status: cancel-all reverts pending changes to last applied config

- lib.common.revert_to_applied(): restore a config file from its
  _last_applied_config snapshot (stamped hash); no baseline -> skip with
  reason, file untouched
- firewall config_apply now stamps the applied baseline like the other
  subsystems; GET /firewall/config and the state collector strip the
  internal _last_applied_* keys
- POST /status/cancel-all + /api/status/cancel-all: revert pending
  subsystems, {cancelled, skipped, errors}, partial-failure safe
- dashboard: "Cancel All Changes" button with confirm modal
  (CancelConfirm, reuses the pending-changes modal rows); the pending
  changes card is hidden entirely when nothing is pending
- tests: revert_to_applied, status_cancel_all, firewall stamping/meta
  stripping, /api/status/cancel-all route, node tests for CancelConfirm;
  firewall _config_apply tests no longer write the real repo config
- docs: api.md, state-model.md, config.md, hoover.md

daemon/handlers/firewall.py

@@ -34,7 +34,7 @@ from daemon.iface import (
     POST_FIREWALL_ZONES_SERVICES,
 )
 from daemon.server import ConflictError, NotFoundError, refresh_state, registry
-from lib.common import load_json, run, save_json
+from lib.common import load_json, run, save_json, stamp_applied, strip_apply_meta
 from lib.firewall import (
     _normalize_target,
     _parse_active_zones,
@@ -391,6 +391,11 @@ def _config_apply(force: bool = False) -> dict[str, Any]:
         "timestamp": "",
     }
     backup_path = _save_backup(full_state)
+    # Record the applied config snapshot + hash so pending-changes detection
+    # and cancel/revert work like the hash-based subsystems.
+    applied_cfg = _get_config()
+    stamp_applied(applied_cfg)
+    _save_config(applied_cfg)
     logger.info("Firewall config applied to %d zones", len(applied))
     return {
         "applied_zones": applied,
@@ -506,9 +511,9 @@ def get_config(_request: Any, _body: Any) -> dict[str, Any]:
         _body: The request body (unused).
 
     Returns:
-        Full firewall config dict.
+        Full firewall config dict (apply bookkeeping keys stripped).
     """
-    return _get_config()
+    return strip_apply_meta(_get_config())
 
 
 @registry.register(POST_FIREWALL_CONFIG)

daemon/handlers/status.py

@@ -1,21 +1,33 @@
 """Aggregate status handler.
 
-Exposes pending changes across all subsystems and a single apply-all
-endpoint that invokes each subsystem's apply in the correct order.
+Exposes pending changes across all subsystems, a single apply-all
+endpoint that invokes each subsystem's apply in the correct order, and a
+cancel-all endpoint that reverts pending edits to the last applied config.
 """
 
 from __future__ import annotations
 
 import logging
+from pathlib import Path
 from typing import Any
 
+from daemon.handlers import dnsmasq as _dnsmasq_h
+from daemon.handlers import firewall as _firewall_h
+from daemon.handlers import nginx as _nginx_h
 from daemon.handlers.dnsmasq import apply_config as dnsmasq_apply_config
 from daemon.handlers.firewall import config_apply as firewall_config_apply
 from daemon.handlers.network import apply_all as network_apply_all
 from daemon.handlers.nginx import apply as nginx_apply
 from daemon.handlers.wireguard import apply as wireguard_apply
-from daemon.iface import GET_STATUS_PENDING, POST_STATUS_APPLY_ALL
+from daemon.iface import (
+    GET_STATUS_PENDING,
+    POST_STATUS_APPLY_ALL,
+    POST_STATUS_CANCEL_ALL,
+)
 from daemon.server import refresh_state, registry
+from lib import network as _net
+from lib import wireguard as _wg
+from lib.common import revert_to_applied
 from lib.firewall import fw_change_summary
 from lib.state import state as state_store
 
@@ -36,6 +48,15 @@ SYS_APPLY = {
     "dnsmasq": dnsmasq_apply_config,
     "nginx": nginx_apply,
 }
+# (module, attribute) pairs for each subsystem's on-disk config path.
+# Resolved at call time so tests can monkeypatch the module constants.
+SYS_CONFIG_PATHS: dict[str, tuple[Any, str]] = {
+    "firewall": (_firewall_h, "CONFIG_FILE"),
+    "dnsmasq": (_dnsmasq_h, "CONFIG_PATH"),
+    "nginx": (_nginx_h, "CONFIG_FILE"),
+    "wireguard": (_wg, "CONFIG_PATH"),
+    "networkd": (_net, "CONFIG_FILE"),
+}
 
 
 @registry.register(GET_STATUS_PENDING)
@@ -126,6 +147,65 @@ def status_apply_all(_request: Any, _body: Any) -> dict[str, Any]:
     return {"applied": applied, "errors": errors}
 
 
+def _config_path(name: str) -> Path:
+    """Return the on-disk config path for subsystem *name*.
+
+    Resolved via the owning module at call time so tests can monkeypatch
+    the module constants (e.g. ``lib.wireguard.CONFIG_PATH``).
+    """
+    module, attr = SYS_CONFIG_PATHS[name]
+    return getattr(module, attr)
+
+
+@registry.register(POST_STATUS_CANCEL_ALL)
+def status_cancel_all(_request: Any, _body: Any) -> dict[str, Any]:
+    """Revert pending changes for all subsystems to the last applied config.
+
+    Restores each pending subsystem's config file from its recorded
+    ``_last_applied_config`` snapshot, discarding unapplied edits.
+    Subsystems without a recorded baseline (never applied) are skipped
+    with a reason instead of being reset. No live-system commands run —
+    cancel only touches the declarative config files.
+
+    Returns:
+        Dict with ``cancelled`` (list of reverted subsystems),
+        ``skipped`` (label -> reason), and ``errors`` (label -> message).
+    """
+    pending_data = status_pending(None, None)
+    fw_pending = pending_data["firewall"]["needs_apply"]
+    hash_pending = {
+        "dnsmasq": pending_data["dnsmasq"]["pending_changes"],
+        "nginx": pending_data["nginx"]["pending_changes"],
+        "wireguard": pending_data["wireguard"]["pending_changes"],
+        "networkd": pending_data["networkd"]["pending_changes"],
+    }
+
+    cancelled: list[str] = []
+    skipped: dict[str, str] = {}
+    errors: dict[str, str] = {}
+
+    for name in SYS_ORDER:
+        pending = fw_pending if name == "firewall" else hash_pending.get(name, False)
+        if not pending:
+            continue
+        label = SYS_LABELS.get(name, name)
+        try:
+            ok, reason = revert_to_applied(_config_path(name))
+            if ok:
+                cancelled.append(name)
+                logger.info("Cancelled pending changes for %s", name)
+            else:
+                skipped[label] = reason
+                logger.warning("Cancel-all skipped %s: %s", label, reason)
+        except Exception as exc:
+            errors[label] = str(exc)
+            logger.error("Cancel-all failed for %s: %s", name, exc)
+
+    if cancelled:
+        refresh_state(SYS_ORDER)
+    return {"cancelled": cancelled, "skipped": skipped, "errors": errors}
+
+
 def _hash_subsystem(name: str, state: dict[str, Any] | None) -> dict[str, Any]:
     """Build pending result for a hash-based subsystem."""
     if state is None:

daemon/iface.py

@@ -209,6 +209,7 @@ GET_WS: Endpoint = _ep("GET", "/ws")
 POST_BATCH: Endpoint = _ep("POST", "/batch")
 GET_STATUS_PENDING: Endpoint = _ep("GET", "/status/pending")
 POST_STATUS_APPLY_ALL: Endpoint = _ep("POST", "/status/apply-all")
+POST_STATUS_CANCEL_ALL: Endpoint = _ep("POST", "/status/cancel-all")
 GET_SYSTEM_METRICS: Endpoint = _ep("GET", "/system/metrics")
 
 # Collect all endpoint module-level constants for __all__ verification

docs/api.md

@@ -1962,7 +1962,8 @@ Aggregate pending changes across all subsystems. Useful for the dashboard to sho
 
 | Field | Type | Description |
 |-------|------|-------------|
-| `subsystems` | `object` | Map of subsystem name to pending status |
+| `firewall` | `object` | `{ needs_apply, change_count, changes: [{summary, detail}] }` |
+| `dnsmasq` / `nginx` / `wireguard` / `networkd` | `object` | `{ pending_changes, summary, changes: [{summary, detail}] }` |
 | `total_changes` | `number` | Total count of pending changes across all subsystems |
 
 ---
@@ -1984,6 +1985,31 @@ Apply pending changes for all subsystems in dependency order.
 
 ---
 
+#### Cancel All Pending Changes
+
+```
+POST /api/status/cancel-all
+```
+
+Revert pending changes for all subsystems to the last applied
+configuration. Restores each pending subsystem's `config.json` from its
+recorded `_last_applied_config` snapshot, discarding unapplied edits.
+Subsystems without a recorded baseline (config never applied) are
+reported as skipped and left untouched. No live-system commands run —
+only the declarative config files are written.
+
+**Request Body:** none.
+
+**Response (`data`):**
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `cancelled` | `[string, ...]` | Subsystems reverted to their last applied config |
+| `skipped` | `object` | Map of subsystem label → reason (e.g. "No baseline recorded (never applied)") |
+| `errors` | `object` | Map of subsystem label → error message |
+
+---
+
 #### Refresh State
 
 ```

docs/config.md

@@ -538,6 +538,8 @@ Both `/api/firewall/zones/<name>/services` and `/api/firewall/config/apply` reco
 
 **Management-lockout guard.** The firewalld *default zone* is the catch-all for interfaces with no explicit assignment (typically the WAN), and it carries the management plane (nginx https) plus remote recovery (ssh). Changing the default zone's service set so that **neither `https` nor `ssh`** remains raises `409 Conflict` — from `POST /firewall/zones/<name>/services` and `POST /firewall/config/apply` — before any mutation runs. Send `"force": true` in the request body to override (the UI shows a confirm dialog with this effect on the Zones page). If the default zone cannot be determined, the guard fails closed.
 
+**Applied baseline.** Like the other config-backed subsystems, a successful apply records `_last_applied_hash` and `_last_applied_config` (the meta-stripped config snapshot) inside `config.json`. They are internal bookkeeping — ignored by all parsing, hashing, and UI surfaces — and let the aggregate cancel action (`POST /api/status/cancel-all`) revert this file to the last applied state. Configs that have never been applied have no baseline and are skipped by cancel.
+
 ## Networkd (IP Configuration)
 
 **File**: `config/network/config.json`

docs/hoover.md

@@ -1172,6 +1172,39 @@ Table({
 })
 ```
 
+### Apply / Cancel
+
+`components/applyconfirm.js` — cross-subsystem apply/cancel buttons with a
+shared expandable-subsystems modal. Both fetch `/api/status/pending` to
+populate the modal rows (`buildRows()`; `SUBSYSTEM_LIST` order: firewall,
+dnsmasq, nginx, wireguard, networkd).
+
+#### `ApplyConfirm(props)`
+
+Button that opens the confirmation modal listing pending subsystems, then
+POSTs `/api/status/apply-all`. When `props.pending` is false it renders a
+disabled "synced" button that toasts on click.
+
+**Parameters:** `pending` (bool), `label`, `syncedLabel`, `cls`,
+`successMsg`, `refresh` (legacy, ignored).
+
+#### `CancelConfirm(props)`
+
+Button that opens the confirmation modal listing the subsystems that
+would be reverted ("Restores the listed subsystems to their last applied
+configuration, discarding changes saved since the last apply"), then
+POSTs `/api/status/cancel-all`. Success toast appends skipped-subsystem
+details when the response has a non-empty `skipped` map; errors from the
+response are toasted separately. State-store models update from the
+daemon's WS delta — no explicit `modelFetch`.
+
+**Parameters:** `label` (default `'Cancel All Changes'`), `cls`
+(default `'btn btn-danger'`).
+
+```javascript
+CancelConfirm({ cls: 'btn btn-sm btn-danger' })
+```
+
 ### Modal
 
 #### `openModal(renderFn)`

docs/state-model.md

@@ -17,6 +17,17 @@ return annotation references them.
 - A subsystem whose collection failed holds `null`/`None` in the state
   store — WS snapshots and deltas skip `null` payloads so a failed
   collector never overwrites good client data.
+- Config-backed subsystems record their applied baseline inside the config
+  file itself: `_last_applied_config` (the full merged config at last
+  apply) and `_last_applied_hash` (its SHA-256). A hash subsystem's
+  `status.pending_changes` is true when the current (merged) config hash
+  differs from the recorded hash; `status.pending_diff` lists the field
+  changes since that snapshot. All apply operations (including firewall
+  `config_apply`) re-stamp the baseline. These bookkeeping keys are
+  internal and stripped from every state/API config payload. Canceling
+  pending changes (`POST /api/status/cancel-all`) restores a pending
+  config file from its snapshot; a subsystem with no recorded baseline
+  (never applied) is reported as skipped, not reset.
 
 ## State shape summary
 

lib/common.py

@@ -55,6 +55,29 @@ def stamp_applied(cfg: dict[str, Any]) -> dict[str, Any]:
     return cfg
 
 
+def revert_to_applied(path: Path) -> tuple[bool, str]:
+    """Restore the config file at *path* to its last-applied snapshot.
+
+    Reads the raw file, and when it records a ``_last_applied_config``
+    snapshot, rewrites the file from that snapshot (stamped with a fresh
+    hash so the pending check reports the config as up to date).
+
+    Args:
+        path: Path to the config JSON file to revert.
+
+    Returns:
+        Tuple ``(True, "")`` when the file was restored, or
+        ``(False, reason)`` when it could not be (missing file or no
+        recorded baseline — i.e. the config was never applied).
+    """
+    cfg = load_json(path)
+    snap = cfg.get(_LAST_APPLIED_CONFIG_KEY)
+    if not isinstance(snap, dict):
+        return False, "No baseline recorded (never applied)"
+    save_json(path, stamp_applied(deepcopy(snap)))
+    return True, ""
+
+
 def deep_diff(old: Any, new: Any, prefix: str = "") -> list[dict[str, Any]]:
     """Return a list of field-level changes between two configurations.
 
@@ -284,6 +307,7 @@ __all__ = [
     "ensure_dirs",
     "get_interface_ip",
     "load_json",
+    "revert_to_applied",
     "run",
     "run_proc",
     "save_json",

lib/state.py

@@ -517,12 +517,12 @@ def _collect_firewall() -> schema.FirewallState:
     except Exception:
         pass
 
-    # Load config
+    # Load config (strip apply bookkeeping keys, as the other collectors do)
     fw_config_path = PROJECT_DIR / "config" / "firewall" / "config.json"
     config_data = {}
     if fw_config_path.exists():
         with contextlib.suppress(Exception):
-            config_data = load_json(fw_config_path)
+            config_data = strip_apply_meta(load_json(fw_config_path))
 
     # Pending changes
     full_state = {

tests/test-cancelconfirm.js

@@ -0,0 +1,87 @@
+/**
+ * Tests for hoover/components/applyconfirm.js — CancelConfirm
+ *
+ * Component-level tests: VNode structure of the cancel button.
+ * Run with `node tests/test-cancelconfirm.js`.
+ */
+
+import { CancelConfirm, buildRows, SUBSYSTEM_LIST } from '../webui/static/hoover/components/applyconfirm.js';
+
+let passed = 0;
+let failed = 0;
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  \u2713 ${name}`);
+    passed++;
+  } catch (e) {
+    console.error(`  \u2717 ${name}: ${e.message}`);
+    failed++;
+  }
+}
+
+function assert(cond, msg) {
+  if (!cond) throw new Error(msg || 'Assertion failed');
+}
+
+function assertEq(a, b, msg) {
+  if (a !== b) throw new Error(msg || `Expected ${b}, got ${a}`);
+}
+
+function assertIncludes(str, substr, msg) {
+  if (!str.includes(substr)) throw new Error(msg || `Expected "${str}" to contain "${substr}"`);
+}
+
+console.log('Testing CancelConfirm component\n');
+
+test('CancelConfirm renders a button vnode', () => {
+  const vnode = CancelConfirm();
+  assertEq(vnode.tag, 'button');
+});
+
+test('CancelConfirm default label', () => {
+  const vnode = CancelConfirm();
+  const text = vnode.ch.find(c => c.tag === '#text');
+  assert(text, 'should have text child');
+  assertEq(text.text, 'Cancel All Changes');
+});
+
+test('CancelConfirm default class is danger', () => {
+  const vnode = CancelConfirm();
+  assertIncludes(vnode.props.class, 'btn-danger');
+  assertIncludes(vnode.props.class, 'btn');
+});
+
+test('CancelConfirm accepts a custom class', () => {
+  const vnode = CancelConfirm({ cls: 'btn btn-sm btn-danger' });
+  assertEq(vnode.props.class, 'btn btn-sm btn-danger');
+});
+
+test('CancelConfirm accepts a custom label', () => {
+  const vnode = CancelConfirm({ label: 'Discard Changes' });
+  const text = vnode.ch.find(c => c.tag === '#text');
+  assertEq(text.text, 'Discard Changes');
+});
+
+test('CancelConfirm has a click handler', () => {
+  const vnode = CancelConfirm();
+  assert(typeof vnode.props['on:click'] === 'function', 'on:click should be a function');
+});
+
+// === shared modal row builder (used by the cancel modal) ===
+test('buildRows still drives the cancel modal rows', () => {
+  const data = {
+    firewall: { needs_apply: true, changes: [{ summary: 'Zone internal: interfaces changed', detail: '' }] },
+    dnsmasq: { pending_changes: true, changes: [{ summary: 'x', detail: '' }] },
+  };
+  const rows = buildRows(data, {});
+  assertEq(rows.length, SUBSYSTEM_LIST.length);
+  const fwRow = rows[0];
+  assertIncludes(fwRow.props.class, 'pending');
+  const dmRow = rows[1];
+  assertIncludes(dmRow.props.class, 'pending');
+});
+
+console.log(`\n${passed} passed, ${failed} failed`);
+process.exit(failed > 0 ? 1 : 0);

tests/test_api.py

@@ -997,4 +997,24 @@ class TestStatusRefresh:
         mock_post.side_effect = RuntimeError("no daemon")
         resp = status_client.post("/api/status/refresh", json={})
         assert resp.status_code == 500
+
+
+class TestStatusCancelAll:
+    @_st("post")
+    def test_success(self, mock_post, status_client):
+        from daemon.iface import POST_STATUS_CANCEL_ALL
+
+        mock_post.return_value = {"cancelled": ["dnsmasq"], "skipped": {}, "errors": {}}
+        resp = status_client.post("/api/status/cancel-all")
+        assert resp.status_code == 200
+        data = resp.get_json()
+        assert data["ok"] is True
+        assert data["data"] == {"cancelled": ["dnsmasq"], "skipped": {}, "errors": {}}
+        mock_post.assert_called_once_with(POST_STATUS_CANCEL_ALL)
+
+    @_st("post")
+    def test_runtime_error(self, mock_post, status_client):
+        mock_post.side_effect = RuntimeError("no daemon")
+        resp = status_client.post("/api/status/cancel-all")
+        assert resp.status_code == 500
         assert resp.get_json()["ok"] is False

tests/test_common.py

@@ -7,6 +7,9 @@ from lib.common import (
     _LAST_APPLIED_CONFIG_KEY,
     config_hash,
     deep_diff,
+    load_json,
+    revert_to_applied,
+    save_json,
     stamp_applied,
     strip_apply_meta,
 )
@@ -82,3 +85,66 @@ class TestDashboardFallback:
         status = {"pending_changes": True, "pending_diff": []}
         assert status["pending_changes"] is True
         assert status["pending_diff"] == []
+
+
+class TestRevertToApplied:
+    def test_restores_snapshot_and_clears_pending(self, tmp_path):
+        path = tmp_path / "config.json"
+        applied = {"zones": {"lan": {"services": ["http"]}}}
+        stamped = dict(applied)
+        stamp_applied(stamped)
+        # Drift the file after apply (the "pending" state).
+        dirty = {"zones": {"lan": {"services": ["http", "ssh"]}}}
+        dirty[_LAST_APPLIED_CONFIG_KEY] = dict(applied)
+        dirty[_APPLY_HASH_KEY] = stamped[_APPLY_HASH_KEY]
+        save_json(path, dirty, indent=2)
+        # Sanity: pending check would report drift.
+        assert dirty[_APPLY_HASH_KEY] != config_hash(dirty)
+
+        ok, reason = revert_to_applied(path)
+        assert ok and reason == ""
+
+        restored = load_json(path)
+        assert _APPLY_HASH_KEY in restored and restored[_APPLY_HASH_KEY] == config_hash(
+            restored
+        )
+        assert (
+            _LAST_APPLIED_CONFIG_KEY in restored
+            and restored[_LAST_APPLIED_CONFIG_KEY] == applied
+        )
+        assert (
+            deep_diff(
+                restored.get(_LAST_APPLIED_CONFIG_KEY, {}), strip_apply_meta(restored)
+            )
+            == []
+        )
+
+    def test_no_baseline(self, tmp_path):
+        path = tmp_path / "config.json"
+        save_json(path, {"zones": {}}, indent=2)
+        ok, reason = revert_to_applied(path)
+        assert not ok
+        assert reason
+        # File untouched.
+        assert _LAST_APPLIED_CONFIG_KEY not in load_json(path)
+
+    def test_missing_file(self, tmp_path):
+        ok, reason = revert_to_applied(tmp_path / "nope.json")
+        assert not ok
+        assert reason
+
+    def test_stale_hash_but_snapshot_present(self, tmp_path):
+        # Baseline recorded, hash stale (drifted) → still revertable.
+        path = tmp_path / "config.json"
+        applied = {"a": 1}
+        stamped = dict(applied)
+        stamp_applied(stamped)
+        stamp = dict(stamped)
+        stamp["a"] = 99  # edited without re-stamping
+        save_json(path, stamp, indent=2)
+        assert stamp[_APPLY_HASH_KEY] != config_hash(stamp)
+
+        ok, _ = revert_to_applied(path)
+        assert ok
+        restored = load_json(path)
+        assert restored[_APPLY_HASH_KEY] == config_hash(restored)

tests/test_firewall.py

@@ -1,5 +1,6 @@
 """Tests for lib/firewall.py (pure logic) and daemon/handlers/firewall.py (privilege boundary)."""
 
+from copy import deepcopy
 from unittest.mock import MagicMock, call, patch
 
 import pytest
@@ -7,6 +8,12 @@ import pytest
 from daemon.handlers import firewall as daemonfirewall
 from daemon.server import ConflictError, NotFoundError
 from lib import firewall
+from lib.common import (
+    _APPLY_HASH_KEY,
+    _LAST_APPLIED_CONFIG_KEY,
+    config_hash,
+    strip_apply_meta,
+)
 
 # ---------------------------------------------------------------------------
 # lib/firewall.py — pure parsing (no sudo)
@@ -531,6 +538,11 @@ class TestDaemonConfigApply:
                 return_value={"zones": {"public": {}}},
             ),
             patch("daemon.handlers.firewall.refresh_state"),
+            patch(
+                "daemon.handlers.firewall._get_config",
+                return_value={"zones": {"public": {}}},
+            ),
+            patch("daemon.handlers.firewall._save_config"),
         ):
             result = daemonfirewall._config_apply()
             assert result["applied_zones"] == ["public"]
@@ -661,10 +673,87 @@ class TestDaemonMgmtLockoutGuard:
                 return_value={"zones": {"public": {}}},
             ),
             patch("daemon.handlers.firewall.refresh_state"),
+            patch(
+                "daemon.handlers.firewall._get_config",
+                return_value={"zones": {"public": {}}},
+            ),
+            patch("daemon.handlers.firewall._save_config"),
         ):
             result = daemonfirewall._config_apply(force=True)
         assert result["applied_zones"] == ["public"]
 
+
+_STAMP_TEST_CFG = {
+    "zones": {
+        "public": {
+            "target": "DEFAULT",
+            "interfaces": ["eth0"],
+            "services": ["http"],
+            "masquerade": False,
+        },
+    },
+}
+
+
+class TestDaemonConfigApplyStamp:
+    """Verify _config_apply records the applied baseline in the config file."""
+
+    ZONE_LIST_ALL_OUT = (
+        "target: default\ninterfaces: \nsources: \nservices: \nports: \n"
+        "protocols: \nforward-ports: \nmasquerade: no\nics: no\nrich-rules: \n"
+        "icmp-blocks: \nmodule: \n"
+    )
+
+    @patch(
+        "lib.firewall.get_config",
+        return_value=_STAMP_TEST_CFG,
+        create=True,
+    )
+    @patch(
+        "daemon.handlers.firewall.run",
+        return_value=ZONE_LIST_ALL_OUT,
+    )
+    def test_stamps_applied_baseline(self, mock_run, mock_cfg):
+        with (
+            patch(
+                "daemon.handlers.firewall._save_backup",
+                return_value="/tmp/rules.json",
+            ),
+            patch(
+                "daemon.handlers.firewall._get_state",
+                return_value={"zones": {"public": {}}},
+            ),
+            patch("daemon.handlers.firewall.refresh_state"),
+            patch(
+                "daemon.handlers.firewall._get_config",
+                return_value=deepcopy(_STAMP_TEST_CFG),
+            ),
+            patch("daemon.handlers.firewall._save_config") as mock_save,
+        ):
+            result = daemonfirewall._config_apply()
+
+        assert result["applied_zones"] == ["public"]
+        saved = mock_save.call_args[0][0]
+        assert saved[_LAST_APPLIED_CONFIG_KEY] == strip_apply_meta(saved)
+        assert saved[_APPLY_HASH_KEY] == config_hash(saved)
+        # The snapshot is the applied (meta-stripped) config.
+        assert saved[_LAST_APPLIED_CONFIG_KEY] == _STAMP_TEST_CFG
+
+
+class TestDaemonGetConfigEndpoint:
+    def test_strips_apply_meta(self):
+        with patch.object(
+            daemonfirewall,
+            "_get_config",
+            return_value={
+                "zones": {},
+                _APPLY_HASH_KEY: "h",
+                _LAST_APPLIED_CONFIG_KEY: {"zones": {}},
+            },
+        ):
+            result = daemonfirewall.get_config(None, None)
+        assert result == {"zones": {}}
+
     @patch(
         "daemon.handlers.firewall._config_apply",
         return_value={"applied_zones": ["public"], "backup": "/tmp/rules.json"},

tests/test_status_cancel.py

@@ -0,0 +1,221 @@
+"""Tests for daemon/handlers/status.py — cancel-all (revert to applied)."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+from typing import Any, ClassVar
+from unittest.mock import patch
+
+from daemon.handlers import status
+from lib.common import (
+    _APPLY_HASH_KEY,
+    _LAST_APPLIED_CONFIG_KEY,
+    config_hash,
+    stamp_applied,
+)
+
+
+def _pending(firewall: bool = False, **flags: bool) -> dict[str, Any]:
+    """Build status_pending() output with the given subsystems pending.
+
+    Mirrors the real handler shape: every subsystem key is always present.
+    """
+    data: dict[str, Any] = {
+        "firewall": {
+            "needs_apply": firewall,
+            "change_count": 1 if firewall else 0,
+            "changes": [],
+        },
+    }
+    total = 1 if firewall else 0
+    for name in ("dnsmasq", "nginx", "wireguard", "networkd"):
+        flagged = bool(flags.get(name, False))
+        data[name] = {
+            "pending_changes": flagged,
+            "summary": "x" if flagged else "Up to date",
+            "changes": [],
+        }
+        total += 1 if flagged else 0
+    data["total_changes"] = total
+    return data
+
+
+class TestConfigPathResolution:
+    """SYS_CONFIG_PATHS points at the constants the handlers actually use."""
+
+    def test_resolves_to_module_constants(self):
+        import daemon.handlers.dnsmasq as dm_h
+        import daemon.handlers.firewall as fw_h
+        import daemon.handlers.nginx as ngx_h
+        import lib.network as net_lib
+        import lib.wireguard as wg_lib
+
+        assert status._config_path("firewall") == fw_h.CONFIG_FILE
+        assert status._config_path("dnsmasq") == dm_h.CONFIG_PATH
+        assert status._config_path("nginx") == ngx_h.CONFIG_FILE
+        assert status._config_path("wireguard") == wg_lib.CONFIG_PATH
+        assert status._config_path("networkd") == net_lib.CONFIG_FILE
+
+    def test_all_subsystems_mapped(self):
+        assert set(status.SYS_CONFIG_PATHS) == set(status.SYS_ORDER)
+
+
+class TestStatusCancelAll:
+    """Test the cancel-all endpoint.
+
+    Patches the ``_config_path`` seam directly since it resolves the real
+    module constants via getattr at call time.
+    """
+
+    _fake_pending_all: ClassVar[dict[str, Any]] = _pending()
+
+    def _write_config(
+        self, path: Path, cfg: dict[str, Any], baseline: dict | None
+    ) -> None:
+        """Write *cfg* (with an attached applied baseline when *baseline* given)."""
+        path.parent.mkdir(parents=True, exist_ok=True)
+        stamped = dict(cfg)
+        if baseline is not None:
+            b = dict(baseline)
+            stamp_applied(b)
+            stamped[_LAST_APPLIED_CONFIG_KEY] = dict(baseline)
+            stamped[_APPLY_HASH_KEY] = b[_APPLY_HASH_KEY]
+        path.write_text(json.dumps(stamped, indent=2) + "\n")
+
+    def _read_config(self, path: Path) -> dict[str, Any]:
+        return json.loads(path.read_text())
+
+    @patch("daemon.handlers.status.status_pending")
+    @patch("daemon.handlers.status.refresh_state")
+    def test_nothing_pending(self, mock_refresh, mock_pending):
+        mock_pending.return_value = self._fake_pending_all
+        with patch("daemon.handlers.status._config_path", side_effect=AssertionError):
+            result = status.status_cancel_all(None, None)
+        assert result == {"cancelled": [], "skipped": {}, "errors": {}}
+        mock_refresh.assert_not_called()
+
+    def test_reverts_pending_subsystem(self, tmp_path):
+        paths = {name: tmp_path / name / "config.json" for name in status.SYS_ORDER}
+        applied = {"dns": {"upstreams": ["8.8.8.8"]}}
+        # Baseline applied, then the user edited the config (drift).
+        self._write_config(
+            paths["dnsmasq"], {"dns": {"upstreams": ["1.1.1.1"]}}, applied
+        )
+
+        dirty = self._read_config(paths["dnsmasq"])
+        assert dirty[_APPLY_HASH_KEY] != config_hash(dirty)  # really pending
+
+        with (
+            patch(
+                "daemon.handlers.status.status_pending",
+                return_value=_pending(dnsmasq=True),
+            ),
+            patch("daemon.handlers.status.refresh_state") as mock_refresh,
+            patch(
+                "daemon.handlers.status._config_path",
+                side_effect=lambda name: paths[name],
+            ),
+        ):
+            result = status.status_cancel_all(None, None)
+
+        assert result == {
+            "cancelled": ["dnsmasq"],
+            "skipped": {},
+            "errors": {},
+        }
+        mock_refresh.assert_called_once_with(status.SYS_ORDER)
+
+        restored = self._read_config(paths["dnsmasq"])
+        assert restored.get(_LAST_APPLIED_CONFIG_KEY) == applied
+        # Cancel restored the baseline: the pending check now passes.
+        assert restored[_APPLY_HASH_KEY] == config_hash(restored)
+
+    def test_skipped_when_no_baseline(self, tmp_path):
+        paths = {name: tmp_path / name / "config.json" for name in status.SYS_ORDER}
+        cfg_no_baseline = {"peers": {"a": {}}}
+        self._write_config(paths["wireguard"], cfg_no_baseline, None)
+
+        with (
+            patch(
+                "daemon.handlers.status.status_pending",
+                return_value=_pending(wireguard=True),
+            ),
+            patch("daemon.handlers.status.refresh_state") as mock_refresh,
+            patch(
+                "daemon.handlers.status._config_path",
+                side_effect=lambda name: paths[name],
+            ),
+        ):
+            result = status.status_cancel_all(None, None)
+
+        assert result["cancelled"] == []
+        assert "WireGuard" in result["skipped"]
+        assert result["errors"] == {}
+        mock_refresh.assert_not_called()
+        # File left untouched.
+        assert self._read_config(paths["wireguard"]) == cfg_no_baseline
+
+    def test_error_in_one_subsystem_others_still_cancel(self, tmp_path):
+        paths = {name: tmp_path / name / "config.json" for name in status.SYS_ORDER}
+        for name in ("firewall", "nginx"):
+            self._write_config(
+                paths[name],
+                {"zones": {}} if name == "firewall" else {"domains": {}},
+                {"x": 1},
+            )
+
+        def fake_revert(path):
+            if "nginx" in str(path):
+                raise RuntimeError("disk full")
+            return True, ""
+
+        with (
+            patch(
+                "daemon.handlers.status.status_pending",
+                return_value=_pending(firewall=True, nginx=True),
+            ),
+            patch("daemon.handlers.status.refresh_state"),
+            patch("daemon.handlers.status.revert_to_applied", side_effect=fake_revert),
+            patch(
+                "daemon.handlers.status._config_path",
+                side_effect=lambda name: paths[name],
+            ),
+        ):
+            result = status.status_cancel_all(None, None)
+
+        # SYS_ORDER runs firewall before nginx.
+        assert result["cancelled"] == ["firewall"]
+        assert result["errors"] == {"Nginx": "disk full"}
+        assert result["skipped"] == {}
+
+    def test_order_matches_sys_order(self, tmp_path):
+        paths = {name: tmp_path / name / "config.json" for name in status.SYS_ORDER}
+        call_order = []
+
+        def fake_revert(path):
+            call_order.append(next(n for n, p in paths.items() if p == path))
+            return True, ""
+
+        with (
+            patch(
+                "daemon.handlers.status.status_pending",
+                return_value=_pending(
+                    firewall=True,
+                    dnsmasq=True,
+                    nginx=True,
+                    wireguard=True,
+                    networkd=True,
+                ),
+            ),
+            patch("daemon.handlers.status.refresh_state"),
+            patch("daemon.handlers.status.revert_to_applied", side_effect=fake_revert),
+            patch(
+                "daemon.handlers.status._config_path",
+                side_effect=lambda name: paths[name],
+            ),
+        ):
+            result = status.status_cancel_all(None, None)
+
+        assert result["cancelled"] == status.SYS_ORDER
+        assert call_order == status.SYS_ORDER

webui/api/status.py

@@ -14,6 +14,7 @@ from daemon.iface import (
     GET_STATUS_PENDING,
     GET_SYSTEM_METRICS,
     POST_STATUS_APPLY_ALL,
+    POST_STATUS_CANCEL_ALL,
     POST_STATUS_REFRESH,
 )
 from webui.api.common import _error, _ok
@@ -56,6 +57,24 @@ def apply_all():
         return _error(str(exc), 500)
 
 
+@bp.route("/cancel-all", methods=["POST"])
+def cancel_all():
+    """Revert pending changes for all subsystems to the last applied config.
+
+    Endpoint:
+        POST /api/status/cancel-all
+
+    Returns:
+        JSON response with the reverted subsystems, skipped subsystems
+        (label -> reason), and any errors encountered.
+    """
+    try:
+        return _ok(post(POST_STATUS_CANCEL_ALL))
+    except RuntimeError as exc:
+        logger.error("Failed to cancel all pending changes: %s", exc)
+        return _error(str(exc), 500)
+
+
 @bp.route("/refresh", methods=["POST"])
 def refresh():
     """Re-collect state from the daemon, optionally filtered by subsystem.

webui/static/hoover/components/applyconfirm.js

@@ -140,3 +140,91 @@ export function ApplyConfirm(props = {}) {
         },
     }, props.pending ? label : syncedLabel);
 }
+
+/**
+ * POST cancel-all, toast result, close modal. State-store models update from
+ * the daemon's WS delta — no explicit refresh.
+ */
+async function doCancelAll() {
+    if (isModalProcessing()) return;
+    setModalProcessing(true);
+    try {
+        const resp = await apiFetch('/api/status/cancel-all', { method: 'POST' });
+        if (resp.ok) {
+            const data = resp.data || {};
+            let msg = 'Pending changes cancelled';
+            const nSkipped = Object.keys(data.skipped || {}).length;
+            if (nSkipped) {
+                msg += ` (${nSkipped} skipped: ` +
+                    Object.entries(data.skipped).map(([k, v]) => `${k} — ${v}`).join('; ') + ')';
+            }
+            toast(msg, nSkipped ? 'warning' : 'success', nSkipped ? 8000 : undefined);
+            const errs = data.errors || {};
+            const nErrs = Object.keys(errs).length;
+            if (nErrs) {
+                toast('Cancel failed for: ' +
+                    Object.entries(errs).map(([k, v]) => `${k} — ${v}`).join('; '),
+                    'error', 8000);
+            }
+            closeModal();
+            // No modelFetch — WS delta updates all affected subsystems.
+        } else {
+            toast(resp.error || 'Cancel failed', 'error');
+        }
+    } finally {
+        setModalProcessing(false);
+        refreshModals();
+    }
+}
+
+/**
+ * Fetch pending state, then open the cancel confirmation modal.
+ */
+async function openCancelModal() {
+    const pendingResp = await apiFetch('/api/status/pending');
+    if (!pendingResp.ok) {
+        toast(pendingResp.error || 'Could not fetch pending changes', 'error');
+        return;
+    }
+
+    const pendingData = pendingResp.data || {};
+    const totalChanges = pendingData.total_changes || 0;
+
+    const expanded = reactive({});
+
+    openModal((inner) => {
+        if (totalChanges === 0) {
+            modalVNodes(inner, html`<div>
+<h2 class="modal-title">Confirm: Cancel All Changes</h2>
+<div class="apply-no-changes">No pending changes to cancel.</div>
+<div class="apply-modal-actions"><button class="btn btn-outline" onClick="${() => closeModal()}">Close</button></div>
+</div>`);
+            return;
+        }
+
+        const rows = buildRows(pendingData, expanded);
+
+        modalVNodes(inner, html`<div>
+<h2 class="modal-title">Confirm: Cancel All Changes</h2>
+<p>Restores the listed subsystems to their last applied configuration, discarding changes saved since the last apply.</p>
+<div class="modal-body">${rows}</div>
+<div class="apply-modal-actions"><button class="btn btn-outline" onClick="${() => closeModal()}">Keep Changes</button><button class="btn btn-danger" onClick="${() => doCancelAll()}">Cancel All Changes</button></div>
+</div>`);
+    });
+}
+
+/**
+ * Cancel button with cross-subsystem confirmation modal.
+ *
+ * @param {object} props
+ * @param {string}  [props.label] - Button text (default: 'Cancel All Changes')
+ * @param {string}  [props.cls]   - Button CSS classes (default: 'btn btn-danger')
+ */
+export function CancelConfirm(props = {}) {
+    const label = props.label || 'Cancel All Changes';
+
+    return h('button', {
+        class: props.cls !== undefined ? props.cls : 'btn btn-danger',
+        'on:click': () => openCancelModal(),
+    }, label);
+}

webui/static/hoover/index.js

@@ -53,7 +53,7 @@ export { Badge, StatusDot, Empty, Card, ConfirmDelete, Table, ActionButton, cert
 export { openModal, closeModal, closeAllModals, modalVNodes, refreshModals, formModal, MultiSelectModal, QuickModal, isModalProcessing, setModalProcessing } from './components/modal.js';
 
 /* ── UI Components: Apply ────────────────────────────────────── */
-export { ApplyConfirm } from './components/applyconfirm.js';
+export { ApplyConfirm, CancelConfirm } from './components/applyconfirm.js';
 
 /* ── UI Components: Toast ────────────────────────────────────── */
 export { ToastContainer } from './components/toast.js';

webui/static/pages/dashboard.js

@@ -1,4 +1,4 @@
-import { html, PageHeader, definePage, getModel, renderGuardMulti, ServiceStatus, StatCard, Table, Badge, ActionButton, fmtBytes } from '/static/hoover/index.js';
+import { html, PageHeader, definePage, getModel, renderGuardMulti, ServiceStatus, StatCard, Table, Badge, ActionButton, CancelConfirm, fmtBytes } from '/static/hoover/index.js';
 
 // Render a single firewall change as "current → new".
 // `live` is the currently applied value; `config` is the target value it
@@ -144,7 +144,7 @@ export default definePage({
                 meta=${expiringCerts.length ? expiringCerts.length + ' expiring' : 'All valid'} />
         </div>`;
 
-        // ── Pending changes ──
+        // ── Pending changes (hidden entirely when nothing is pending) ──
         const pendingCard = pendingBlocks.length > 0
             ? html`<div class="card">
                 <div class="card-header">Pending Changes <span style="margin-left:8px"><${Badge} text=${String(totalChanges)} variant="warning" /></span></div>
@@ -157,15 +157,15 @@ export default definePage({
                             </ul>
                         </li>`)}
                     </ul>
-                    <${ActionButton} url="/api/status/apply-all" label="Apply All Changes"
-                        successMsg="All changes applied"
-                        cls="btn btn-sm btn-primary" />
+                    <div style="display:flex;gap:8px;flex-wrap:wrap">
+                        <${ActionButton} url="/api/status/apply-all" label="Apply All Changes"
+                            successMsg="All changes applied"
+                            cls="btn btn-sm btn-primary" />
+                        <${CancelConfirm} cls="btn btn-sm btn-danger" />
+                    </div>
                 </div>
             </div>`
-            : html`<div class="card">
-                <div class="card-header">Pending Changes</div>
-                <div class="card-body"><${Badge} text="All configured" variant="success" /></div>
-            </div>`;
+            : null;
 
         // ── System resources ──
         const memPct = sysMem.used_pct || 0;