disallow to disable guard during focus

README.md

@@ -77,6 +77,10 @@ agent enforces them on your machine:
   `*discord*`, matched against the process name and its command line.
 * **When** — only while a focus interval runs (the default), always, or on a
   schedule. Breaks can keep the block on or let it go.
+* **One-way while you work** — the guard can be switched on whenever you like, but
+  not off while an interval is live, breaks and pauses included; the desktop app's
+  local enforcement switches lock the same way. Finishing or dropping the interval
+  frees it. A guard you can disable the moment it starts to bite is decoration.
 * Every attempt that gets turned away is recorded — and teased about in the
   evening report.
 

android/app/src/main/kotlin/tech/kadence/android/blocker/BlockerEngine.kt

@@ -62,6 +62,7 @@ import tech.kadence.core.DomainMatcher
 import tech.kadence.core.IntervalFacts
 import tech.kadence.core.evaluatePolicy
 import tech.kadence.core.expandDomains
+import tech.kadence.core.guardLocked
 import tech.kadence.core.invalidExpansions
 import tech.kadence.core.unexpandableMasks
 import tech.kadence.core.zoneOrDefault
@@ -83,7 +84,10 @@ data class BlockerUi(
     val reason: String = "",
     val enabled: Boolean = false,
     val mode: String = MODE_DURING_WORK,
-    val strict: Boolean = false,
+    /** The guard is locked on — an interval is live, so it cannot be switched off. */
+    val locked: Boolean = false,
+    /** The server's sentence for why, shown under the toggle. */
+    val lockReason: String = "",
     val killApps: Boolean = true,
     val notifyOnBlock: Boolean = true,
     /** Hostnames in the expanded set — `all_domains`, so it is non-zero even when idle. */
@@ -481,7 +485,8 @@ class BlockerEngine(
             reason = dto.reason,
             enabled = dto.enabled,
             mode = dto.mode,
-            strict = dto.strict,
+            locked = dto.locked,
+            lockReason = dto.lockReason,
             killApps = dto.killApps,
             notifyOnBlock = dto.notifyOnBlock,
             hostnames = dto.allDomains.size,
@@ -509,7 +514,8 @@ class BlockerEngine(
             reason = verdict.reason,
             enabled = current?.enabled ?: false,
             mode = current?.mode ?: MODE_DURING_WORK,
-            strict = current?.strict ?: false,
+            locked = guardLocked(current ?: BlockerRules(), timerFacts()),
+            lockReason = "",
             killApps = current?.killBlockedApps ?: true,
             notifyOnBlock = current?.notifyOnBlock ?: true,
             hostnames = current?.let { expandDomains(it).size } ?: 0,
@@ -648,6 +654,5 @@ fun BlockerSettingsDto.toCore(): BlockerRules = BlockerRules(
     blockedApps = blockedApps,
     killBlockedApps = killBlockedApps,
     schedule = schedule.map { BlockWindow(it.label, it.start, it.end, it.days) },
-    strict = strict,
     notifyOnBlock = notifyOnBlock,
 )

android/app/src/main/kotlin/tech/kadence/android/data/dto/Dtos.kt

@@ -140,7 +140,9 @@ data class BlockerPolicyDto(
     val reason: String = "",
     val mode: String = "during_work",
     val enabled: Boolean = false,
-    val strict: Boolean = false,
+    /** The guard is on and an interval is live, so it may not be switched off. */
+    val locked: Boolean = false,
+    @SerialName("lock_reason") val lockReason: String = "",
     @SerialName("redirect_ip") val redirectIp: String = "127.0.0.1",
     /** Empty whenever `active` is false — read `all_domains` instead. */
     val domains: List<String> = emptyList(),
@@ -395,7 +397,6 @@ data class BlockerSettingsDto(
     @SerialName("blocked_apps") val blockedApps: List<String> = emptyList(),
     @SerialName("kill_blocked_apps") val killBlockedApps: Boolean = true,
     val schedule: List<BlockWindowDto> = emptyList(),
-    val strict: Boolean = false,
     @SerialName("notify_on_block") val notifyOnBlock: Boolean = true,
 )
 

android/app/src/main/kotlin/tech/kadence/android/ui/blocker/BlockerScreen.kt

@@ -237,18 +237,26 @@ fun BlockerScreen(
         Panel(padding = 0.dp) {
             ToggleRow(
                 label = "Focus guard on",
-                detail = if (ui.enabled) {
+                detail = when {
-                    "Everything below applies."
+                    ui.locked -> ui.lockReason.ifBlank {
-                } else {
+                        "Finish or drop the interval to switch the guard off."
-                    "Off everywhere — the phone, the desktop app and the web UI all " +
+                    }
+                    ui.enabled -> "Everything below applies."
+                    else -> "Off everywhere — the phone, the desktop app and the web UI all " +
                         "stop enforcing."
                 },
                 checked = ui.enabled,
-                // The rules are the server's document and there is no outbox for it:
+                // Two reasons this says no, both said out loud rather than left as a
-                // a settings PUT is a deep merge of a shared object, and queueing one
+                // grey switch:
-                // would mean replaying a stale version over whatever the web UI did
+                //  * offline — the rules are the server's document and there is no
-                // meanwhile. So offline these say no, rather than appearing to work.
+                //    outbox for it: a settings PUT is a deep merge of a shared object,
-                enabled = ui.connection == Connection.Online,
+                //    and queueing one would mean replaying a stale version over
+                //    whatever the web UI did meanwhile;
+                //  * locked — the server refuses to switch the guard off while an
+                //    interval is running or paused, which is the whole point of it.
+                // Switching it *on* is never refused, which is why `locked` already has
+                // "and the guard is on" folded into it server-side.
+                enabled = ui.connection == Connection.Online && !ui.locked,
                 onChange = { value -> patch(mapOf("enabled" to value)) },
             )
         }

android/app/src/test/kotlin/tech/kadence/android/BlockerEngineTest.kt

@@ -75,6 +75,15 @@ class BlockerEngineTest {
         return engine
     }
 
+    @Test
+    fun `the lock reaches the screen from the server's policy`() {
+        // The screen never decides this itself — it renders what the server said,
+        // and the server has already folded "and the guard is on" into `locked`.
+        val ui = engine().state.value
+        assertTrue(ui.locked)
+        assertEquals("Finish or drop the interval to switch the focus guard off.", ui.lockReason)
+    }
+
     @Before
     fun setUp() {
         server = MockWebServer()

android/app/src/test/kotlin/tech/kadence/android/BlockerSettingsTest.kt

@@ -49,7 +49,6 @@ class BlockerSettingsTest {
         assertEquals(listOf("*discord*", "instagram"), blocker.blockedApps)
         assertFalse(blocker.killBlockedApps)
         assertFalse(blocker.notifyOnBlock)
-        assertTrue(blocker.strict)
         assertEquals(1, blocker.schedule.size)
         assertEquals("Work mornings", blocker.schedule[0].label)
         assertEquals(listOf(0, 1, 2, 3, 4), blocker.schedule[0].days)
@@ -106,7 +105,6 @@ class BlockerSettingsTest {
         assertTrue(blocker.blockedApps.isEmpty())
         assertTrue(blocker.killBlockedApps)
         assertTrue(blocker.notifyOnBlock)
-        assertFalse(blocker.strict)
         assertEquals(BlockerRules.DEFAULT_SUBDOMAINS, blocker.subdomainExpansions)
     }
 
@@ -118,7 +116,7 @@ class BlockerSettingsTest {
             {"settings":{"blocker":{
                 "enabled":null,"mode":null,"blocked_domains":null,
                 "allowed_domains":null,"blocked_apps":null,"subdomain_expansions":null,
-                "kill_blocked_apps":null,"notify_on_block":null,"strict":null
+                "kill_blocked_apps":null,"notify_on_block":null
             }}}
             """.trimIndent(),
         )
@@ -138,4 +136,24 @@ class BlockerSettingsTest {
         val inactive = KadenceJson.decodeFromString<BlockerPolicyDto>(fixture("blocker_policy_inactive.json"))
         assertTrue(inactive.invalidExpansions.isEmpty())
     }
+
+    @Test
+    fun `the policy carries whether the guard is locked on`() {
+        val active = KadenceJson.decodeFromString<BlockerPolicyDto>(fixture("blocker_policy_active.json"))
+        assertTrue(active.locked)
+        assertEquals("Finish or drop the interval to switch the focus guard off.", active.lockReason)
+
+        val inactive = KadenceJson.decodeFromString<BlockerPolicyDto>(fixture("blocker_policy_inactive.json"))
+        assertFalse(inactive.locked)
+        assertEquals("", inactive.lockReason)
+    }
+
+    @Test
+    fun `a backend too old to send the lock reads as unlocked`() {
+        // The switch then looks operable and the server still refuses the write with a
+        // 409 — which is why the lock cannot live in the UI alone.
+        val policy = KadenceJson.decodeFromString<BlockerPolicyDto>("""{"enabled":true}""")
+        assertFalse(policy.locked)
+        assertEquals("", policy.lockReason)
+    }
 }

android/app/src/test/resources/fixtures/blocker_policy_active.json

@@ -3,7 +3,8 @@
   "reason": "a work interval is running",
   "mode": "during_work",
   "enabled": true,
-  "strict": false,
+  "locked": true,
+  "lock_reason": "Finish or drop the interval to switch the focus guard off.",
   "redirect_ip": "127.0.0.1",
   "domains": ["youtube.com", "www.youtube.com", "m.youtube.com", "reddit.com", "www.reddit.com", "m.reddit.com"],
   "apps": ["steam*", "*discord*"],

android/app/src/test/resources/fixtures/blocker_policy_inactive.json

@@ -3,7 +3,8 @@
   "reason": "no work interval is running",
   "mode": "during_work",
   "enabled": true,
-  "strict": false,
+  "locked": false,
+  "lock_reason": "",
   "redirect_ip": "127.0.0.1",
   "domains": [],
   "apps": [],

android/app/src/test/resources/fixtures/settings.json

@@ -27,7 +27,6 @@
       "schedule": [
         {"label": "Work mornings", "start": "09:00:00", "end": "12:00:00", "days": [0, 1, 2, 3, 4]}
       ],
-      "strict": true,
       "notify_on_block": false,
       "redirect_ip": "0.0.0.0",
       "app_poll_seconds": 5

android/core/src/main/kotlin/tech/kadence/core/Blocker.kt

@@ -39,7 +39,6 @@ data class BlockerRules(
     val blockedApps: List<String> = emptyList(),
     val killBlockedApps: Boolean = true,
     val schedule: List<BlockWindow> = emptyList(),
-    val strict: Boolean = false,
     val notifyOnBlock: Boolean = true,
 ) {
     companion object {
@@ -246,6 +245,20 @@ fun evaluatePolicy(
     }
 }
 
+/**
+ * The port of `guard_locked()`: whether the guard may be switched off right now.
+ *
+ * A free function rather than a field on [PolicyVerdict], because this is a verdict
+ * about *editing* the rules and not about whether to block — and the two answers do
+ * disagree: scheduled mode outside its window is `active = false`, `locked = true`.
+ *
+ * Any kind of interval counts, running or paused. Switching the guard *on* is never
+ * locked, which is why "and the guard is on" is folded in here rather than left to
+ * the screen.
+ */
+fun guardLocked(rules: BlockerRules, current: IntervalFacts?): Boolean =
+    rules.enabled && current != null && current.isActiveStatus
+
 /** Convenience for callers that only have an IANA zone id string. */
 fun zoneOrDefault(timezone: String?): ZoneId =
     runCatching { ZoneId.of(timezone?.trim().orEmpty()) }.getOrElse { ZoneId.systemDefault() }

android/core/src/test/kotlin/tech/kadence/core/BlockerTest.kt

@@ -303,4 +303,42 @@ class BlockerTest {
 
         assertEquals(listOf("reddit.com", "www.reddit.com", "m.reddit.com"), expandDomains(rules))
     }
+
+    // ---- the lock -----------------------------------------------------------
+    // Parity with `blocker_service.guard_locked()`.
+
+    @Test
+    fun `a live interval of any kind locks the guard on`() {
+        val on = BlockerRules(enabled = true)
+        assertTrue(guardLocked(on, working))
+        assertTrue(guardLocked(on, IntervalFacts("work", "paused")))
+        assertTrue(guardLocked(on, breaking))
+        assertTrue(guardLocked(on, IntervalFacts("long_break", "paused")))
+    }
+
+    @Test
+    fun `nothing live leaves the guard switchable`() {
+        val on = BlockerRules(enabled = true)
+        assertFalse(guardLocked(on, null))
+        assertFalse(guardLocked(on, IntervalFacts("work", "completed")))
+        assertFalse(guardLocked(on, IntervalFacts("work", "abandoned")))
+    }
+
+    @Test
+    fun `a guard that is off is never locked, so it can always be switched on`() {
+        assertFalse(guardLocked(BlockerRules(enabled = false), working))
+    }
+
+    @Test
+    fun `scheduled mode outside its window is inactive and still locked`() {
+        // The distinction `active` cannot express: nothing is being blocked right now,
+        // and the guard still must not be switched off before the window opens.
+        val rules = BlockerRules(
+            enabled = true,
+            mode = "scheduled",
+            schedule = listOf(BlockWindow("Work hours", "09:00", "18:00", listOf(0))),
+        )
+        assertFalse(evaluatePolicy(rules, working, at("2026-10-19", "20:00")).active)
+        assertTrue(guardLocked(rules, working))
+    }
 }

backend/app/api/routes_settings.py

@@ -38,13 +38,20 @@ def put_settings(session: DbSession, patch: dict[str, Any] = Body(...)) -> dict:
         # `exc.errors()` can carry exception objects in `ctx`, which JSON cannot
         # take; pydantic's own `json()` renders them as text.
         raise HTTPException(status_code=422, detail=json.loads(exc.json())) from exc
+    except blocker_service.GuardLocked as exc:
+        # 409, not 422: the body is valid, the current state refuses it. A plain
+        # string detail is what every client's error path already surfaces.
+        raise HTTPException(status_code=409, detail=str(exc)) from exc
     return {"settings": settings_service.mask_secrets(updated.model_dump(mode="json"))}
 
 
 @router.post("/reset")
 def reset_settings(session: DbSession) -> dict:
     """Back to defaults, re-seeded from the environment."""
-    updated = settings_service.save_settings(session, settings_service.settings_from_env())
+    try:
+        updated = settings_service.reset_to_env(session)
+    except blocker_service.GuardLocked as exc:
+        raise HTTPException(status_code=409, detail=str(exc)) from exc
     return {"settings": settings_service.mask_secrets(updated.model_dump(mode="json"))}
 
 

backend/app/services/blocker_service.py

@@ -187,12 +187,59 @@ def schedule_active(settings: AppSettings, moment: datetime | None = None) -> bo
     return False
 
 
+GUARD_LOCK_NOTE = "Finish or drop the interval to switch the focus guard off."
+"""Said in one voice: the 409 detail, and the `lock_reason` every client renders."""
+
+
+class GuardLocked(RuntimeError):
+    """Switching the guard off was refused because an interval is live."""
+
+
+def guard_locked(session: Session, settings: AppSettings) -> bool:
+    """The guard is on and an interval is live, so it may not be switched off.
+
+    Any kind, running or paused — `pomodoro.current_session` is exactly that. A
+    break is not an escape hatch and neither is pausing the clock.
+
+    Deliberately keyed off `blocker.enabled` rather than off `policy()["active"]`:
+    in `scheduled` mode outside every window nothing is being blocked right now,
+    and the guard still must not be quietly switched off before the window opens.
+    """
+    return settings.blocker.enabled and pomodoro.current_session(session) is not None
+
+
+def ensure_guard_not_switched_off(
+    session: Session, before: AppSettings, after: AppSettings
+) -> None:
+    """Refuse a settings write that would turn the guard off mid-interval.
+
+    Compares the two documents rather than reading the patch. The patch is a deep
+    merge of a shared object and arrives loosely typed — `{"enabled": "no"}`
+    coerces to `False`, so inspecting the raw keys would have to re-implement
+    pydantic to be right — and "did the stored value go from on to off" is the
+    only question that cannot be fooled. It also means an unrelated patch, a
+    full-document echo and a re-sent `enabled: false` all pass by construction.
+
+    Switching the guard *on* is never refused.
+    """
+    if not after.blocker.enabled and guard_locked(session, before):
+        raise GuardLocked(GUARD_LOCK_NOTE)
+
+
 def policy(session: Session, settings: AppSettings) -> dict[str, Any]:
-    """What the desktop app polls: should I block, and what."""
+    """What the desktop app polls: should I block, and what.
+
+    `active` and `locked` answer two different questions and do disagree: in
+    `scheduled` mode outside every window, nothing is blocked (`active` false)
+    while the guard is still locked on (`locked` true) because an interval runs.
+    """
     blocker = settings.blocker
     current = pomodoro.current_session(session)
     active = False
     reason = "disabled"
+    # The same rule as `guard_locked()`, reusing the row this function already
+    # fetched rather than querying twice — `test_blocker.py` pins the two together.
+    locked = blocker.enabled and current is not None
 
     if blocker.enabled:
         if blocker.mode == "always":
@@ -218,7 +265,8 @@ def policy(session: Session, settings: AppSettings) -> dict[str, Any]:
         "reason": reason,
         "mode": blocker.mode,
         "enabled": blocker.enabled,
-        "strict": blocker.strict,
+        "locked": locked,
+        "lock_reason": GUARD_LOCK_NOTE if locked else "",
         "redirect_ip": blocker.redirect_ip,
         "domains": expand_domains(settings) if active else [],
         "apps": [app.strip() for app in blocker.blocked_apps if app.strip()] if active else [],

backend/app/services/settings_service.py

@@ -20,7 +20,7 @@ from sqlalchemy.orm import Session
 
 from app.config import env_settings
 from app.models import SettingsRow
-from app.services import pomodoro
+from app.services import blocker_service, pomodoro
 from app.settings_schema import SECRET_FIELDS, SECRET_MASK, AppSettings
 
 _SETTINGS_ID = 1
@@ -192,10 +192,17 @@ def unmask_secrets(stored: dict[str, Any], incoming: dict[str, Any]) -> dict[str
 
 def apply_patch(session: Session, patch: dict[str, Any]) -> AppSettings:
     """Merge a partial settings document (as the UI sends it) and store it."""
-    current = load_settings(session).model_dump(mode="json")
+    stored = load_settings(session)
+    current = stored.model_dump(mode="json")
     patch = unmask_secrets(current, patch)
     merged = _merge(current, patch)
-    updated = save_settings(session, AppSettings.model_validate(merged))
+    candidate = AppSettings.model_validate(merged)
+
+    # Validate, then refuse, then write: a malformed patch stays a 422 rather
+    # than becoming a 409, and nothing is stored either way.
+    blocker_service.ensure_guard_not_switched_off(session, stored, candidate)
+
+    updated = save_settings(session, candidate)
 
     # A changed Focus/Short/Long minute (directly, or via a preset) resizes
     # whatever interval is already running or paused — see
@@ -203,3 +210,16 @@ def apply_patch(session: Session, patch: dict[str, Any]) -> AppSettings:
     # is simplest to always run it rather than detect which keys changed.
     pomodoro.rescale_current(session, updated)
     return updated
+
+
+def reset_to_env(session: Session) -> AppSettings:
+    """Back to the environment seed — refused if that would unguard a live interval.
+
+    `settings_from_env` never touches the `blocker` subtree, so a reset always
+    lands on the schema default `enabled = False`: without this check one POST
+    would switch the focus guard off mid-interval.
+    """
+    stored = load_settings(session)
+    fresh = settings_from_env()
+    blocker_service.ensure_guard_not_switched_off(session, stored, fresh)
+    return save_settings(session, fresh)

backend/app/settings_schema.py

@@ -204,8 +204,6 @@ class BlockerSettings(BaseModel):
     """Terminate a blocked app when it appears; otherwise only warn and log."""
 
     schedule: list[BlockWindow] = Field(default_factory=list)
-    strict: bool = False
-    """The desktop app refuses to switch blocking off while a work interval runs."""
 
     redirect_ip: str = "127.0.0.1"
     app_poll_seconds: int = Field(default=5, ge=1, le=60)

backend/tests/test_api.py

@@ -125,6 +125,36 @@ def test_invalid_settings_are_rejected(client):
     assert client.put("/api/settings", json={"timezone": "Mars/Olympus"}).status_code == 422
 
 
+def test_switching_the_guard_off_mid_interval_is_a_409(client):
+    assert client.put("/api/settings", json={"blocker": {"enabled": True}}).status_code == 200
+    client.post("/api/timer/start", json={"kind": "work"})
+
+    assert client.get("/api/blocker/policy").json()["locked"] is True
+
+    refused = client.put("/api/settings", json={"blocker": {"enabled": False}})
+    assert refused.status_code == 409
+    assert "focus guard" in refused.json()["detail"]
+
+    # Turning it on, and editing anything else, are both still fine.
+    assert client.put("/api/settings", json={"blocker": {"enabled": True}}).status_code == 200
+    lists = client.put("/api/settings", json={"blocker": {"blocked_apps": ["steam"]}})
+    assert lists.status_code == 200
+    assert lists.json()["settings"]["blocker"]["enabled"] is True
+
+    client.post("/api/timer/complete", json={"auto_next": False})
+    assert client.put("/api/settings", json={"blocker": {"enabled": False}}).status_code == 200
+
+
+def test_resetting_the_settings_cannot_unguard_a_live_interval(client):
+    client.put("/api/settings", json={"blocker": {"enabled": True}})
+    client.post("/api/timer/start", json={"kind": "short_break"})
+
+    assert client.post("/api/settings/reset").status_code == 409
+
+    client.post("/api/timer/complete", json={"auto_next": False})
+    assert client.post("/api/settings/reset").status_code == 200
+
+
 def test_notification_test_endpoint_falls_back_to_the_log(client):
     body = client.post("/api/notifications/test", json={}).json()
     assert body["deliveries"][0]["channel"] == "log"

backend/tests/test_blocker.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import pytest
 from app.services import blocker_service, pomodoro, settings_service
 
 
@@ -189,3 +190,179 @@ def test_the_policy_carries_the_allow_masks_for_the_stub(session, settings):
     assert result["allowed"] == ["music.youtube.com", "*.docs.google.com"]
     assert "music.youtube.com" not in result["domains"]
     assert "m.youtube.com" in result["all_domains"]
+
+
+# --------------------------------------------------------------------------
+# The lock: the guard will not be switched off mid-interval
+#
+# Only `apply_patch` and `reset_to_env` carry the check. `save_settings` stays an
+# unguarded low-level writer on purpose — the env seed, the password CLI and the
+# tests above all go through it — which is why these exercise the real write path.
+# --------------------------------------------------------------------------
+def _guarded(session, settings):
+    settings.blocker.enabled = True
+    settings_service.save_settings(session, settings)
+
+
+def test_the_guard_cannot_be_switched_off_while_an_interval_runs(session, settings):
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+
+    # And nothing was written on the way out.
+    assert settings_service.load_settings(session).blocker.enabled is True
+
+
+def test_pausing_is_not_an_escape_hatch(session, settings):
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+    pomodoro.pause(session, settings)
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+
+
+@pytest.mark.parametrize("kind", ["short_break", "long_break"])
+@pytest.mark.parametrize("pause", [False, True])
+def test_a_break_is_not_an_escape_hatch_either(session, settings, kind, pause):
+    """The lock is kind-blind: `current_session` is the whole rule."""
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind=kind)
+    if pause:
+        pomodoro.pause(session, settings)
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+
+
+def test_the_guard_can_always_be_switched_on_mid_interval(session, settings):
+    pomodoro.start(session, settings, kind="work")
+    updated = settings_service.apply_patch(session, {"blocker": {"enabled": True}})
+    assert updated.blocker.enabled is True
+
+
+def test_the_guard_switches_off_freely_when_nothing_is_running(session, settings):
+    _guarded(session, settings)
+    updated = settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+    assert updated.blocker.enabled is False
+
+
+def test_the_guard_switches_off_once_the_interval_is_over(session, settings):
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+    pomodoro.complete(session, settings, auto_next=False)
+
+    updated = settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+    assert updated.blocker.enabled is False
+
+
+def test_an_unrelated_blocker_patch_still_saves_mid_interval(session, settings):
+    """What the web app's list editor sends — the regression the check is shaped for."""
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    updated = settings_service.apply_patch(
+        session,
+        {"blocker": {"blocked_domains": ["youtube.com"], "blocked_apps": ["steam"]}},
+    )
+    assert updated.blocker.blocked_domains == ["youtube.com"]
+    assert updated.blocker.enabled is True
+
+
+def test_re_sending_an_already_off_guard_is_not_a_refusal(session, settings):
+    pomodoro.start(session, settings, kind="work")
+    updated = settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+    assert updated.blocker.enabled is False
+
+
+def test_a_full_document_echo_survives_a_live_interval(session, settings):
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    echo = settings_service.load_settings(session).model_dump(mode="json")
+    updated = settings_service.apply_patch(session, echo)
+    assert updated.blocker.enabled is True
+
+
+def test_a_loosely_typed_off_is_still_an_off(session, settings):
+    """`{"enabled": "no"}` coerces to False, which is why the check compares
+    validated documents rather than reading the patch's keys."""
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.apply_patch(session, {"blocker": {"enabled": "no"}})
+
+
+def test_the_policy_reports_the_lock(session, settings):
+    _guarded(session, settings)
+    assert blocker_service.policy(session, settings)["locked"] is False
+    assert blocker_service.policy(session, settings)["lock_reason"] == ""
+
+    pomodoro.start(session, settings, kind="work")
+    live = blocker_service.policy(session, settings)
+    assert live["locked"] is True
+    assert live["lock_reason"] == blocker_service.GUARD_LOCK_NOTE
+
+    pomodoro.pause(session, settings)
+    assert blocker_service.policy(session, settings)["locked"] is True
+
+
+def test_a_guard_that_is_off_is_never_reported_locked(session, settings):
+    """`locked` has "and the guard is on" folded in, so no client re-derives it."""
+    pomodoro.start(session, settings, kind="work")
+    assert blocker_service.policy(session, settings)["locked"] is False
+
+
+def test_the_policy_and_the_predicate_agree(session, settings):
+    """`policy()` re-expresses `guard_locked()` to reuse the row it already has;
+    these two must not drift."""
+    for enabled in (False, True):
+        settings.blocker.enabled = enabled
+        settings_service.save_settings(session, settings)
+        for kind in (None, "work", "short_break"):
+            if kind is not None:
+                pomodoro.start(session, settings, kind=kind)
+            assert blocker_service.policy(session, settings)["locked"] is (
+                blocker_service.guard_locked(session, settings)
+            )
+            if kind is not None:
+                pomodoro.abandon(session, settings, reason="test")
+
+
+def test_scheduled_mode_outside_its_window_is_inactive_and_still_locked(session, settings):
+    """The distinction `active` cannot express: nothing is blocked right now, and
+    the guard still must not be switched off before the window opens."""
+    settings.blocker.enabled = True
+    settings.blocker.mode = "scheduled"
+    settings.blocker.schedule = []
+    settings_service.save_settings(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    result = blocker_service.policy(session, settings)
+    assert result["active"] is False
+    assert result["locked"] is True
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.apply_patch(session, {"blocker": {"enabled": False}})
+
+
+def test_a_reset_cannot_switch_the_guard_off_mid_interval(session, settings):
+    """`settings_from_env` never touches the blocker subtree, so a reset always
+    lands on `enabled = False` — a second, quieter off-switch."""
+    _guarded(session, settings)
+    pomodoro.start(session, settings, kind="work")
+
+    with pytest.raises(blocker_service.GuardLocked):
+        settings_service.reset_to_env(session)
+    assert settings_service.load_settings(session).blocker.enabled is True
+
+    pomodoro.complete(session, settings, auto_next=False)
+    assert settings_service.reset_to_env(session).blocker.enabled is False
+
+
+def test_a_reset_is_fine_while_an_interval_runs_if_the_guard_is_off(session, settings):
+    pomodoro.start(session, settings, kind="work")
+    assert settings_service.reset_to_env(session).blocker.enabled is False

desktop/kadence_desktop/controller.py

@@ -37,6 +37,14 @@ log = logging.getLogger(__name__)
 
 KIND_LABELS = {"work": "Focus", "short_break": "Short break", "long_break": "Long break"}
 
+#: The local switches that stop this machine enforcing. While the server reports
+#: the guard locked, these only go one way — on. Turning enforcement off is what a
+#: focus guard exists to make inconvenient, and this app is the thing enforcing.
+_ENFORCEMENT_KEYS = ("enforce_blocking", "block_hosts_file", "block_apps")
+
+#: Said when the policy has not been polled yet, so there is no server sentence.
+_GUARD_LOCK_FALLBACK = "Finish or drop the interval to switch the focus guard off."
+
 
 def clock(seconds: int) -> str:
     seconds = max(0, int(seconds))
@@ -252,6 +260,20 @@ class Controller(QObject):
     def blockerReason(self) -> str:
         return str(self._policy.get("reason", ""))
 
+    @pyqtProperty(bool, notify=blockerChanged)
+    def blockerLocked(self) -> bool:
+        """The server will not let the guard be switched off right now.
+
+        Not the same as [blockerActive]: in scheduled mode outside every window
+        nothing is being blocked and the guard is still locked on, because an
+        interval is running or paused.
+        """
+        return bool(self._policy.get("locked"))
+
+    @pyqtProperty(str, notify=blockerChanged)
+    def blockerLockNote(self) -> str:
+        return str(self._policy.get("lock_reason", ""))
+
     @pyqtProperty("QVariantList", notify=blockerChanged)
     def blockedDomains(self) -> list[str]:
         """Every hostname the policy wants blocked, server-expanded.
@@ -447,6 +469,15 @@ class Controller(QObject):
     @pyqtSlot(str, "QVariant")
     def setConfig(self, key: str, value: Any) -> None:
         """Change a desktop-local setting and apply it immediately."""
+        if key in _ENFORCEMENT_KEYS and not value and self.blockerLocked:
+            # This machine is the one that actually enforces, so switching
+            # enforcement off here is the real escape hatch — the server's
+            # `blocker.enabled` is untouchable from this app anyway. The greyed
+            # switch in the dialog is not the enforcement: the policy poll can be
+            # seconds stale, and the tray and D-Bus come through here too.
+            self.toast.emit(self.blockerLockNote or _GUARD_LOCK_FALLBACK)
+            self.configChanged.emit()  # snap the switch back to the stored value
+            return
         if key == "autostart":
             autostart.set_autostart(bool(value), minimized=self._config.start_minimized)
         elif key == "service_enabled":

desktop/kadence_desktop/qml/SettingsDialog.qml

@@ -81,6 +81,13 @@ Window {
         property string detail: ""
         property bool on: false
         property bool available: true
+        /**
+         * A one-way ratchet: while this is set the switch can be turned on but not
+         * off, so it greys only when it is *already* on. `available` greys both
+         * directions, which is the wrong shape for "you may not switch this off".
+         */
+        property bool lockedOn: false
+        readonly property bool settable: available && !(lockedOn && on)
         signal toggledTo(bool value)
 
         Layout.fillWidth: true
@@ -91,7 +98,7 @@ Window {
             spacing: 1
             Label {
                 text: toggleRow.label
-                color: toggleRow.available ? Theme.ink : Theme.faint
+                color: toggleRow.settable ? Theme.ink : Theme.faint
                 font.pixelSize: 13
                 font.family: Theme.sansFamily
             }
@@ -107,7 +114,7 @@ Window {
         }
         Switch {
             checked: toggleRow.on
-            enabled: toggleRow.available
+            enabled: toggleRow.settable
             onToggled: toggleRow.toggledTo(checked)
         }
     }
@@ -264,11 +271,16 @@ Window {
                     visible: controller.blockerError !== ""
                     text: controller.blockerError
                 }
+                Banner {
+                    visible: controller.blockerLocked
+                    text: controller.blockerLockNote
+                }
 
                 Toggle {
                     label: "Enforce the server's rules here"
                     detail: "Off, this machine is a timer and nothing else."
                     on: dialog.config.enforce_blocking
+                    lockedOn: controller.blockerLocked
                     onToggledTo: (value) => controller.setConfig("enforce_blocking", value)
                 }
                 Toggle {
@@ -276,6 +288,7 @@ Window {
                     detail: "The managed region of /etc/hosts, plus a local DNS stub for the masks it cannot express."
                     on: dialog.config.block_hosts_file
                     available: dialog.config.enforce_blocking
+                    lockedOn: controller.blockerLocked
                     onToggledTo: (value) => controller.setConfig("block_hosts_file", value)
                 }
                 Toggle {
@@ -283,6 +296,7 @@ Window {
                     detail: "/proc is scanned every few seconds and matches are asked to quit, then made to."
                     on: dialog.config.block_apps
                     available: dialog.config.enforce_blocking
+                    lockedOn: controller.blockerLocked
                     onToggledTo: (value) => controller.setConfig("block_apps", value)
                 }
             }

frontend/src/lib/types.ts

@@ -88,7 +88,10 @@ export interface BlockerPolicy {
   reason: string;
   mode: string;
   enabled: boolean;
-  strict: boolean;
+  /** The guard is on and an interval is live, so it may not be switched off. Not the same as `active`: scheduled mode outside its window is inactive and still locked. */
+  locked: boolean;
+  /** Why it is locked, in the server's words — `""` when it is not. */
+  lock_reason: string;
   redirect_ip: string;
   domains: string[];
   apps: string[];
@@ -209,7 +212,6 @@ export interface AppSettings {
     blocked_apps: string[];
     kill_blocked_apps: boolean;
     schedule: { label: string; start: string; end: string; days: number[] }[];
-    strict: boolean;
     redirect_ip: string;
     app_poll_seconds: number;
     notify_on_block: boolean;

frontend/src/pages/BlockerPage.tsx

@@ -6,6 +6,10 @@
  * are answered by the desktop app's local DNS stub for the zones it can route.
  * The stats show what is really in force (`domains` is empty while blocking is
  * off) and every banner says plainly what could not be enforced.
+ *
+ * The switch is one-way while you work: the server refuses to turn the guard off
+ * while an interval is running or paused, so `policy.locked` greys it — turning
+ * it *on* is never refused.
  */
 import { useEffect, useMemo, useState } from "react";
 import {
@@ -97,6 +101,8 @@ export default function BlockerPage({ onToast }: { onToast: (message: string) =>
     [unexpandable],
   );
   const badExpansions = policy.data?.invalid_expansions ?? [];
+  /** The server has already folded "and the guard is on" in, so an off guard stays switchable on. */
+  const locked = policy.data?.locked ?? false;
   const top = useMemo(() => events.data?.by_target.slice(0, 8) ?? [], [events.data]);
 
   return (
@@ -106,15 +112,23 @@ export default function BlockerPage({ onToast }: { onToast: (message: string) =>
         title={policy.data?.active ? "Blocking is on" : "Blocking is off"}
         caption="Rules live here; the desktop app enforces them on your machine."
         actions={
-          <FormControlLabel
+          <Stack alignItems="flex-end">
-            control={
+            <FormControlLabel
-              <Switch
+              control={
-                checked={blocker?.enabled ?? false}
+                <Switch
-                onChange={(event) => void patch({ enabled: event.target.checked })}
+                  checked={blocker?.enabled ?? false}
-              />
+                  disabled={locked}
-            }
+                  onChange={(event) => void patch({ enabled: event.target.checked })}
-            label="Enabled"
+                />
-          />
+              }
+              label="Enabled"
+            />
+            {locked && (
+              <Typography variant="caption" color="text.secondary">
+                {policy.data?.lock_reason}
+              </Typography>
+            )}
+          </Stack>
         }
       />