diff --git a/Auto Run Docs/SpecKit-web-header-analyzer-Phase-05-Analysis-Execution.md b/Auto Run Docs/SpecKit-web-header-analyzer-Phase-05-Analysis-Execution.md
index ec44068..cfb797c 100644
--- a/Auto Run Docs/SpecKit-web-header-analyzer-Phase-05-Analysis-Execution.md	
+++ b/Auto Run Docs/SpecKit-web-header-analyzer-Phase-05-Analysis-Execution.md	
@@ -33,7 +33,7 @@ Frontend uses `fetch` with `ReadableStream` reader (not native `EventSource`, wh
 
 - [x] T025 [US3] Write failing tests (TDD Red) in `backend/tests/api/test_analysis_router.py` — happy path (valid headers → 200 with SSE progress + result), error path (empty → 400), oversized (>1MB → 413), partial failure (some tests error → mixed results per FR-25), timeout (30s limit per NFR-13, partial results per NFR-14)
 - [x] T026 [US3] Create `backend/app/schemas/analysis.py` (request/response schemas) and `backend/app/routers/analysis.py` — FastAPI router with `POST /api/analyse` using SSE for progress streaming. Accepts headers string + config (test IDs, resolve, decode-all). Invokes `HeaderAnalyzer` with 30s timeout (NFR-13). Streams progress events then final result. Sanitises input (NFR-09), validates size ≤1MB (NFR-10). Stateless — no job_id, no in-memory state (Assumption 3). Register router in `backend/app/main.py`. Verify `test_analysis_router.py` passes (TDD Green)
-- [ ] T027 [US3] Write failing tests (TDD Red) in `frontend/src/__tests__/ProgressIndicator.test.tsx` (render at various states, timeout display) and `frontend/src/__tests__/useAnalysis.test.ts` (hook state transitions, SSE handling)
+- [x] T027 [US3] Write failing tests (TDD Red) in `frontend/src/__tests__/ProgressIndicator.test.tsx` (render at various states, timeout display) and `frontend/src/__tests__/useAnalysis.test.ts` (hook state transitions, SSE handling)
 - [ ] T028 [P] [US3] Create `frontend/src/hooks/useAnalysis.ts` — custom hook managing analysis lifecycle. Submits to `POST /api/analyse` via API client, consumes SSE stream for real-time progress (no polling). States: idle, submitting, analysing (with progress), complete, error, timeout. Returns: `submit()`, `cancel()`, `progress`, `result`, `error`, `status`. Verify `useAnalysis.test.ts` passes (TDD Green)
 - [ ] T029 [P] [US3] Create `frontend/src/components/ProgressIndicator.tsx` — progress bar with percentage, current test name (FR-22), countdown timer from 30s (NFR-13), elapsed time. Colour-coded: green progressing, amber near timeout, red on timeout. FontAwesome spinner. Timeout notification listing incomplete tests (NFR-14). Verify `ProgressIndicator.test.tsx` passes (TDD Green)
 
diff --git a/frontend/src/__tests__/ProgressIndicator.test.tsx b/frontend/src/__tests__/ProgressIndicator.test.tsx
new file mode 100644
index 0000000..b32c18e
--- /dev/null
+++ b/frontend/src/__tests__/ProgressIndicator.test.tsx
@@ -0,0 +1,124 @@
+import type { ReactElement } from "react";
+import { act } from "react-dom/test-utils";
+import { createRoot } from "react-dom/client";
+import { afterEach, describe, expect, it } from "vitest";
+
+import ProgressIndicator from "../components/ProgressIndicator";
+import type { AnalysisProgress } from "../types/analysis";
+
+type RenderResult = {
+  container: HTMLDivElement;
+};
+
+const cleanups: Array<() => void> = [];
+
+const render = (ui: ReactElement): RenderResult => {
+  const container = document.createElement("div");
+  document.body.appendChild(container);
+  const root = createRoot(container);
+
+  act(() => {
+    root.render(ui);
+  });
+
+  cleanups.push(() => {
+    act(() => {
+      root.unmount();
+    });
+    container.remove();
+  });
+
+  return { container };
+};
+
+const getByTestId = (container: HTMLElement, testId: string): HTMLElement => {
+  const element = container.querySelector(`[data-testid="${testId}"]`);
+  if (!element) {
+    throw new Error(`Expected element ${testId} to be rendered.`);
+  }
+  return element as HTMLElement;
+};
+
+const baseProgress: AnalysisProgress = {
+  currentIndex: 1,
+  totalTests: 4,
+  currentTest: "SpamAssassin Rule Hits",
+  elapsedMs: 12000,
+  percentage: 50,
+};
+
+afterEach(() => {
+  while (cleanups.length > 0) {
+    const cleanup = cleanups.pop();
+    if (cleanup) {
+      cleanup();
+    }
+  }
+});
+
+describe("ProgressIndicator", () => {
+  it("renders progress details while analysing", () => {
+    const { container } = render(
+      <ProgressIndicator status="analysing" progress={baseProgress} timeoutSeconds={30} />,
+    );
+
+    const indicator = getByTestId(container, "progress-indicator");
+    expect(indicator.getAttribute("data-status")).toBe("analysing");
+    expect(indicator.getAttribute("data-variant")).toBe("normal");
+
+    expect(getByTestId(container, "progress-percentage").textContent ?? "").toMatch(
+      /50%/,
+    );
+    expect(getByTestId(container, "progress-current-test").textContent ?? "").toMatch(
+      /SpamAssassin Rule Hits/,
+    );
+    expect(getByTestId(container, "progress-elapsed").textContent ?? "").toMatch(/12s/);
+    expect(getByTestId(container, "progress-remaining").textContent ?? "").toMatch(/18s/);
+    expect(getByTestId(container, "progress-spinner")).toBeTruthy();
+
+    const progressbar = container.querySelector('[role="progressbar"]');
+    expect(progressbar?.getAttribute("aria-valuenow")).toBe("50");
+    expect(progressbar?.getAttribute("aria-valuemax")).toBe("100");
+  });
+
+  it("uses warning styling when near timeout", () => {
+    const nearTimeout: AnalysisProgress = {
+      ...baseProgress,
+      elapsedMs: 28000,
+      percentage: 93,
+    };
+
+    const { container } = render(
+      <ProgressIndicator status="analysing" progress={nearTimeout} timeoutSeconds={30} />,
+    );
+
+    const indicator = getByTestId(container, "progress-indicator");
+    expect(indicator.getAttribute("data-variant")).toBe("warning");
+    expect(getByTestId(container, "progress-remaining").textContent ?? "").toMatch(/2s/);
+  });
+
+  it("shows a timeout notification with incomplete tests", () => {
+    const { container } = render(
+      <ProgressIndicator
+        status="timeout"
+        progress={baseProgress}
+        timeoutSeconds={30}
+        incompleteTests={["Mimecast Fingerprint", "Proofpoint TAP"]}
+      />,
+    );
+
+    const indicator = getByTestId(container, "progress-indicator");
+    expect(indicator.getAttribute("data-status")).toBe("timeout");
+    expect(indicator.getAttribute("data-variant")).toBe("timeout");
+
+    const alert = container.querySelector('[role="alert"]');
+    expect(alert).not.toBeNull();
+    expect(alert?.textContent ?? "").toMatch(/timeout/i);
+    expect(getByTestId(container, "timeout-tests").textContent ?? "").toMatch(
+      /Mimecast Fingerprint/,
+    );
+    expect(getByTestId(container, "timeout-tests").textContent ?? "").toMatch(
+      /Proofpoint TAP/,
+    );
+  });
+});
diff --git a/frontend/src/__tests__/useAnalysis.test.ts b/frontend/src/__tests__/useAnalysis.test.ts
new file mode 100644
index 0000000..63c6e1c
--- /dev/null
+++ b/frontend/src/__tests__/useAnalysis.test.ts
@@ -0,0 +1,277 @@
+import type { ReactElement } from "react";
+import { useEffect } from "react";
+import { act } from "react-dom/test-utils";
+import { createRoot } from "react-dom/client";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { apiClient } from "../lib/api-client";
+import type { AnalysisConfig, AnalysisProgress, AnalysisReport } from "../types/analysis";
+import useAnalysis from "../hooks/useAnalysis";
+
+type RenderResult = {
+  container: HTMLDivElement;
+};
+
+type AnalysisRequest = {
+  headers: string;
+  config: AnalysisConfig;
+};
+
+type HarnessProps = {
+  request: AnalysisRequest;
+  onStatusChange?: (status: string) => void;
+};
+
+const cleanups: Array<() => void> = [];
+
+const render = (ui: ReactElement): RenderResult => {
+  const container = document.createElement("div");
+  document.body.appendChild(container);
+  const root = createRoot(container);
+
+  act(() => {
+    root.render(ui);
+  });
+
+  cleanups.push(() => {
+    act(() => {
+      root.unmount();
+    });
+    container.remove();
+  });
+
+  return { container };
+};
+
+const flushPromises = async (): Promise<void> => {
+  await new Promise((resolve) => setTimeout(resolve, 0));
+};
+
+const getByTestId = (container: HTMLElement, testId: string): HTMLElement => {
+  const element = container.querySelector(`[data-testid="${testId}"]`);
+  if (!element) {
+    throw new Error(`Expected element ${testId} to be rendered.`);
+  }
+  return element as HTMLElement;
+};
+
+const baseConfig: AnalysisConfig = {
+  testIds: [101],
+  resolve: true,
+  decodeAll: false,
+};
+
+const baseRequest: AnalysisRequest = {
+  headers: "X-Test: value",
+  config: baseConfig,
+};
+
+const progressEvent: AnalysisProgress = {
+  currentIndex: 0,
+  totalTests: 3,
+  currentTest: "SpamAssassin Rule Hits",
+  elapsedMs: 500,
+  percentage: 33,
+};
+
+const completeReport: AnalysisReport = {
+  results: [],
+  hopChain: [],
+  securityAppliances: [],
+  metadata: {
+    totalTests: 3,
+    passedTests: 3,
+    failedTests: 0,
+    skippedTests: 0,
+    elapsedMs: 1500,
+    timedOut: false,
+    incompleteTests: [],
+  },
+};
+
+const timeoutReport: AnalysisReport = {
+  results: [],
+  hopChain: [],
+  securityAppliances: [],
+  metadata: {
+    totalTests: 5,
+    passedTests: 2,
+    failedTests: 1,
+    skippedTests: 0,
+    elapsedMs: 30000,
+    timedOut: true,
+    incompleteTests: ["Mimecast Fingerprint", "Proofpoint TAP"],
+  },
+};
+
+const AnalysisHarness = ({ request, onStatusChange }: HarnessProps) => {
+  const { status, progress, result, error, submit, cancel } = useAnalysis();
+
+  useEffect(() => {
+    onStatusChange?.(status);
+  }, [status, onStatusChange]);
+
+  return (
+    <div>
+      <span data-testid="status">{status}</span>
+      <span data-testid="current-test">{progress?.currentTest ?? ""}</span>
+      <span data-testid="percentage">{progress?.percentage ?? ""}</span>
+      <span data-testid="result-total">{result?.metadata.totalTests ?? ""}</span>
+      <span data-testid="error">{error ?? ""}</span>
+      <button data-testid="submit" onClick={() => submit(request)}>
+        Submit
+      </button>
+      <button data-testid="cancel" onClick={() => cancel()}>
+        Cancel
+      </button>
+    </div>
+  );
+};
+
+afterEach(() => {
+  while (cleanups.length > 0) {
+    const cleanup = cleanups.pop();
+    if (cleanup) {
+      cleanup();
+    }
+  }
+  vi.restoreAllMocks();
+});
+
+describe("useAnalysis", () => {
+  it("starts in the idle state", () => {
+    const { container } = render(<AnalysisHarness request={baseRequest} />);
+
+    expect(getByTestId(container, "status").textContent).toBe("idle");
+    expect(getByTestId(container, "current-test").textContent).toBe("");
+    expect(getByTestId(container, "error").textContent).toBe("");
+  });
+
+  it("submits analysis and handles SSE progress + result", async () => {
+    const streamSpy = vi.spyOn(apiClient, "stream").mockImplementation(
+      async (_path, options) => {
+        options.onEvent({ event: "progress", data: progressEvent, raw: "" });
+        options.onEvent({ event: "result", data: completeReport, raw: "" });
+      },
+    );
+
+    const statuses: string[] = [];
+    const { container } = render(
+      <AnalysisHarness request={baseRequest} onStatusChange={(status) => statuses.push(status)} />,
+    );
+
+    act(() => {
+      getByTestId(container, "submit").dispatchEvent(
+        new MouseEvent("click", { bubbles: true }),
+      );
+    });
+
+    await act(async () => {
+      await flushPromises();
+    });
+
+    expect(streamSpy).toHaveBeenCalledWith(
+      "/api/analyse",
+      expect.objectContaining({
+        body: baseRequest,
+        onEvent: expect.any(Function),
+        signal: expect.any(AbortSignal),
+      }),
+    );
+
+    expect(statuses).toEqual(["idle", "submitting", "analysing", "complete"]);
+    expect(getByTestId(container, "current-test").textContent).toMatch(
+      /SpamAssassin Rule Hits/,
+    );
+    expect(getByTestId(container, "percentage").textContent).toBe("33");
+    expect(getByTestId(container, "result-total").textContent).toBe("3");
+  });
+
+  it("marks the analysis as timed out when the report indicates timeout", async () => {
+    vi.spyOn(apiClient, "stream").mockImplementation(async (_path, options) => {
+      options.onEvent({ event: "result", data: timeoutReport, raw: "" });
+    });
+
+    const statuses: string[] = [];
+    const { container } = render(
+      <AnalysisHarness request={baseRequest} onStatusChange={(status) => statuses.push(status)} />,
+    );
+
+    act(() => {
+      getByTestId(container, "submit").dispatchEvent(
+        new MouseEvent("click", { bubbles: true }),
+      );
+    });
+
+    await act(async () => {
+      await flushPromises();
+    });
+
+    expect(statuses).toEqual(["idle", "submitting", "timeout"]);
+    expect(getByTestId(container, "result-total").textContent).toBe("5");
+  });
+
+  it("surfaces stream errors and moves to error state", async () => {
+    vi.spyOn(apiClient, "stream").mockRejectedValue(new Error("Network error"));
+
+    const statuses: string[] = [];
+    const { container } = render(
+      <AnalysisHarness request={baseRequest} onStatusChange={(status) => statuses.push(status)} />,
+    );
+
+    act(() => {
+      getByTestId(container, "submit").dispatchEvent(
+        new MouseEvent("click", { bubbles: true }),
+      );
+    });
+
+    await act(async () => {
+      await flushPromises();
+    });
+
+    expect(statuses).toEqual(["idle", "submitting", "error"]);
+    expect(getByTestId(container, "error").textContent ?? "").toMatch(/Network error/);
+  });
+
+  it("cancels an in-flight analysis request", async () => {
+    let abortSignal: AbortSignal | undefined;
+    vi.spyOn(apiClient, "stream").mockImplementation(async (_path, options) => {
+      abortSignal = options.signal;
+      await new Promise<void>((resolve) => {
+        if (abortSignal?.aborted) {
+          resolve();
+          return;
+        }
+        abortSignal?.addEventListener("abort", () => resolve(), { once: true });
+      });
+    });
+
+    const statuses: string[] = [];
+    const { container } = render(
+      <AnalysisHarness request={baseRequest} onStatusChange={(status) => statuses.push(status)} />,
+    );
+
+    act(() => {
+      getByTestId(container, "submit").dispatchEvent(
+        new MouseEvent("click", { bubbles: true }),
+      );
+    });
+
+    await act(async () => {
+      await flushPromises();
+    });
+
+    act(() => {
+      getByTestId(container, "cancel").dispatchEvent(
+        new MouseEvent("click", { bubbles: true }),
+      );
+    });
+
+    await act(async () => {
+      await flushPromises();
+    });
+
+    expect(abortSignal?.aborted).toBe(true);
+    expect(statuses).toContain("idle");
+  });
+});