diff --git a/packages/api/src/__tests__/assistant-tools-chargeability-report.test.ts b/packages/api/src/__tests__/assistant-tools-chargeability-report.test.ts
new file mode 100644
index 0000000..cd206c4
--- /dev/null
+++ b/packages/api/src/__tests__/assistant-tools-chargeability-report.test.ts
@@ -0,0 +1,204 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { PermissionKey } from "@capakraken/shared";
+import { listAssignmentBookings } from "@capakraken/application";
+
+vi.mock("@capakraken/application", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@capakraken/application")>();
+  return {
+    ...actual,
+    approveEstimateVersion: vi.fn(),
+    cloneEstimate: vi.fn(),
+    commitDispoImportBatch: vi.fn(),
+    countPlanningEntries: vi.fn().mockResolvedValue({ countsByRoleId: new Map() }),
+    createEstimateExport: vi.fn(),
+    createEstimatePlanningHandoff: vi.fn(),
+    createEstimateRevision: vi.fn(),
+    assessDispoImportReadiness: vi.fn(),
+    loadResourceDailyAvailabilityContexts: vi.fn().mockResolvedValue(new Map()),
+    getDashboardDemand: vi.fn().mockResolvedValue([]),
+    getDashboardBudgetForecast: vi.fn().mockResolvedValue([]),
+    getDashboardOverview: vi.fn(),
+    getDashboardSkillGapSummary: vi.fn().mockResolvedValue({
+      roleGaps: [],
+      totalOpenPositions: 0,
+      skillSupplyTop10: [],
+      resourcesByRole: [],
+    }),
+    getDashboardProjectHealth: vi.fn().mockResolvedValue([]),
+    getDashboardPeakTimes: vi.fn().mockResolvedValue([]),
+    getDashboardTopValueResources: vi.fn().mockResolvedValue([]),
+    getEstimateById: vi.fn(),
+    listAssignmentBookings: vi.fn().mockResolvedValue([]),
+    stageDispoImportBatch: vi.fn(),
+    submitEstimateVersion: vi.fn(),
+    updateEstimateDraft: vi.fn(),
+  };
+});
+
+import { executeTool } from "../router/assistant-tools.js";
+import { createToolContext } from "./assistant-tools-report-test-helpers.js";
+
+describe("assistant chargeability report tools", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns the chargeability report readmodel through the assistant", async () => {
+    vi.mocked(listAssignmentBookings).mockResolvedValue([
+      {
+        id: "assignment_confirmed",
+        projectId: "project_confirmed",
+        resourceId: "resource_1",
+        startDate: new Date("2026-03-02T00:00:00.000Z"),
+        endDate: new Date("2026-03-06T00:00:00.000Z"),
+        hoursPerDay: 4,
+        dailyCostCents: 0,
+        status: "CONFIRMED",
+        project: {
+          id: "project_confirmed",
+          name: "Confirmed Project",
+          shortCode: "CP",
+          status: "ACTIVE",
+          orderType: "CLIENT",
+          dynamicFields: null,
+        },
+        resource: { id: "resource_1", displayName: "Alice", chapter: "CGI" },
+      },
+    ]);
+
+    const ctx = createToolContext(
+      {
+        resource: {
+          findMany: vi.fn().mockResolvedValue([
+            {
+              id: "resource_1",
+              eid: "E-001",
+              displayName: "Alice",
+              fte: 1,
+              availability: { monday: 8, tuesday: 8, wednesday: 8, thursday: 8, friday: 8 },
+              countryId: "country_es",
+              federalState: null,
+              metroCityId: "city_1",
+              chargeabilityTarget: 80,
+              country: {
+                id: "country_es",
+                code: "ES",
+                dailyWorkingHours: 8,
+                scheduleRules: null,
+              },
+              orgUnit: { id: "org_1", name: "CGI" },
+              managementLevelGroup: { id: "mgmt_1", name: "Senior", targetPercentage: 0.8 },
+              managementLevel: { id: "level_1", name: "L7" },
+              metroCity: { id: "city_1", name: "Barcelona" },
+            },
+          ]),
+        },
+        project: {
+          findMany: vi.fn().mockResolvedValue([
+            { id: "project_confirmed", utilizationCategory: { code: "Chg" } },
+          ]),
+        },
+        vacation: {
+          findMany: vi.fn().mockResolvedValue([]),
+        },
+        holidayCalendar: {
+          findMany: vi.fn().mockResolvedValue([]),
+        },
+      },
+      {
+        permissions: [PermissionKey.VIEW_COSTS, PermissionKey.USE_ASSISTANT_ADVANCED_TOOLS],
+      },
+    );
+
+    const result = await executeTool(
+      "get_chargeability_report",
+      JSON.stringify({
+        startMonth: "2026-03",
+        endMonth: "2026-03",
+        resourceLimit: 10,
+      }),
+      ctx,
+    );
+
+    const parsed = JSON.parse(result.content) as {
+      monthKeys: string[];
+      groupTotals: Array<{ monthKey: string; chargeabilityPct: number; targetPct: number }>;
+      resourceCount: number;
+      returnedResourceCount: number;
+      truncated: boolean;
+      explainability: {
+        locationFields: string[];
+        monthDerivationFields: string[];
+        activeFilters: string[];
+        formulas: {
+          sah: string;
+          chargeabilityPct: string;
+          targetHours: string;
+          gapHours: string;
+        };
+        notes: string[];
+      };
+      resources: Array<{
+        displayName: string;
+        targetPct: number;
+        months: Array<{ monthKey: string; sah: number; chargeabilityPct: number }>;
+      }>;
+    };
+
+    expect(parsed.monthKeys).toEqual(["2026-03"]);
+    expect(parsed.groupTotals).toEqual([
+      expect.objectContaining({
+        monthKey: "2026-03",
+        chargeabilityPct: expect.any(Number),
+        targetPct: 80,
+      }),
+    ]);
+    expect(parsed.resourceCount).toBe(1);
+    expect(parsed.returnedResourceCount).toBe(1);
+    expect(parsed.truncated).toBe(false);
+    expect(parsed.explainability).toEqual({
+      locationFields: [
+        "country",
+        "federalState",
+        "city",
+        "orgUnit",
+        "managementLevelGroup",
+        "managementLevel",
+      ],
+      monthDerivationFields: [
+        "baseAvailableHours",
+        "publicHolidayCount",
+        "publicHolidayWorkdayCount",
+        "publicHolidayHoursDeduction",
+        "absenceDayEquivalent",
+        "absenceHoursDeduction",
+        "effectiveAvailableHours",
+      ],
+      activeFilters: [],
+      formulas: {
+        sah: "baseAvailableHours - publicHolidayHoursDeduction - absenceHoursDeduction = effectiveAvailableHours",
+        chargeabilityPct: "chargeabilityHours / sahHours",
+        targetHours: "sahHours * targetPct",
+        gapHours: "chargeabilityHours - targetHours",
+      },
+      notes: [
+        "Location fields explain why two resources can have different SAH in the same month because country, federal state, and city holidays may differ.",
+        "Holiday deductions and absence deductions are tracked separately; absence does not deduct days that are already public holidays.",
+        "Include proposed work changes chargeability ratios and hours, but it does not change holiday or absence-based SAH derivation.",
+      ],
+    });
+    expect(parsed.resources).toEqual([
+      expect.objectContaining({
+        displayName: "Alice",
+        targetPct: 80,
+        months: [
+          expect.objectContaining({
+            monthKey: "2026-03",
+            sah: expect.any(Number),
+            chargeabilityPct: expect.any(Number),
+          }),
+        ],
+      }),
+    ]);
+  });
+});