diff --git a/home-assistant/src/home_assistant.rs b/home-assistant/src/home_assistant.rs
index 3e9c417..80cc380 100644
--- a/home-assistant/src/home_assistant.rs
+++ b/home-assistant/src/home_assistant.rs
@@ -1,4 +1,4 @@
-use std::convert::Infallible;
+use std::{convert::Infallible, sync::Arc};
 
 use pyo3::{
     types::PyAnyMethods as _, Borrowed, Bound, FromPyObject, IntoPyObject, Py, PyAny, PyErr, Python,
@@ -33,22 +33,26 @@ impl<'py> IntoPyObject<'py> for &HomeAssistant {
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Clone, Snafu)]
 pub enum GetStatesError {
     /// couldn't get the `states` attribute on the Home Assistant object
-    GetStatesAttributeError { source: PyErr },
+    GetStatesAttributeError { source: Arc<PyErr> },
 
     /// couldn't extract the `states` as a [`StateMachine`]
-    ExtractStateMachineError { source: TypeByNameValidationError },
+    ExtractStateMachineError {
+        source: Arc<TypeByNameValidationError>,
+    },
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Clone, Snafu)]
 pub enum GetServicesError {
     /// couldn't get the `services` attribute on the Home Assistant object
-    GetServicesAttributeError { source: PyErr },
+    GetServicesAttributeError { source: Arc<PyErr> },
 
     /// couldn't extract the `states` as a [`ServiceRegistry`]
-    ExtractServiceRegistryError { source: TypeByNameValidationError },
+    ExtractServiceRegistryError {
+        source: Arc<TypeByNameValidationError>,
+    },
 }
 
 impl HomeAssistant {
@@ -74,15 +78,23 @@ impl HomeAssistant {
         let states = self
             .0
             .getattr(py, "states")
+            .map_err(Arc::new)
             .context(GetStatesAttributeSnafu)?;
-        states.extract(py).context(ExtractStateMachineSnafu)
+        states
+            .extract(py)
+            .map_err(Arc::new)
+            .context(ExtractStateMachineSnafu)
     }
 
     pub fn services(&self, py: Python<'_>) -> Result<ServiceRegistry, GetServicesError> {
         let services = self
             .0
             .getattr(py, "services")
+            .map_err(Arc::new)
             .context(GetServicesAttributeSnafu)?;
-        services.extract(py).context(ExtractServiceRegistrySnafu)
+        services
+            .extract(py)
+            .map_err(Arc::new)
+            .context(ExtractServiceRegistrySnafu)
     }
 }
diff --git a/home-assistant/src/input_number/attributes.rs b/home-assistant/src/input_number/attributes.rs
new file mode 100644
index 0000000..5eefdf6
--- /dev/null
+++ b/home-assistant/src/input_number/attributes.rs
@@ -0,0 +1,16 @@
+use pyo3::FromPyObject;
+
+use super::InputNumberMode;
+
+#[derive(Debug, FromPyObject)]
+#[pyo3(from_item_all)]
+pub struct InputNumberAttributes {
+    initial: Option<f64>,
+    editable: bool,
+    min: f64,
+    max: f64,
+    step: f64,
+    mode: InputNumberMode,
+    // todo: CustomUnitOfMeasurement type? probably not?
+    unit_of_measurement: Option<String>,
+}
diff --git a/home-assistant/src/input_number/mod.rs b/home-assistant/src/input_number/mod.rs
index 8b13789..5090d76 100644
--- a/home-assistant/src/input_number/mod.rs
+++ b/home-assistant/src/input_number/mod.rs
@@ -1 +1,73 @@
+use std::{future::Future, sync::Arc};
 
+use emitter_and_signal::{Signal, SignalExt};
+use pyo3::{Py, PyAny, PyErr, Python};
+use snafu::{ResultExt, Snafu};
+
+use crate::{
+    domain::Domain,
+    entity_id::EntityId,
+    home_assistant::HomeAssistant,
+    object_id::ObjectId,
+    state::HomeAssistantState,
+    state_object::{self, StateObject, StateObjectSignalError},
+};
+
+mod attributes;
+mod mode;
+
+pub use attributes::InputNumberAttributes;
+pub use mode::InputNumberMode;
+
+#[derive(Debug, Snafu)]
+pub enum CreateSignalError {
+    /// couldn't get the underlying state object signal
+    StateObjectSignalError {
+        source: state_object::CreateSignalError,
+    },
+
+    /// couldn't map the state object to a power value
+    MappedSignalError {
+        source: emitter_and_signal::signal_ext::ProducerAlreadyExited,
+    },
+}
+
+pub fn signal<'py>(
+    py: Python<'py>,
+    home_assistant: &'py HomeAssistant,
+    object_id: ObjectId,
+) -> Result<
+    (
+        Signal<Option<Arc<Result<HomeAssistantState<f64>, StateObjectSignalError<Arc<PyErr>>>>>>,
+        impl Future<Output = Result<(), emitter_and_signal::signal::JoinError>>,
+    ),
+    CreateSignalError,
+> {
+    let entity_id = EntityId(Domain::InputNumber, object_id);
+
+    let (signal, task1) =
+        StateObject::<HomeAssistantState<f64>, InputNumberAttributes, Py<PyAny>>::signal(
+            py,
+            home_assistant,
+            entity_id,
+        )
+        .context(StateObjectSignalSnafu)?;
+
+    let (signal, task2) = signal
+        .map(|state_object_arc_result_option| {
+            state_object_arc_result_option.map(|state_object_arc_result| {
+                Arc::new(
+                    (&*state_object_arc_result)
+                        .as_ref()
+                        .map(|state_object| state_object.state.clone())
+                        .map_err(|e| e.clone()),
+                )
+            })
+        })
+        .context(MappedSignalSnafu)?;
+
+    Ok((
+        signal,
+        async move { tokio::try_join!(task1, task2).map(|_| ()) },
+    ))
+}
diff --git a/home-assistant/src/input_number/mode.rs b/home-assistant/src/input_number/mode.rs
new file mode 100644
index 0000000..1ce34b1
--- /dev/null
+++ b/home-assistant/src/input_number/mode.rs
@@ -0,0 +1,10 @@
+use python_utils::{FromPyFromStr, ToStrToPy};
+use strum::EnumString;
+
+#[derive(Debug, Clone, Default, EnumString, strum::Display, FromPyFromStr, ToStrToPy)]
+#[strum(serialize_all = "snake_case")]
+pub enum InputNumberMode {
+    Box,
+    #[default]
+    Slider,
+}
diff --git a/home-assistant/src/light/mod.rs b/home-assistant/src/light/mod.rs
index 6e6b4a2..ac977a2 100644
--- a/home-assistant/src/light/mod.rs
+++ b/home-assistant/src/light/mod.rs
@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use attributes::LightAttributes;
 use pyo3::{FromPyObject, Py, PyAny, Python};
 use snafu::{ResultExt, Snafu};
@@ -29,15 +31,15 @@ impl HomeAssistantLight {
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Clone, Snafu)]
 pub enum GetStateObjectError {
     /// couldn't get the state machine registry
     GetStatesError { source: GetStatesError },
 
     /// this state object exists in the state machine registry, but it couldn't be extracted as a light state object
-    GetStateError { source: GetStateError<
+    GetStateError { source: Arc<GetStateError<
         <StateObject<HomeAssistantState<LightState>, LightAttributes, Py<PyAny>> as FromPyObject<'static, 'static>>::Error
-    > },
+    >> },
 
     /// this entity does not have a state object in the registry
     EntityMissing,
@@ -55,6 +57,7 @@ impl HomeAssistantLight {
             let entity_id = self.entity_id();
             let state_object = states
                 .get(py, entity_id)
+                .map_err(Arc::new)
                 .context(GetStateSnafu)?
                 .ok_or(GetStateObjectError::EntityMissing)?;
 
diff --git a/home-assistant/src/light/protocol.rs b/home-assistant/src/light/protocol.rs
index f480537..2c8a150 100644
--- a/home-assistant/src/light/protocol.rs
+++ b/home-assistant/src/light/protocol.rs
@@ -30,9 +30,7 @@ impl GetState for HomeAssistantLight {
             HomeAssistantState::Err(error_state) => {
                 Err(GetStateError::Error { state: error_state })
             }
-            HomeAssistantState::Unexpected(state) => {
-                Err(GetStateError::UnexpectedError { state })
-            }
+            HomeAssistantState::Unexpected(state) => Err(GetStateError::UnexpectedError { state }),
         }
     }
 }
diff --git a/home-assistant/src/sensor/device_classes/power.rs b/home-assistant/src/sensor/device_classes/power.rs
index f624873..09a0b94 100644
--- a/home-assistant/src/sensor/device_classes/power.rs
+++ b/home-assistant/src/sensor/device_classes/power.rs
@@ -2,7 +2,7 @@ use std::{future::Future, sync::Arc};
 
 use emitter_and_signal::{Signal, SignalExt};
 use pyo3::{FromPyObject, Py, PyAny, PyErr, Python};
-use python_utils::{FromPyFromStr, FromPyObjectViaParse, ToStrToPy};
+use python_utils::{FromPyFromStr, ToStrToPy};
 use snafu::{ResultExt, Snafu};
 use string_literal::StringLiteral;
 
@@ -12,6 +12,7 @@ use crate::{
     entity_id::EntityId,
     home_assistant::HomeAssistant,
     object_id::ObjectId,
+    state::HomeAssistantState,
     state_object::{self, StateObject, StateObjectSignalError},
     unit_of_measurement::power::UnitOfMeasurement,
 };
@@ -47,7 +48,11 @@ pub fn signal<'py>(
     object_id: ObjectId,
 ) -> Result<
     (
-        Signal<Option<Arc<Result<uom::si::f64::Power, StateObjectSignalError<PyErr>>>>>,
+        Signal<
+            Option<
+                Result<HomeAssistantState<uom::si::f64::Power>, StateObjectSignalError<Arc<PyErr>>>,
+            >,
+        >,
         impl Future<Output = Result<(), emitter_and_signal::signal::JoinError>>,
     ),
     CreateSignalError,
@@ -55,7 +60,7 @@ pub fn signal<'py>(
     let entity_id = EntityId(Domain::Sensor, object_id);
 
     let (signal, task1) =
-        StateObject::<FromPyObjectViaParse<f64>, PowerSensorAttributes, Py<PyAny>>::signal(
+        StateObject::<HomeAssistantState<f64>, PowerSensorAttributes, Py<PyAny>>::signal(
             py,
             home_assistant,
             entity_id,
@@ -65,18 +70,17 @@ pub fn signal<'py>(
     let (signal, task2) = signal
         .map(|state_object_result_option| {
             state_object_result_option.map(|state_object_result| {
-                Arc::new(
-                    Result::as_ref(&state_object_result)
-                        .map(|state_object| {
-                            let amount = state_object.state.0;
-                            let unit_of_measurement = state_object.attributes.unit_of_measurement;
-
-                            let power = unit_of_measurement.into_uom(amount);
-
-                            power
-                        })
-                        .map_err(|e| todo!()),
-                )
+                Result::as_ref(&state_object_result)
+                    .map(
+                        |StateObject {
+                             state, attributes, ..
+                         }| {
+                            state
+                                .as_ref()
+                                .map(|&amount| attributes.unit_of_measurement.into_uom(amount))
+                        },
+                    )
+                    .map_err(Clone::clone)
             })
         })
         .context(MappedSignalSnafu)?;
diff --git a/home-assistant/src/state/error_state.rs b/home-assistant/src/state/error_state.rs
index 1037256..91e238f 100644
--- a/home-assistant/src/state/error_state.rs
+++ b/home-assistant/src/state/error_state.rs
@@ -4,7 +4,7 @@ use strum::EnumString;
 /// A state in Home Assistant that is known to represent an error of some kind:
 /// * `unavailable` (the device is likely offline or unreachable from the Home Assistant instance)
 /// * `unknown` (I don't know how to explain this one)
-#[derive(Debug, Clone, EnumString, strum::Display, FromPyFromStr, ToStrToPy)]
+#[derive(Debug, Clone, Copy, EnumString, strum::Display, FromPyFromStr, ToStrToPy)]
 #[strum(serialize_all = "snake_case")]
 pub enum ErrorState {
     Unavailable,
diff --git a/home-assistant/src/state/mod.rs b/home-assistant/src/state/mod.rs
index ab5eefb..4ae8694 100644
--- a/home-assistant/src/state/mod.rs
+++ b/home-assistant/src/state/mod.rs
@@ -47,3 +47,42 @@ impl<State: FromStr> FromStr for HomeAssistantState<State> {
         Ok(HomeAssistantState::Unexpected(UnexpectedState(s.into())))
     }
 }
+
+impl<State> HomeAssistantState<State> {
+    pub fn as_ref(&self) -> HomeAssistantState<&State> {
+        match self {
+            HomeAssistantState::Ok(state) => HomeAssistantState::Ok(state),
+            HomeAssistantState::Err(error_state) => HomeAssistantState::Err(*error_state),
+            HomeAssistantState::Unexpected(unexpected_state) => {
+                // TODO: just considered cheap enough to clone implicitly
+                HomeAssistantState::Unexpected(unexpected_state.clone())
+            }
+        }
+    }
+
+    pub fn map<Mapped>(self, f: impl FnOnce(State) -> Mapped) -> HomeAssistantState<Mapped> {
+        match self {
+            HomeAssistantState::Ok(state) => HomeAssistantState::Ok(f(state)),
+            HomeAssistantState::Err(error_state) => HomeAssistantState::Err(error_state),
+            HomeAssistantState::Unexpected(unexpected_state) => {
+                HomeAssistantState::Unexpected(unexpected_state)
+            }
+        }
+    }
+}
+
+impl<State> HomeAssistantState<&State> {
+    pub fn cloned(self) -> HomeAssistantState<State>
+    where
+        State: Clone,
+    {
+        self.map(Clone::clone)
+    }
+
+    pub fn copied(self) -> HomeAssistantState<State>
+    where
+        State: Copy,
+    {
+        self.map(|&s| s)
+    }
+}
diff --git a/home-assistant/src/state_object.rs b/home-assistant/src/state_object.rs
index 325810f..ddb36a3 100644
--- a/home-assistant/src/state_object.rs
+++ b/home-assistant/src/state_object.rs
@@ -62,7 +62,7 @@ impl<
                     Arc<
                         Result<
                             Self,
-                            StateObjectSignalError<<Self as FromPyObject<'a, 'py>>::Error>,
+                            StateObjectSignalError<Arc<<Self as FromPyObject<'a, 'py>>::Error>>,
                         >,
                     >,
                 >,
@@ -74,6 +74,16 @@ impl<
         let state_machine = home_assistant.states(py).context(GetStatesSnafu)?;
         let current = state_machine
             .get(py, entity_id.clone())
+            .map_err(|e| match e {
+                GetStateError::GetStateObjectError { source } => {
+                    GetStateError::GetStateObjectError { source }
+                }
+                GetStateError::ExtractStateObjectError { source } => {
+                    GetStateError::ExtractStateObjectError {
+                        source: Arc::new(source),
+                    }
+                }
+            })
             .context(GetFromStateMachineSnafu)
             .transpose();