diff --git a/web/src/components/copy-button.test.tsx b/web/src/components/copy-button.test.tsx
new file mode 100644
index 0000000..43c0b9e
--- /dev/null
+++ b/web/src/components/copy-button.test.tsx
@@ -0,0 +1,166 @@
+import "../test/setup-dom";
+
+import { act, cleanup, fireEvent, render, waitFor } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, mock } from "bun:test";
+import { CopyButton } from "./copy-button";
+import { browserAnalytics } from "@/lib/browser-analytics";
+import { AnalyticsEvent } from "@/lib/analytics-events";
+
+const originalCapture = browserAnalytics.capture;
+const originalClipboard = Object.getOwnPropertyDescriptor(navigator, "clipboard");
+const originalSetTimeout = window.setTimeout;
+const originalClearTimeout = window.clearTimeout;
+
+let nextTimerId = 1;
+let pendingTimers = new Map<number, () => void>();
+let pendingTimerDelays = new Map<number, number>();
+
+function installDeterministicTimers(): void {
+  nextTimerId = 1;
+  pendingTimers = new Map();
+  pendingTimerDelays = new Map();
+  window.setTimeout = ((callback: TimerHandler, delay?: number) => {
+    const id = nextTimerId++;
+    pendingTimers.set(id, callback as () => void);
+    pendingTimerDelays.set(id, delay ?? 0);
+    return id;
+  }) as unknown as typeof window.setTimeout;
+  window.clearTimeout = ((id: number) => {
+    pendingTimers.delete(id);
+    pendingTimerDelays.delete(id);
+  }) as typeof window.clearTimeout;
+}
+
+function flushPendingTimer(): void {
+  const [id, callback] = pendingTimers.entries().next().value ?? [];
+  if (id !== undefined && callback) {
+    pendingTimers.delete(id);
+    callback();
+  }
+}
+
+function installClipboard(writeText = mock(async (_value: string) => undefined)) {
+  Object.defineProperty(navigator, "clipboard", {
+    configurable: true,
+    value: { writeText },
+  });
+  return writeText;
+}
+
+beforeEach(() => {
+  installDeterministicTimers();
+  installClipboard();
+  browserAnalytics.capture = mock();
+});
+
+afterEach(() => {
+  cleanup();
+  window.setTimeout = originalSetTimeout;
+  window.clearTimeout = originalClearTimeout;
+  browserAnalytics.capture = originalCapture;
+  pendingTimers.clear();
+  pendingTimerDelays.clear();
+
+  if (originalClipboard) {
+    Object.defineProperty(navigator, "clipboard", originalClipboard);
+  } else {
+    delete (navigator as unknown as { clipboard?: unknown }).clipboard;
+  }
+});
+
+describe("CopyButton", () => {
+  it("synthesizes a bounded accessible label and preserves custom props", () => {
+    const longValue = "abcdefghijklmnopqrstuvwxyz0123456789";
+    const { getByRole } = render(
+      <CopyButton value={longValue} label="Copy code" className="custom-class" />,
+    );
+    const button = getByRole("button");
+
+    expect(button.getAttribute("aria-label")).toBe("Copy code abcdefghijklmnopqrstuvwx");
+    expect(button.className).toContain("custom-class");
+
+    cleanup();
+    const custom = render(
+      <CopyButton value="secret" label="Copy" ariaLabel="Copy secret value" />,
+    ).getByRole("button");
+    expect(custom.getAttribute("aria-label")).toBe("Copy secret value");
+  });
+
+  it("copies the value, shows the configured label, and emits analytics once", async () => {
+    const writeText = installClipboard();
+    const { getByRole } = render(
+      <CopyButton
+        value="hello"
+        label="Copy"
+        copiedLabel="Copied!"
+        analyticsEvent={AnalyticsEvent.SummaryCopied}
+        analyticsProperties={{ source: "test" }}
+      />,
+    );
+    const button = getByRole("button");
+
+    fireEvent.click(button);
+    await waitFor(() => expect(button.textContent).toContain("Copied!"));
+
+    expect(writeText).toHaveBeenCalledWith("hello");
+    expect(browserAnalytics.capture).toHaveBeenCalledTimes(1);
+    expect(browserAnalytics.capture).toHaveBeenCalledWith(AnalyticsEvent.SummaryCopied, {
+      source: "test",
+    });
+  });
+
+  it("returns to the normal label after the scheduled reset", async () => {
+    const { getByRole } = render(<CopyButton value="hello" />);
+    const button = getByRole("button");
+
+    fireEvent.click(button);
+    await waitFor(() => expect(button.textContent).toContain("Copied"));
+    expect(pendingTimers.size).toBe(1);
+    expect(pendingTimerDelays.get([...pendingTimers.keys()][0])).toBe(1600);
+
+    act(() => flushPendingTimer());
+    expect(button.textContent).toContain("Copy");
+  });
+
+  it("replaces the pending reset on repeated successful clicks", async () => {
+    const { getByRole } = render(<CopyButton value="hello" />);
+    const button = getByRole("button");
+
+    fireEvent.click(button);
+    await waitFor(() => expect(button.textContent).toContain("Copied"));
+    const firstTimer = [...pendingTimers.keys()][0];
+
+    fireEvent.click(button);
+    await waitFor(() => expect(button.textContent).toContain("Copied"));
+
+    expect(pendingTimers.size).toBe(1);
+    expect(pendingTimers.has(firstTimer)).toBe(false);
+  });
+
+  it("keeps the normal label and skips analytics when copying fails", async () => {
+    const writeText = installClipboard(mock(async () => Promise.reject(new Error("blocked"))));
+    const { getByRole } = render(
+      <CopyButton value="hello" analyticsEvent={AnalyticsEvent.SummaryCopied} />,
+    );
+    const button = getByRole("button");
+
+    fireEvent.click(button);
+    await waitFor(() => expect(writeText).toHaveBeenCalledWith("hello"));
+
+    expect(button.textContent).toContain("Copy");
+    expect(browserAnalytics.capture).not.toHaveBeenCalled();
+    expect(pendingTimers.size).toBe(0);
+  });
+
+  it("clears a pending reset when unmounted", async () => {
+    const { getByRole, unmount } = render(<CopyButton value="hello" />);
+    const button = getByRole("button");
+
+    fireEvent.click(button);
+    await waitFor(() => expect(button.textContent).toContain("Copied"));
+    expect(pendingTimers.size).toBe(1);
+
+    unmount();
+    expect(pendingTimers.size).toBe(0);
+  });
+});