diff --git a/src/app/api/bugreport/status/route.ts b/src/app/api/bugreport/status/route.ts
index a1f5aa88c..d7387fb4c 100644
--- a/src/app/api/bugreport/status/route.ts
+++ b/src/app/api/bugreport/status/route.ts
@@ -12,17 +12,16 @@ import { apiSuccess, apiError } from "@/lib/api-response";
 import { annotate } from "@/lib/logging/context";
 import { checkRateLimit } from "@/lib/rate-limit";
 import { prisma } from "@/lib/db";
+import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 
-export const GET = apiHandler(async () => {
-  const { user } = await requireAuth();
-
-  // Light rate limit — the endpoint is cheap, but no reason to let a logged-in
-  // client hammer Postgres in a loop.
-  const rl = await checkRateLimit(`bugreport-status:${user.id}`, 30, 60 * 1000);
-  if (!rl.allowed) {
-    return apiError("Rate limit exceeded", 429);
-  }
+interface BugreportStatusCacheValue {
+  configured: boolean;
+  enabled: boolean;
+  hasToken: boolean;
+  hasRepo: boolean;
+}
 
+async function buildBugreportStatusValue(): Promise<BugreportStatusCacheValue> {
   const appSettings = await prisma.appSettings.findUnique({
     where: { id: "singleton" },
     select: {
@@ -42,10 +41,44 @@ export const GET = apiHandler(async () => {
   // Default ON when the column has never been written.
   const enabled = appSettings?.bugReportEnabled !== false;
 
+  return { configured, enabled, hasToken, hasRepo };
+}
+
+export const GET = apiHandler(async () => {
+  const { user } = await requireAuth();
+
+  // Light rate limit — the endpoint is cheap, but no reason to let a logged-in
+  // client hammer Postgres in a loop.
+  const rl = await checkRateLimit(`bugreport-status:${user.id}`, 30, 60 * 1000);
+  if (!rl.allowed) {
+    return apiError("Rate limit exceeded", 429);
+  }
+
+  // Cache the global app-settings shape on a singleton key (per blueprint §3).
+  // `isAdmin` lives outside the cache because it varies per request. The
+  // `invalidateAppSettings()` helper called from
+  // `PATCH /api/admin/app-settings` evicts this entry when bug-report
+  // configuration changes.
+  const status = await cached(
+    caches.bugreportStatus as ServerCache<BugreportStatusCacheValue>,
+    "singleton",
+    () => buildBugreportStatusValue(),
+    annotate,
+  );
+
   annotate({
     action: { name: "bugreport.status" },
-    meta: { configured, enabled, has_token: hasToken, has_repo: hasRepo },
+    meta: {
+      configured: status.configured,
+      enabled: status.enabled,
+      has_token: status.hasToken,
+      has_repo: status.hasRepo,
+    },
   });
 
-  return apiSuccess({ configured, enabled, isAdmin: user.role === "ADMIN" });
+  return apiSuccess({
+    configured: status.configured,
+    enabled: status.enabled,
+    isAdmin: user.role === "ADMIN",
+  });
 });
diff --git a/src/app/api/dashboard/chart-overlay-prefs/route.ts b/src/app/api/dashboard/chart-overlay-prefs/route.ts
index 36b15a483..c3b842ea0 100644
--- a/src/app/api/dashboard/chart-overlay-prefs/route.ts
+++ b/src/app/api/dashboard/chart-overlay-prefs/route.ts
@@ -25,6 +25,7 @@ import {
   serializeDashboardLayout,
   type DashboardLayout,
 } from "@/lib/dashboard-layout";
+import { invalidateUserDashboardWidgets } from "@/lib/cache/invalidate";
 import { Prisma } from "@/generated/prisma/client";
 import { z } from "zod/v4";
 import type { NextRequest } from "next/server";
@@ -86,6 +87,11 @@ export const PUT = apiHandler(async (request: NextRequest) => {
     { isolationLevel: "Serializable" },
   );
 
+  // The partial-update path mutates the same `User.dashboardWidgetsJson`
+  // blob the `/api/dashboard/widgets` GET reads from. Bust the cache so
+  // the next dashboard mount surfaces the new chartOverlayPrefs slot.
+  invalidateUserDashboardWidgets(user.id);
+
   annotate({
     action: { name: "dashboard.chartOverlayPrefs.update" },
     meta: {
diff --git a/src/app/api/dashboard/widgets/route.ts b/src/app/api/dashboard/widgets/route.ts
index 11b90ce81..89de13a32 100644
--- a/src/app/api/dashboard/widgets/route.ts
+++ b/src/app/api/dashboard/widgets/route.ts
@@ -22,6 +22,7 @@ import {
 import { Prisma } from "@/generated/prisma/client";
 import { z } from "zod/v4";
 import { invalidateUserDashboardWidgets } from "@/lib/cache/invalidate";
+import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 import type { NextRequest } from "next/server";
 
 // Single source of truth — every widget id rendered by the Settings →
@@ -94,15 +95,26 @@ const layoutSchema = z.object({
     .optional(),
 });
 
+async function buildDashboardLayout(userId: string): Promise<DashboardLayout> {
+  const row = await prisma.user.findUnique({
+    where: { id: userId },
+    select: { dashboardWidgetsJson: true },
+  });
+  return resolveDashboardLayout(row?.dashboardWidgetsJson);
+}
+
 export const GET = apiHandler(async () => {
   const { user } = await requireAuth();
 
-  const row = await prisma.user.findUnique({
-    where: { id: user.id },
-    select: { dashboardWidgetsJson: true },
-  });
-
-  const layout = resolveDashboardLayout(row?.dashboardWidgetsJson);
+  // 5-minute TTL per blueprint §5; the layout changes only when the user
+  // hits the Settings → Dashboard save button, which invalidates this
+  // cache via `invalidateUserDashboardWidgets()`.
+  const layout = await cached(
+    caches.dashboardWidgets as ServerCache<DashboardLayout>,
+    user.id,
+    () => buildDashboardLayout(user.id),
+    annotate,
+  );
   return apiSuccess(layout);
 });
 
diff --git a/src/app/api/medications/route.ts b/src/app/api/medications/route.ts
index f002a412b..eb18ad5bf 100644
--- a/src/app/api/medications/route.ts
+++ b/src/app/api/medications/route.ts
@@ -16,40 +16,34 @@ import {
 import { serializeScheduleRecurrence } from "@/lib/medication-schedule";
 import { getUserTodayBounds } from "@/lib/timezone";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
+import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 import { NextRequest } from "next/server";
 
-export const GET = apiHandler(async () => {
-  const { user } = await requireAuth();
+type MedicationsListResult = Array<Record<string, unknown>>;
 
-  // Compute today's UTC range for event counting
-  const userTz = user.timezone || "Europe/Berlin";
+async function buildMedicationsList(
+  userId: string,
+  userTz: string,
+): Promise<MedicationsListResult> {
   const { start: todayStartUtc, end: todayEndUtc } = getUserTodayBounds(
     new Date(),
     userTz,
   );
 
-  // Run all three queries in parallel
   const [medications, latestIntakes, todayEvents] = await Promise.all([
     prisma.medication.findMany({
-      where: { userId: user.id },
+      where: { userId },
       include: { schedules: true },
       orderBy: { createdAt: "desc" },
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
-      where: {
-        userId: user.id,
-        skipped: false,
-        takenAt: { not: null },
-      },
+      where: { userId, skipped: false, takenAt: { not: null } },
       _max: { takenAt: true },
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
-      where: {
-        userId: user.id,
-        scheduledFor: { gte: todayStartUtc, lte: todayEndUtc },
-      },
+      where: { userId, scheduledFor: { gte: todayStartUtc, lte: todayEndUtc } },
       _count: { id: true },
     }),
   ]);
@@ -76,24 +70,36 @@ export const GET = apiHandler(async () => {
     getEvent()?.addWarning("Medication categories could not be loaded");
   }
 
+  return medications.map((m) => ({
+    ...m,
+    category: categoryMap[m.id] ?? "OTHER",
+    lastTakenAt: lastTakenAtByMedicationId[m.id] ?? null,
+    todayEventCount: todayEventCountByMedId[m.id] ?? 0,
+  }));
+}
+
+export const GET = apiHandler(async () => {
+  const { user } = await requireAuth();
+
+  const userTz = user.timezone || "Europe/Berlin";
+
+  // Cache the list shape on userId. The 60s TTL bounds the cross-midnight
+  // staleness window for `todayEventCount` (the only time-of-day-derived
+  // field in the response); writes via POST/PUT/DELETE flush through
+  // `invalidateUserMedications` before the next read lands.
+  const result = await cached(
+    caches.medications as ServerCache<MedicationsListResult>,
+    user.id,
+    () => buildMedicationsList(user.id, userTz),
+    annotate,
+  );
+
   annotate({
     action: { name: "medication.list" },
-    meta: { count: medications.length },
+    meta: { count: result.length },
   });
 
-  return apiSuccess(
-    medications.map((m) => ({
-      ...m,
-      // v1.4.25 W4d — `category` is the existing clinical taxonomy
-      // (BLOOD_PRESSURE / VITAMIN / ...) from the side-table; the
-      // Prisma model has its own `treatmentClass` (GENERIC | GLP1) that
-      // spreads through `...m` and unlocks the GLP-1 surfaces. Two
-      // orthogonal concepts, both exposed.
-      category: categoryMap[m.id] ?? "OTHER",
-      lastTakenAt: lastTakenAtByMedicationId[m.id] ?? null,
-      todayEventCount: todayEventCountByMedId[m.id] ?? 0,
-    })),
-  );
+  return apiSuccess(result);
 });
 
 export const POST = apiHandler(async (request: NextRequest) => {
diff --git a/src/app/api/mood/analytics/route.ts b/src/app/api/mood/analytics/route.ts
index 6be9db8f2..1002560a3 100644
--- a/src/app/api/mood/analytics/route.ts
+++ b/src/app/api/mood/analytics/route.ts
@@ -3,6 +3,7 @@ import { apiSuccess } from "@/lib/api-response";
 import { summarize, type DataPoint } from "@/lib/analytics/trends";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
+import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 
 export const dynamic = "force-dynamic";
 
@@ -26,11 +27,17 @@ function aggregateDailyAverages(
     }));
 }
 
-export const GET = apiHandler(async () => {
-  const { user } = await requireAuth();
+interface MoodAnalyticsResult {
+  entries: Array<{ date: string; score: number; samples: number }>;
+  summary: ReturnType<typeof summarize>;
+  entryCount: number;
+}
 
+async function buildMoodAnalyticsResponse(
+  userId: string,
+): Promise<MoodAnalyticsResult> {
   const moodEntries = await prisma.moodEntry.findMany({
-    where: { userId: user.id },
+    where: { userId },
     orderBy: { moodLoggedAt: "asc" },
     select: { date: true, score: true, moodLoggedAt: true },
   });
@@ -39,7 +46,6 @@ export const GET = apiHandler(async () => {
     moodEntries.map((e) => ({ date: e.date, score: e.score })),
   );
 
-  // Build DataPoint array for summarize() using moodLoggedAt as the date
   const dataPoints: DataPoint[] = moodEntries.map((e) => ({
     date: e.moodLoggedAt,
     value: e.score,
@@ -47,10 +53,23 @@ export const GET = apiHandler(async () => {
 
   const summary = summarize(dataPoints);
 
+  return { entries, summary, entryCount: moodEntries.length };
+}
+
+export const GET = apiHandler(async () => {
+  const { user } = await requireAuth();
+
+  const result = await cached(
+    caches.moodAnalytics as ServerCache<MoodAnalyticsResult>,
+    user.id,
+    () => buildMoodAnalyticsResponse(user.id),
+    annotate,
+  );
+
   annotate({
     action: { name: "mood.analytics" },
-    meta: { entryCount: moodEntries.length },
+    meta: { entryCount: result.entryCount },
   });
 
-  return apiSuccess({ entries, summary });
+  return apiSuccess({ entries: result.entries, summary: result.summary });
 });
diff --git a/src/app/api/workouts/__tests__/canonical-dedup.test.ts b/src/app/api/workouts/__tests__/canonical-dedup.test.ts
index b220c5f02..c24ad2064 100644
--- a/src/app/api/workouts/__tests__/canonical-dedup.test.ts
+++ b/src/app/api/workouts/__tests__/canonical-dedup.test.ts
@@ -16,6 +16,8 @@
 import { describe, expect, it, vi, beforeEach } from "vitest";
 import { NextRequest } from "next/server";
 
+import { __resetAllCachesForTests } from "@/lib/cache/server-cache";
+
 vi.mock("@/lib/db", () => ({
   prisma: {
     workout: {
@@ -100,6 +102,11 @@ function makeRow(
 describe("GET /api/workouts — canonical dedup", () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    // Reset every server cache between tests so a fixed userId doesn't
+    // carry cached state across cases (v1.4.34.2 — added when the
+    // `/api/workouts` GET handler started reading through
+    // `caches.workouts`).
+    __resetAllCachesForTests();
     vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
     // Default: no per-user source-priority override → fall back to the
     // canonical APPLE_HEALTH ≻ WITHINGS ≻ MANUAL ≻ IMPORT ladder.
diff --git a/src/app/api/workouts/route.ts b/src/app/api/workouts/route.ts
index b3a965b2c..4fe739e6a 100644
--- a/src/app/api/workouts/route.ts
+++ b/src/app/api/workouts/route.ts
@@ -54,10 +54,119 @@ import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
 import { apiSuccess } from "@/lib/api-response";
 import { pickCanonicalWorkoutRows } from "@/lib/measurements/pick-canonical-workout-rows";
+import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 
 const DEFAULT_LIMIT = 50;
 const MAX_LIMIT = 200;
 
+interface WorkoutsParams {
+  readonly limit: number;
+  readonly offset: number;
+  readonly since: string | null;
+  readonly until: string | null;
+  readonly sportType: string | null;
+}
+
+interface WorkoutsResult {
+  workouts: Array<{
+    id: string;
+    sportType: string | null;
+    startedAt: Date | null;
+    endedAt: Date | null;
+    durationSec: number | null;
+    distanceM: number | null;
+    activeEnergyKcal: number | null;
+    avgHr: number | null;
+    maxHr: number | null;
+    source: string;
+    externalId: string | null;
+  }>;
+  meta: {
+    total: number;
+    limit: number;
+    offset: number;
+    droppedDuplicates: number;
+  };
+}
+
+async function buildWorkoutsResponse(
+  userId: string,
+  params: WorkoutsParams,
+): Promise<WorkoutsResult> {
+  const { limit, offset, since, until, sportType } = params;
+
+  const where: Record<string, unknown> = { userId };
+  if (since || until) {
+    const range: Record<string, Date> = {};
+    if (since) {
+      const d = new Date(since);
+      if (!Number.isNaN(d.getTime())) range.gte = d;
+    }
+    if (until) {
+      const d = new Date(until);
+      if (!Number.isNaN(d.getTime())) range.lte = d;
+    }
+    if (Object.keys(range).length > 0) {
+      where.startedAt = range;
+    }
+  }
+  if (sportType) {
+    where.sportType = sportType;
+  }
+
+  const rows = await prisma.workout.findMany({
+    where,
+    orderBy: [{ startedAt: "desc" }, { id: "asc" }],
+    select: {
+      id: true,
+      source: true,
+      externalId: true,
+      sportType: true,
+      startedAt: true,
+      endedAt: true,
+      durationSec: true,
+      totalDistanceM: true,
+      totalEnergyKcal: true,
+      avgHeartRate: true,
+      maxHeartRate: true,
+      createdAt: true,
+    },
+  });
+
+  const userRow = await prisma.user.findUnique({
+    where: { id: userId },
+    select: { sourcePriorityJson: true },
+  });
+  const canonical = pickCanonicalWorkoutRows(
+    rows,
+    userRow?.sourcePriorityJson ?? null,
+  );
+
+  const page = canonical.slice(offset, offset + limit).map((row) => ({
+    id: row.id,
+    sportType: row.sportType,
+    startedAt: row.startedAt,
+    endedAt: row.endedAt,
+    durationSec: row.durationSec,
+    distanceM: row.totalDistanceM,
+    activeEnergyKcal: row.totalEnergyKcal,
+    avgHr: row.avgHeartRate,
+    maxHr: row.maxHeartRate,
+    source: row.source,
+    externalId: row.externalId,
+  }));
+
+  return {
+    workouts: page,
+    meta: {
+      total: canonical.length,
+      limit,
+      offset,
+      droppedDuplicates: rows.length - canonical.length,
+    },
+  };
+}
+
 export const GET = apiHandler(async (request: NextRequest) => {
   const { user } = await requireAuth();
   annotate({ action: { name: "workouts.list" } });
@@ -79,80 +188,15 @@ export const GET = apiHandler(async (request: NextRequest) => {
   const until = searchParams.get("until");
   const sportType = searchParams.get("sportType");
 
-  const where: Record<string, unknown> = { userId: user.id };
-  if (since || until) {
-    const range: Record<string, Date> = {};
-    if (since) {
-      const d = new Date(since);
-      if (!Number.isNaN(d.getTime())) range.gte = d;
-    }
-    if (until) {
-      const d = new Date(until);
-      if (!Number.isNaN(d.getTime())) range.lte = d;
-    }
-    if (Object.keys(range).length > 0) {
-      where.startedAt = range;
-    }
-  }
-  if (sportType) {
-    where.sportType = sportType;
-  }
+  const params: WorkoutsParams = { limit, offset, since, until, sportType };
+  const cacheKey = `${user.id}|${limit}|${offset}|${since ?? ""}|${until ?? ""}|${sportType ?? ""}`;
 
-  // Read the full filtered set, descending start. The picker requires
-  // deterministic input order; the `(startedAt, id)` secondary sort
-  // pins the tie-break for rows that share a millisecond stamp.
-  const rows = await prisma.workout.findMany({
-    where,
-    orderBy: [{ startedAt: "desc" }, { id: "asc" }],
-    select: {
-      id: true,
-      source: true,
-      externalId: true,
-      sportType: true,
-      startedAt: true,
-      endedAt: true,
-      durationSec: true,
-      totalDistanceM: true,
-      totalEnergyKcal: true,
-      avgHeartRate: true,
-      maxHeartRate: true,
-      createdAt: true,
-    },
-  });
-
-  // Pass the user's source-priority blob so the picker honours the
-  // per-user ladder. The picker preserves input order on the returned
-  // subset; descending-start input → descending-start output.
-  const userRow = await prisma.user.findUnique({
-    where: { id: user.id },
-    select: { sourcePriorityJson: true },
-  });
-  const canonical = pickCanonicalWorkoutRows(
-    rows,
-    userRow?.sourcePriorityJson ?? null,
+  const result = await cached(
+    caches.workouts as ServerCache<WorkoutsResult>,
+    cacheKey,
+    () => buildWorkoutsResponse(user.id, params),
+    annotate,
   );
 
-  const page = canonical.slice(offset, offset + limit).map((row) => ({
-    id: row.id,
-    sportType: row.sportType,
-    startedAt: row.startedAt,
-    endedAt: row.endedAt,
-    durationSec: row.durationSec,
-    distanceM: row.totalDistanceM,
-    activeEnergyKcal: row.totalEnergyKcal,
-    avgHr: row.avgHeartRate,
-    maxHr: row.maxHeartRate,
-    source: row.source,
-    externalId: row.externalId,
-  }));
-
-  return apiSuccess({
-    workouts: page,
-    meta: {
-      total: canonical.length,
-      limit,
-      offset,
-      droppedDuplicates: rows.length - canonical.length,
-    },
-  });
+  return apiSuccess(result);
 });