diff --git a/docs/examples/playground/app1.py b/docs/examples/playground/app1.py
new file mode 100644
index 0000000..cd5b120
--- /dev/null
+++ b/docs/examples/playground/app1.py
@@ -0,0 +1,26 @@
+from pandas import DataFrame
+from shiny.express import ui
+from shinyecharts.express import Chart, InitOptions
+from shinyecharts.renderer import ChartRenderer
+
+init_options = InitOptions(width=600, height=400, renderer="canvas")
+
+data = DataFrame(
+    [[0, 1, 2, 3], [1, 4, 5, 6], [2, -2, 4, 9]],
+    columns=["a", "b", "c", "d"],
+)
+
+
+@ChartRenderer
+def render_lines():
+    return Chart().data(data).encode("a", "b").encode("a", "c", color="pink")
+
+
+@ChartRenderer
+def render_scatter():
+    return Chart().data(data).encode("a", "b", type="scatter")
+
+
+@ChartRenderer
+def render_bar():
+    return Chart().data(data).encode("a", "b", type="bar").encode("a", "c", type="bar")
diff --git a/docs/shinylive.md b/docs/shinylive.md
new file mode 100644
index 0000000..d7ae857
--- /dev/null
+++ b/docs/shinylive.md
@@ -0,0 +1 @@
+https://shinylive.io/py/editor/#code=NobwRAdghgtgpmAXGKAHVA6VBPMAaMAYwHsIAXOcpMAMwCdiYACVKCAEygGcmBLGVMTpkmAEShkoAMTqw4AHQiKAxEwCyAVy4ioAGwDuUbDwBGcPgKEV2eJsTIALOHX28u5gILo+PCPaY0xBocivSMTFwOvBDYGHAAHqh0cFw8-ILCTBq8oQzMkdHYcIQOUMJplpkAwqXCtgCSELxkAPKoZLykXLnhBTHFtWRcGMTtnRAVGSIAMtEKEGH5Uf0lZUMYyRzOzhZTTDVrAEqU7Nt0iorRzQD6ox1dTAC8TI3NbfcTABSu7I6PAGwABkBticvAA5g4yI8ACzA2ybU7JOiPeRENgAN24aIAlBcOBIoE8xISZHJPoomFSmMBgCCmABGWwAJlsAGYALq2YBMpgw2wAVls-y5NNZTAAtOL+UwAJwcrmU6kkXQaGATR7ANFQNG2NEmXVMNGEQ1o9hoxUQPFKG26OY8Z4UiDUpizCBwT7xVEoQ3Yb0G-BMMjEYi6DqoR7sXiEMifMh0CHg5zeqDxNy42y6OBJjiR6OxnHWl0YKDsdjXdwJlIUoi4pVUktlivOXjVs11q34xQAAQOwmOW2RilONCYiOc104kncBcQ9bHcDIGjozr7sauZFuYy6tinUEjhJxGBnW4+nzt7q41rAAF88OBoPBqMkAI7ZZLwcjDMjxMj4IikBQVDIH0RSrOUt4ckAA
diff --git a/shinyecharts/_core.py b/shinyecharts/_core.py
index cc62b23..283bbdf 100644
--- a/shinyecharts/_core.py
+++ b/shinyecharts/_core.py
@@ -5,11 +5,13 @@
 from pandas import DataFrame
 
 
+# -------------------------
+# Utils
+# -------------------------
 def snake_to_camel_case(snake_str: str) -> str:
     return snake_str[0].lower() + snake_str.title()[1:].replace("_", "")
 
 
-# TODO: Do not check for DataFrame instance here
 def df_to_dataset(df: DataFrame = None) -> dict:
     return {"dataset": {"source": [df.columns.to_list()] + df.to_numpy().tolist()}}
 
@@ -29,6 +31,9 @@ def to_dict(self):
         )
 
 
+# -------------------------
+# Option
+# -------------------------
 class BaseOption(object):
     CHART_TYPE: str = None
 
diff --git a/shinyecharts/chart.py b/shinyecharts/chart.py
index 03f183b..84a8fdd 100644
--- a/shinyecharts/chart.py
+++ b/shinyecharts/chart.py
@@ -20,41 +20,38 @@ class InitOptions(object):
 class Chart(object):
     """Chart"""
 
+    _theme: str = None
+    _option: dict = dict()
+    _data: DataFrame = None
+
     def __init__(
         self,
         init_options: InitOptions = InitOptions(),
-        theme: str | None = "dark",
+        theme: str = None,
         data: DataFrame = None,
     ) -> None:
-        self.init_options = init_options
-        self.theme = theme
-        self.data = data
-
-        # TODO: Move to class attributes
-        self.option = dict()
-
-    # TODO: Remove
-    def set_pie_data(self, data: DataFrame) -> Chart:
-        pass
+        self._init_options = init_options
+        self._theme = theme
+        self._data = data
 
     # Set option attributes
     def attr(self, **kwargs) -> Chart:
         pass
 
     # TODO: Set data here
-    def set_data(self, data: DataFrame) -> Chart:
+    def set_data(self, data: DataFrame | dict) -> Chart:
         pass
 
     def set_option(self, option: dict | ChartOption | BaseOption) -> Chart:
-        self.option = option if isinstance(option, dict) else option.to_dict()
+        self._option = option if isinstance(option, dict) else option.to_dict()
         return self
 
     def to_dict(self) -> dict:
         dataset = (
-            df_to_dataset(self.data) if isinstance(self.data, DataFrame) else dict()
+            df_to_dataset(self._data) if isinstance(self._data, DataFrame) else dict()
         )
         return {
-            "initOptions": asdict(self.init_options),
-            "option": dataset | self.option,
-            "theme": self.theme,
+            "initOptions": asdict(self._init_options),
+            "option": dataset | self._option,
+            "theme": self._theme,
         }
diff --git a/shinyecharts/chartcontext.py b/shinyecharts/chartcontext.py
new file mode 100644
index 0000000..84ae88f
--- /dev/null
+++ b/shinyecharts/chartcontext.py
@@ -0,0 +1,3 @@
+class ChartContext(object):
+    def __init__(self, id):
+        self.id = id
diff --git a/shinyecharts/express.py b/shinyecharts/express.py
index dd768f4..67b61c4 100644
--- a/shinyecharts/express.py
+++ b/shinyecharts/express.py
@@ -1,6 +1,54 @@
 from __future__ import annotations
 
+from pandas import DataFrame
 
+from .chart import Chart as BaseChart
+from .chart import InitOptions
+
+
+class Chart(BaseChart):
+    def __init__(self, options: InitOptions = InitOptions()):
+        super().__init__(options)
+        self._option = dict(xAxis=dict(), yAxis=dict())
+        self.legend()
+
+    def _update_option(self, **kwargs):
+        self._option.update(**kwargs)
+
+    def dark(self) -> Chart:
+        self._theme = "dark"
+        return self
+
+    def data(self, df: DataFrame) -> Chart:
+        self._data = df
+        return self
+
+    def x_axis(self, type: str = "value") -> Chart:
+        self._update_option(xAxis=dict(type=type))
+        return self
+
+    def y_axis(self):
+        return self
+
+    def encode(
+        self, x: str | int = "x", y: str | int = "y", type: str = "line", **kwargs
+    ) -> Chart:
+        if type == "bar":
+            self.x_axis("category")
+
+        series = dict(name=y, type=type, encode=dict(x=x, y=y)) | kwargs
+        if "series" in self._option.keys():
+            self._option["series"].append(series)
+        else:
+            self._update_option(series=[series])
+        return self
+
+    def legend(self, show=True, **kwargs) -> Chart:
+        self._option.update(legend=dict(show=True) | kwargs)
+        return self
+
+
+# -------------------------
 class PieChart(object):
     pass
 
diff --git a/tests/test_express.py b/tests/test_express.py
new file mode 100644
index 0000000..a0f58c1
--- /dev/null
+++ b/tests/test_express.py
@@ -0,0 +1,17 @@
+from pandas import DataFrame
+from shinyecharts.express import Chart
+
+
+def test_chart():
+    # Prepare
+    data = DataFrame([[1, 2], [2, 4]], columns=["x", "y"])
+
+    # Act
+    chart = Chart().dark().data(data).encode("x", "y")
+    print(chart._option)
+    print(chart.to_dict())
+
+    chart_dict = chart.to_dict()
+
+    # Assert
+    assert chart_dict["theme"] == "dark"