diff --git a/src/daemon/http/usage-summary.test.ts b/src/daemon/http/usage-summary.test.ts
new file mode 100644
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+++ b/src/daemon/http/usage-summary.test.ts
@@ -0,0 +1,257 @@
+import { describe, it, expect, beforeEach } from "bun:test";
+import { createMemoryUsageTrackingDriver } from "@routstr/sdk/storage";
+import type { UsageTrackingEntry } from "@routstr/sdk/storage";
+import type { ClientEntry } from "../../utils/clients";
+import { getUsageSummary } from "./usage-summary";
+
+// ─── Test fixtures ────────────────────────────────────────────────────────────
+//
+// All timestamps fall within 30 days of 2026-06-02 (today as of this writing).
+// tz = 300 (UTC-5 / EST). After shifting by -300min, UTC dates become:
+//   d1: 2026-05-20T10:00Z → shifted 2026-05-20T05:00Z → local day "2026-05-20", hour 05
+//   d2: 2026-05-21T03:00Z → shifted 2026-05-20T22:00Z → local day "2026-05-20", hour 22
+//   d3: 2026-05-21T06:00Z → shifted 2026-05-21T01:00Z → local day "2026-05-21", hour 01
+
+const D1 = new Date("2026-05-20T10:00:00Z").getTime(); // local 2026-05-20, hour 05
+const D2 = new Date("2026-05-21T03:00:00Z").getTime(); // local 2026-05-20, hour 22
+const D3 = new Date("2026-05-21T06:00:00Z").getTime(); // local 2026-05-21, hour 01
+
+const BASE_ENTRY: Omit<UsageTrackingEntry, "id" | "timestamp" | "modelId" | "client" | "totalTokens"> = {
+  baseUrl: "https://api.openai.com/",
+  requestId: "req-1",
+  cost: 0.01,
+  satsCost: 10,
+  promptTokens: 100,
+  completionTokens: 50,
+};
+
+function makeEntry(
+  id: string,
+  overrides: Partial<UsageTrackingEntry> & Pick<UsageTrackingEntry, "id" | "timestamp" | "modelId" | "totalTokens">,
+): UsageTrackingEntry {
+  return {
+    ...BASE_ENTRY,
+    ...overrides,
+    id,
+  };
+}
+
+// Seed entries:
+// - 2 entries for model-a, client-1 (owned by npub1)
+// - 1 entry for model-b, client-2 (no npub)
+// - 1 entry for model-a, no client (null client)
+// - totalTokens spread across tiny (< 1000) and small (1000-10000) buckets
+
+const ENTRIES: UsageTrackingEntry[] = [
+  // model-a, client-1, day 2026-05-20 (D1), totalTokens=500 (tiny)
+  makeEntry("e1", {
+    id: "e1",
+    timestamp: D1,
+    modelId: "model-a",
+    client: "client-1",
+    totalTokens: 500,
+    promptTokens: 350,
+    completionTokens: 150,
+    satsCost: 10,
+    cost: 0.01,
+  }),
+  // model-a, client-1, day 2026-05-20 (D2), totalTokens=2000 (small)
+  makeEntry("e2", {
+    id: "e2",
+    timestamp: D2,
+    modelId: "model-a",
+    client: "client-1",
+    totalTokens: 2000,
+    promptTokens: 1400,
+    completionTokens: 600,
+    satsCost: 20,
+    cost: 0.02,
+  }),
+  // model-b, client-2, day 2026-05-21 (D3), totalTokens=800 (tiny)
+  makeEntry("e3", {
+    id: "e3",
+    timestamp: D3,
+    modelId: "model-b",
+    client: "client-2",
+    totalTokens: 800,
+    promptTokens: 600,
+    completionTokens: 200,
+    satsCost: 8,
+    cost: 0.008,
+  }),
+  // model-a, no client, day 2026-05-21 (D3), totalTokens=5000 (small)
+  makeEntry("e4", {
+    id: "e4",
+    timestamp: D3 + 1000,
+    modelId: "model-a",
+    client: undefined,
+    totalTokens: 5000,
+    promptTokens: 3500,
+    completionTokens: 1500,
+    satsCost: 50,
+    cost: 0.05,
+  }),
+];
+
+const CLIENTS: ClientEntry[] = [
+  {
+    clientId: "client-1",
+    name: "Client One",
+    apiKey: "sk-client1",
+    createdAt: D1 - 86400000,
+    ownerNpub: "npub1abc",
+  },
+  {
+    clientId: "client-2",
+    name: "Client Two",
+    apiKey: "sk-client2",
+    createdAt: D1 - 86400000,
+    // no ownerNpub
+  },
+];
+
+const TZ = 300; // UTC-5 / EST
+
+describe("getUsageSummary", () => {
+  let driver: ReturnType<typeof createMemoryUsageTrackingDriver>;
+
+  beforeEach(async () => {
+    // Reset module-level cache between tests by creating a fresh driver with a
+    // distinct entry count each time — the cache key changes.
+    driver = createMemoryUsageTrackingDriver(ENTRIES);
+  });
+
+  it("returns correct totals", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+
+    expect(summary.totals.requests).toBe(4);
+    expect(summary.totals.totalTokens).toBe(500 + 2000 + 800 + 5000);
+    expect(summary.totals.promptTokens).toBe(350 + 1400 + 600 + 3500);
+    expect(summary.totals.completionTokens).toBe(150 + 600 + 200 + 1500);
+    expect(summary.totals.satsCost).toBe(10 + 20 + 8 + 50);
+    expect(summary.totals.cost).toBeCloseTo(0.01 + 0.02 + 0.008 + 0.05, 5);
+  });
+
+  it("returns models sorted desc by satsCost", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { models } = summary;
+
+    // model-a: 3 entries (e1, e2, e4) total satsCost = 10+20+50 = 80
+    // model-b: 1 entry (e3) satsCost = 8
+    expect(models).toHaveLength(2);
+    expect(models[0]!.modelId).toBe("model-a");
+    expect(models[0]!.satsCost).toBe(80);
+    expect(models[0]!.requests).toBe(3);
+    expect(models[1]!.modelId).toBe("model-b");
+    expect(models[1]!.satsCost).toBe(8);
+  });
+
+  it("returns days most-recent-first with correct tz-bucketing", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { days } = summary;
+
+    // D1 (10:00Z) → local 2026-05-20, D2 (03:00Z) → local 2026-05-20, D3 (06:00Z) → local 2026-05-21
+    // So: day 2026-05-20 has e1+e2, day 2026-05-21 has e3+e4
+    expect(days.length).toBeGreaterThanOrEqual(2);
+
+    // Most-recent-first: 2026-05-21 first
+    expect(days[0]!.date).toBe("2026-05-21");
+    expect(days[0]!.requests).toBe(2); // e3, e4
+    expect(days[0]!.satsCost).toBe(8 + 50);
+
+    expect(days[1]!.date).toBe("2026-05-20");
+    expect(days[1]!.requests).toBe(2); // e1, e2
+    expect(days[1]!.satsCost).toBe(10 + 20);
+  });
+
+  it("returns empty hoursToday (test entries are not today)", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    // Test entries are in May 2026, not today (June 2026)
+    expect(summary.hoursToday).toHaveLength(0);
+  });
+
+  it("returns correct sizeBuckets", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { sizeBuckets } = summary;
+
+    // tiny [0, 1000): e1 (500) + e3 (800) = 2 entries
+    expect(sizeBuckets.tiny.count).toBe(2);
+    expect(sizeBuckets.tiny.cost).toBe(10 + 8);
+
+    // small [1000, 10000): e2 (2000) + e4 (5000) = 2 entries
+    expect(sizeBuckets.small.count).toBe(2);
+    expect(sizeBuckets.small.cost).toBe(20 + 50);
+
+    // medium, large, huge should be 0
+    expect(sizeBuckets.medium.count).toBe(0);
+    expect(sizeBuckets.large.count).toBe(0);
+    expect(sizeBuckets.huge.count).toBe(0);
+  });
+
+  it("returns per-client topModels for top non-null clients", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { clients } = summary;
+
+    // client-1: e1 + e2 (model-a), satsCost = 30
+    // client-2: e3 (model-b), satsCost = 8
+    // unknown (null client): e4 (model-a), satsCost = 50
+    // Sorted desc by satsCost: unknown (50), client-1 (30), client-2 (8)
+
+    const c1 = clients.find((c) => c.client === "client-1");
+    expect(c1).toBeDefined();
+    expect(c1!.requests).toBe(2);
+    expect(c1!.satsCost).toBe(30);
+    // client-1 is in top 3 non-null clients, should have topModels
+    expect(c1!.topModels.length).toBeGreaterThan(0);
+    expect(c1!.topModels[0]!.modelId).toBe("model-a");
+
+    const c2 = clients.find((c) => c.client === "client-2");
+    expect(c2).toBeDefined();
+    expect(c2!.requests).toBe(1);
+    expect(c2!.satsCost).toBe(8);
+
+    // unknown client (null group) should have empty topModels
+    const unknown = clients.find((c) => c.client === "unknown");
+    expect(unknown).toBeDefined();
+    expect(unknown!.topModels).toHaveLength(0);
+  });
+
+  it("folds client rows into npubs correctly", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { npubs } = summary;
+
+    // Only client-1 has ownerNpub = "npub1abc"
+    // npub1abc: e1 + e2 = requests 2, satsCost 30
+    expect(npubs).toHaveLength(1);
+    expect(npubs[0]!.npub).toBe("npub1abc");
+    expect(npubs[0]!.requests).toBe(2);
+    expect(npubs[0]!.satsCost).toBe(30);
+    // Top models for npub1abc (clients: ["client-1"]): only model-a
+    expect(npubs[0]!.topModels.length).toBeGreaterThan(0);
+    expect(npubs[0]!.topModels[0]!.modelId).toBe("model-a");
+  });
+
+  it("returns recent entries (up to 50)", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    expect(summary.recent).toHaveLength(4); // only 4 entries in driver
+    // Should be sorted desc by timestamp
+    expect(summary.recent[0]!.timestamp).toBeGreaterThanOrEqual(summary.recent[1]!.timestamp);
+  });
+
+  it("returns providers correctly", async () => {
+    const summary = await getUsageSummary(driver, CLIENTS, TZ);
+    const { providers } = summary;
+
+    // All entries use the same baseUrl
+    expect(providers).toHaveLength(1);
+    expect(providers[0]!.baseUrl).toBe("https://api.openai.com/");
+    expect(providers[0]!.requests).toBe(4);
+  });
+
+  it("caches results for same key within TTL", async () => {
+    const summary1 = await getUsageSummary(driver, CLIENTS, TZ);
+    const summary2 = await getUsageSummary(driver, CLIENTS, TZ);
+    // Same object reference means it was served from cache
+    expect(summary1).toBe(summary2);
+  });
+});