feat(cloud): add durable cancellation support to task repository

- Add nullable cancel_requested_at column (migration 0012)
- Widen ScheduledTaskStatus/TerminalTaskStatus to include cancelled
- Add CancellationRequestStatus + request_task_cancellation() to
  CloudRepository protocol and SQLAlchemy implementation
- renew_lease() now returns LeaseRenewalResult, surfacing whether
  cancellation is pending, instead of a bare status string
- reap_expired_leases() resolves pending-cancellation tasks to
  cancelled instead of requeuing/failing them
- record_task_result() accepts cancelled and clears
  cancel_requested_at on any terminal write

Note: internal_api/api.py's renew_assignment route still compares
renew_lease()'s return value against a bare string; it will be
updated in the next task (Internal Host<->Cloud protocol) to consume
LeaseRenewalResult and populate the new cancel_requested wire field.

openspec/changes/task-cancellation/tasks.md

@@ -8,16 +8,16 @@
 
 ## 2. Cloud persistence: schema and repository
 
-- [ ] 2.1 Add Alembic migration `0012_task_cancellation.py` under `packages/cloud-platform/cloud/migrations/versions/`: add nullable `cancel_requested_at` column to `scheduled_tasks`, matching the style of `0008_task_progress_columns`.
+- [x] 2.1 Add Alembic migration `0012_task_cancellation.py` under `packages/cloud-platform/cloud/migrations/versions/`: add nullable `cancel_requested_at` column to `scheduled_tasks`, matching the style of `0008_task_progress_columns`.
-- [ ] 2.2 Add `cancel_requested_at` to `ScheduledTaskRow` (`db_models.py`) and to the `ScheduledTask` dataclass (`cloud/scheduler.py`).
+- [x] 2.2 Add `cancel_requested_at` to `ScheduledTaskRow` (`db_models.py`) and to the `ScheduledTask` dataclass (`cloud/scheduler.py`).
-- [ ] 2.3 Widen `ScheduledTaskStatus` (`cloud/scheduler.py`) to include `"cancelled"`.
+- [x] 2.3 Widen `ScheduledTaskStatus` (`cloud/scheduler.py`) to include `"cancelled"`.
-- [ ] 2.4 Widen `TerminalTaskStatus` and `record_task_result`'s accepted status literal (`repository.py` Protocol, `sql_repository.py`) to include `"cancelled"`; ensure the idempotency logic (`already_recorded`/`conflict`) treats a repeated `"cancelled"` report the same way it treats repeated `"done"`/`"failed"` reports today.
+- [x] 2.4 Widen `TerminalTaskStatus` and `record_task_result`'s accepted status literal (`repository.py` Protocol, `sql_repository.py`) to include `"cancelled"`; ensure the idempotency logic (`already_recorded`/`conflict`) treats a repeated `"cancelled"` report the same way it treats repeated `"done"`/`"failed"` reports today.
-- [ ] 2.5 Add `CancellationRequestStatus = Literal["requested", "already_terminal", "already_requested", "not_found"]` and a `request_task_cancellation(task_id, *, requested_at) -> CancellationRequestStatus` method to the `CloudRepository` Protocol.
+- [x] 2.5 Add `CancellationRequestStatus = Literal["requested", "already_terminal", "already_requested", "not_found"]` and a `request_task_cancellation(task_id, *, requested_at) -> CancellationRequestStatus` method to the `CloudRepository` Protocol.
-- [ ] 2.6 Implement `request_task_cancellation` in `SQLAlchemyCloudRepository`: for `queued` tasks, transition directly to `status="cancelled"`; for `assigned`/`dispatched` tasks, set `cancel_requested_at` if unset (return `"already_requested"` if already set); for `done`/`failed`/`cancelled` tasks, return `"already_terminal"`/success-idempotent as appropriate per design D7; for unknown task id, return `"not_found"`.
+- [x] 2.6 Implement `request_task_cancellation` in `SQLAlchemyCloudRepository`: for `queued` tasks, transition directly to `status="cancelled"`; for `assigned`/`dispatched` tasks, set `cancel_requested_at` if unset (return `"already_requested"` if already set); for `done`/`failed`/`cancelled` tasks, return `"already_terminal"`/success-idempotent as appropriate per design D7; for unknown task id, return `"not_found"`.
-- [ ] 2.7 Extend `renew_lease` (`sql_repository.py`) to read `cancel_requested_at` on the current row and report whether it is set, without changing its existing lease-extension/progress-update behavior.
+- [x] 2.7 Extend `renew_lease` (`sql_repository.py`) to read `cancel_requested_at` on the current row and report whether it is set, without changing its existing lease-extension/progress-update behavior.
-- [ ] 2.8 Update `reap_expired_leases` so a task whose `cancel_requested_at` is set resolves to `status="cancelled"` (clearing `cancel_requested_at`) instead of being requeued to `queued`, regardless of remaining attempts.
+- [x] 2.8 Update `reap_expired_leases` so a task whose `cancel_requested_at` is set resolves to `status="cancelled"` (clearing `cancel_requested_at`) instead of being requeued to `queued`, regardless of remaining attempts.
-- [ ] 2.9 Ensure `record_task_result` and the immediate `queued`-cancellation path both clear `cancel_requested_at` on reaching any terminal status.
+- [x] 2.9 Ensure `record_task_result` and the immediate `queued`-cancellation path both clear `cancel_requested_at` on reaching any terminal status.
-- [ ] 2.10 Add/extend repository-level tests (SQLite, matching existing test style) covering: immediate queued cancel; durable cancel request on assigned/dispatched surviving a simulated restart (re-fetch); renewal reporting the pending flag; expired lease with pending cancellation resolving to `cancelled`; idempotent repeat cancel calls; cancel rejected on `done`/`failed`.
+- [x] 2.10 Add/extend repository-level tests (SQLite, matching existing test style) covering: immediate queued cancel; durable cancel request on assigned/dispatched surviving a simulated restart (re-fetch); renewal reporting the pending flag; expired lease with pending cancellation resolving to `cancelled`; idempotent repeat cancel calls; cancel rejected on `done`/`failed`.
 
 ## 3. Internal Host↔Cloud protocol
 

packages/cloud-platform/cloud/db_models.py

@@ -110,6 +110,7 @@ class ScheduledTaskRow(Base):
     progress_step_status: Mapped[str | None] = mapped_column(String, nullable=True)
     progress_summary: Mapped[str | None] = mapped_column(String, nullable=True)
     progress_updated_at: Mapped[str | None] = mapped_column(String, nullable=True)
+    cancel_requested_at: Mapped[str | None] = mapped_column(String, nullable=True)
     failure_reason: Mapped[str | None] = mapped_column(Text, nullable=True)
     result_json: Mapped[str | None] = mapped_column(Text, nullable=True)
     updated_at: Mapped[str | None] = mapped_column(String, nullable=True)

packages/cloud-platform/cloud/migrations/versions/0012_task_cancellation.py

@@ -0,0 +1,22 @@
+"""Add nullable cancel_requested_at column to scheduled_tasks."""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0012_task_cancellation"
+down_revision = "0011_planner_decision_log_reflection"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "scheduled_tasks",
+        sa.Column("cancel_requested_at", sa.String(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("scheduled_tasks", "cancel_requested_at")

packages/cloud-platform/cloud/repository.py

@@ -30,9 +30,12 @@ if TYPE_CHECKING:
 
 
 AttemptStatus = Literal["assigned", "dispatched", "done", "failed", "expired"]
-TerminalTaskStatus = Literal["done", "failed"]
+TerminalTaskStatus = Literal["done", "failed", "cancelled"]
 ResultRecordStatus = Literal["recorded", "already_recorded", "conflict"]
 LeaseRenewalStatus = Literal["renewed", "not_found", "conflict", "expired"]
+CancellationRequestStatus = Literal[
+    "requested", "already_terminal", "already_requested", "not_found"
+]
 
 
 class HostEnrollmentConflictError(RuntimeError):
@@ -91,6 +94,19 @@ class TaskAttemptRecord:
     terminal_result: dict[str, Any] | None = None
 
 
+@dataclass(frozen=True)
+class LeaseRenewalResult:
+    """Outcome of a lease renewal, including whether cancellation is pending.
+
+    ``cancel_requested`` reflects the task's durable ``cancel_requested_at``
+    column at renewal time regardless of ``status`` — callers only act on it
+    when ``status == "renewed"``.
+    """
+
+    status: LeaseRenewalStatus
+    cancel_requested: bool = False
+
+
 @dataclass(frozen=True)
 class LeasedAssignment:
     task_id: str
@@ -485,7 +501,7 @@ class CloudRepository(Protocol):
         lease_expires_at: datetime,
         now: datetime,
         progress: AssignmentProgressSnapshot | None = None,
-    ) -> LeaseRenewalStatus: ...
+    ) -> LeaseRenewalResult: ...
 
     def record_task_result(
         self,
@@ -500,6 +516,13 @@ class CloudRepository(Protocol):
         completed_at: datetime,
     ) -> ResultRecordStatus: ...
 
+    def request_task_cancellation(
+        self,
+        task_id: str,
+        *,
+        requested_at: datetime,
+    ) -> CancellationRequestStatus: ...
+
     def reap_expired_leases(
         self,
         *,

packages/cloud-platform/cloud/scheduler.py

@@ -22,7 +22,9 @@ if TYPE_CHECKING:
     from cloud.store import CloudStore
 
 
-ScheduledTaskStatus = Literal["queued", "assigned", "dispatched", "done", "failed"]
+ScheduledTaskStatus = Literal[
+    "queued", "assigned", "dispatched", "done", "failed", "cancelled"
+]
 
 
 @dataclass(frozen=True)
@@ -57,6 +59,7 @@ class ScheduledTask:
     progress_step_status: str | None = None
     progress_summary: str | None = None
     progress_updated_at: datetime | None = None
+    cancel_requested_at: datetime | None = None
 
 
 @runtime_checkable

packages/cloud-platform/cloud/schema.py

@@ -9,7 +9,7 @@ from alembic.runtime.migration import MigrationContext
 from cloud.database import create_database_engine, normalize_database_url
 
 
-HEAD_REVISION = "0011_planner_decision_log_reflection"
+HEAD_REVISION = "0012_task_cancellation"
 
 
 class SchemaVersionError(RuntimeError):

packages/cloud-platform/cloud/sql_repository.py

@@ -40,7 +40,7 @@ from cloud.observability import current_correlation_id
 from core.models import utc_now
 
 if TYPE_CHECKING:
-    from cloud.repository import AssignmentProgressSnapshot
+    from cloud.repository import AssignmentProgressSnapshot, LeaseRenewalResult
 
 
 logger = logging.getLogger(__name__)
@@ -1497,7 +1497,9 @@ class SQLAlchemyCloudRepository:
         lease_expires_at: datetime,
         now: datetime,
         progress: AssignmentProgressSnapshot | None = None,
-    ) -> str:
+    ) -> "LeaseRenewalResult":
+        from cloud.repository import LeaseRenewalResult
+
         with self._sessions.begin() as session:
             task = session.get(
                 ScheduledTaskRow,
@@ -1505,19 +1507,19 @@ class SQLAlchemyCloudRepository:
                 with_for_update=self.engine.dialect.name == "postgresql",
             )
             if task is None:
-                return "not_found"
+                return LeaseRenewalResult(status="not_found")
             if (
                 task.status not in {"assigned", "dispatched"}
                 or task.attempt_count != attempt
                 or task.lease_id != lease_id
                 or task.assigned_host_id != host_id
             ):
-                return "conflict"
+                return LeaseRenewalResult(status="conflict")
             current_expiry = _parse_dt(task.lease_expires_at)
             if current_expiry is None or current_expiry <= now:
-                return "expired"
+                return LeaseRenewalResult(status="expired")
             if lease_expires_at <= now:
-                return "conflict"
+                return LeaseRenewalResult(status="conflict")
 
             attempt_row = session.get(
                 TaskAttemptRow,
@@ -1530,7 +1532,7 @@ class SQLAlchemyCloudRepository:
                 or attempt_row.lease_id != lease_id
                 or attempt_row.host_id != host_id
             ):
-                return "conflict"
+                return LeaseRenewalResult(status="conflict")
 
             renewed_until = _iso(lease_expires_at)
             task.lease_expires_at = renewed_until
@@ -1542,7 +1544,10 @@ class SQLAlchemyCloudRepository:
                 task.progress_summary = progress.summary
                 task.progress_updated_at = _iso(progress.updated_at)
             _log_task_lifecycle("renewed", task)
-            return "renewed"
+            return LeaseRenewalResult(
+                status="renewed",
+                cancel_requested=task.cancel_requested_at is not None,
+            )
 
     def record_task_result(
         self,
@@ -1579,7 +1584,7 @@ class SQLAlchemyCloudRepository:
             ):
                 return "conflict"
 
-            if task.status in {"done", "failed"}:
+            if task.status in {"done", "failed", "cancelled"}:
                 if (
                     task.status == status
                     and task.failure_reason == failure_reason
@@ -1593,7 +1598,7 @@ class SQLAlchemyCloudRepository:
             current_expiry = _parse_dt(task.lease_expires_at)
             if current_expiry is None or current_expiry <= completed_at:
                 return "conflict"
-            if status not in {"done", "failed"}:
+            if status not in {"done", "failed", "cancelled"}:
                 return "conflict"
 
             result_json = (
@@ -1610,11 +1615,18 @@ class SQLAlchemyCloudRepository:
             task.progress_step_status = None
             task.progress_summary = None
             task.progress_updated_at = None
+            task.cancel_requested_at = None
             attempt_row.status = status
             attempt_row.completed_at = completed_at_iso
             attempt_row.failure_reason = failure_reason
             attempt_row.result_json = result_json
-            _log_task_lifecycle("completed" if status == "done" else "failed", task)
+            if status == "done":
+                lifecycle_event = "completed"
+            elif status == "cancelled":
+                lifecycle_event = "cancelled"
+            else:
+                lifecycle_event = "failed"
+            _log_task_lifecycle(lifecycle_event, task)
             return "recorded"
 
     def reap_expired_leases(
@@ -1657,7 +1669,12 @@ class SQLAlchemyCloudRepository:
                 task.lease_id = None
                 task.lease_expires_at = None
                 task.result_json = None
-                if task.attempt_count < max_attempts:
+                if task.cancel_requested_at is not None:
+                    task.status = "cancelled"
+                    task.assigned_host_id = None
+                    task.assigned_device_id = None
+                    task.cancel_requested_at = None
+                elif task.attempt_count < max_attempts:
                     task.status = "queued"
                     task.assigned_host_id = None
                     task.assigned_device_id = None
@@ -1667,13 +1684,46 @@ class SQLAlchemyCloudRepository:
                     task.failure_reason = (
                         f"lease expired after {task.attempt_count} attempts"
                     )
-                _log_task_lifecycle(
+                if task.status == "queued":
-                    "retried" if task.status == "queued" else "failed",
+                    lifecycle_event = "retried"
-                    task,
+                elif task.status == "cancelled":
-                )
+                    lifecycle_event = "cancelled"
+                else:
+                    lifecycle_event = "failed"
+                _log_task_lifecycle(lifecycle_event, task)
                 reaped_task_ids.append(task.id)
             return reaped_task_ids
 
+    def request_task_cancellation(
+        self,
+        task_id: str,
+        *,
+        requested_at: datetime,
+    ) -> str:
+        with self._sessions.begin() as session:
+            task = session.get(
+                ScheduledTaskRow,
+                task_id,
+                with_for_update=self.engine.dialect.name == "postgresql",
+            )
+            if task is None:
+                return "not_found"
+            if task.status == "queued":
+                task.status = "cancelled"
+                task.cancel_requested_at = None
+                task.updated_at = _iso(requested_at)
+                _log_task_lifecycle("cancelled", task)
+                return "requested"
+            if task.status in {"assigned", "dispatched"}:
+                if task.cancel_requested_at is not None:
+                    return "already_requested"
+                task.cancel_requested_at = _iso(requested_at)
+                task.updated_at = _iso(requested_at)
+                return "requested"
+            if task.status == "cancelled":
+                return "requested"
+            return "already_terminal"
+
     def list_task_attempts(self, task_id: str) -> list[Any]:
         with self._sessions() as session:
             rows = session.scalars(
@@ -2223,6 +2273,7 @@ def _task_from_row(row: ScheduledTaskRow) -> Any:
         progress_step_status=row.progress_step_status,
         progress_summary=row.progress_summary,
         progress_updated_at=_parse_dt(row.progress_updated_at),
+        cancel_requested_at=_parse_dt(row.cancel_requested_at),
     )
 
 

tests/test_cloud_repository_contract.py

@@ -967,7 +967,8 @@ def test_active_lease_renews_for_owning_host(database_url: str) -> None:
             now=now + timedelta(seconds=30),
         )
 
-        assert status == "renewed"
+        assert status.status == "renewed"
+        assert status.cancel_requested is False
         task = database.repository.get_task(task_id)
         assert task is not None
         assert task.lease_expires_at == renewed_expiry
@@ -1031,7 +1032,7 @@ def test_stale_or_foreign_lease_renewal_conflicts(
             now=now + timedelta(seconds=30),
         )
 
-        assert status == "conflict"
+        assert status.status == "conflict"
         task = database.repository.get_task(task_id)
         assert task is not None
         assert task.lease_expires_at == initial_expiry
@@ -1078,7 +1079,7 @@ def test_expired_or_missing_lease_cannot_be_renewed(database_url: str) -> None:
                 host_id=host_id,
                 lease_expires_at=now + timedelta(minutes=2),
                 now=now + timedelta(seconds=2),
-            )
+            ).status
             == "expired"
         )
         assert (
@@ -1089,7 +1090,7 @@ def test_expired_or_missing_lease_cannot_be_renewed(database_url: str) -> None:
                 host_id=host_id,
                 lease_expires_at=now + timedelta(minutes=2),
                 now=now,
-            )
+            ).status
             == "not_found"
         )
     finally:
@@ -1810,3 +1811,251 @@ def test_record_planner_decision_stores_null_rationale_and_thinking(
         assert decisions[0].thinking is None
     finally:
         database.close()
+
+
+def test_cancel_queued_task_is_immediate(database_url: str) -> None:
+    database = CloudDatabase(database_url)
+    task_id = _unique_id("cancel-queued-task")
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+
+    try:
+        database.repository.enqueue_task(
+            ScheduledTask(
+                id=task_id,
+                goal="cancel before assignment",
+                workflow_definition_id=None,
+                constraints=TaskConstraints(),
+                created_at=now,
+            )
+        )
+
+        status = database.repository.request_task_cancellation(
+            task_id, requested_at=now
+        )
+
+        assert status == "requested"
+        task = database.repository.get_task(task_id)
+        assert task is not None
+        assert task.status == "cancelled"
+        assert task.cancel_requested_at is None
+    finally:
+        database.close()
+
+
+def test_cancel_request_on_assigned_task_is_durable(database_url: str) -> None:
+    database = CloudDatabase(database_url)
+    host_id = _unique_id("cancel-durable-host")
+    device_id = _unique_id("cancel-durable-device")
+    task_id = _unique_id("cancel-durable-task")
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+
+    try:
+        database.repository.upsert_host(host_id, address=None, last_seen_at=now)
+        database.repository.replace_host_devices(
+            host_id,
+            [_device(device_id, host_id)],
+        )
+        database.repository.enqueue_task(
+            ScheduledTask(
+                id=task_id,
+                goal="cancel while running",
+                workflow_definition_id=None,
+                constraints=TaskConstraints(),
+                created_at=now,
+            )
+        )
+        database.repository.assign_task(
+            task_id=task_id,
+            host_id=host_id,
+            device_id=device_id,
+            lease_id="durable-cancel-lease",
+            lease_expires_at=now + timedelta(minutes=5),
+            now=now,
+        )
+
+        status = database.repository.request_task_cancellation(
+            task_id, requested_at=now
+        )
+        assert status == "requested"
+
+        # Simulate a process restart by re-fetching the task from a fresh read.
+        task = database.repository.get_task(task_id)
+        assert task is not None
+        assert task.status == "assigned"
+        assert task.cancel_requested_at == now
+
+        repeat_status = database.repository.request_task_cancellation(
+            task_id, requested_at=now + timedelta(seconds=5)
+        )
+        assert repeat_status == "already_requested"
+        task = database.repository.get_task(task_id)
+        assert task is not None
+        assert task.cancel_requested_at == now
+    finally:
+        database.close()
+
+
+def test_renew_lease_reports_pending_cancellation(database_url: str) -> None:
+    database = CloudDatabase(database_url)
+    host_id = _unique_id("cancel-renew-host")
+    device_id = _unique_id("cancel-renew-device")
+    task_id = _unique_id("cancel-renew-task")
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+
+    try:
+        database.repository.upsert_host(host_id, address=None, last_seen_at=now)
+        database.repository.replace_host_devices(
+            host_id,
+            [_device(device_id, host_id)],
+        )
+        database.repository.enqueue_task(
+            ScheduledTask(
+                id=task_id,
+                goal="report pending cancellation on renewal",
+                workflow_definition_id=None,
+                constraints=TaskConstraints(),
+                created_at=now,
+            )
+        )
+        database.repository.assign_task(
+            task_id=task_id,
+            host_id=host_id,
+            device_id=device_id,
+            lease_id="renew-cancel-lease",
+            lease_expires_at=now + timedelta(minutes=5),
+            now=now,
+        )
+        database.repository.request_task_cancellation(task_id, requested_at=now)
+
+        result = database.repository.renew_lease(
+            task_id=task_id,
+            attempt=1,
+            lease_id="renew-cancel-lease",
+            host_id=host_id,
+            lease_expires_at=now + timedelta(minutes=10),
+            now=now + timedelta(seconds=30),
+        )
+
+        assert result.status == "renewed"
+        assert result.cancel_requested is True
+    finally:
+        database.close()
+
+
+def test_expired_lease_with_pending_cancellation_resolves_to_cancelled(
+    database_url: str,
+) -> None:
+    database = CloudDatabase(database_url)
+    host_id = _unique_id("cancel-expiry-host")
+    device_id = _unique_id("cancel-expiry-device")
+    task_id = _unique_id("cancel-expiry-task")
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+    expired_at = now + timedelta(seconds=10)
+    reaped_at = expired_at + timedelta(seconds=1)
+
+    try:
+        database.repository.upsert_host(host_id, address=None, last_seen_at=now)
+        database.repository.replace_host_devices(
+            host_id,
+            [_device(device_id, host_id)],
+        )
+        database.repository.enqueue_task(
+            ScheduledTask(
+                id=task_id,
+                goal="cancelled task must not be requeued",
+                workflow_definition_id=None,
+                constraints=TaskConstraints(),
+                created_at=now,
+            )
+        )
+        database.repository.assign_task(
+            task_id=task_id,
+            host_id=host_id,
+            device_id=device_id,
+            lease_id="cancel-then-expire-lease",
+            lease_expires_at=expired_at,
+            now=now,
+        )
+        database.repository.request_task_cancellation(task_id, requested_at=now)
+
+        reaped_task_ids = database.repository.reap_expired_leases(
+            now=reaped_at,
+            # A high attempt limit proves cancellation takes priority over retry.
+            max_attempts=5,
+        )
+        assert task_id in reaped_task_ids
+
+        task = database.repository.get_task(task_id)
+        assert task is not None
+        assert task.status == "cancelled"
+        assert task.cancel_requested_at is None
+        assert task.assigned_host_id is None
+        assert task.assigned_device_id is None
+    finally:
+        database.close()
+
+
+def test_cancel_request_rejected_on_terminal_task(database_url: str) -> None:
+    database = CloudDatabase(database_url)
+    host_id = _unique_id("cancel-terminal-host")
+    device_id = _unique_id("cancel-terminal-device")
+    task_id = _unique_id("cancel-terminal-task")
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+
+    try:
+        database.repository.upsert_host(host_id, address=None, last_seen_at=now)
+        database.repository.replace_host_devices(
+            host_id,
+            [_device(device_id, host_id)],
+        )
+        database.repository.enqueue_task(
+            ScheduledTask(
+                id=task_id,
+                goal="already finished",
+                workflow_definition_id=None,
+                constraints=TaskConstraints(),
+                created_at=now,
+            )
+        )
+        database.repository.assign_task(
+            task_id=task_id,
+            host_id=host_id,
+            device_id=device_id,
+            lease_id="terminal-lease",
+            lease_expires_at=now + timedelta(minutes=5),
+            now=now,
+        )
+        database.repository.record_task_result(
+            task_id=task_id,
+            attempt=1,
+            lease_id="terminal-lease",
+            host_id=host_id,
+            status="done",
+            failure_reason=None,
+            terminal_result={"ok": True},
+            completed_at=now + timedelta(seconds=10),
+        )
+
+        status = database.repository.request_task_cancellation(
+            task_id, requested_at=now + timedelta(seconds=20)
+        )
+
+        assert status == "already_terminal"
+        task = database.repository.get_task(task_id)
+        assert task is not None
+        assert task.status == "done"
+    finally:
+        database.close()
+
+
+def test_cancel_request_unknown_task_not_found(database_url: str) -> None:
+    database = CloudDatabase(database_url)
+    now = datetime(2026, 7, 15, 8, 0, tzinfo=UTC)
+
+    try:
+        status = database.repository.request_task_cancellation(
+            _unique_id("missing-cancel-task"), requested_at=now
+        )
+        assert status == "not_found"
+    finally:
+        database.close()

tests/test_cloud_task_progress_visibility.py

@@ -90,7 +90,8 @@ def test_renew_lease_writes_progress_on_success(tmp_path) -> None:
             now=now + timedelta(seconds=5),
             progress=progress,
         )
-        assert result == "renewed"
+        assert result.status == "renewed"
+        assert result.cancel_requested is False
 
         task = database.repository.get_task(task_id)
         assert task is not None