diff --git a/selfprivacy_api/graphql/common_types/service.py b/selfprivacy_api/graphql/common_types/service.py
index 275c14c..fb6c972 100644
--- a/selfprivacy_api/graphql/common_types/service.py
+++ b/selfprivacy_api/graphql/common_types/service.py
@@ -103,6 +103,69 @@ def service_dns_to_graphql(record: ServiceDnsRecord) -> DnsRecord:
     )
 
 
+@strawberry.interface
+class ConfigItem:
+    field_id: str
+    description: str
+    widget: str
+    type: str
+
+
+@strawberry.type
+class StringConfigItem(ConfigItem):
+    value: str
+    default_value: str
+    regex: Optional[str]
+
+
+@strawberry.type
+class BoolConfigItem(ConfigItem):
+    value: bool
+    default_value: bool
+
+
+@strawberry.type
+class EnumConfigItem(ConfigItem):
+    value: str
+    default_value: str
+    options: list[str]
+
+
+def config_item_to_graphql(item: dict) -> ConfigItem:
+    item_type = item.get("type")
+    if item_type == "string":
+        return StringConfigItem(
+            field_id=item["id"],
+            description=item["description"],
+            widget=item["widget"],
+            type=item_type,
+            value=item["value"],
+            default_value=item["default_value"],
+            regex=item.get("regex"),
+        )
+    elif item_type == "bool":
+        return BoolConfigItem(
+            field_id=item["id"],
+            description=item["description"],
+            widget=item["widget"],
+            type=item_type,
+            value=item["value"],
+            default_value=item["default_value"],
+        )
+    elif item_type == "enum":
+        return EnumConfigItem(
+            field_id=item["id"],
+            description=item["description"],
+            widget=item["widget"],
+            type=item_type,
+            value=item["value"],
+            default_value=item["default_value"],
+            options=item["options"],
+        )
+    else:
+        raise ValueError(f"Unknown config item type {item_type}")
+
+
 @strawberry.type
 class Service:
     id: str
@@ -112,6 +175,7 @@ class Service:
     is_movable: bool
     is_required: bool
     is_enabled: bool
+    is_installed: bool
     can_be_backed_up: bool
     backup_description: str
     status: ServiceStatusEnum
@@ -132,6 +196,19 @@ class Service:
         """Get storage usage for a service"""
         return get_storage_usage(self)
 
+    @strawberry.field
+    def configuration(self) -> Optional[List[ConfigItem]]:
+        """Get service configuration"""
+        service = get_service_by_id(self.id)
+        if service is None:
+            return None
+        config_items = service.get_configuration()
+        # If it is an empty dict, return none
+        if not config_items:
+            return None
+        # By the "type" field convert every dict into a ConfigItem. In the future there will be more types.
+        return [config_item_to_graphql(config_items[item]) for item in config_items]
+
     # TODO: fill this
     @strawberry.field
     def backup_snapshots(self) -> Optional[List["SnapshotInfo"]]:
@@ -156,6 +233,7 @@ def service_to_graphql_service(service: ServiceInterface) -> Service:
         is_movable=service.is_movable(),
         is_required=service.is_required(),
         is_enabled=service.is_enabled(),
+        is_installed=service.is_installed(),
         can_be_backed_up=service.can_be_backed_up(),
         backup_description=service.get_backup_description(),
         status=ServiceStatusEnum(service.get_status().value),
diff --git a/selfprivacy_api/graphql/mutations/services_mutations.py b/selfprivacy_api/graphql/mutations/services_mutations.py
index be0cb77..34f9539 100644
--- a/selfprivacy_api/graphql/mutations/services_mutations.py
+++ b/selfprivacy_api/graphql/mutations/services_mutations.py
@@ -33,6 +33,51 @@ class ServiceMutationReturn(GenericMutationReturn):
     service: typing.Optional[Service] = None
 
 
+@strawberry.input
+class SetServiceConfigurationInput:
+    """Set service configuration input type.
+    The values might be of different types: str or bool.
+    """
+
+    service_id: str
+    configuration: strawberry.scalars.JSON
+    """Yes, it is a JSON scalar, which is supposed to be a Map<str, Union[str, int, bool]>.
+    I can't define it as a proper type because GraphQL doesn't support unions in input types.
+    There is a @oneOf directive, but it doesn't fit this usecase.
+
+    Other option would have been doing something like this:
+    ```python
+    @strawberry.type
+    class StringConfigurationInputField:
+        fieldId: str
+        value: str
+
+    @strawberry.type
+    class BoolConfigurationInputField:
+        fieldId: str
+        value: bool
+
+    // ...
+
+    @strawberry.input
+    class SetServiceConfigurationInput:
+        service_id: str
+        stringFields: List[StringConfigurationInputField]
+        boolFields: List[BoolConfigurationInputField]
+        enumFields: List[EnumConfigurationInputField]
+        intFields: List[IntConfigurationInputField]
+    ```
+
+    But it would be very painful to maintain and will break compatibility with
+    every change.
+
+    Be careful when parsing it. Probably it will be wise to add a parser/validator
+    later when we get a new Pydantic integration in Strawberry.
+
+    -- Inex, 26.07.2024
+    """
+
+
 @strawberry.input
 class MoveServiceInput:
     """Move service input type."""
@@ -157,6 +202,41 @@ class ServicesMutations:
             service=service_to_graphql_service(service),
         )
 
+    @strawberry.mutation(permission_classes=[IsAuthenticated])
+    def set_service_configuration(
+        self, input: SetServiceConfigurationInput
+    ) -> ServiceMutationReturn:
+        """Set the new configuration values"""
+        service = get_service_by_id(input.service_id)
+        if service is None:
+            return ServiceMutationReturn(
+                success=False,
+                message=f"Service does not exist: {input.service_id}",
+                code=404,
+            )
+        try:
+            service.set_configuration(input.configuration)
+            return ServiceMutationReturn(
+                success=True,
+                message="Service configuration updated.",
+                code=200,
+                service=service_to_graphql_service(service),
+            )
+        except ValueError as e:
+            return ServiceMutationReturn(
+                success=False,
+                message=e.args[0],
+                code=400,
+                service=service_to_graphql_service(service),
+            )
+        except Exception as e:
+            return ServiceMutationReturn(
+                success=False,
+                message=pretty_error(e),
+                code=400,
+                service=service_to_graphql_service(service),
+            )
+
     @strawberry.mutation(permission_classes=[IsAuthenticated])
     def move_service(self, input: MoveServiceInput) -> ServiceJobMutationReturn:
         """Move service."""
diff --git a/selfprivacy_api/graphql/schema.py b/selfprivacy_api/graphql/schema.py
index b5e6765..761bd24 100644
--- a/selfprivacy_api/graphql/schema.py
+++ b/selfprivacy_api/graphql/schema.py
@@ -38,6 +38,12 @@ from selfprivacy_api.graphql.subscriptions.jobs import (
 )
 from selfprivacy_api.graphql.subscriptions.logs import log_stream
 
+from selfprivacy_api.graphql.common_types.service import (
+    StringConfigItem,
+    BoolConfigItem,
+    EnumConfigItem,
+)
+
 from selfprivacy_api.graphql.mutations.users_mutations import UsersMutations
 from selfprivacy_api.graphql.queries.users import Users
 from selfprivacy_api.jobs.test import test_job
@@ -190,4 +196,9 @@ schema = strawberry.Schema(
     query=Query,
     mutation=Mutation,
     subscription=Subscription,
+    types=[
+        StringConfigItem,
+        BoolConfigItem,
+        EnumConfigItem,
+    ],
 )
diff --git a/selfprivacy_api/migrations/add_roundcube.py b/selfprivacy_api/migrations/add_roundcube.py
index 3c422c2..68505ea 100644
--- a/selfprivacy_api/migrations/add_roundcube.py
+++ b/selfprivacy_api/migrations/add_roundcube.py
@@ -17,9 +17,6 @@ class AddRoundcube(Migration):
         with FlakeServiceManager() as manager:
             if "roundcube" not in manager.services:
                 return True
-        with ReadUserData() as data:
-            if "roundcube" not in data["modules"]:
-                return True
         return False
 
     def migrate(self) -> None:
@@ -28,9 +25,3 @@ class AddRoundcube(Migration):
                 manager.services[
                     "roundcube"
                 ] = "git+https://git.selfprivacy.org/SelfPrivacy/selfprivacy-nixos-config.git?ref=flakes&dir=sp-modules/roundcube"
-        with WriteUserData() as data:
-            if "roundcube" not in data["modules"]:
-                data["modules"]["roundcube"] = {
-                    "enable": False,
-                    "subdomain": "roundcube",
-                }
diff --git a/selfprivacy_api/services/bitwarden/__init__.py b/selfprivacy_api/services/bitwarden/__init__.py
index 56ee6e5..4614c15 100644
--- a/selfprivacy_api/services/bitwarden/__init__.py
+++ b/selfprivacy_api/services/bitwarden/__init__.py
@@ -1,18 +1,47 @@
 """Class representing Bitwarden service"""
 import base64
 import subprocess
-from typing import Optional, List
-
-from selfprivacy_api.utils import get_domain
+from typing import List
 
 from selfprivacy_api.utils.systemd import get_service_status
 from selfprivacy_api.services.service import Service, ServiceStatus
 from selfprivacy_api.services.bitwarden.icon import BITWARDEN_ICON
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    BoolServiceConfigItem,
+    ServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
 
 
 class Bitwarden(Service):
     """Class representing Bitwarden service."""
 
+    config_items: dict[str, ServiceConfigItem] = {
+        "subdomain": StringServiceConfigItem(
+            id="subdomain",
+            default_value="password",
+            description="Subdomain",
+            regex=SUBDOMAIN_REGEX,
+            widget="subdomain",
+        ),
+        "signupsAllowed": BoolServiceConfigItem(
+            id="signupsAllowed",
+            default_value=True,
+            description="Allow new user signups",
+        ),
+        "sendsAllowed": BoolServiceConfigItem(
+            id="sendsAllowed",
+            default_value=True,
+            description="Allow users to use Bitwarden Send",
+        ),
+        "emergencyAccessAllowed": BoolServiceConfigItem(
+            id="emergencyAccessAllowed",
+            default_value=True,
+            description="Allow users to enable Emergency Access",
+        ),
+    }
+
     @staticmethod
     def get_id() -> str:
         """Return service id."""
@@ -37,16 +66,6 @@ class Bitwarden(Service):
     def get_user() -> str:
         return "vaultwarden"
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        return f"https://password.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        return "password"
-
     @staticmethod
     def is_movable() -> bool:
         return True
@@ -84,14 +103,6 @@ class Bitwarden(Service):
     def restart():
         subprocess.run(["systemctl", "restart", "vaultwarden.service"])
 
-    @staticmethod
-    def get_configuration():
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         return ""
diff --git a/selfprivacy_api/services/config_item.py b/selfprivacy_api/services/config_item.py
new file mode 100644
index 0000000..eba557a
--- /dev/null
+++ b/selfprivacy_api/services/config_item.py
@@ -0,0 +1,245 @@
+from abc import ABC, abstractmethod
+import re
+from typing import Optional
+
+from selfprivacy_api.utils import (
+    ReadUserData,
+    WriteUserData,
+    check_if_subdomain_is_taken,
+)
+
+
+class ServiceConfigItem(ABC):
+    id: str
+    description: str
+    widget: str
+    type: str
+
+    @abstractmethod
+    def get_value(self, service_id):
+        pass
+
+    @abstractmethod
+    def set_value(self, value, service_id):
+        pass
+
+    @abstractmethod
+    def validate_value(self, value):
+        return True
+
+    def as_dict(self, service_options):
+        return {
+            "id": self.id,
+            "type": self.type,
+            "description": self.description,
+            "widget": self.widget,
+            "value": self.get_value(service_options),
+        }
+
+
+class StringServiceConfigItem(ServiceConfigItem):
+    def __init__(
+        self,
+        id: str,
+        default_value: str,
+        description: str,
+        regex: Optional[str] = None,
+        widget: Optional[str] = None,
+        allow_empty: bool = False,
+    ):
+        if widget == "subdomain" and not regex:
+            raise ValueError("Subdomain widget requires regex")
+        self.id = id
+        self.type = "string"
+        self.default_value = default_value
+        self.description = description
+        self.regex = re.compile(regex) if regex else None
+        self.widget = widget if widget else "text"
+        self.allow_empty = allow_empty
+
+    def get_value(self, service_id):
+        with ReadUserData() as user_data:
+            if "modules" in user_data and service_id in user_data["modules"]:
+                return user_data["modules"][service_id].get(self.id, self.default_value)
+            return self.default_value
+
+    def set_value(self, value, service_id):
+        if not self.validate_value(value):
+            raise ValueError(f"Value {value} is not valid")
+        with WriteUserData() as user_data:
+            if "modules" not in user_data:
+                user_data["modules"] = {}
+            if service_id not in user_data["modules"]:
+                user_data["modules"][service_id] = {}
+            user_data["modules"][service_id][self.id] = value
+
+    def as_dict(self, service_options):
+        return {
+            "id": self.id,
+            "type": self.type,
+            "description": self.description,
+            "widget": self.widget,
+            "value": self.get_value(service_options),
+            "default_value": self.default_value,
+            "regex": self.regex.pattern if self.regex else None,
+        }
+
+    def validate_value(self, value):
+        if not isinstance(value, str):
+            return False
+        if not self.allow_empty and not value:
+            return False
+        if self.regex and not self.regex.match(value):
+            return False
+        if self.widget == "subdomain":
+            if check_if_subdomain_is_taken(value):
+                return False
+        return True
+
+
+class BoolServiceConfigItem(ServiceConfigItem):
+    def __init__(
+        self,
+        id: str,
+        default_value: bool,
+        description: str,
+        widget: Optional[str] = None,
+    ):
+        self.id = id
+        self.type = "bool"
+        self.default_value = default_value
+        self.description = description
+        self.widget = widget if widget else "switch"
+
+    def get_value(self, service_id):
+        with ReadUserData() as user_data:
+            if "modules" in user_data and service_id in user_data["modules"]:
+                return user_data["modules"][service_id].get(self.id, self.default_value)
+            return self.default_value
+
+    def set_value(self, value, service_id):
+        if not self.validate_value(value):
+            raise ValueError(f"Value {value} is not a boolean")
+        with WriteUserData() as user_data:
+            if "modules" not in user_data:
+                user_data["modules"] = {}
+            if service_id not in user_data["modules"]:
+                user_data["modules"][service_id] = {}
+            user_data["modules"][service_id][self.id] = value
+
+    def as_dict(self, service_options):
+        return {
+            "id": self.id,
+            "type": self.type,
+            "description": self.description,
+            "widget": self.widget,
+            "value": self.get_value(service_options),
+            "default_value": self.default_value,
+        }
+
+    def validate_value(self, value):
+        return isinstance(value, bool)
+
+
+class EnumServiceConfigItem(ServiceConfigItem):
+    def __init__(
+        self,
+        id: str,
+        default_value: str,
+        description: str,
+        options: list[str],
+        widget: Optional[str] = None,
+    ):
+        self.id = id
+        self.type = "enum"
+        self.default_value = default_value
+        self.description = description
+        self.options = options
+        self.widget = widget if widget else "select"
+
+    def get_value(self, service_id):
+        with ReadUserData() as user_data:
+            if "modules" in user_data and service_id in user_data["modules"]:
+                return user_data["modules"][service_id].get(self.id, self.default_value)
+            return self.default_value
+
+    def set_value(self, value, service_id):
+        if not self.validate_value(value):
+            raise ValueError(f"Value {value} is not in options")
+        with WriteUserData() as user_data:
+            if "modules" not in user_data:
+                user_data["modules"] = {}
+            if service_id not in user_data["modules"]:
+                user_data["modules"][service_id] = {}
+            user_data["modules"][service_id][self.id] = value
+
+    def as_dict(self, service_options):
+        return {
+            "id": self.id,
+            "type": self.type,
+            "description": self.description,
+            "widget": self.widget,
+            "value": self.get_value(service_options),
+            "default_value": self.default_value,
+            "options": self.options,
+        }
+
+    def validate_value(self, value):
+        if not isinstance(value, str):
+            return False
+        return value in self.options
+
+
+# TODO: unused for now
+class IntServiceConfigItem(ServiceConfigItem):
+    def __init__(
+        self,
+        id: str,
+        default_value: int,
+        description: str,
+        widget: Optional[str] = None,
+        min_value: Optional[int] = None,
+        max_value: Optional[int] = None,
+    ) -> None:
+        self.id = id
+        self.type = "int"
+        self.default_value = default_value
+        self.description = description
+        self.widget = widget if widget else "number"
+        self.min_value = min_value
+        self.max_value = max_value
+
+    def get_value(self, service_id):
+        with ReadUserData() as user_data:
+            if "modules" in user_data and service_id in user_data["modules"]:
+                return user_data["modules"][service_id].get(self.id, self.default_value)
+            return self.default_value
+
+    def set_value(self, value, service_id):
+        if not self.validate_value(value):
+            raise ValueError(f"Value {value} is not valid")
+        with WriteUserData() as user_data:
+            if "modules" not in user_data:
+                user_data["modules"] = {}
+            if service_id not in user_data["modules"]:
+                user_data["modules"][service_id] = {}
+            user_data["modules"][service_id][self.id] = value
+
+    def as_dict(self, service_options):
+        return {
+            "id": self.id,
+            "type": self.type,
+            "description": self.description,
+            "widget": self.widget,
+            "value": self.get_value(service_options),
+            "default_value": self.default_value,
+            "min_value": self.min_value,
+            "max_value": self.max_value,
+        }
+
+    def validate_value(self, value):
+        if not isinstance(value, int):
+            return False
+        return (self.min_value is None or value >= self.min_value) and (
+            self.max_value is None or value <= self.max_value
+        )
diff --git a/selfprivacy_api/services/forgejo/__init__.py b/selfprivacy_api/services/forgejo/__init__.py
index 06cf614..a5b07b0 100644
--- a/selfprivacy_api/services/forgejo/__init__.py
+++ b/selfprivacy_api/services/forgejo/__init__.py
@@ -1,13 +1,20 @@
 """Class representing Bitwarden service"""
 import base64
 import subprocess
-from typing import Optional, List
+from typing import List
 
-from selfprivacy_api.utils import get_domain
+from selfprivacy_api.utils import ReadUserData, WriteUserData
 
 from selfprivacy_api.utils.systemd import get_service_status
 from selfprivacy_api.services.service import Service, ServiceStatus
 from selfprivacy_api.services.forgejo.icon import FORGEJO_ICON
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    BoolServiceConfigItem,
+    EnumServiceConfigItem,
+    ServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
 
 
 class Forgejo(Service):
@@ -16,6 +23,54 @@ class Forgejo(Service):
     Previously was Gitea, so some IDs are still called gitea for compatibility.
     """
 
+    config_items: dict[str, ServiceConfigItem] = {
+        "subdomain": StringServiceConfigItem(
+            id="subdomain",
+            default_value="git",
+            description="Subdomain",
+            regex=SUBDOMAIN_REGEX,
+            widget="subdomain",
+        ),
+        "appName": StringServiceConfigItem(
+            id="appName",
+            default_value="SelfPrivacy git Service",
+            description="The name displayed in the web interface",
+        ),
+        "enableLfs": BoolServiceConfigItem(
+            id="enableLfs",
+            default_value=True,
+            description="Enable Git LFS",
+        ),
+        "forcePrivate": BoolServiceConfigItem(
+            id="forcePrivate",
+            default_value=False,
+            description="Force all new repositories to be private",
+        ),
+        "disableRegistration": BoolServiceConfigItem(
+            id="disableRegistration",
+            default_value=False,
+            description="Disable registration of new users",
+        ),
+        "requireSigninView": BoolServiceConfigItem(
+            id="requireSigninView",
+            default_value=False,
+            description="Force users to log in to view any page",
+        ),
+        "defaultTheme": EnumServiceConfigItem(
+            id="defaultTheme",
+            default_value="forgejo-auto",
+            description="Default theme",
+            options=[
+                "forgejo-auto",
+                "forgejo-light",
+                "forgejo-dark",
+                "auto",
+                "gitea",
+                "arc-green",
+            ],
+        ),
+    }
+
     @staticmethod
     def get_id() -> str:
         """Return service id. For compatibility keep in gitea."""
@@ -36,16 +91,6 @@ class Forgejo(Service):
         """Read SVG icon from file and return it as base64 encoded string."""
         return base64.b64encode(FORGEJO_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        return f"https://git.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        return "git"
-
     @staticmethod
     def is_movable() -> bool:
         return True
@@ -82,14 +127,6 @@ class Forgejo(Service):
     def restart():
         subprocess.run(["systemctl", "restart", "forgejo.service"])
 
-    @staticmethod
-    def get_configuration():
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         return ""
diff --git a/selfprivacy_api/services/jitsimeet/__init__.py b/selfprivacy_api/services/jitsimeet/__init__.py
index 27a497a..0bf0370 100644
--- a/selfprivacy_api/services/jitsimeet/__init__.py
+++ b/selfprivacy_api/services/jitsimeet/__init__.py
@@ -1,21 +1,40 @@
 """Class representing Jitsi Meet service"""
 import base64
 import subprocess
-from typing import Optional, List
+from typing import List
 
 from selfprivacy_api.jobs import Job
 from selfprivacy_api.utils.systemd import (
     get_service_status_from_several_units,
 )
 from selfprivacy_api.services.service import Service, ServiceStatus
-from selfprivacy_api.utils import get_domain
 from selfprivacy_api.utils.block_devices import BlockDevice
 from selfprivacy_api.services.jitsimeet.icon import JITSI_ICON
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    ServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
 
 
 class JitsiMeet(Service):
     """Class representing Jitsi service"""
 
+    config_items: dict[str, ServiceConfigItem] = {
+        "subdomain": StringServiceConfigItem(
+            id="subdomain",
+            default_value="meet",
+            description="Subdomain",
+            regex=SUBDOMAIN_REGEX,
+            widget="subdomain",
+        ),
+        "appName": StringServiceConfigItem(
+            id="appName",
+            default_value="Jitsi Meet",
+            description="The name displayed in the web interface",
+        ),
+    }
+
     @staticmethod
     def get_id() -> str:
         """Return service id."""
@@ -36,16 +55,6 @@ class JitsiMeet(Service):
         """Read SVG icon from file and return it as base64 encoded string."""
         return base64.b64encode(JITSI_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        return f"https://meet.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        return "meet"
-
     @staticmethod
     def is_movable() -> bool:
         return False
@@ -88,14 +97,6 @@ class JitsiMeet(Service):
         )
         subprocess.run(["systemctl", "restart", "jicofo.service"], check=False)
 
-    @staticmethod
-    def get_configuration():
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         return ""
diff --git a/selfprivacy_api/services/mailserver/__init__.py b/selfprivacy_api/services/mailserver/__init__.py
index aba302d..d5dd481 100644
--- a/selfprivacy_api/services/mailserver/__init__.py
+++ b/selfprivacy_api/services/mailserver/__init__.py
@@ -89,14 +89,6 @@ class MailServer(Service):
         subprocess.run(["systemctl", "restart", "dovecot2.service"], check=False)
         subprocess.run(["systemctl", "restart", "postfix.service"], check=False)
 
-    @staticmethod
-    def get_configuration():
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         return ""
diff --git a/selfprivacy_api/services/nextcloud/__init__.py b/selfprivacy_api/services/nextcloud/__init__.py
index 275b11d..4cd0156 100644
--- a/selfprivacy_api/services/nextcloud/__init__.py
+++ b/selfprivacy_api/services/nextcloud/__init__.py
@@ -1,19 +1,32 @@
 """Class representing Nextcloud service."""
 import base64
 import subprocess
-from typing import Optional, List
-
-from selfprivacy_api.utils import get_domain
+from typing import List
 
 from selfprivacy_api.utils.systemd import get_service_status
 from selfprivacy_api.services.service import Service, ServiceStatus
 
 from selfprivacy_api.services.nextcloud.icon import NEXTCLOUD_ICON
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    ServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
 
 
 class Nextcloud(Service):
     """Class representing Nextcloud service."""
 
+    config_items: dict[str, ServiceConfigItem] = {
+        "subdomain": StringServiceConfigItem(
+            id="subdomain",
+            default_value="cloud",
+            description="Subdomain",
+            regex=SUBDOMAIN_REGEX,
+            widget="subdomain",
+        ),
+    }
+
     @staticmethod
     def get_id() -> str:
         """Return service id."""
@@ -34,16 +47,6 @@ class Nextcloud(Service):
         """Read SVG icon from file and return it as base64 encoded string."""
         return base64.b64encode(NEXTCLOUD_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        return f"https://cloud.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        return "cloud"
-
     @staticmethod
     def is_movable() -> bool:
         return True
@@ -84,15 +87,6 @@ class Nextcloud(Service):
         """Restart Nextcloud service."""
         subprocess.Popen(["systemctl", "restart", "phpfpm-nextcloud.service"])
 
-    @staticmethod
-    def get_configuration() -> dict:
-        """Return Nextcloud configuration."""
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         """Return Nextcloud logs."""
diff --git a/selfprivacy_api/services/ocserv/__init__.py b/selfprivacy_api/services/ocserv/__init__.py
index f600772..818b1d8 100644
--- a/selfprivacy_api/services/ocserv/__init__.py
+++ b/selfprivacy_api/services/ocserv/__init__.py
@@ -33,10 +33,6 @@ class Ocserv(Service):
         """Return service url."""
         return None
 
-    @classmethod
-    def get_subdomain(cls) -> typing.Optional[str]:
-        return "vpn"
-
     @staticmethod
     def is_movable() -> bool:
         return False
@@ -69,12 +65,12 @@ class Ocserv(Service):
     def restart():
         subprocess.run(["systemctl", "restart", "ocserv.service"], check=False)
 
-    @staticmethod
-    def get_configuration():
+    @classmethod
+    def get_configuration(cls):
         return {}
 
-    @staticmethod
-    def set_configuration(config_items):
+    @classmethod
+    def set_configuration(cls, config_items):
         return super().set_configuration(config_items)
 
     @staticmethod
diff --git a/selfprivacy_api/services/pleroma/__init__.py b/selfprivacy_api/services/pleroma/__init__.py
index 64edd96..e300844 100644
--- a/selfprivacy_api/services/pleroma/__init__.py
+++ b/selfprivacy_api/services/pleroma/__init__.py
@@ -1,9 +1,7 @@
 """Class representing Nextcloud service."""
 import base64
 import subprocess
-from typing import Optional, List
-
-from selfprivacy_api.utils import get_domain
+from typing import List
 
 from selfprivacy_api.services.owned_path import OwnedPath
 from selfprivacy_api.utils.systemd import get_service_status
@@ -31,16 +29,6 @@ class Pleroma(Service):
     def get_svg_icon() -> str:
         return base64.b64encode(PLEROMA_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        return f"https://social.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        return "social"
-
     @staticmethod
     def is_movable() -> bool:
         return True
@@ -72,12 +60,12 @@ class Pleroma(Service):
         subprocess.run(["systemctl", "restart", "pleroma.service"])
         subprocess.run(["systemctl", "restart", "postgresql.service"])
 
-    @staticmethod
-    def get_configuration(config_items):
+    @classmethod
+    def get_configuration(cls):
         return {}
 
-    @staticmethod
-    def set_configuration(config_items):
+    @classmethod
+    def set_configuration(cls, config_items):
         return super().set_configuration(config_items)
 
     @staticmethod
diff --git a/selfprivacy_api/services/roundcube/__init__.py b/selfprivacy_api/services/roundcube/__init__.py
index 22604f5..8349ccd 100644
--- a/selfprivacy_api/services/roundcube/__init__.py
+++ b/selfprivacy_api/services/roundcube/__init__.py
@@ -2,21 +2,35 @@
 
 import base64
 import subprocess
-from typing import List, Optional
+from typing import List
 
 from selfprivacy_api.jobs import Job
 from selfprivacy_api.utils.systemd import (
     get_service_status_from_several_units,
 )
 from selfprivacy_api.services.service import Service, ServiceStatus
-from selfprivacy_api.utils import ReadUserData, get_domain
 from selfprivacy_api.utils.block_devices import BlockDevice
 from selfprivacy_api.services.roundcube.icon import ROUNDCUBE_ICON
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    ServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
 
 
 class Roundcube(Service):
     """Class representing roundcube service"""
 
+    config_items: dict[str, ServiceConfigItem] = {
+        "subdomain": StringServiceConfigItem(
+            id="subdomain",
+            default_value="roundcube",
+            description="Subdomain",
+            regex=SUBDOMAIN_REGEX,
+            widget="subdomain",
+        ),
+    }
+
     @staticmethod
     def get_id() -> str:
         """Return service id."""
@@ -37,21 +51,6 @@ class Roundcube(Service):
         """Read SVG icon from file and return it as base64 encoded string."""
         return base64.b64encode(ROUNDCUBE_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> Optional[str]:
-        """Return service url."""
-        domain = get_domain()
-        subdomain = cls.get_subdomain()
-        return f"https://{subdomain}.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> Optional[str]:
-        with ReadUserData() as data:
-            if "roundcube" in data["modules"]:
-                return data["modules"]["roundcube"]["subdomain"]
-
-        return "roundcube"
-
     @staticmethod
     def is_movable() -> bool:
         return False
@@ -93,14 +92,6 @@ class Roundcube(Service):
             check=False,
         )
 
-    @staticmethod
-    def get_configuration():
-        return {}
-
-    @staticmethod
-    def set_configuration(config_items):
-        return super().set_configuration(config_items)
-
     @staticmethod
     def get_logs():
         return ""
diff --git a/selfprivacy_api/services/service.py b/selfprivacy_api/services/service.py
index 6e3decf..17b6f4f 100644
--- a/selfprivacy_api/services/service.py
+++ b/selfprivacy_api/services/service.py
@@ -3,7 +3,9 @@ from abc import ABC, abstractmethod
 from typing import List, Optional
 
 from selfprivacy_api import utils
-from selfprivacy_api.utils import ReadUserData, WriteUserData
+from selfprivacy_api.services.config_item import ServiceConfigItem
+from selfprivacy_api.utils.default_subdomains import DEFAULT_SUBDOMAINS
+from selfprivacy_api.utils import ReadUserData, WriteUserData, get_domain
 from selfprivacy_api.utils.waitloop import wait_until_true
 from selfprivacy_api.utils.block_devices import BlockDevice, BlockDevices
 
@@ -33,6 +35,8 @@ class Service(ABC):
     can be installed, configured and used by a user.
     """
 
+    config_items: dict[str, "ServiceConfigItem"] = {}
+
     @staticmethod
     @abstractmethod
     def get_id() -> str:
@@ -66,20 +70,27 @@ class Service(ABC):
         pass
 
     @classmethod
-    @abstractmethod
     def get_url(cls) -> Optional[str]:
         """
         The url of the service if it is accessible from the internet browser.
         """
-        pass
+        domain = get_domain()
+        subdomain = cls.get_subdomain()
+        return f"https://{subdomain}.{domain}"
 
     @classmethod
-    @abstractmethod
     def get_subdomain(cls) -> Optional[str]:
         """
         The assigned primary subdomain for this service.
         """
-        pass
+        name = cls.get_id()
+        with ReadUserData() as user_data:
+            if "modules" in user_data:
+                if name in user_data["modules"]:
+                    if "subdomain" in user_data["modules"][name]:
+                        return user_data["modules"][name]["subdomain"]
+
+        return DEFAULT_SUBDOMAINS.get(name)
 
     @classmethod
     def get_user(cls) -> Optional[str]:
@@ -135,6 +146,16 @@ class Service(ABC):
         with ReadUserData() as user_data:
             return user_data.get("modules", {}).get(name, {}).get("enable", False)
 
+    @classmethod
+    def is_installed(cls) -> bool:
+        """
+        `True` if the service is installed.
+        `False` if there is no module data in user data
+        """
+        name = cls.get_id()
+        with ReadUserData() as user_data:
+            return user_data.get("modules", {}).get(name, {}) != {}
+
     @staticmethod
     @abstractmethod
     def get_status() -> ServiceStatus:
@@ -179,15 +200,24 @@ class Service(ABC):
         """Restart the service. Usually this means restarting systemd unit."""
         pass
 
-    @staticmethod
-    @abstractmethod
-    def get_configuration():
-        pass
+    @classmethod
+    def get_configuration(cls):
+        return {
+            key: cls.config_items[key].as_dict(cls.get_id()) for key in cls.config_items
+        }
 
-    @staticmethod
-    @abstractmethod
-    def set_configuration(config_items):
-        pass
+    @classmethod
+    def set_configuration(cls, config_items):
+        for key, value in config_items.items():
+            if key not in cls.config_items:
+                raise ValueError(f"Key {key} is not valid for {cls.get_id()}")
+            if cls.config_items[key].validate_value(value) is False:
+                raise ValueError(f"Value {value} is not valid for {key}")
+        for key, value in config_items.items():
+            cls.config_items[key].set_value(
+                value,
+                cls.get_id(),
+            )
 
     @staticmethod
     @abstractmethod
diff --git a/selfprivacy_api/services/test_service/__init__.py b/selfprivacy_api/services/test_service/__init__.py
index de3c493..1a2fd9d 100644
--- a/selfprivacy_api/services/test_service/__init__.py
+++ b/selfprivacy_api/services/test_service/__init__.py
@@ -1,6 +1,5 @@
 """Class representing Bitwarden service"""
 import base64
-import typing
 import subprocess
 
 from typing import List
@@ -57,16 +56,6 @@ class DummyService(Service):
         # return ""
         return base64.b64encode(BITWARDEN_ICON.encode("utf-8")).decode("utf-8")
 
-    @classmethod
-    def get_url(cls) -> typing.Optional[str]:
-        """Return service url."""
-        domain = "test.com"
-        return f"https://password.{domain}"
-
-    @classmethod
-    def get_subdomain(cls) -> typing.Optional[str]:
-        return "password"
-
     @classmethod
     def is_movable(cls) -> bool:
         return cls.movable
@@ -163,12 +152,12 @@ class DummyService(Service):
         cls.set_status(ServiceStatus.RELOADING)  # is a correct one?
         cls.change_status_with_async_delay(ServiceStatus.ACTIVE, cls.startstop_delay)
 
-    @staticmethod
-    def get_configuration():
+    @classmethod
+    def get_configuration(cls):
         return {}
 
-    @staticmethod
-    def set_configuration(config_items):
+    @classmethod
+    def set_configuration(cls, config_items):
         return super().set_configuration(config_items)
 
     @staticmethod
diff --git a/selfprivacy_api/utils/__init__.py b/selfprivacy_api/utils/__init__.py
index 779bdf6..53568ce 100644
--- a/selfprivacy_api/utils/__init__.py
+++ b/selfprivacy_api/utils/__init__.py
@@ -8,6 +8,11 @@ import subprocess
 import portalocker
 import typing
 
+from selfprivacy_api.utils.default_subdomains import (
+    DEFAULT_SUBDOMAINS,
+    RESERVED_SUBDOMAINS,
+)
+
 
 USERDATA_FILE = "/etc/nixos/userdata.json"
 SECRETS_FILE = "/etc/selfprivacy/secrets.json"
@@ -133,6 +138,20 @@ def is_username_forbidden(username):
     return False
 
 
+def check_if_subdomain_is_taken(subdomain: str) -> bool:
+    """Check if subdomain is already taken or reserved"""
+    if subdomain in RESERVED_SUBDOMAINS:
+        return True
+    with ReadUserData() as data:
+        for module in data["modules"]:
+            if (
+                data["modules"][module].get("subdomain", DEFAULT_SUBDOMAINS[module])
+                == subdomain
+            ):
+                return True
+    return False
+
+
 def parse_date(date_str: str) -> datetime.datetime:
     """Parse date string which can be in one of these formats:
     - %Y-%m-%dT%H:%M:%S.%fZ
@@ -199,3 +218,10 @@ def hash_password(password):
     hashed_password = hashed_password.decode("ascii")
     hashed_password = hashed_password.rstrip()
     return hashed_password
+
+
+def write_to_log(message):
+    with open("/etc/selfprivacy/log", "a") as log:
+        log.write(f"{datetime.datetime.now()} {message}\n")
+        log.flush()
+        os.fsync(log.fileno())
diff --git a/selfprivacy_api/utils/default_subdomains.py b/selfprivacy_api/utils/default_subdomains.py
new file mode 100644
index 0000000..f6665fc
--- /dev/null
+++ b/selfprivacy_api/utils/default_subdomains.py
@@ -0,0 +1,21 @@
+DEFAULT_SUBDOMAINS = {
+    "bitwarden": "password",
+    "gitea": "git",
+    "jitsi-meet": "meet",
+    "simple-nixos-mailserver": "",
+    "nextcloud": "cloud",
+    "ocserv": "vpn",
+    "pleroma": "social",
+    "roundcube": "roundcube",
+    "testservice": "test",
+}
+
+RESERVED_SUBDOMAINS = [
+    "admin",
+    "administrator",
+    "api",
+    "auth",
+    "user",
+    "users",
+    "ntfy",
+]
diff --git a/selfprivacy_api/utils/regex_strings.py b/selfprivacy_api/utils/regex_strings.py
new file mode 100644
index 0000000..718e2ab
--- /dev/null
+++ b/selfprivacy_api/utils/regex_strings.py
@@ -0,0 +1 @@
+SUBDOMAIN_REGEX = r"^[A-Za-z0-9][A-Za-z0-9\-]{0,61}[A-Za-z0-9]$"
diff --git a/tests/test_config_item.py b/tests/test_config_item.py
new file mode 100644
index 0000000..724c29e
--- /dev/null
+++ b/tests/test_config_item.py
@@ -0,0 +1,157 @@
+import pytest
+from selfprivacy_api.services.config_item import (
+    StringServiceConfigItem,
+    BoolServiceConfigItem,
+    EnumServiceConfigItem,
+)
+from selfprivacy_api.utils.regex_strings import SUBDOMAIN_REGEX
+
+
+@pytest.fixture
+def service_options():
+    return {}
+
+
+def test_string_service_config_item(service_options):
+    item = StringServiceConfigItem(
+        id="test_string",
+        default_value="1337",
+        description="Test digits string",
+        regex=r"^\d+$",
+        widget="text",
+        allow_empty=False,
+    )
+    assert item.get_value(service_options) == "1337"
+    item.set_value("123", service_options)
+    assert item.get_value(service_options) == "123"
+    with pytest.raises(ValueError):
+        item.set_value("abc", service_options)
+    assert item.validate_value("123") is True
+    assert item.validate_value("abc") is False
+    assert item.validate_value("123abc") is False
+    assert item.validate_value("") is False
+    assert item.validate_value(None) is False
+    assert item.validate_value(123) is False
+    assert item.validate_value("123.0") is False
+    assert item.validate_value(True) is False
+
+
+def test_string_service_config_item_allows_empty(service_options):
+    item = StringServiceConfigItem(
+        id="test_string",
+        default_value="1337",
+        description="Test digits string",
+        widget="text",
+        allow_empty=True,
+    )
+    assert item.get_value(service_options) == "1337"
+    item.set_value("", service_options)
+    assert item.get_value(service_options) == ""
+    assert item.validate_value("") is True
+    assert item.validate_value(None) is False
+    assert item.validate_value(123) is False
+    assert item.validate_value("123") is True
+    assert item.validate_value("abc") is True
+    assert item.validate_value("123abc") is True
+    assert item.validate_value("123.0") is True
+    assert item.validate_value(True) is False
+
+
+def test_string_service_config_item_not_allows_empty(service_options):
+    item = StringServiceConfigItem(
+        id="test_string",
+        default_value="1337",
+        description="Test digits string",
+        widget="text",
+    )
+    assert item.get_value(service_options) == "1337"
+    with pytest.raises(ValueError):
+        item.set_value("", service_options)
+    assert item.get_value(service_options) == "1337"
+    assert item.validate_value("") is False
+    assert item.validate_value(None) is False
+    assert item.validate_value(123) is False
+    assert item.validate_value("123") is True
+    assert item.validate_value("abc") is True
+    assert item.validate_value("123abc") is True
+    assert item.validate_value("123.0") is True
+    assert item.validate_value(True) is False
+
+
+def test_bool_service_config_item(service_options):
+    item = BoolServiceConfigItem(
+        id="test_bool",
+        default_value=True,
+        description="Test bool",
+        widget="switch",
+    )
+    assert item.get_value(service_options) is True
+    item.set_value(False, service_options)
+    assert item.get_value(service_options) is False
+    assert item.validate_value(True) is True
+    assert item.validate_value(False) is True
+    assert item.validate_value("True") is False
+    assert item.validate_value("False") is False
+    assert item.validate_value(1) is False
+    assert item.validate_value(0) is False
+    assert item.validate_value("1") is False
+
+
+def test_enum_service_config_item(service_options):
+    item = EnumServiceConfigItem(
+        id="test_enum",
+        default_value="option1",
+        description="Test enum",
+        options=["option1", "option2", "option3"],
+        widget="select",
+    )
+    assert item.get_value(service_options) == "option1"
+    item.set_value("option2", service_options)
+    assert item.get_value(service_options) == "option2"
+    with pytest.raises(ValueError):
+        item.set_value("option4", service_options)
+    assert item.validate_value("option1") is True
+    assert item.validate_value("option4") is False
+    assert item.validate_value("option2") is True
+    assert item.validate_value(1) is False
+    assert item.validate_value("1") is False
+    assert item.validate_value(True) is False
+
+
+def test_string_service_config_item_subdomain(service_options, dummy_service):
+    item = StringServiceConfigItem(
+        id="test_subdomain",
+        default_value="example",
+        description="Test subdomain string",
+        widget="subdomain",
+        allow_empty=False,
+        regex=SUBDOMAIN_REGEX,
+    )
+    assert item.get_value(service_options) == "example"
+    item.set_value("subdomain", service_options)
+    assert item.get_value(service_options) == "subdomain"
+    with pytest.raises(ValueError):
+        item.set_value(
+            "invalid-subdomain-because-it-is-very-very-very-very-very-very-long",
+            service_options,
+        )
+    assert item.validate_value("subdomain") is True
+    assert (
+        item.validate_value(
+            "invalid-subdomain-because-it-is-very-very-very-very-very-very-long"
+        )
+        is False
+    )
+    assert item.validate_value("api") is False
+    assert item.validate_value("auth") is False
+    assert item.validate_value("user") is False
+    assert item.validate_value("users") is False
+    assert item.validate_value("ntfy") is False
+    assert item.validate_value("") is False
+    assert item.validate_value(None) is False
+    assert item.validate_value(123) is False
+    assert item.validate_value("123") is True
+    assert item.validate_value("abc") is True
+    assert item.validate_value("123abc") is True
+    assert item.validate_value("123.0") is False
+    assert item.validate_value(True) is False
diff --git a/tests/test_graphql/test_services.py b/tests/test_graphql/test_services.py
index b7faf3d..b349f53 100644
--- a/tests/test_graphql/test_services.py
+++ b/tests/test_graphql/test_services.py
@@ -188,6 +188,7 @@ allServices {
     id
     status
     isEnabled
+    url
 }
 """
 
@@ -347,6 +348,7 @@ def test_get_services(authorized_client, only_dummy_service):
     assert api_dummy_service["id"] == "testservice"
     assert api_dummy_service["status"] == ServiceStatus.ACTIVE.value
     assert api_dummy_service["isEnabled"] is True
+    assert api_dummy_service["url"] == "https://test.test-domain.tld"
 
 
 def test_enable_return_value(authorized_client, only_dummy_service):