "factor_work",
-            labelKey: "mood.tag.factorWork",
-            icon: "Briefcase",
-            kind: "RATED",
-            scaleMin: 1,
-            scaleMax: 5,
-            inverse: false,
-          },
-          {
-            key: "factor_conflict",
-            labelKey: "mood.tag.factorConflict",
-            icon: "Swords",
-            kind: "RATED",
-            scaleMin: 1,
-            scaleMax: 2,
-            inverse: true,
-          },
-        ],
-      },
-    ]);
+function flat(body: Body): Record<string, TagOut> {
+  const out: Record<string, TagOut> = {};
+  for (const c of body.data.categories) for (const t of c.tags) out[t.key] = t;
+  return out;
+}
 
-    const res = await GET();
+describe("GET /api/mood/tags — effective per-user set (v1.13.0)", () => {
+  it("emits rated-factor metadata + custom/label fields and omits hidden by default", async () => {
+    const res = await GET(req());
     expect(res.status).toBe(200);
-    const body = (await res.json()) as {
-      data: {
-        categories: Array<{
-          key: string;
-          tags: Array<{
-            key: string;
-            kind: string;
-            scaleMin: number;
-            scaleMax: number;
-            inverse: boolean;
-          }>;
-        }>;
-      };
-    };
+    const tags = flat((await res.json()) as Body);
 
-    // The Prisma select must request the new columns.
-    const selectArg = categoryFindMany.mock.calls[0]?.[0] as {
-      select: { tags: { select: Record<string, boolean> } };
-    };
-    expect(selectArg.select.tags.select).toMatchObject({
-      kind: true,
-      scaleMin: true,
-      scaleMax: true,
-      inverse: true,
+    // Catalogue tag: custom=false, label=null, labelKey kept, metadata present.
+    expect(tags.happy).toMatchObject({
+      custom: false,
+      label: null,
+      labelKey: "mood.tag.happy",
+      kind: "BINARY",
+      scaleMin: 1,
+      scaleMax: 5,
+      inverse: false,
+    });
+    expect(tags.happy.hidden).toBeUndefined();
+
+    // Custom tag merged in: custom=true, decrypted label, labelKey null.
+    expect(tags["custom:abc"]).toMatchObject({
+      custom: true,
+      label: "Migräne",
+      labelKey: null,
     });
 
-    const factor = body.data.categories[0].tags[0];
-    expect(factor.kind).toBe("RATED");
-    expect(factor.scaleMin).toBe(1);
-    expect(factor.scaleMax).toBe(5);
-    expect(factor.inverse).toBe(false);
+    // Hidden catalogue tag omitted by default.
+    expect(tags.sad).toBeUndefined();
 
-    const conflict = body.data.categories[0].tags[1];
-    expect(conflict.scaleMax).toBe(2);
-    expect(conflict.inverse).toBe(true);
+    // Tag query scopes to catalogue OR the caller's own customs.
+    const tagWhere = tagFindMany.mock.calls[0]?.[0]?.where;
+    expect(tagWhere.OR).toEqual([{ userId: null }, { userId: "user-1" }]);
+  });
+
+  it("surfaces hidden catalogue tags with hidden:true under ?include=hidden", async () => {
+    const res = await GET(req("http://localhost/api/mood/tags?include=hidden"));
+    const tags = flat((await res.json()) as Body);
+    expect(tags.sad).toMatchObject({ hidden: true, custom: false });
+    expect(tags.happy).toMatchObject({ hidden: false });
+    // Custom tags never carry a hidden flag.
+    expect(tags["custom:abc"].hidden).toBeUndefined();
   });
 });
diff --git a/src/app/api/mood/tags/custom/[key]/route.ts b/src/app/api/mood/tags/custom/[key]/route.ts
new file mode 100644
index 000000000..c8dd7b9cf
--- /dev/null
+++ b/src/app/api/mood/tags/custom/[key]/route.ts
@@ -0,0 +1,113 @@
+import { NextRequest } from "next/server";
+
+import { prisma } from "@/lib/db";
+import { apiSuccess, apiError, returnAllZodIssues } from "@/lib/api-response";
+import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { annotate } from "@/lib/logging/context";
+import {
+  updateCustomTagSchema,
+  encryptCustomLabel,
+  decryptCustomLabel,
+  isCustomTagKey,
+} from "@/lib/mood/custom-tags";
+
+export const dynamic = "force-dynamic";
+
+type RouteParams = { params: Promise<{ key: string }> };
+
+/**
+ * v1.13.0 — update / delete a per-user custom mood tag.
+ *
+ * Both handlers resolve the `custom:`-prefixed key against the CALLER's own
+ * rows only — another user's key (or a catalogue key) is a 404, so a tag can
+ * never be edited or removed across the ownership boundary.
+ */
+
+/** `PATCH /api/mood/tags/custom/:key` — rename / recolour / (de)activate. */
+export const PATCH = apiHandler(
+  async (request: NextRequest, { params }: RouteParams) => {
+    const { user } = await requireAuth();
+    const { key } = await params;
+    if (!isCustomTagKey(key)) return apiError("Not a custom tag", 404);
+
+    const parsed = updateCustomTagSchema.safeParse(await request.json());
+    if (!parsed.success) return returnAllZodIssues(parsed.error, 422);
+
+    const owned = await prisma.moodTag.findFirst({
+      where: { key, userId: user.id },
+      select: { id: true },
+    });
+    if (!owned) return apiError("Custom tag not found", 404);
+
+    const updated = await prisma.moodTag.update({
+      where: { id: owned.id },
+      data: {
+        ...(parsed.data.label !== undefined
+          ? { labelEncrypted: encryptCustomLabel(parsed.data.label) }
+          : {}),
+        ...(parsed.data.icon !== undefined ? { icon: parsed.data.icon } : {}),
+        ...(parsed.data.isActive !== undefined
+          ? { isActive: parsed.data.isActive }
+          : {}),
+      },
+      select: {
+        key: true,
+        icon: true,
+        kind: true,
+        scaleMin: true,
+        scaleMax: true,
+        inverse: true,
+        isActive: true,
+        labelEncrypted: true,
+      },
+    });
+
+    annotate({ action: { name: "mood.tag.custom.update" } });
+
+    return apiSuccess({
+      key: updated.key,
+      labelKey: null,
+      label: decryptCustomLabel(updated.labelEncrypted),
+      icon: updated.icon,
+      kind: updated.kind,
+      scaleMin: updated.scaleMin,
+      scaleMax: updated.scaleMax,
+      inverse: updated.inverse,
+      isActive: updated.isActive,
+      custom: true,
+    });
+  },
+);
+
+/**
+ * `DELETE /api/mood/tags/custom/:key` — soft-deactivate by default (history
+ * intact); `?purge=true` hard-deletes the row and cascades its entry links.
+ */
+export const DELETE = apiHandler(
+  async (request: NextRequest, { params }: RouteParams) => {
+    const { user } = await requireAuth();
+    const { key } = await params;
+    if (!isCustomTagKey(key)) return apiError("Not a custom tag", 404);
+
+    const owned = await prisma.moodTag.findFirst({
+      where: { key, userId: user.id },
+      select: { id: true },
+    });
+    if (!owned) return apiError("Custom tag not found", 404);
+
+    const purge = request.nextUrl.searchParams.get("purge") === "true";
+    if (purge) {
+      // FK cascade removes the `mood_entry_tag_links` rows too.
+      await prisma.moodTag.delete({ where: { id: owned.id } });
+    } else {
+      await prisma.moodTag.update({
+        where: { id: owned.id },
+        data: { isActive: false },
+      });
+    }
+
+    annotate({ action: { name: "mood.tag.custom.delete" }, meta: { purge } });
+
+    return apiSuccess({ key, purged: purge });
+  },
+);
diff --git a/src/app/api/mood/tags/custom/route.ts b/src/app/api/mood/tags/custom/route.ts
new file mode 100644
index 000000000..2736816c8
--- /dev/null
+++ b/src/app/api/mood/tags/custom/route.ts
@@ -0,0 +1,74 @@
+import { NextRequest } from "next/server";
+
+import { prisma } from "@/lib/db";
+import { apiSuccess, apiError, returnAllZodIssues } from "@/lib/api-response";
+import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { annotate } from "@/lib/logging/context";
+import {
+  createCustomTagSchema,
+  mintCustomTagKey,
+  encryptCustomLabel,
+  CUSTOM_CATEGORY_ID,
+  MAX_CUSTOM_TAGS_PER_USER,
+} from "@/lib/mood/custom-tags";
+
+export const dynamic = "force-dynamic";
+
+/**
+ * v1.13.0 — create a per-user custom mood tag.
+ *
+ * `POST /api/mood/tags/custom` — body `{ label, icon?, categoryKey? }`. Mints
+ * a `custom:<uuid>` key, encrypts the label at rest, and stores a BINARY tag
+ * under the global `custom` category owned by the caller. Capped per user.
+ */
+export const POST = apiHandler(async (request: NextRequest) => {
+  const { user } = await requireAuth();
+
+  const parsed = createCustomTagSchema.safeParse(await request.json());
+  if (!parsed.success) return returnAllZodIssues(parsed.error, 422);
+
+  const activeCount = await prisma.moodTag.count({
+    where: { userId: user.id, isActive: true },
+  });
+  if (activeCount >= MAX_CUSTOM_TAGS_PER_USER) {
+    return apiError(
+      `Custom tag limit reached (${MAX_CUSTOM_TAGS_PER_USER})`,
+      422,
+    );
+  }
+
+  const key = mintCustomTagKey();
+  const created = await prisma.moodTag.create({
+    data: {
+      categoryId: CUSTOM_CATEGORY_ID,
+      key,
+      // Catalogue rows resolve `labelKey` against the locale; a custom tag
+      // renders its decrypted `label` instead, so labelKey just mirrors the
+      // key for a stable, non-empty value.
+      labelKey: key,
+      labelEncrypted: encryptCustomLabel(parsed.data.label),
+      icon: parsed.data.icon ?? null,
+      kind: "BINARY",
+      sortOrder: activeCount,
+      userId: user.id,
+    },
+    select: { key: true, icon: true, kind: true, scaleMin: true, scaleMax: true, inverse: true },
+  });
+
+  annotate({ action: { name: "mood.tag.custom.create" }, meta: { icon: created.icon } });
+
+  return apiSuccess(
+    {
+      key: created.key,
+      labelKey: null,
+      label: parsed.data.label,
+      icon: created.icon,
+      kind: created.kind,
+      scaleMin: created.scaleMin,
+      scaleMax: created.scaleMax,
+      inverse: created.inverse,
+      custom: true,
+    },
+    201,
+  );
+});
diff --git a/src/app/api/mood/tags/route.ts b/src/app/api/mood/tags/route.ts
index ba13023ba..c4589267d 100644
--- a/src/app/api/mood/tags/route.ts
+++ b/src/app/api/mood/tags/route.ts
@@ -1,55 +1,116 @@
+import { NextRequest } from "next/server";
+
 import { prisma } from "@/lib/db";
 import { apiSuccess } from "@/lib/api-response";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
+import { decryptCustomLabel } from "@/lib/mood/custom-tags";
 
 export const dynamic = "force-dynamic";
 
 /**
- * v1.8.5 — structured mood-tag taxonomy catalog.
+ * v1.8.5 / v1.13.0 — the EFFECTIVE per-user mood-tag taxonomy.
  *
- * Returns the active Category -> Tag tree the mood-logging form renders
- * as a pick-from-catalog capture surface. Global reference data (one
- * shared catalog for the deployment, seeded by migration 0101), so the
- * read carries no per-user filter and no encryption. The `labelKey`
- * fields resolve client-side against the active locale.
+ * Returns the active Category → Tag tree the mood-logging form renders as a
+ * pick-from-catalogue surface. The catalogue is global reference data (seeded
+ * by migration); v1.13.0 layers two per-user adjustments on top so the read
+ * is now user-scoped:
+ *   - the user's own custom tags (`mood_tags.user_id = me`, `custom:` keys)
+ *     appear under the seeded `custom` category, their label decrypted;
+ *   - catalogue tags the user hid (`mood_tag_hidden`) are omitted — unless
+ *     `?include=hidden` is set, in which case they're returned with
+ *     `hidden: true` so the management screen can toggle them back on.
+ *
+ * Every tag carries `custom: boolean` + `label: string | null`: render
+ * `label` for a custom tag, resolve `labelKey` against the locale for a
+ * catalogue tag. Backward-compatible — a client that ignores the new fields
+ * just sees the same categories → tags shape.
  */
-export const GET = apiHandler(async () => {
-  // Auth-gated like every app route — the catalog is not public, but it
-  // is identical for every authenticated user.
-  await requireAuth();
+export const GET = apiHandler(async (request: NextRequest) => {
+  const { user } = await requireAuth();
+  const includeHidden =
+    request.nextUrl.searchParams.get("include") === "hidden";
 
-  const categories = await prisma.moodTagCategory.findMany({
-    where: { isActive: true },
-    orderBy: { sortOrder: "asc" },
-    select: {
-      key: true,
-      labelKey: true,
-      icon: true,
-      tags: {
-        where: { isActive: true },
-        orderBy: { sortOrder: "asc" },
-        // v1.12.0 — emit the rated-factor metadata so the client can
-        // branch rendering: `kind = 'BINARY'` → a toggle chip; `'RATED'`
-        // → a 1..scaleMax segmented control (Yes/No when scaleMax = 2).
-        // `inverse` flags factors where a higher score means a worse day.
-        select: {
-          key: true,
-          labelKey: true,
-          icon: true,
-          kind: true,
-          scaleMin: true,
-          scaleMax: true,
-          inverse: true,
-        },
+  const [categories, tags, hiddenRows] = await Promise.all([
+    prisma.moodTagCategory.findMany({
+      where: { isActive: true },
+      orderBy: { sortOrder: "asc" },
+      select: { id: true, key: true, labelKey: true, icon: true },
+    }),
+    // Catalogue tags (user_id NULL) + this user's own custom tags. Another
+    // user's customs are excluded by construction.
+    prisma.moodTag.findMany({
+      where: { isActive: true, OR: [{ userId: null }, { userId: user.id }] },
+      orderBy: { sortOrder: "asc" },
+      select: {
+        id: true,
+        categoryId: true,
+        key: true,
+        labelKey: true,
+        icon: true,
+        kind: true,
+        scaleMin: true,
+        scaleMax: true,
+        inverse: true,
+        userId: true,
+        labelEncrypted: true,
       },
-    },
-  });
+    }),
+    prisma.moodTagHidden.findMany({
+      where: { userId: user.id },
+      select: { moodTagId: true },
+    }),
+  ]);
+
+  const hiddenIds = new Set(hiddenRows.map((r) => r.moodTagId));
+
+  const tagsByCategory = new Map<string, typeof tags>();
+  for (const t of tags) {
+    const isCustom = t.userId !== null;
+    const isHidden = !isCustom && hiddenIds.has(t.id);
+    if (isHidden && !includeHidden) continue;
+    const list = tagsByCategory.get(t.categoryId) ?? [];
+    list.push(t);
+    tagsByCategory.set(t.categoryId, list);
+  }
+
+  const responseCategories = categories
+    .map((c) => {
+      const catTags = (tagsByCategory.get(c.id) ?? []).map((t) => {
+        const isCustom = t.userId !== null;
+        return {
+          key: t.key,
+          labelKey: isCustom ? null : t.labelKey,
+          label: isCustom ? decryptCustomLabel(t.labelEncrypted) : null,
+          icon: t.icon,
+          kind: t.kind,
+          scaleMin: t.scaleMin,
+          scaleMax: t.scaleMax,
+          inverse: t.inverse,
+          custom: isCustom,
+          ...(includeHidden && !isCustom
+            ? { hidden: hiddenIds.has(t.id) }
+            : {}),
+        };
+      });
+      return {
+        key: c.key,
+        labelKey: c.labelKey,
+        icon: c.icon,
+        tags: catTags,
+      };
+    })
+    // Drop a category with no visible tags (e.g. `custom` for a user with
+    // none yet) so the picker grid stays tight.
+    .filter((c) => c.tags.length > 0);
 
   annotate({
     action: { name: "mood.tags.catalog.read" },
-    meta: { category_count: categories.length },
+    meta: {
+      category_count: responseCategories.length,
+      include_hidden: includeHidden,
+    },
   });
 
-  return apiSuccess({ categories });
+  return apiSuccess({ categories: responseCategories });
 });
diff --git a/src/lib/mood/__tests__/custom-tags.test.ts b/src/lib/mood/__tests__/custom-tags.test.ts
new file mode 100644
index 000000000..13697e6a9
--- /dev/null
+++ b/src/lib/mood/__tests__/custom-tags.test.ts
@@ -0,0 +1,80 @@
+import { describe, it, expect, vi } from "vitest";
+
+vi.mock("@/lib/crypto", () => ({
+  encrypt: (s: string) => `enc:${s}`,
+  decrypt: (s: string) => {
+    if (!s.startsWith("enc:")) throw new Error("bad ciphertext");
+    return s.slice(4);
+  },
+}));
+
+import {
+  isCustomTagKey,
+  mintCustomTagKey,
+  encryptCustomLabel,
+  decryptCustomLabel,
+  createCustomTagSchema,
+  updateCustomTagSchema,
+  hideCatalogueTagSchema,
+  CUSTOM_TAG_KEY_PREFIX,
+} from "@/lib/mood/custom-tags";
+import { resolveTagKeysToIds } from "@/lib/mood/tag-links";
+
+describe("custom-tag helpers", () => {
+  it("mints prefixed, unique keys and recognises them", () => {
+    const a = mintCustomTagKey();
+    const b = mintCustomTagKey();
+    expect(a.startsWith(CUSTOM_TAG_KEY_PREFIX)).toBe(true);
+    expect(a).not.toBe(b);
+    expect(isCustomTagKey(a)).toBe(true);
+    expect(isCustomTagKey("happy")).toBe(false);
+  });
+
+  it("round-trips a label and tolerates a corrupt ciphertext", () => {
+    const enc = encryptCustomLabel("Migräne");
+    expect(decryptCustomLabel(enc)).toBe("Migräne");
+    expect(decryptCustomLabel(null)).toBeNull();
+    expect(decryptCustomLabel("garbage")).toBeNull();
+  });
+});
+
+describe("custom-tag schemas", () => {
+  it("accepts a valid create and rejects a bad icon / empty / over-long label", () => {
+    expect(createCustomTagSchema.safeParse({ label: "Date night", icon: "Heart" }).success).toBe(true);
+    expect(createCustomTagSchema.safeParse({ label: "  ok  " }).success).toBe(true);
+    expect(createCustomTagSchema.safeParse({ label: "x", icon: "NotAnIcon" }).success).toBe(false);
+    expect(createCustomTagSchema.safeParse({ label: "" }).success).toBe(false);
+    expect(createCustomTagSchema.safeParse({ label: "a".repeat(41) }).success).toBe(false);
+  });
+
+  it("requires at least one field on update and validates hidden flag", () => {
+    expect(updateCustomTagSchema.safeParse({}).success).toBe(false);
+    expect(updateCustomTagSchema.safeParse({ isActive: false }).success).toBe(true);
+    expect(hideCatalogueTagSchema.safeParse({ hidden: true }).success).toBe(true);
+    expect(hideCatalogueTagSchema.safeParse({ hidden: "yes" }).success).toBe(false);
+  });
+});
+
+describe("resolveTagKeysToIds — custom-tag ownership scoping (v1.13.0)", () => {
+  function fakeDb(rows: Array<{ id: string }>) {
+    return { moodTag: { findMany: vi.fn().mockResolvedValue(rows) } };
+  }
+
+  it("scopes custom keys to the caller (catalogue OR own custom) when an owner is given", async () => {
+    const db = fakeDb([{ id: "id1" }]);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    await resolveTagKeysToIds(["happy", "custom:mine"], db as any, "user-1");
+    const where = db.moodTag.findMany.mock.calls[0][0].where;
+    expect(where.OR).toEqual([{ userId: null }, { userId: "user-1" }]);
+    expect(where.isActive).toBe(true);
+  });
+
+  it("falls back to catalogue-only (never matching any custom) without an owner", async () => {
+    const db = fakeDb([]);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    await resolveTagKeysToIds(["happy"], db as any);
+    const where = db.moodTag.findMany.mock.calls[0][0].where;
+    expect(where.userId).toBeNull();
+    expect(where.OR).toBeUndefined();
+  });
+});
diff --git a/src/lib/mood/custom-tags.ts b/src/lib/mood/custom-tags.ts
new file mode 100644
index 000000000..69078d5f9
--- /dev/null
+++ b/src/lib/mood/custom-tags.ts
@@ -0,0 +1,125 @@
+import { randomUUID } from "node:crypto";
+
+import { z } from "zod/v4";
+
+import { encrypt, decrypt } from "@/lib/crypto";
+
+/**
+ * v1.13.0 — per-user custom mood-tag helpers (iOS v1.13.0 contract).
+ *
+ * Custom tags live in the same `mood_tags` table as the global catalogue,
+ * distinguished by a non-null `userId`. Their key carries a reserved
+ * `custom:` prefix so it never collides with a bare catalogue slug, and the
+ * write path (`tag-links.ts`) routes a `custom:` key to the caller's own rows
+ * and a bare key to the catalogue. v1 customs are BINARY only; the label is
+ * held AES-256-GCM-encrypted at rest (it is user prose, possibly
+ * health-adjacent — iOS F4 push-back).
+ */
+
+/** Reserved key prefix for a user-minted custom tag. */
+export const CUSTOM_TAG_KEY_PREFIX = "custom:";
+
+/** Stable category key + seeded id every custom tag hangs under. */
+export const CUSTOM_CATEGORY_KEY = "custom";
+export const CUSTOM_CATEGORY_ID = "mtc_custom";
+
+/** Per-user ceiling on custom tags (422 over the cap). */
+export const MAX_CUSTOM_TAGS_PER_USER = 50;
+
+/**
+ * Allow-list of Lucide icon names a custom tag may use. Kept to names the iOS
+ * client maps to an SF Symbol (`MoodTagSFSymbol`) so a custom tag never falls
+ * back to the generic glyph on one platform; iOS extends its map to cover the
+ * final list. An unknown name → 422. `Tag` is the default.
+ */
+export const CUSTOM_TAG_ICON_ALLOWLIST = [
+  "Tag",
+  "Heart",
+  "Smile",
+  "Frown",
+  "Dumbbell",
+  "Moon",
+  "Sun",
+  "Wine",
+  "Coffee",
+  "House",
+  "Briefcase",
+  "Book",
+  "Music",
+  "Plane",
+  "Car",
+  "Users",
+  "Pill",
+  "Activity",
+  "Brain",
+  "Cloud",
+  "Star",
+  "Zap",
+] as const;
+
+const ICON_SET = new Set<string>(CUSTOM_TAG_ICON_ALLOWLIST);
+
+/** Is `key` a custom-tag key (vs a bare catalogue slug)? */
+export function isCustomTagKey(key: string): boolean {
+  return key.startsWith(CUSTOM_TAG_KEY_PREFIX);
+}
+
+/** Mint a fresh, collision-proof custom-tag key. */
+export function mintCustomTagKey(): string {
+  return `${CUSTOM_TAG_KEY_PREFIX}${randomUUID()}`;
+}
+
+/** Encrypt a custom label for storage in `label_encrypted`. */
+export function encryptCustomLabel(label: string): string {
+  return encrypt(label);
+}
+
+/**
+ * Decrypt a stored custom label. Returns null on a missing or corrupt
+ * ciphertext so one bad row never throws the whole effective-set read.
+ */
+export function decryptCustomLabel(encoded: string | null): string | null {
+  if (!encoded) return null;
+  try {
+    return decrypt(encoded);
+  } catch {
+    return null;
+  }
+}
+
+const labelSchema = z
+  .string()
+  .trim()
+  .min(1, "Label must not be empty")
+  .max(40, "Label must be at most 40 characters");
+
+const iconSchema = z
+  .string()
+  .refine((v) => ICON_SET.has(v), "Unknown icon")
+  .nullish();
+
+/** POST body — create a custom tag. */
+export const createCustomTagSchema = z.object({
+  label: labelSchema,
+  icon: iconSchema,
+  // Reserved for a future per-tag category choice; v1 pins everything to the
+  // `custom` category, so a supplied value other than `custom` is rejected.
+  categoryKey: z.literal(CUSTOM_CATEGORY_KEY).optional(),
+});
+
+/** PATCH body — update a custom tag (every field optional). */
+export const updateCustomTagSchema = z
+  .object({
+    label: labelSchema.optional(),
+    icon: iconSchema,
+    isActive: z.boolean().optional(),
+  })
+  .refine(
+    (v) => v.label !== undefined || v.icon !== undefined || v.isActive !== undefined,
+    "At least one field is required",
+  );
+
+/** PUT body — hide / show a catalogue tag for the user. */
+export const hideCatalogueTagSchema = z.object({
+  hidden: z.boolean(),
+});
diff --git a/src/lib/mood/tag-links.ts b/src/lib/mood/tag-links.ts
index 3e631d938..4d268d229 100644
--- a/src/lib/mood/tag-links.ts
+++ b/src/lib/mood/tag-links.ts
@@ -110,7 +110,14 @@ export async function resolveRatedFactors(
   for (const f of factors) byKey.set(f.key, f.rating);
 
   const rows = await db.moodTag.findMany({
-    where: { key: { in: [...byKey.keys()] }, isActive: true, kind: "RATED" },
+    // Rated factors are catalogue-only (v1 customs are BINARY); pin to
+    // `user_id IS NULL` so a custom row can never be resolved as a factor.
+    where: {
+      key: { in: [...byKey.keys()] },
+      isActive: true,
+      kind: "RATED",
+      userId: null,
+    },
     select: { id: true, key: true, scaleMin: true, scaleMax: true },
   });
 
@@ -132,17 +139,30 @@ export async function resolveRatedFactors(
 }
 
 /**
- * Resolve catalog tag keys to ids, dropping unknown / inactive keys.
- * Returns the ids in catalog order (deduped).
+ * Resolve tag keys to ids, dropping unknown / inactive keys. Returns the ids
+ * (deduped).
+ *
+ * v1.13.0 — when `ownerUserId` is given, a `custom:`-prefixed key resolves
+ * ONLY against that user's own custom tags; a bare catalogue key resolves
+ * against the global catalogue. A custom key owned by someone else simply
+ * does not match (dropped silently — the same posture as an unknown key), so
+ * a caller can never link another user's custom tag. Without `ownerUserId`
+ * the resolution is catalogue-only (`user_id IS NULL`), never matching any
+ * custom row — the safe default, since `{ userId: undefined }` in a Prisma
+ * filter would otherwise match every row.
  */
 export async function resolveTagKeysToIds(
   keys: string[],
   db: TagLinkDb = prisma,
+  ownerUserId?: string,
 ): Promise<string[]> {
   const unique = Array.from(new Set(keys));
   if (unique.length === 0) return [];
+  const ownerClause = ownerUserId
+    ? { OR: [{ userId: null }, { userId: ownerUserId }] }
+    : { userId: null };
   const rows = await db.moodTag.findMany({
-    where: { key: { in: unique }, isActive: true },
+    where: { key: { in: unique }, isActive: true, ...ownerClause },
     select: { id: true },
   });
   return rows.map((row) => row.id);
@@ -188,7 +208,7 @@ export async function createTagLinks(
     });
   }
 
-  const tagIds = (await resolveTagKeysToIds(keys, db)).filter(
+  const tagIds = (await resolveTagKeysToIds(keys, db, userId)).filter(
     // A key already written as a rated link is not re-inserted as a
     // bare binary row (that would lose the rating to `skipDuplicates`).
     (id) => !ratedTagIds.has(id),
@@ -215,7 +235,7 @@ export async function replaceTagLinks(
   db: TagLinkDb = prisma,
 ): Promise<void> {
   await assertEntryOwnership(moodEntryId, userId, db);
-  const desiredIds = new Set(await resolveTagKeysToIds(keys, db));
+  const desiredIds = new Set(await resolveTagKeysToIds(keys, db, userId));
   const existing = await db.moodEntryTagLink.findMany({
     where: { moodEntryId },
     select: { moodTagId: true },
diff --git a/tests/integration/setup.ts b/tests/integration/setup.ts
index 24955a0c7..c55e3ae6a 100644
--- a/tests/integration/setup.ts
+++ b/tests/integration/setup.ts
@@ -26,6 +26,11 @@ export function getPrismaClient(): PrismaClient {
   return prisma;
 }
 
+/** Lazily-captured global mood-tag catalogue (NULL user_id rows). */
+let catalogueSnapshot:
+  | Awaited<ReturnType<PrismaClient["moodTag"]["findMany"]>>
+  | null = null;
+
 /**
  * Truncate every user-facing table in dependency-safe order using
  * `TRUNCATE … RESTART IDENTITY CASCADE`. Call from beforeEach() to make
@@ -74,8 +79,29 @@ export async function truncateAllTables(client: PrismaClient): Promise<void> {
     "workouts",
   ];
 
+  // v1.13.0 — the mood-tag catalogue (`mood_tags` rows with NULL user_id) is
+  // global reference data seeded by migrations and is intentionally NOT in the
+  // truncate list, so tests can rely on it. But `mood_tags.user_id` now FKs to
+  // `users`, so `TRUNCATE users CASCADE` cascades into `mood_tags` and wipes
+  // the catalogue too (TRUNCATE CASCADE truncates dependent tables wholesale,
+  // regardless of the ON DELETE action). Snapshot the catalogue once (before
+  // the first truncate clears it) and restore it after each truncate so the
+  // migration-seeded catalogue persists across tests as it did before the FK.
+  if (catalogueSnapshot === null) {
+    catalogueSnapshot = await client.moodTag.findMany({
+      where: { userId: null },
+    });
+  }
+
   const quoted = tables.map((t) => `"${t}"`).join(", ");
   await client.$executeRawUnsafe(
     `TRUNCATE TABLE ${quoted} RESTART IDENTITY CASCADE;`,
   );
+
+  if (catalogueSnapshot.length > 0) {
+    await client.moodTag.createMany({
+      data: catalogueSnapshot,
+      skipDuplicates: true,
+    });
+  }
 }