diff --git a/canvas/src/components/tabs/chat/__tests__/AttachmentViews.test.tsx b/canvas/src/components/tabs/chat/__tests__/AttachmentViews.test.tsx
new file mode 100644
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--- /dev/null
+++ b/canvas/src/components/tabs/chat/__tests__/AttachmentViews.test.tsx
@@ -0,0 +1,185 @@
+// @vitest-environment jsdom
+/**
+ * AttachmentViews — pure presentational components for chat attachments.
+ *
+ * Covers:
+ *   - PendingAttachmentPill renders file name, formatted size, × button
+ *   - PendingAttachmentPill × button has correct aria-label
+ *   - PendingAttachmentPill calls onRemove when × clicked
+ *   - PendingAttachmentPill renders exactly one button
+ *   - AttachmentChip renders attachment name and download glyph
+ *   - AttachmentChip renders size when provided
+ *   - AttachmentChip omits size span when size is undefined
+ *   - AttachmentChip calls onDownload(attachment) on click
+ *   - AttachmentChip title attribute for hover tooltip
+ *   - AttachmentChip tone=user applies blue accent classes
+ *   - AttachmentChip tone=agent applies surface classes
+ *   - AttachmentChip renders exactly one button
+ *
+ * NOTE: No @testing-library/jest-dom import — use textContent / className /
+ * getAttribute checks to avoid "expect is not defined" errors in this vitest
+ * configuration.
+ */
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { cleanup, render, screen } from "@testing-library/react";
+import React from "react";
+
+import { AttachmentChip, PendingAttachmentPill } from "../AttachmentViews";
+import type { ChatAttachment } from "../types";
+
+afterEach(() => {
+  cleanup();
+  vi.restoreAllMocks();
+});
+
+// ─── Helpers ────────────────────────────────────────────────────────────────────
+
+/** Create a File with actual content so size > 0 in jsdom. */
+function makeFile(name: string, content: string): File {
+  return new File([content], name, { type: "application/octet-stream" });
+}
+
+function makeAttachment(name: string, size?: number): ChatAttachment {
+  return { name, uri: `workspace:/tmp/${name}`, size };
+}
+
+// ─── PendingAttachmentPill ─────────────────────────────────────────────────────
+
+describe("PendingAttachmentPill", () => {
+  it("renders the file name", () => {
+    const file = makeFile("report.pdf", "PDF content here");
+    const { container } = render(
+      <PendingAttachmentPill file={file} onRemove={vi.fn()} />,
+    );
+    expect(container.textContent).toContain("report.pdf");
+  });
+
+  it("renders the formatted file size (KB)", () => {
+    // 50 KB = 50 * 1024 bytes
+    const content = "x".repeat(50 * 1024);
+    const file = makeFile("data.csv", content);
+    const { container } = render(
+      <PendingAttachmentPill file={file} onRemove={vi.fn()} />,
+    );
+    expect(container.textContent).toContain("50 KB");
+  });
+
+  it("renders 0 B for empty file", () => {
+    const file = makeFile("empty.txt", "");
+    const { container } = render(
+      <PendingAttachmentPill file={file} onRemove={vi.fn()} />,
+    );
+    expect(container.textContent).toContain("0 B");
+  });
+
+  it("renders size in MB for files >= 1 MB", () => {
+    // 2.5 MB = 2.5 * 1024 * 1024 bytes
+    const content = "x".repeat(Math.round(2.5 * 1024 * 1024));
+    const file = makeFile("video.mp4", content);
+    const { container } = render(
+      <PendingAttachmentPill file={file} onRemove={vi.fn()} />,
+    );
+    expect(container.textContent).toContain("2.5 MB");
+  });
+
+  it("× button has aria-label with file name", () => {
+    const file = makeFile("notes.txt", "some content");
+    render(<PendingAttachmentPill file={file} onRemove={vi.fn()} />);
+    const btn = screen.getByRole("button");
+    expect(btn.getAttribute("aria-label")).toBe("Remove notes.txt");
+  });
+
+  it("calls onRemove when × button is clicked", () => {
+    const file = makeFile("doc.pdf", "pdf data");
+    const onRemove = vi.fn();
+    render(<PendingAttachmentPill file={file} onRemove={onRemove} />);
+    screen.getByRole("button").click();
+    expect(onRemove).toHaveBeenCalledTimes(1);
+  });
+
+  it("renders exactly one button (the × remove button)", () => {
+    const file = makeFile("img.png", "image bytes");
+    const { container } = render(
+      <PendingAttachmentPill file={file} onRemove={vi.fn()} />,
+    );
+    expect(container.querySelectorAll("button")).toHaveLength(1);
+  });
+});
+
+// ─── AttachmentChip ───────────────────────────────────────────────────────────
+
+describe("AttachmentChip", () => {
+  it("renders the attachment name", () => {
+    const att = makeAttachment("chart.svg", 2048);
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="user" />,
+    );
+    expect(container.textContent).toContain("chart.svg");
+  });
+
+  it("renders size when provided", () => {
+    const att = makeAttachment("dump.sql", 1024 * 150); // 150 KB
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="user" />,
+    );
+    expect(container.textContent).toContain("150 KB");
+  });
+
+  it("omits size span when attachment.size is undefined", () => {
+    const att = makeAttachment("notes.md"); // no size
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="user" />,
+    );
+    // The only <span> should be the truncated filename; no size <span>
+    const spans = Array.from(container.querySelectorAll("span"));
+    const sizeSpans = spans.filter(
+      (s) => s.className && s.className.includes("tabular-nums"),
+    );
+    expect(sizeSpans).toHaveLength(0);
+  });
+
+  it("has title attribute with download hint", () => {
+    const att = makeAttachment("readme.txt", 64);
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="agent" />,
+    );
+    const btn = container.querySelector("button");
+    expect(btn?.getAttribute("title")).toBe("Download readme.txt");
+  });
+
+  it("calls onDownload with the attachment on click", () => {
+    const att = makeAttachment("export.csv", 8192);
+    const onDownload = vi.fn();
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={onDownload} tone="agent" />,
+    );
+    container.querySelector("button")!.click();
+    expect(onDownload).toHaveBeenCalledWith(att);
+  });
+
+  it("tone=user applies blue accent class", () => {
+    const att = makeAttachment("photo.jpg", 512);
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="user" />,
+    );
+    const btn = container.querySelector("button")!;
+    expect(btn.className).toContain("blue-400");
+  });
+
+  it("tone=agent does not apply blue accent class", () => {
+    const att = makeAttachment("photo.jpg", 512);
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="agent" />,
+    );
+    const btn = container.querySelector("button")!;
+    expect(btn.className).not.toContain("blue-400");
+  });
+
+  it("renders exactly one button", () => {
+    const att = makeAttachment("icon.svg", 128);
+    const { container } = render(
+      <AttachmentChip attachment={att} onDownload={vi.fn()} tone="user" />,
+    );
+    expect(container.querySelectorAll("button")).toHaveLength(1);
+  });
+});