diff --git a/fastmcp_tasks/fastmcp_tasks/models.py b/fastmcp_tasks/fastmcp_tasks/models.py
index d6b3a9875..1ce1cc07a 100644
--- a/fastmcp_tasks/fastmcp_tasks/models.py
+++ b/fastmcp_tasks/fastmcp_tasks/models.py
@@ -45,9 +45,7 @@ __all__ = [
 #: the tasks extension in for the request.
 MISSING_REQUIRED_CLIENT_CAPABILITY = -32003
 
-TaskStatus = Literal[
-    "working", "input_required", "completed", "failed", "cancelled"
-]
+TaskStatus = Literal["working", "input_required", "completed", "failed", "cancelled"]
 
 
 class _TaskFields(BaseModel):
@@ -69,7 +67,9 @@ class _TaskFields(BaseModel):
     created_at: str = Field(serialization_alias="createdAt")
     last_updated_at: str = Field(serialization_alias="lastUpdatedAt")
     ttl_ms: float | None = Field(serialization_alias="ttlMs")
-    status_message: str | None = Field(default=None, serialization_alias="statusMessage")
+    status_message: str | None = Field(
+        default=None, serialization_alias="statusMessage"
+    )
     poll_interval_ms: float | None = Field(
         default=None, serialization_alias="pollIntervalMs"
     )
diff --git a/pyproject.toml b/pyproject.toml
index e4deaae1e..d34a8fc68 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -155,10 +155,9 @@ exclude = [
     "examples/providers/sqlite",        # needs aiosqlite
     "examples/memory.py",               # needs asyncpg, numpy, pydantic_ai, pgvector
     "examples/get_file.py",             # needs aiohttp
-    # The moved task tests pass at runtime but carry ty diagnostics (mostly
-    # None-narrowing on optional result fields); a follow-up commit fixes them
-    # and removes this exclusion.
-    "tests/tasks",
+    # Skipped pending client task support; rewritten in the client-task follow-up.
+    "tests/tasks/client/test_task_context_validation.py",
+    "tests/tasks/client/test_task_result_caching.py",
 ]
 
 [tool.ty.environment]
diff --git a/tests/tasks/server/test_concurrent_dependencies.py b/tests/tasks/server/test_concurrent_dependencies.py
index 009723d25..4cc33e5dc 100644
--- a/tests/tasks/server/test_concurrent_dependencies.py
+++ b/tests/tasks/server/test_concurrent_dependencies.py
@@ -99,6 +99,7 @@ async def test_concurrent_background_tasks_with_context():
     assert len(finals) == 4
     for final in finals:
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"]["result"].startswith("bg:")
 
 
@@ -134,6 +135,7 @@ async def test_concurrent_background_tasks_with_progress():
     assert len(finals) == 4
     for final in finals:
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"]["result"].startswith("bg:")
 
 
@@ -202,6 +204,7 @@ async def test_sync_context_functions_work_in_background_without_deps():
         final = await wait_for_task(mcp, created.task_id)
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"has_headers": "False"}
 
 
@@ -225,4 +228,5 @@ async def test_sync_context_functions_work_in_background_with_context():
         final = await wait_for_task(mcp, created.task_id)
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"]["is_background"] == "True"
diff --git a/tests/tasks/server/test_context_background_task.py b/tests/tasks/server/test_context_background_task.py
index 6cbc79e3f..0bf470f6b 100644
--- a/tests/tasks/server/test_context_background_task.py
+++ b/tests/tasks/server/test_context_background_task.py
@@ -356,6 +356,7 @@ class TestBackgroundTaskIntegration:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "done"}
 
     async def test_context_wiring_in_background_task(self):
@@ -382,6 +383,7 @@ class TestBackgroundTaskIntegration:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {
             "task_id_set": True,
             "is_background": True,
@@ -406,6 +408,7 @@ class TestBackgroundTaskIntegration:
             parked = await wait_for_task(
                 mcp, created.task_id, target_states=frozenset({"input_required"})
             )
+            assert parked.input_requests is not None
             key = next(iter(parked.input_requests))
             await update_task(
                 mcp,
@@ -415,6 +418,7 @@ class TestBackgroundTaskIntegration:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "Hello, Bob!"}
 
     async def test_elicit_decline_flow(self):
@@ -436,11 +440,13 @@ class TestBackgroundTaskIntegration:
             parked = await wait_for_task(
                 mcp, created.task_id, target_states=frozenset({"input_required"})
             )
+            assert parked.input_requests is not None
             key = next(iter(parked.input_requests))
             await update_task(mcp, created.task_id, {key: {"action": "decline"}})
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "User declined"}
 
     async def test_elicit_with_pydantic_model(self):
@@ -466,6 +472,7 @@ class TestBackgroundTaskIntegration:
             parked = await wait_for_task(
                 mcp, created.task_id, target_states=frozenset({"input_required"})
             )
+            assert parked.input_requests is not None
             key = next(iter(parked.input_requests))
             await update_task(
                 mcp,
@@ -475,6 +482,7 @@ class TestBackgroundTaskIntegration:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "Alice is 30"}
 
 
@@ -511,6 +519,7 @@ class TestAccessTokenInBackgroundTasks:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {
             "result": "roundtrip-jwt|test-client"
         }
@@ -530,6 +539,7 @@ class TestAccessTokenInBackgroundTasks:
             final = await wait_for_task(mcp, created.task_id)
 
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "no-token"}
 
 
diff --git a/tests/tasks/server/test_custom_subclass_tasks.py b/tests/tasks/server/test_custom_subclass_tasks.py
index c9b41fafc..6c45baafb 100644
--- a/tests/tasks/server/test_custom_subclass_tasks.py
+++ b/tests/tasks/server/test_custom_subclass_tasks.py
@@ -92,6 +92,7 @@ async def test_custom_tool_background_execution(custom_tool_server):
         final = await run_task(custom_tool_server, "custom_tool", {})
 
     assert final.status == "completed"
+    assert final.result is not None
     assert "Custom tool executed" in final.result["content"][0]["text"]
 
 
@@ -101,6 +102,7 @@ async def test_custom_tool_with_arguments(custom_tool_server):
         final = await run_task(custom_tool_server, "custom_logic", {"duration": 1})
 
     assert final.status == "completed"
+    assert final.result is not None
     assert "Completed after 1 units" in final.result["content"][0]["text"]
 
 
diff --git a/tests/tasks/server/test_extension.py b/tests/tasks/server/test_extension.py
index 64eb9ad5a..21fd2b7fd 100644
--- a/tests/tasks/server/test_extension.py
+++ b/tests/tasks/server/test_extension.py
@@ -12,6 +12,7 @@ from __future__ import annotations
 import asyncio
 from contextlib import AsyncExitStack
 from types import SimpleNamespace
+from typing import cast
 
 import pytest
 from fastmcp_tasks.models import (
@@ -19,6 +20,7 @@ from fastmcp_tasks.models import (
     CreateTaskResult,
 )
 from mcp.server.context import ServerRequestContext
+from mcp.server.session import ServerSession
 from mcp.shared.exceptions import MCPError
 
 from fastmcp import FastMCP
@@ -140,6 +142,7 @@ async def test_required_tool_tasks_when_opted_in():
         created = await submit_task(mcp, "must_task", {"n": 10})
         final = await wait_for_task(mcp, created.task_id)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"]["result"] == 11
 
 
@@ -197,6 +200,7 @@ async def test_task_arguments_are_coerced_like_sync_path():
     async with running_task_server(mcp):
         # "6" coerces to int 6 exactly as the synchronous path would.
         final = await run_task(mcp, "square", {"n": "6"})
+        assert final.result is not None
         assert final.result["structuredContent"]["result"] == 36
 
 
@@ -308,7 +312,7 @@ async def test_legacy_era_opt_in_is_ignored():
     mcp = _tasks_server()
     async with running_task_server(mcp):
         srctx = ServerRequestContext(
-            session=SimpleNamespace(),
+            session=cast(ServerSession, SimpleNamespace()),
             lifespan_context={},
             protocol_version="2025-06-18",
             method="tools/call",
@@ -324,7 +328,7 @@ async def test_legacy_era_required_tool_raises_missing_capability():
     mcp = _tasks_server()
     async with running_task_server(mcp):
         srctx = ServerRequestContext(
-            session=SimpleNamespace(),
+            session=cast(ServerSession, SimpleNamespace()),
             lifespan_context={},
             protocol_version="2025-06-18",
             method="tools/call",
diff --git a/tests/tasks/server/test_progress_dependency.py b/tests/tasks/server/test_progress_dependency.py
index 98401d9d2..d948ed251 100644
--- a/tests/tasks/server/test_progress_dependency.py
+++ b/tests/tasks/server/test_progress_dependency.py
@@ -48,6 +48,7 @@ async def test_progress_in_background_task():
         created = await submit_task(mcp, "test_task", {})
         final = await wait_for_task(mcp, created.task_id)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "done"}
 
 
@@ -97,6 +98,7 @@ async def test_progress_status_message_in_background_task():
         release.set()
         final = await wait_for_task(mcp, created.task_id)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "done"}
 
 
diff --git a/tests/tasks/server/test_server_tasks_parameter.py b/tests/tasks/server/test_server_tasks_parameter.py
index 6ebb6d121..e815e79c0 100644
--- a/tests/tasks/server/test_server_tasks_parameter.py
+++ b/tests/tasks/server/test_server_tasks_parameter.py
@@ -130,6 +130,7 @@ async def test_task_with_custom_tool_name():
     async with running_task_server(mcp):
         final = await run_task(mcp, "custom-tool-name")
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {
             "result": "result from custom-named tool"
         }
diff --git a/tests/tasks/server/test_snapshot_restore.py b/tests/tasks/server/test_snapshot_restore.py
index 532ed7cbb..d69ff89df 100644
--- a/tests/tasks/server/test_snapshot_restore.py
+++ b/tests/tasks/server/test_snapshot_restore.py
@@ -48,6 +48,7 @@ async def test_snapshot_restored_before_user_code_runs():
         final = await wait_for_task(mcp, created.task_id)
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": True}
 
 
@@ -75,6 +76,7 @@ async def test_get_access_token_in_bg_task_without_context_dep():
         final = await wait_for_task(mcp, created.task_id)
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": "jwt-3897"}
 
 
@@ -99,6 +101,7 @@ async def test_restore_failure_is_nonfatal():
             final = await wait_for_task(mcp, created.task_id)
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": False}
 
 
diff --git a/tests/tasks/server/test_task_config.py b/tests/tasks/server/test_task_config.py
index 2f687da77..dc214acb5 100644
--- a/tests/tasks/server/test_task_config.py
+++ b/tests/tasks/server/test_task_config.py
@@ -180,6 +180,7 @@ class TestToolExecutionMetadata:
             return "ok"
 
         tool = await mcp.get_tool("my_tool")
+        assert tool is not None
         execution = tool.to_mcp_tool().execution
         assert isinstance(execution, ToolExecution)
         assert execution.task_support == "optional"
@@ -194,6 +195,7 @@ class TestToolExecutionMetadata:
             return "ok"
 
         tool = await mcp.get_tool("my_tool")
+        assert tool is not None
         execution = tool.to_mcp_tool().execution
         assert isinstance(execution, ToolExecution)
         assert execution.task_support == "required"
@@ -208,6 +210,7 @@ class TestToolExecutionMetadata:
             return "ok"
 
         tool = await mcp.get_tool("my_tool")
+        assert tool is not None
         assert tool.to_mcp_tool().execution is None
 
 
diff --git a/tests/tasks/server/test_task_dependencies.py b/tests/tasks/server/test_task_dependencies.py
index e40770d46..d00a4dab4 100644
--- a/tests/tasks/server/test_task_dependencies.py
+++ b/tests/tasks/server/test_task_dependencies.py
@@ -73,6 +73,7 @@ async def test_background_tool_receives_docket_dependency(dependency_server):
         final = await run_task(dependency_server, "tool_with_docket_dependency", {})
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": "Docket: True"}
     assert len(dependency_server._injected_values) == 1
     dep_type, dep_value = dependency_server._injected_values[0]
@@ -88,6 +89,7 @@ async def test_background_tool_receives_server_dependency(dependency_server):
         final = await run_task(dependency_server, "tool_with_server_dependency", {})
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {
         "result": f"Server: {dependency_server.name}"
     }
@@ -107,6 +109,7 @@ async def test_background_tool_receives_custom_depends(dependency_server):
         )
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": 50}  # 5 * 10
     assert len(dependency_server._injected_values) == 1
     dep_type, dep_value = dependency_server._injected_values[0]
@@ -124,6 +127,7 @@ async def test_background_tool_with_multiple_dependencies(dependency_server):
         )
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {
         "result": f"test on {dependency_server.name}"
     }
@@ -180,6 +184,7 @@ async def test_dependency_context_managers_cleaned_up_in_background():
         final = await run_task(mcp, "use_connection", {"name": "test"})
 
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": "Used: connection"}
     assert cleanup_called == ["enter", "exit"]
 
diff --git a/tests/tasks/server/test_task_elicitation_relay.py b/tests/tasks/server/test_task_elicitation_relay.py
index a36e202fe..ab1096bbd 100644
--- a/tests/tasks/server/test_task_elicitation_relay.py
+++ b/tests/tasks/server/test_task_elicitation_relay.py
@@ -62,6 +62,7 @@ async def _drive(server: FastMCP, name: str, answers: list[dict[str, Any]]) -> s
         await update_task(server, created.task_id, {key: answer})
     final = await wait_for_task(server, created.task_id)
     assert final.status == "completed", final.error
+    assert final.result is not None
     return final.result["content"][0]["text"]
 
 
@@ -214,4 +215,5 @@ async def test_unanswered_input_times_out_to_cancel(monkeypatch):
         # Never answer; the worker's bounded wait resolves to cancel.
         final = await wait_for_task(mcp, created.task_id, timeout=10.0)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["content"][0]["text"] == "Cancelled as expected"
diff --git a/tests/tasks/server/test_task_methods.py b/tests/tasks/server/test_task_methods.py
index 3558ba8f8..d7bc39731 100644
--- a/tests/tasks/server/test_task_methods.py
+++ b/tests/tasks/server/test_task_methods.py
@@ -53,7 +53,9 @@ async def test_tasks_get_returns_status_and_inlined_result():
 
         final = await wait_for_task(mcp, created.task_id)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": 42}
+        assert final.result is not None
         assert final.result["isError"] is False
 
 
diff --git a/tests/tasks/server/test_task_mount.py b/tests/tasks/server/test_task_mount.py
index 97408d1d0..15dfbee4d 100644
--- a/tests/tasks/server/test_task_mount.py
+++ b/tests/tasks/server/test_task_mount.py
@@ -20,6 +20,7 @@ Two architectural notes vs. SEP-1686:
 from __future__ import annotations
 
 import asyncio
+from typing import cast
 
 import mcp_types as mt
 import pytest
@@ -31,7 +32,7 @@ from mcp_types import ToolExecution
 from fastmcp import Context, FastMCP
 from fastmcp.server.dependencies import CurrentFastMCP
 from fastmcp.server.middleware import CallNext, Middleware, MiddlewareContext
-from fastmcp.server.providers.proxy import ProxyTool
+from fastmcp.server.providers.proxy import ClientFactoryT, ProxyTool
 from fastmcp.tools.base import ToolResult
 from fastmcp.utilities.tasks import TaskConfig
 from fastmcp_tasks import TasksExtension
@@ -90,6 +91,7 @@ class TestMountedToolTasks:
             assert created.status == "working"
             final = await wait_for_task(parent_server, created.task_id)
             assert final.status == "completed"
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == 72
 
     async def test_mounted_and_parent_tasks_both_work(self, parent_server):
@@ -102,7 +104,9 @@ class TestMountedToolTasks:
             )
             parent_final = await wait_for_task(parent_server, parent_created.task_id)
             child_final = await wait_for_task(parent_server, child_created.task_id)
+            assert parent_final.result is not None
             assert parent_final.result["structuredContent"]["result"] == 50
+            assert child_final.result is not None
             assert child_final.result["structuredContent"]["result"] == 6
 
     async def test_sync_only_mounted_tool_runs_synchronously(self, parent_server):
@@ -129,6 +133,7 @@ class TestMountedToolTasksNoPrefix:
                 parent,
                 (await submit_task(parent, "multiply", {"a": 5, "b": 6})).task_id,
             )
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == 30
 
 
@@ -137,7 +142,7 @@ class TestMountedTaskDependencies:
         child = FastMCP("dep-child")
 
         @child.tool(task=True)
-        async def tool_with_docket(docket: CurrentDocket = CurrentDocket()) -> str:  # type: ignore[assignment,valid-type]
+        async def tool_with_docket(docket: Docket = CurrentDocket()) -> str:
             return f"docket available: {docket is not None}"
 
         parent = FastMCP("dep-parent")
@@ -149,6 +154,7 @@ class TestMountedTaskDependencies:
                 parent,
                 (await submit_task(parent, "child_tool_with_docket", {})).task_id,
             )
+            assert final.result is not None
             assert "docket available: True" in final.result["content"][0]["text"]
 
 
@@ -157,7 +163,7 @@ class TestMountedTaskServerContext:
         child = FastMCP("child")
 
         @child.tool(task=True)
-        async def whoami(server: CurrentFastMCP = CurrentFastMCP()) -> str:  # type: ignore[assignment,valid-type]
+        async def whoami(server: FastMCP = CurrentFastMCP()) -> str:
             return f"server name: {server.name}"
 
         parent = FastMCP("parent")
@@ -168,6 +174,7 @@ class TestMountedTaskServerContext:
             final = await wait_for_task(
                 parent, (await submit_task(parent, "child_whoami", {})).task_id
             )
+            assert final.result is not None
             assert "server name: child" in final.result["content"][0]["text"]
 
     async def test_context_fastmcp_resolves_to_child_server(self):
@@ -185,6 +192,7 @@ class TestMountedTaskServerContext:
             final = await wait_for_task(
                 parent, (await submit_task(parent, "child_whoami_ctx", {})).task_id
             )
+            assert final.result is not None
             assert "context server: child" in final.result["content"][0]["text"]
 
 
@@ -217,7 +225,9 @@ class TestMultipleMounts:
                     await submit_task(parent, "math2_subtract", {"a": 10, "b": 5})
                 ).task_id,
             )
+            assert r1.result is not None
             assert r1.result["structuredContent"]["result"] == 15
+            assert r2.result is not None
             assert r2.result["structuredContent"]["result"] == 5
 
     async def test_same_function_names_do_not_collide(self):
@@ -246,7 +256,9 @@ class TestMultipleMounts:
                 parent,
                 (await submit_task(parent, "c2_process", {"value": 10})).task_id,
             )
+            assert r1.result is not None
             assert r1.result["structuredContent"]["result"] == 20
+            assert r2.result is not None
             assert r2.result["structuredContent"]["result"] == 30
 
     async def test_nested_mount_prefix_accumulation(self):
@@ -267,6 +279,7 @@ class TestMultipleMounts:
                 parent,
                 (await submit_task(parent, "child_gc_deep_tool", {})).task_id,
             )
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == "deep"
 
 
@@ -286,6 +299,8 @@ class TestMountedTaskMetadata:
 
         child_mcp = child_tool.to_mcp_tool(name=child_tool.name)
         parent_mcp = parent_tool.to_mcp_tool(name=parent_tool.name)
+        assert child_mcp.execution is not None
+        assert parent_mcp.execution is not None
         assert child_mcp.execution.task_support == "optional"
         assert parent_mcp.execution.task_support == "optional"
 
@@ -296,7 +311,7 @@ class TestMountedTaskMetadata:
             input_schema={"type": "object", "properties": {}},
             execution=ToolExecution(task_support="optional"),
         )
-        proxy = ProxyTool.from_mcp_tool(lambda: None, mcp_tool)  # type: ignore[arg-type]
+        proxy = ProxyTool.from_mcp_tool(cast(ClientFactoryT, lambda: None), mcp_tool)
         result = proxy.to_mcp_tool(name=proxy.name)
         assert result.execution is not None
         assert result.execution.task_support == "optional"
@@ -339,6 +354,7 @@ class TestMountedTaskConfigModes:
                     await submit_task(parent_with_modes, "child_optional_tool", {})
                 ).task_id,
             )
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == "optional result"
 
     async def test_required_mode_with_task_through_mount(self, parent_with_modes):
@@ -349,6 +365,7 @@ class TestMountedTaskConfigModes:
                     await submit_task(parent_with_modes, "child_required_tool", {})
                 ).task_id,
             )
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == "required result"
 
     async def test_required_mode_without_task_through_mount(self, parent_with_modes):
@@ -417,6 +434,7 @@ class TestMiddlewareWithMountedTasks:
         async with running_task_server(parent):
             created = await submit_task(parent, "c_gc_compute", {"x": 5})
             final = await wait_for_task(parent, created.task_id)
+            assert final.result is not None
             assert final.result["structuredContent"]["result"] == 10
 
         assert calls == ["parent:before", "parent:after", "grandchild:tool"]
diff --git a/tests/tasks/server/test_task_security.py b/tests/tasks/server/test_task_security.py
index 088f52153..f20ea606c 100644
--- a/tests/tasks/server/test_task_security.py
+++ b/tests/tasks/server/test_task_security.py
@@ -47,7 +47,9 @@ async def test_same_client_can_access_all_its_tasks(task_server: FastMCP):
         second = await run_task(
             task_server, "secret_tool", {"data": "second"}, access_token=token
         )
+        assert first.result is not None
         assert "first" in first.result["content"][0]["text"]
+        assert second.result is not None
         assert "second" in second.result["content"][0]["text"]
 
 
@@ -55,6 +57,7 @@ async def test_unauthenticated_client_can_access_its_tasks(task_server: FastMCP)
     """An anonymous caller can resolve tasks in the anonymous keyspace."""
     async with running_task_server(task_server):
         final = await run_task(task_server, "secret_tool", {"data": "hello"})
+        assert final.result is not None
         assert "hello" in final.result["content"][0]["text"]
 
 
diff --git a/tests/tasks/server/test_task_tools.py b/tests/tasks/server/test_task_tools.py
index 31aa1666f..2ffd0f192 100644
--- a/tests/tasks/server/test_task_tools.py
+++ b/tests/tasks/server/test_task_tools.py
@@ -84,6 +84,7 @@ async def test_task_tool_coerces_model_arguments():
         final = await run_task(mcp, "inspect_items", arguments)
 
     assert sync_result.structured_content == expected
+    assert final.result is not None
     assert final.result["structuredContent"] == expected
 
 
@@ -99,6 +100,7 @@ async def test_task_arguments_are_coerced_like_sync_path():
     async with running_task_server(mcp):
         final = await run_task(mcp, "square", {"n": "1"})
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": 1}
 
 
@@ -137,6 +139,7 @@ async def test_valid_argument_submits_under_strict_validation():
     async with running_task_server(mcp):
         final = await run_task(mcp, "square", {"n": 4})
     assert final.status == "completed"
+    assert final.result is not None
     assert final.result["structuredContent"] == {"result": 16}
 
 
@@ -202,6 +205,7 @@ async def test_tool_task_executes_in_background():
         finish.set()
         final = await wait_for_task(mcp, created.task_id)
         assert final.status == "completed"
+        assert final.result is not None
         assert final.result["structuredContent"] == {"result": "completed"}
 
 
diff --git a/tests/tasks/server/test_wire_models.py b/tests/tasks/server/test_wire_models.py
index b36486e97..76419e0fe 100644
--- a/tests/tasks/server/test_wire_models.py
+++ b/tests/tasks/server/test_wire_models.py
@@ -22,6 +22,7 @@ from fastmcp_tasks.models import (
     CancelTaskResult,
     CreateTaskResult,
     GetTaskResult,
+    TaskStatus,
     UpdateTaskResult,
 )
 from jsonschema import Draft202012Validator
@@ -72,10 +73,10 @@ def test_create_task_result_matches_schema():
         ("cancelled", {}),
     ],
 )
-def test_get_task_result_matches_schema(status: str, payload: dict[str, Any]):
+def test_get_task_result_matches_schema(status: TaskStatus, payload: dict[str, Any]):
     result = GetTaskResult(
         task_id="t1",
-        status=status,  # type: ignore[arg-type]
+        status=status,
         created_at=_ISO,
         last_updated_at=_ISO,
         ttl_ms=900000,
@@ -111,9 +112,7 @@ def test_null_ttl_is_permitted_by_schema():
     )
     dumped = result.model_dump(by_alias=True, mode="json", exclude_none=False)
     # Drop the other None optionals the runner would also drop, keeping ttlMs=null.
-    dumped = {
-        k: v for k, v in dumped.items() if v is not None or k == "ttlMs"
-    }
+    dumped = {k: v for k, v in dumped.items() if v is not None or k == "ttlMs"}
     _validate("CreateTaskResult", dumped)
 
 
diff --git a/tests/tasks/task_helpers.py b/tests/tasks/task_helpers.py
index 3f8563b12..405996ada 100644
--- a/tests/tasks/task_helpers.py
+++ b/tests/tasks/task_helpers.py
@@ -25,7 +25,7 @@ from __future__ import annotations
 import asyncio
 import contextlib
 from types import SimpleNamespace
-from typing import Any
+from typing import Any, cast
 
 from fastmcp_tasks.handlers import tasks_cancel, tasks_get, tasks_update
 from fastmcp_tasks.models import (
@@ -37,6 +37,7 @@ from fastmcp_tasks.models import (
 from mcp.server.auth.middleware.auth_context import auth_context_var
 from mcp.server.auth.middleware.bearer_auth import AuthenticatedUser
 from mcp.server.context import ServerRequestContext
+from mcp.server.session import ServerSession
 from mcp_types import CLIENT_CAPABILITIES_META_KEY
 
 from fastmcp.server.auth import AccessToken
@@ -91,7 +92,7 @@ def _opted_in_request(
         "_meta": opt_in_meta(settings),
     }
     srctx = ServerRequestContext(
-        session=SimpleNamespace(),
+        session=cast(ServerSession, SimpleNamespace()),
         lifespan_context={},
         protocol_version="2026-07-28",
         method="tools/call",
@@ -202,9 +203,7 @@ async def run_task(
     timeout: float = 5.0,
 ) -> GetTaskResult:
     """Submit a task and wait for it to reach a terminal state."""
-    created = await submit_task(
-        server, name, arguments, access_token=access_token
-    )
+    created = await submit_task(server, name, arguments, access_token=access_token)
     return await wait_for_task(
         server, created.task_id, access_token=access_token, timeout=timeout
     )