diff --git a/src/namespace/namespace.rs b/src/namespace/namespace.rs
index 966a13e..eeb9d80 100644
--- a/src/namespace/namespace.rs
+++ b/src/namespace/namespace.rs
@@ -1,7 +1,7 @@
 use pyo3::{pyclass, pymethods, types::PyCFunction, IntoPy, Py, PyErr, PyObject, PyResult, Python};
-use teo::prelude::{handler::Group as TeoHandlerGroup, model::Field as TeoField, model::Property as TeoProperty, model::Relation as TeoRelation, request, Enum as TeoEnum, Member as TeoEnumMember, Middleware, Model as TeoModel, Namespace as TeoNamespace, Next};
+use teo::prelude::{handler::Group as TeoHandlerGroup, model::Field as TeoField, model::Property as TeoProperty, model::Relation as TeoRelation, pipeline::{self, item::validator::Validity}, request, Enum as TeoEnum, Member as TeoEnumMember, Middleware, Model as TeoModel, Namespace as TeoNamespace, Next, Value};
 
-use crate::{utils::{check_callable::check_callable, await_coroutine_if_needed::await_coroutine_if_needed_value_with_locals}, object::{arguments::teo_args_to_py_args, value::teo_value_to_py_any}, model::{model::Model, field::field::Field, relation::relation::Relation, property::property::Property}, result::{IntoPyResultWithGil, IntoTeoPathResult, IntoTeoResult}, r#enum::{r#enum::Enum, member::member::EnumMember}, request::{Request, RequestCtx}, dynamic::py_ctx_object_from_teo_transaction_ctx, response::Response, handler::group::HandlerGroup};
+use crate::{utils::{check_callable::check_callable, await_coroutine_if_needed::await_coroutine_if_needed_value_with_locals}, object::{arguments::teo_args_to_py_args, model::teo_model_object_to_py_any, py_any_to_teo_object, teo_object_to_py_any, value::{py_any_to_teo_value, teo_value_to_py_any}}, model::{model::Model, field::field::Field, relation::relation::Relation, property::property::Property}, result::{IntoPyResultWithGil, IntoTeoPathResult, IntoTeoResult}, r#enum::{r#enum::Enum, member::member::EnumMember}, request::{Request, RequestCtx}, dynamic::py_ctx_object_from_teo_transaction_ctx, response::Response, handler::group::HandlerGroup};
 
 #[pyclass]
 pub struct Namespace {
@@ -151,6 +151,116 @@ impl Namespace {
         Ok(())
     }
 
+    pub fn define_pipeline_item(&mut self, py: Python<'_>, name: &str, callback: PyObject) -> PyResult<()> {
+        check_callable(callback.as_ref(py))?;
+        let callback_owned = &*Box::leak(Box::new(Py::from(callback)));
+        let main_thread_locals = &*Box::leak(Box::new(pyo3_asyncio::tokio::get_current_locals(py)?));
+        self.teo_namespace.define_pipeline_item(name, move |args, ctx: pipeline::Ctx| async move {
+            let result = Python::with_gil(|py| {
+                let value = teo_object_to_py_any(py, ctx.value())?;
+                let args = teo_args_to_py_args(py, &args)?;
+                let object = teo_model_object_to_py_any(py, ctx.object())?;
+                let ctx = py_ctx_object_from_teo_transaction_ctx(py, ctx.transaction_ctx(), "")?;
+                let result = callback_owned.call1(py, (value, args, object, ctx))?;
+                Ok(result)
+            }).into_teo_result()?;
+            let awaited_result = await_coroutine_if_needed_value_with_locals(result, main_thread_locals).await.into_teo_result()?;
+            Python::with_gil(|py| {
+                let result = py_any_to_teo_object(py, awaited_result).into_teo_result()?;
+                Ok(result)
+            })
+        });
+        Ok(())
+    }
+
+    pub fn define_transform_pipeline_item(&mut self, py: Python<'_>, name: &str, callback: PyObject) -> PyResult<()> {
+        self.define_pipeline_item(py, name, callback)
+    }
+
+    pub fn define_validator_pipeline_item(&mut self, py: Python<'_>, name: &str, callback: PyObject) -> PyResult<()> {
+        check_callable(callback.as_ref(py))?;
+        let callback_owned = &*Box::leak(Box::new(Py::from(callback)));
+        let main_thread_locals = &*Box::leak(Box::new(pyo3_asyncio::tokio::get_current_locals(py)?));
+        self.teo_namespace.define_validator_pipeline_item(name, move |_: Value, args, ctx: pipeline::Ctx| async move {
+            let result = Python::with_gil(|py| {
+                let value = teo_object_to_py_any(py, ctx.value())?;
+                let args = teo_args_to_py_args(py, &args)?;
+                let object = teo_model_object_to_py_any(py, ctx.object())?;
+                let ctx = py_ctx_object_from_teo_transaction_ctx(py, ctx.transaction_ctx(), "")?;
+                let result = callback_owned.call1(py, (value, args, object, ctx))?;
+                Ok(result)
+            }).into_teo_result()?;
+            let awaited_result = await_coroutine_if_needed_value_with_locals(result, main_thread_locals).await.into_teo_result()?;
+            Python::with_gil(|py| {
+                let result = py_any_to_teo_value(py, awaited_result.as_ref(py)).into_teo_result()?;
+                Ok::<Validity, teo::prelude::Error>(match result {
+                    Value::String(s) => {
+                        Validity::Invalid(s.to_owned())
+                    },
+                    Value::Bool(b) => if b {
+                        Validity::Valid
+                    } else {
+                        Validity::Invalid("value is invalid".to_owned())
+                    },
+                    _ => Validity::Valid
+                })
+            })
+        });
+        Ok(())
+    }
+
+    pub fn define_callback_pipeline_item(&mut self, py: Python<'_>, name: &str, callback: PyObject) -> PyResult<()> {
+        check_callable(callback.as_ref(py))?;
+        let callback_owned = &*Box::leak(Box::new(Py::from(callback)));
+        let main_thread_locals = &*Box::leak(Box::new(pyo3_asyncio::tokio::get_current_locals(py)?));
+        self.teo_namespace.define_callback_pipeline_item(name, move |args, ctx: pipeline::Ctx| async move {
+            let result = Python::with_gil(|py| {
+                let value = teo_object_to_py_any(py, ctx.value())?;
+                let args = teo_args_to_py_args(py, &args)?;
+                let object = teo_model_object_to_py_any(py, ctx.object())?;
+                let ctx = py_ctx_object_from_teo_transaction_ctx(py, ctx.transaction_ctx(), "")?;
+                let result = callback_owned.call1(py, (value, args, object, ctx))?;
+                Ok(result)
+            }).into_teo_result()?;
+            let _ = await_coroutine_if_needed_value_with_locals(result, main_thread_locals).await.into_teo_result()?;
+            Ok(())
+        });
+        Ok(())
+    }
+
+    pub fn define_compare_pipeline_item(&mut self, py: Python<'_>, name: &str, callback: PyObject) -> PyResult<()> {
+        check_callable(callback.as_ref(py))?;
+        let callback_owned = &*Box::leak(Box::new(Py::from(callback)));
+        let main_thread_locals = &*Box::leak(Box::new(pyo3_asyncio::tokio::get_current_locals(py)?));
+        self.teo_namespace.define_compare_pipeline_item(name, move |old: Value, new: Value, args, ctx: pipeline::Ctx| async move {
+            let result = Python::with_gil(|py| {
+                let value_old = teo_value_to_py_any(py, &old)?;
+                let value_new = teo_value_to_py_any(py, &new)?;
+                let args = teo_args_to_py_args(py, &args)?;
+                let object = teo_model_object_to_py_any(py, ctx.object())?;
+                let ctx = py_ctx_object_from_teo_transaction_ctx(py, ctx.transaction_ctx(), "")?;
+                let result = callback_owned.call1(py, (value_old, value_new, args, object, ctx))?;
+                Ok(result)
+            }).into_teo_result()?;
+            let awaited_result = await_coroutine_if_needed_value_with_locals(result, main_thread_locals).await.into_teo_result()?;
+            Python::with_gil(|py| {
+                let result = py_any_to_teo_value(py, awaited_result.into_ref(py)).into_teo_result()?;
+                Ok::<Validity, teo::prelude::Error>(match result {
+                    Value::String(s) => {
+                        Validity::Invalid(s.to_owned())
+                    },
+                    Value::Bool(b) => if b {
+                        Validity::Valid
+                    } else {
+                        Validity::Invalid("value is invalid".to_owned())
+                    },
+                    _ => Validity::Valid
+                })
+            })
+        });
+        Ok(())
+    }
+
     pub fn define_handler(&mut self, py: Python<'_>, name: String, callback: PyObject) -> PyResult<()> {
         check_callable(callback.as_ref(py))?;
         let main_thread_locals = &*Box::leak(Box::new(pyo3_asyncio::tokio::get_current_locals(py)?));