diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 33f81a9..1905002 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -41,7 +41,7 @@ repos:
     rev: v3.3.1
     hooks:
       - id: pyupgrade
-        args: [--py37-plus]
+        args: [--py39-plus, --keep-runtime-typing]
   - repo: https://github.com/PyCQA/isort
     rev: 5.11.4
     hooks:
diff --git a/pyproject.toml b/pyproject.toml
index 7c1154f..67f0ce6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -154,7 +154,7 @@ max-line-length-suggestions = 88
 runtime-typing = false
 
 [tool.pytest.ini_options]
-addopts = "-v -Wdefault --cov=aiortm --cov-report=term-missing:skip-covered"
+addopts = "-Wdefault --cov=aiortm --cov-report=term-missing:skip-covered"
 asyncio_mode = "auto"
 pythonpath = ["src"]
 
diff --git a/src/aiortm/client.py b/src/aiortm/client.py
index 92424d7..88b0888 100644
--- a/src/aiortm/client.py
+++ b/src/aiortm/client.py
@@ -97,6 +97,8 @@ async def call_api_auth(self, api_method: str, **params: Any) -> dict[str, Any]:
 
     async def call_api(self, api_method: str, **params: Any) -> dict[str, Any]:
         """Call an api method."""
+        # Remove empty values.
+        params = {key: value for key, value in params.items() if value is not None}
         all_params = {"method": api_method} | params | {"format": "json"}
         all_params |= {"api_sig": self._sign_request(all_params)}
         response = await self.request(REST_URL, params=all_params)
@@ -111,7 +113,10 @@ async def call_api(self, api_method: str, **params: Any) -> dict[str, Any]:
         response_text = await response.text()
 
         if "rtm.auth" not in api_method:
-            _LOGGER.debug("Response text: %s", response_text)
+            logged_response_text = response_text
+            if self.api_key in response_text:
+                logged_response_text = response_text.replace(self.api_key, "API_KEY")
+            _LOGGER.debug("Response text: %s", logged_response_text)
 
         # API doesn't return a JSON encoded response.
         # It's text/javascript mimetype but with a JSON string in the text.
diff --git a/src/aiortm/model/__init__.py b/src/aiortm/model/__init__.py
index e4e2144..0e4268a 100644
--- a/src/aiortm/model/__init__.py
+++ b/src/aiortm/model/__init__.py
@@ -3,6 +3,7 @@
 from typing import TYPE_CHECKING
 
 from .contacts import Contacts
+from .tasks import Tasks
 from .timelines import Timelines
 
 if TYPE_CHECKING:
@@ -15,9 +16,11 @@ class RTM:
 
     api: "Auth"
     contacts: "Contacts" = field(init=False)
+    tasks: "Tasks" = field(init=False)
     timelines: "Timelines" = field(init=False)
 
     def __post_init__(self) -> None:
         """Set up the instance."""
         self.contacts = Contacts(self.api)
+        self.tasks = Tasks(self.api)
         self.timelines = Timelines(self.api)
diff --git a/src/aiortm/model/tasks.py b/src/aiortm/model/tasks.py
new file mode 100644
index 0000000..1e3cb5a
--- /dev/null
+++ b/src/aiortm/model/tasks.py
@@ -0,0 +1,153 @@
+"""Provide a model for tasks."""
+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import datetime
+from typing import TYPE_CHECKING, Any, Literal, Optional
+
+from pydantic import BaseModel as PydanticBaseModel, Field, validator
+
+from .response import BaseResponse, TransactionResponse
+
+if TYPE_CHECKING:
+    from ..client import Auth
+
+# pylint: disable=consider-alternative-union-syntax
+
+
+class BaseModel(PydanticBaseModel):
+    """Represent a base model that turns empty string to None."""
+
+    @validator("*", pre=True)
+    def empty_str_to_none(cls, value: Any) -> Any:  # pylint: disable=no-self-argument
+        """Turn empty string to None."""
+        if value == "":
+            return None
+        return value
+
+
+class TaskResponse(BaseModel):
+    """Represent a response for a task."""
+
+    id: int
+    due: Optional[datetime]
+    has_due_time: bool
+    added: datetime
+    completed: Optional[datetime]
+    deleted: Optional[datetime]
+    priority: Literal["N", "1", "2", "3"]
+    postponed: bool
+    estimate: Optional[str]
+
+
+class TaskSeriesResponse(BaseModel):
+    """Represent a response for a task series."""
+
+    id: int
+    created: datetime
+    modified: datetime
+    name: str
+    source: str
+    location_id: Optional[str]
+    url: Optional[str]
+    tags: list[str]
+    participants: list[str]
+    notes: list[str]
+    task: list[TaskResponse]
+
+
+class TaskListResponse(BaseModel):
+    """Represent a response for a task list."""
+
+    id: int
+    taskseries: list[TaskSeriesResponse]
+    current: Optional[datetime]
+
+
+class RootTaskResponse(BaseModel):
+    """Represent a response for the root tasks object."""
+
+    rev: str
+    task_list: list[TaskListResponse] = Field(..., alias="list")
+
+    @validator("task_list", pre=True)
+    def ensure_taskseries(  # pylint: disable=no-self-argument
+        cls, value: list[dict[str, Any]]
+    ) -> list[dict[str, Any]]:
+        """Ensure that taskseries exist."""
+        for item in value:
+            if "taskseries" not in item:
+                item["taskseries"] = []
+        return value
+
+
+class TaskModifiedResponse(BaseResponse):
+    """Represent a response for a modified task."""
+
+    transaction: TransactionResponse
+    task_list: TaskListResponse = Field(..., alias="list")
+
+
+class TasksResponse(BaseResponse):
+    """Represent a response for a list of tasks."""
+
+    tasks: RootTaskResponse
+
+
+@dataclass
+class Tasks:
+    """Represent the tasks model."""
+
+    api: Auth
+
+    async def add(
+        self,
+        timeline: int,
+        name: str,
+        list_id: int | None = None,
+        parse: bool | None = None,
+    ) -> TaskModifiedResponse:
+        """Add a task."""
+        result = await self.api.call_api_auth(
+            "rtm.tasks.add", timeline=timeline, name=name, list_id=list_id, parse=parse
+        )
+        return TaskModifiedResponse(**result)
+
+    async def complete(
+        self, timeline: int, list_id: int, taskseries_id: int, task_id: int
+    ) -> TaskModifiedResponse:
+        """Complete a task."""
+        result = await self.api.call_api_auth(
+            "rtm.tasks.complete",
+            timeline=timeline,
+            list_id=list_id,
+            taskseries_id=taskseries_id,
+            task_id=task_id,
+        )
+        return TaskModifiedResponse(**result)
+
+    async def delete(
+        self, timeline: int, list_id: int, taskseries_id: int, task_id: int
+    ) -> TaskModifiedResponse:
+        """Delete a task."""
+        result = await self.api.call_api_auth(
+            "rtm.tasks.delete",
+            timeline=timeline,
+            list_id=list_id,
+            taskseries_id=taskseries_id,
+            task_id=task_id,
+        )
+        return TaskModifiedResponse(**result)
+
+    async def get_list(
+        self, list_id: int | None = None, last_sync: datetime | None = None
+    ) -> TasksResponse:
+        """Get a list of tasks."""
+        last_sync_string: str | None = None
+        if last_sync is not None:
+            last_sync_string = last_sync.isoformat()
+
+        result = await self.api.call_api_auth(
+            "rtm.tasks.getList", list_id=list_id, last_sync=last_sync_string
+        )
+        return TasksResponse(**result)
diff --git a/tests/fixtures/tasks/add.json b/tests/fixtures/tasks/add.json
new file mode 100644
index 0000000..d9a166e
--- /dev/null
+++ b/tests/fixtures/tasks/add.json
@@ -0,0 +1,36 @@
+{
+  "rsp": {
+    "stat": "ok",
+    "transaction": { "id": "12451745176", "undoable": "0" },
+    "list": {
+      "id": "48730705",
+      "taskseries": [
+        {
+          "id": "493137362",
+          "created": "2023-01-02T01:55:25Z",
+          "modified": "2023-01-02T01:55:25Z",
+          "name": "Test task",
+          "source": "api:test-api-key",
+          "url": "",
+          "location_id": "",
+          "tags": [],
+          "participants": [],
+          "notes": [],
+          "task": [
+            {
+              "id": "924832826",
+              "due": "",
+              "has_due_time": "0",
+              "added": "2023-01-02T01:55:25Z",
+              "completed": "",
+              "deleted": "",
+              "priority": "N",
+              "postponed": "0",
+              "estimate": ""
+            }
+          ]
+        }
+      ]
+    }
+  }
+}
diff --git a/tests/fixtures/tasks/complete.json b/tests/fixtures/tasks/complete.json
new file mode 100644
index 0000000..75be80a
--- /dev/null
+++ b/tests/fixtures/tasks/complete.json
@@ -0,0 +1,36 @@
+{
+  "rsp": {
+    "stat": "ok",
+    "transaction": { "id": "12475899884", "undoable": "1" },
+    "list": {
+      "id": "48730705",
+      "taskseries": [
+        {
+          "id": "493137362",
+          "created": "2023-01-02T01:55:25Z",
+          "modified": "2023-01-05T00:04:52Z",
+          "name": "Test task",
+          "source": "api:test-api-key",
+          "url": "",
+          "location_id": "",
+          "tags": [],
+          "participants": [],
+          "notes": [],
+          "task": [
+            {
+              "id": "924832826",
+              "due": "",
+              "has_due_time": "0",
+              "added": "2023-01-02T01:55:25Z",
+              "completed": "2023-01-05T00:04:52Z",
+              "deleted": "",
+              "priority": "N",
+              "postponed": "0",
+              "estimate": ""
+            }
+          ]
+        }
+      ]
+    }
+  }
+}
diff --git a/tests/fixtures/tasks/delete.json b/tests/fixtures/tasks/delete.json
new file mode 100644
index 0000000..00efd1f
--- /dev/null
+++ b/tests/fixtures/tasks/delete.json
@@ -0,0 +1,36 @@
+{
+  "rsp": {
+    "stat": "ok",
+    "transaction": { "id": "12476056249", "undoable": "1" },
+    "list": {
+      "id": "48730705",
+      "taskseries": [
+        {
+          "id": "493137362",
+          "created": "2023-01-02T01:55:25Z",
+          "modified": "2023-01-05T00:34:45Z",
+          "name": "Test task",
+          "source": "api:test-api-key",
+          "url": "",
+          "location_id": "",
+          "tags": [],
+          "participants": [],
+          "notes": [],
+          "task": [
+            {
+              "id": "924832826",
+              "due": "",
+              "has_due_time": "0",
+              "added": "2023-01-02T01:55:25Z",
+              "completed": "2023-01-05T00:04:52Z",
+              "deleted": "2023-01-05T00:34:45Z",
+              "priority": "N",
+              "postponed": "0",
+              "estimate": ""
+            }
+          ]
+        }
+      ]
+    }
+  }
+}
diff --git a/tests/fixtures/tasks/get_list.json b/tests/fixtures/tasks/get_list.json
index 00eb7a5..62db371 100644
--- a/tests/fixtures/tasks/get_list.json
+++ b/tests/fixtures/tasks/get_list.json
@@ -7,6 +7,31 @@
         {
           "id": "48730705",
           "taskseries": [
+            {
+              "id": "493137362",
+              "created": "2023-01-02T01:55:25Z",
+              "modified": "2023-01-02T01:55:25Z",
+              "name": "Test task",
+              "source": "api:test-api-key",
+              "url": "",
+              "location_id": "",
+              "tags": [],
+              "participants": [],
+              "notes": [],
+              "task": [
+                {
+                  "id": "924832826",
+                  "due": "",
+                  "has_due_time": "0",
+                  "added": "2023-01-02T01:55:25Z",
+                  "completed": "",
+                  "deleted": "",
+                  "priority": "N",
+                  "postponed": "0",
+                  "estimate": ""
+                }
+              ]
+            },
             {
               "id": "475830808",
               "created": "2022-05-18T14:27:08Z",
diff --git a/tests/fixtures/tasks/get_list_last_sync.json b/tests/fixtures/tasks/get_list_last_sync.json
new file mode 100644
index 0000000..9bb68c8
--- /dev/null
+++ b/tests/fixtures/tasks/get_list_last_sync.json
@@ -0,0 +1,69 @@
+{
+  "rsp": {
+    "stat": "ok",
+    "tasks": {
+      "rev": "828de7te6o7skrgkhnd0jxkwi9e8orv",
+      "list": [
+        {
+          "id": "48730705",
+          "current": "2022-05-18T14:27:08Z",
+          "taskseries": [
+            {
+              "id": "493137362",
+              "created": "2023-01-02T01:55:25Z",
+              "modified": "2023-01-02T01:55:25Z",
+              "name": "Test task",
+              "source": "api:test-api-key",
+              "url": "",
+              "location_id": "",
+              "tags": [],
+              "participants": [],
+              "notes": [],
+              "task": [
+                {
+                  "id": "924832826",
+                  "due": "",
+                  "has_due_time": "0",
+                  "added": "2023-01-02T01:55:25Z",
+                  "completed": "",
+                  "deleted": "",
+                  "priority": "N",
+                  "postponed": "0",
+                  "estimate": ""
+                }
+              ]
+            },
+            {
+              "id": "475830808",
+              "created": "2022-05-18T14:27:08Z",
+              "modified": "2022-05-18T14:27:55Z",
+              "name": "Register for RTM",
+              "source": "js",
+              "url": "",
+              "location_id": "",
+              "tags": [],
+              "participants": [],
+              "notes": [],
+              "task": [
+                {
+                  "id": "878061281",
+                  "due": "",
+                  "has_due_time": "0",
+                  "added": "2022-05-18T14:27:08Z",
+                  "completed": "2022-05-18T14:27:55Z",
+                  "deleted": "",
+                  "priority": "N",
+                  "postponed": "0",
+                  "estimate": ""
+                }
+              ]
+            }
+          ]
+        },
+        { "id": "48730706", "current": "2022-05-18T14:27:08Z" },
+        { "id": "48730707", "current": "2022-05-18T14:27:08Z" },
+        { "id": "48730708", "current": "2022-05-18T14:27:08Z" }
+      ]
+    }
+  }
+}
diff --git a/tests/model/test_tasks.py b/tests/model/test_tasks.py
new file mode 100644
index 0000000..89766a2
--- /dev/null
+++ b/tests/model/test_tasks.py
@@ -0,0 +1,213 @@
+"""Test the tasks model."""
+from __future__ import annotations
+
+from collections.abc import Callable
+from datetime import datetime
+from typing import Any
+
+from aioresponses import aioresponses
+import pytest
+
+from aiortm.client import AioRTMClient
+
+from ..util import load_fixture
+
+
+@pytest.fixture(name="tasks_add", scope="session")
+def tasks_add_fixture() -> str:
+    """Return a response for rtm.tasks.getList."""
+    return load_fixture("tasks/add.json")
+
+
+@pytest.fixture(name="response")
+def response_fixture(request: pytest.FixtureRequest) -> str:
+    """Return a response for the rtm api."""
+    return load_fixture(request.param)
+
+
+async def test_tasks_add(
+    client: AioRTMClient,
+    mock_response: aioresponses,
+    tasks_add: str,
+    timelines_create: str,
+    generate_url: Callable[..., str],
+) -> None:
+    """Test tasks add."""
+    mock_response.get(
+        generate_url(
+            api_key="test-api-key",
+            auth_token="test-token",
+            method="rtm.timelines.create",
+        ),
+        body=timelines_create,
+    )
+    mock_response.get(
+        generate_url(
+            api_key="test-api-key",
+            auth_token="test-token",
+            method="rtm.tasks.add",
+            timeline=1234567890,
+            name="Test task",
+        ),
+        body=tasks_add,
+    )
+
+    timeline_response = await client.rtm.timelines.create()
+    timeline = timeline_response.timeline
+    result = await client.rtm.tasks.add(timeline=timeline, name="Test task")
+
+    assert result.stat == "ok"
+    assert result.transaction.id == 12451745176
+    assert result.transaction.undoable == 0
+    assert result.task_list.id == 48730705
+    assert result.task_list.taskseries[0].id == 493137362
+    assert result.task_list.taskseries[0].created == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+    assert result.task_list.taskseries[0].modified == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+    assert result.task_list.taskseries[0].name == "Test task"
+    assert result.task_list.taskseries[0].source == "api:test-api-key"
+    assert result.task_list.taskseries[0].task[0].id == 924832826
+    assert result.task_list.taskseries[0].task[0].added == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+
+
+@pytest.mark.parametrize(
+    "method, transaction, modified, deleted, response",
+    [
+        (
+            "complete",
+            12475899884,
+            datetime.fromisoformat("2023-01-05T00:04:52+00:00"),
+            None,
+            "tasks/complete.json",
+        ),
+        (
+            "delete",
+            12476056249,
+            datetime.fromisoformat("2023-01-05T00:34:45+00:00"),
+            datetime.fromisoformat("2023-01-05T00:34:45+00:00"),
+            "tasks/delete.json",
+        ),
+    ],
+    indirect=["response"],
+)
+async def test_tasks_complete_delete(
+    client: AioRTMClient,
+    mock_response: aioresponses,
+    timelines_create: str,
+    generate_url: Callable[..., str],
+    method: str,
+    transaction: int,
+    modified: datetime,
+    deleted: datetime | None,
+    response: str,
+) -> None:
+    """Test tasks complete and delete."""
+    # pylint: disable=too-many-arguments
+    mock_response.get(
+        generate_url(
+            api_key="test-api-key",
+            auth_token="test-token",
+            method="rtm.timelines.create",
+        ),
+        body=timelines_create,
+    )
+    mock_response.get(
+        generate_url(
+            api_key="test-api-key",
+            auth_token="test-token",
+            method=f"rtm.tasks.{method}",
+            timeline=1234567890,
+            list_id=48730705,
+            taskseries_id=493137362,
+            task_id=924832826,
+        ),
+        body=response,
+    )
+
+    timeline_response = await client.rtm.timelines.create()
+    timeline = timeline_response.timeline
+    method_object = getattr(client.rtm.tasks, method)
+    result = await method_object(
+        timeline=timeline, list_id=48730705, taskseries_id=493137362, task_id=924832826
+    )
+
+    assert result.stat == "ok"
+    assert result.transaction.id == transaction
+    assert result.transaction.undoable == 1
+    assert result.task_list.id == 48730705
+    assert result.task_list.taskseries[0].id == 493137362
+    assert result.task_list.taskseries[0].created == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+    assert result.task_list.taskseries[0].modified == modified
+    assert result.task_list.taskseries[0].name == "Test task"
+    assert result.task_list.taskseries[0].source == "api:test-api-key"
+    assert result.task_list.taskseries[0].task[0].id == 924832826
+    assert result.task_list.taskseries[0].task[0].completed == datetime.fromisoformat(
+        "2023-01-05T00:04:52+00:00"
+    )
+    assert result.task_list.taskseries[0].task[0].deleted == deleted
+
+
+@pytest.mark.parametrize(
+    "response, response_params, method_params, current",
+    [
+        (
+            "tasks/get_list.json",
+            {},
+            {},
+            None,
+        ),
+        (
+            "tasks/get_list_last_sync.json",
+            {"last_sync": "2022-05-18T14:27:08+00:00"},
+            {"last_sync": datetime.fromisoformat("2022-05-18T14:27:08+00:00")},
+            datetime.fromisoformat("2022-05-18T14:27:08+00:00"),
+        ),
+    ],
+    indirect=["response"],
+)
+async def test_tasks_get_list(
+    client: AioRTMClient,
+    mock_response: aioresponses,
+    generate_url: Callable[..., str],
+    response: str,
+    response_params: dict[str, Any],
+    method_params: dict[str, Any],
+    current: datetime | None,
+) -> None:
+    """Test tasks get list."""
+    mock_response.get(
+        generate_url(
+            api_key="test-api-key",
+            auth_token="test-token",
+            method="rtm.tasks.getList",
+            **response_params,
+        ),
+        body=response,
+    )
+
+    result = await client.rtm.tasks.get_list(**method_params)
+
+    assert result.stat == "ok"
+    assert result.tasks.rev
+    assert result.tasks.task_list[0].id == 48730705
+    assert result.tasks.task_list[0].current == current
+    assert result.tasks.task_list[0].taskseries[0].id == 493137362
+    assert result.tasks.task_list[0].taskseries[0].created == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+    assert result.tasks.task_list[0].taskseries[0].modified == datetime.fromisoformat(
+        "2023-01-02T01:55:25+00:00"
+    )
+    assert result.tasks.task_list[0].taskseries[0].name == "Test task"
+    assert result.tasks.task_list[0].taskseries[0].source == "api:test-api-key"
+    assert result.tasks.task_list[0].taskseries[0].task[0].id == 924832826
+    assert result.tasks.task_list[0].taskseries[0].task[
+        0
+    ].added == datetime.fromisoformat("2023-01-02T01:55:25+00:00")