diff --git a/src/attune/ops/routes/dashboard.py b/src/attune/ops/routes/dashboard.py
index 925db390..4ae3fce9 100644
--- a/src/attune/ops/routes/dashboard.py
+++ b/src/attune/ops/routes/dashboard.py
@@ -8,7 +8,7 @@
 from fastapi import APIRouter, Request
 from fastapi.responses import HTMLResponse
 
-from attune.ops import data
+from attune.ops import anthropic_cost, data
 
 logger = logging.getLogger(__name__)
 
@@ -60,6 +60,20 @@ async def home(request: Request) -> HTMLResponse:
     runner = getattr(request.app.state, "runner", None)
     recent_runs = [r.to_dict() for r in runner.recent(limit=5)] if runner else []
     attune_ai = next((v for v in versions if v.package == "attune-ai"), None)
+    # Anthropic account-spend tiles (Phase 2 of anthropic-cost-integration).
+    # Defensive try/except — a fetch crash must not block the dashboard
+    # render, so we degrade silently (no tile cluster) on unexpected
+    # errors. Categorized failures (no_key, auth_failed, rate_limited,
+    # network) come back through cost_error and the template renders
+    # the right CTA / notice / fallback per-kind.
+    refresh = request.query_params.get("refresh") == "1"
+    try:
+        cost_summary, cost_error = anthropic_cost.fetch_summary(refresh=refresh)
+    except Exception:  # noqa: BLE001
+        # INTENTIONAL: defensive degradation; surface in DEBUG logs but
+        # never block the home page render on a billing-fetch surprise.
+        logger.debug("anthropic_cost.fetch_summary raised", exc_info=True)
+        cost_summary, cost_error = None, None
     return _render(
         request,
         "home.html",
@@ -71,6 +85,8 @@ async def home(request: Request) -> HTMLResponse:
         sparkline=sparkline,
         recent_runs=recent_runs,
         attune_ai=attune_ai,
+        cost_summary=cost_summary,
+        cost_error=cost_error,
     )
 
 
diff --git a/src/attune/ops/static/css/main.css b/src/attune/ops/static/css/main.css
index 2109cdd9..10e49e3d 100644
--- a/src/attune/ops/static/css/main.css
+++ b/src/attune/ops/static/css/main.css
@@ -268,6 +268,29 @@ a.kpi:hover {
   color: var(--fg-subtle);
 }
 
+/* Account-spend cluster (Phase 2 anthropic-cost-integration).
+   Visually distinguishes Anthropic-billing tiles from workflow-
+   telemetry tiles above so users can tell at a glance which numbers
+   come from which data source. Thin left-edge accent on each tile
+   in the cluster + tighter top margin so the two clusters read as
+   related-but-distinct rather than as a single grid. */
+.kpi-cluster-account {
+  margin-top: -8px;
+}
+.kpi-cluster-account .kpi {
+  border-left: 3px solid var(--accent);
+}
+.kpi-cluster-account .kpi-value-small {
+  font-size: 18px;
+  font-weight: 500;
+}
+.kpi-cluster-account .kpi-cta {
+  border-left-color: var(--fg-muted);
+}
+.kpi-cluster-account .kpi-notice {
+  border-left-color: var(--warn, #c87a00);
+}
+
 /* ---------- Panels ---------- */
 
 .panel {
diff --git a/src/attune/ops/templates/home.html b/src/attune/ops/templates/home.html
index 35cd00d9..3319c0db 100644
--- a/src/attune/ops/templates/home.html
+++ b/src/attune/ops/templates/home.html
@@ -40,6 +40,49 @@ <h1>attune ops</h1>
   </a>
 </section>
 
+{# Account-spend cluster (Phase 2 of anthropic-cost-integration).
+   Visually distinguished from the workflow-telemetry cluster above
+   via the .kpi-cluster-account class — these numbers come from the
+   Anthropic admin API, not local usage.jsonl. Gated on cost_summary
+   availability; CTA when no admin key; friendly notice on auth fail;
+   silent fall-through on transient errors so the dashboard stays
+   functional. #}
+{% if cost_summary is not none %}
+  <section class="kpi-grid kpi-cluster-account">
+    <a class="kpi" href="/telemetry">
+      <div class="kpi-label">Today (account)</div>
+      <div class="kpi-value">${{ '%.2f'|format(cost_summary.today_usd) }}</div>
+      <div class="kpi-foot">Anthropic billing &middot; {{ cost_summary.source }}</div>
+    </a>
+    <a class="kpi" href="/telemetry">
+      <div class="kpi-label">7d (account)</div>
+      <div class="kpi-value">${{ '%.2f'|format(cost_summary.seven_day_usd) }}</div>
+      <div class="kpi-foot">last 7 days, all workspaces</div>
+    </a>
+    <a class="kpi" href="/telemetry">
+      <div class="kpi-label">MTD (account)</div>
+      <div class="kpi-value">${{ '%.2f'|format(cost_summary.month_to_date_usd) }}</div>
+      <div class="kpi-foot">month-to-date</div>
+    </a>
+  </section>
+{% elif cost_error is not none and cost_error.kind == "no_key" %}
+  <section class="kpi-grid kpi-cluster-account">
+    <a class="kpi kpi-cta" href="https://github.com/Smart-AI-Memory/attune-ai/blob/main/docs/reference/" rel="noopener">
+      <div class="kpi-label">Set up cost reporting</div>
+      <div class="kpi-value kpi-value-small">Connect billing</div>
+      <div class="kpi-foot">Add an Anthropic admin API key to see account-wide spend here.</div>
+    </a>
+  </section>
+{% elif cost_error is not none and cost_error.kind == "auth_failed" %}
+  <section class="kpi-grid kpi-cluster-account">
+    <a class="kpi kpi-notice" href="/telemetry">
+      <div class="kpi-label">Account billing</div>
+      <div class="kpi-value kpi-value-small">Key rejected</div>
+      <div class="kpi-foot">Anthropic admin key was rejected. Refresh the key to see account-wide spend.</div>
+    </a>
+  </section>
+{% endif %}
+
 <section class="panel">
   <h2>Recent runs</h2>
   {% if recent_runs %}
diff --git a/tests/unit/ops/test_anthropic_cost_home_integration.py b/tests/unit/ops/test_anthropic_cost_home_integration.py
new file mode 100644
index 00000000..92186e1a
--- /dev/null
+++ b/tests/unit/ops/test_anthropic_cost_home_integration.py
@@ -0,0 +1,172 @@
+"""Phase 2 of anthropic-cost-integration — home page wiring.
+
+The spec (docs/specs/anthropic-cost-integration/tasks.md, task 2.4)
+specifies four scenarios this file covers:
+
+1. No admin key → CTA tile, no traceback, dashboard otherwise functional
+2. Valid CostSummary → all three account KPI tiles populated
+3. Auth-failed error → friendly notice, dashboard otherwise functional
+4. ?refresh=1 query param → fetch called with refresh=True
+
+The fetch_summary call is mocked at its import site in dashboard.py
+(not at its definition site) so the dispatch in the home route picks
+up the mock. See CLAUDE.md lesson "Real project files on disk override
+test mocks" for the rationale.
+"""
+
+from __future__ import annotations
+
+from datetime import date, datetime, timezone
+from unittest.mock import patch
+
+import pytest
+
+pytest.importorskip("fastapi")
+pytest.importorskip("jinja2")
+
+from fastapi.testclient import TestClient  # noqa: E402
+
+from attune.ops.anthropic_cost import CostFetchError, CostSummary  # noqa: E402
+from attune.ops.config import build_config  # noqa: E402
+from attune.ops.server import create_app  # noqa: E402
+
+
+def _client(tmp_path, monkeypatch) -> TestClient:
+    monkeypatch.setenv("ATTUNE_HOME", str(tmp_path / "attune-home"))
+    config = build_config(
+        project_root=tmp_path,
+        trusted_hosts=("testserver", "test"),
+    )
+    app = create_app(config)
+    return TestClient(app)
+
+
+def _valid_summary() -> CostSummary:
+    return CostSummary(
+        today_usd=4.72,
+        seven_day_usd=18.31,
+        month_to_date_usd=42.50,
+        thirty_day_usd=42.50,
+        by_day=[(date(2026, 5, 19), 4.72)],
+        by_model=[("claude-sonnet-4-5", 4.72)],
+        by_cost_type=[("input_tokens", 1.10), ("output_tokens", 3.62)],
+        fetched_at=datetime(2026, 5, 19, 12, 0, tzinfo=timezone.utc),
+        source="live",
+    )
+
+
+def test_home_renders_cta_when_no_admin_key(tmp_path, monkeypatch):
+    """Home page shows the no-key CTA, no traceback, dashboard renders."""
+    err = CostFetchError(kind="no_key", message="no admin key configured")
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        return_value=(None, err),
+    ):
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/")
+
+    assert resp.status_code == 200
+    # CTA copy and class are present.
+    assert "Set up cost reporting" in resp.text
+    assert "Connect billing" in resp.text
+    assert "kpi-cluster-account" in resp.text
+    # Telemetry tiles still render — dashboard is otherwise functional.
+    assert "Today's events" in resp.text
+    assert "7-day spend" in resp.text
+
+
+def test_home_renders_three_tiles_with_valid_summary(tmp_path, monkeypatch):
+    """All three account-spend KPI tiles populated with formatted USD."""
+    summary = _valid_summary()
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        return_value=(summary, None),
+    ):
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/")
+
+    assert resp.status_code == 200
+    # Three tile labels.
+    assert "Today (account)" in resp.text
+    assert "7d (account)" in resp.text
+    assert "MTD (account)" in resp.text
+    # Formatted dollar values.
+    assert "$4.72" in resp.text
+    assert "$18.31" in resp.text
+    assert "$42.50" in resp.text
+    # Source indicator visible on the today tile.
+    assert "live" in resp.text
+
+
+def test_home_renders_notice_on_auth_failed(tmp_path, monkeypatch):
+    """auth_failed surfaces a friendly notice; dashboard stays functional."""
+    err = CostFetchError(kind="auth_failed", message="key rejected (HTTP 401)")
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        return_value=(None, err),
+    ):
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/")
+
+    assert resp.status_code == 200
+    assert "Key rejected" in resp.text
+    assert "kpi-notice" in resp.text
+    # Friendly notice — no raw HTTP status or stack trace surfaced.
+    assert "HTTP 401" not in resp.text
+    # Workflow and version tiles still render.
+    assert "Workflows" in resp.text
+
+
+def test_home_passes_refresh_true_when_query_param_set(tmp_path, monkeypatch):
+    """?refresh=1 → fetch_summary called with refresh=True."""
+    summary = _valid_summary()
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        return_value=(summary, None),
+    ) as mock_fetch:
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/?refresh=1")
+
+    assert resp.status_code == 200
+    mock_fetch.assert_called_once()
+    # Keyword arg, per the helper's keyword-only signature.
+    assert mock_fetch.call_args.kwargs.get("refresh") is True
+
+
+def test_home_default_call_passes_refresh_false(tmp_path, monkeypatch):
+    """Without ?refresh=1, fetch_summary is called with refresh=False."""
+    summary = _valid_summary()
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        return_value=(summary, None),
+    ) as mock_fetch:
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/")
+
+    assert resp.status_code == 200
+    mock_fetch.assert_called_once()
+    assert mock_fetch.call_args.kwargs.get("refresh") is False
+
+
+def test_home_degrades_silently_on_fetch_exception(tmp_path, monkeypatch):
+    """Unexpected fetch exception → no tile cluster, dashboard renders.
+
+    Defensive try/except in the home route should swallow surprises and
+    let the rest of the page render. The cost-cluster simply doesn't
+    appear; no traceback bleeds into the HTML.
+    """
+    with patch(
+        "attune.ops.anthropic_cost.fetch_summary",
+        side_effect=RuntimeError("anthropic edge melted"),
+    ):
+        with _client(tmp_path, monkeypatch) as client:
+            resp = client.get("/")
+
+    assert resp.status_code == 200
+    # No tile cluster rendered.
+    assert "kpi-cluster-account" not in resp.text
+    # No traceback / exception text leaked.
+    assert "anthropic edge melted" not in resp.text
+    assert "Traceback" not in resp.text
+    # Dashboard otherwise functional.
+    assert "attune ops" in resp.text  # hero title