diff --git a/Cargo.toml b/Cargo.toml
index ad49935..7eb41dc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "oink"
-version = "0.2.1"
+version = "0.2.2"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
diff --git a/src/config.rs b/src/config.rs
index 4a15926..5b05e4d 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -17,8 +17,8 @@ use toml::{
 
 use crate::{ error, util };
 
-pub type Context = BTreeMap<String, ContextValue>;
-pub type Table = toml::map::Map<String, Value>;
+pub type Context	= BTreeMap<String, ContextValue>;
+pub type Table		= toml::map::Map<String, Value>;
 
 ///	configuration struct
 pub struct Config {
@@ -59,13 +59,15 @@ impl Config {
 	///	build context from "vars" and "colors" config sections
 	pub fn context(&self, target: &Table) -> Context {
 		let mut output = Context::new();
+		let mut def: Vec<ContextValue> = Vec::new();
 
 		//	pull global vars
 		if let Some(Value::Table(vars)) = self.inner.get("vars") {
 			for (key, value) in vars.iter() {
 				let key = key.to_owned();
 				if let Some(value) = util::convert(value) {
-					output.insert(key, value);
+					output.insert(key.clone(), value);
+					def.push(ContextValue::String(key));
 				}
 			}
 		}
@@ -74,7 +76,9 @@ impl Config {
 		for (key, value) in target.iter() {
 			if key.to_uppercase() == *key {
 				if let Some(value) = util::convert(value) {
-					output.insert(key.to_owned(), value);
+					let key = key.to_owned();
+					output.insert(key.clone(), value);
+					def.push(ContextValue::String(key));
 				}
 			}
 		}
@@ -91,10 +95,15 @@ impl Config {
 				for(key, value) in palette.iter() {
 					output.insert(key.to_owned(), value.as_str().unwrap().into());
 				}
-				output.insert("palette".to_string(), colors.into());
+				let key = "palette".to_string();
+				output.insert(key.clone(), colors.into());
+				def.push(ContextValue::String(key));
 			}
 		}
 
+		//	insert set vars list
+		output.insert("def".to_string(), def.into());
+
 		output
 	}
 
diff --git a/src/filter.rs b/src/filter.rs
new file mode 100644
index 0000000..591beae
--- /dev/null
+++ b/src/filter.rs
@@ -0,0 +1,7 @@
+
+use upon::Value;
+
+pub fn has(list: Vec<Value>, key: String) -> bool {
+	return list.contains(&Value::String(key));
+}
+
diff --git a/src/main.rs b/src/main.rs
index 7659394..5c60335 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ use pico_args::Arguments;
 
 mod config;
 mod error;
+mod filter;
 mod operation;
 mod util;
 
diff --git a/src/operation.rs b/src/operation.rs
index 34c7af1..447c854 100644
--- a/src/operation.rs
+++ b/src/operation.rs
@@ -17,7 +17,10 @@ use termion::{
 use toml::{ map::Map, Value };
 use upon::Engine;
 
-use crate::config::Config;
+use crate::{
+	config::Config,
+	filter
+};
 
 static SUCCESS: Fg<color::Green>	= Fg(color::Green);
 static WARNING: Fg<color::Yellow>	= Fg(color::Yellow);
@@ -68,7 +71,8 @@ pub fn build(targets: &Vec<Map<String, Value>>, template_dir: String, config: &C
 	let home = var("HOME").unwrap();
 	println!("running build:");
 
-	let engine = Engine::new();
+	let mut engine = Engine::new();
+	engine.add_filter("has", filter::has);
 
 	for target in targets {
 		let context = config.context(target);