diff --git a/src/node/handler.rs b/src/node/handler.rs
new file mode 100644
index 0000000..018d4dd
--- /dev/null
+++ b/src/node/handler.rs
@@ -0,0 +1,53 @@
+pub trait NodeHandler {
+    fn run(&self, inputs: Vec<f64>) -> f64;
+}
+
+pub struct NodeFunction {
+    function: fn(Vec<f64>) -> f64,
+}
+
+impl NodeFunction {
+    pub fn new(function: fn(Vec<f64>) -> f64) -> NodeFunction {
+        NodeFunction { function }
+    }
+}
+
+impl NodeHandler for NodeFunction {
+    fn run(&self, inputs: Vec<f64>) -> f64 {
+        (self.function)(inputs)
+    }
+}
+
+pub struct NodeNumber {
+    number: f64,
+}
+
+impl NodeNumber {
+    pub fn new(number: Option<f64>) -> NodeNumber {
+        NodeNumber {
+            number: number.unwrap_or(0f64),
+        }
+    }
+}
+
+impl NodeHandler for NodeNumber {
+    fn run(&self, inputs: Vec<f64>) -> f64 {
+        self.number
+    }
+}
+
+pub struct NodeVariable {
+    getter: fn() -> f64,
+}
+
+impl NodeVariable {
+    pub fn new(getter: fn() -> f64) -> NodeVariable {
+        NodeVariable { getter }
+    }
+}
+
+impl NodeHandler for NodeVariable {
+    fn run(&self, inputs: Vec<f64>) -> f64 {
+        (self.getter)()
+    }
+}