diff --git a/CHANGELOG.md b/CHANGELOG.md
index 86b59907..ccc2c32e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 **aiken**: Fancy errors using [miette](https://github.com/zkat/miette)
 **aiken**: Typechecking
+**aiken**: Inject `aiken/builtin` module with some functions from `DefaultFunction` in UPLC directly exposed
 **aiken-lang**: add `infer` method to `UntypedModule` which returns a `TypedModule`
 
 ### Changed
diff --git a/Cargo.lock b/Cargo.lock
index 6907b6d0..38d31c98 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -80,6 +80,7 @@ dependencies = [
  "itertools",
  "miette",
  "pretty_assertions",
+ "strum",
  "thiserror",
  "uplc",
  "vec1",
@@ -928,6 +929,12 @@ version = "0.1.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ef03e0a2b150c7a90d01faf6254c9c48a41e95fb2a8c2ac1c6f0d2b9aefc342"
 
+[[package]]
+name = "rustversion"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97477e48b4cf8603ad5f7aaf897467cf42ab4218a38ef76fb14c2d6773a6d6a8"
+
 [[package]]
 name = "rusty-fork"
 version = "0.3.0"
@@ -1010,6 +1017,25 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
+[[package]]
+name = "strum"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
+
+[[package]]
+name = "strum_macros"
+version = "0.24.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e385be0d24f186b4ce2f9982191e7101bb737312ad61c1f2f984f34bcf85d59"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn",
+]
+
 [[package]]
 name = "supports-color"
 version = "1.3.0"
@@ -1192,6 +1218,8 @@ dependencies = [
  "proptest",
  "serde",
  "serde_json",
+ "strum",
+ "strum_macros",
  "thiserror",
 ]
 
diff --git a/crates/cli/src/project.rs b/crates/cli/src/project.rs
index 7e53bea3..bc5ab999 100644
--- a/crates/cli/src/project.rs
+++ b/crates/cli/src/project.rs
@@ -37,7 +37,7 @@ impl Project {
         let mut module_types = HashMap::new();
 
         module_types.insert("aiken".to_string(), builtins::prelude(&id_gen));
-        module_types.insert("aiken/builtin".to_string(), builtins::plutus());
+        module_types.insert("aiken/builtin".to_string(), builtins::plutus(&id_gen));
 
         Project {
             config,
diff --git a/crates/lang/Cargo.toml b/crates/lang/Cargo.toml
index 29fd52a7..ea87771c 100644
--- a/crates/lang/Cargo.toml
+++ b/crates/lang/Cargo.toml
@@ -15,6 +15,7 @@ chumsky = "0.8.0"
 internment = "0.7.0"
 itertools = "0.10.5"
 miette = "5.2.0"
+strum = "0.24.1"
 thiserror = "1.0.37"
 uplc = { path = '../uplc', version = "0.0.21" }
 vec1 = "1.8.0"
diff --git a/crates/lang/src/builtins.rs b/crates/lang/src/builtins.rs
index e4cc5de5..f033b917 100644
--- a/crates/lang/src/builtins.rs
+++ b/crates/lang/src/builtins.rs
@@ -1,5 +1,7 @@
 use std::{cell::RefCell, collections::HashMap, sync::Arc};
 
+use strum::IntoEnumIterator;
+
 use uplc::builtins::DefaultFunction;
 
 use crate::{
@@ -212,7 +214,7 @@ pub fn prelude(id_gen: &IdGenerator) -> TypeInfo {
     prelude
 }
 
-pub fn plutus() -> TypeInfo {
+pub fn plutus(id_gen: &IdGenerator) -> TypeInfo {
     let mut plutus = TypeInfo {
         name: "aiken/builtin".to_string(),
         package: "".to_string(),
@@ -223,101 +225,174 @@ pub fn plutus() -> TypeInfo {
         accessors: HashMap::new(),
     };
 
-    plutus.values.insert(
-        DefaultFunction::AddInteger.to_string(),
-        DefaultFunction::AddInteger.into(),
-    );
-
-    plutus.values.insert(
-        DefaultFunction::SubtractInteger.to_string(),
-        DefaultFunction::SubtractInteger.into(),
-    );
-
-    plutus.values.insert(
-        DefaultFunction::MultiplyInteger.to_string(),
-        DefaultFunction::MultiplyInteger.into(),
-    );
-
-    plutus.values.insert(
-        DefaultFunction::DivideInteger.to_string(),
-        DefaultFunction::DivideInteger.into(),
-    );
+    for builtin in DefaultFunction::iter() {
+        if let Some(value) = from_default_function(builtin, id_gen) {
+            plutus.values.insert(
+                builtin.to_string().replace("ByteString", "ByteArray"),
+                value,
+            );
+        }
+    }
 
     plutus
 }
 
-impl From<DefaultFunction> for ValueConstructor {
-    fn from(builtin: DefaultFunction) -> Self {
-        let (tipo, arity) = match builtin {
-            DefaultFunction::AddInteger
-            | DefaultFunction::SubtractInteger
-            | DefaultFunction::MultiplyInteger
-            | DefaultFunction::DivideInteger
-            | DefaultFunction::QuotientInteger
-            | DefaultFunction::RemainderInteger
-            | DefaultFunction::ModInteger => {
-                let tipo = function(vec![int(), int()], int());
+pub fn from_default_function(
+    builtin: DefaultFunction,
+    id_gen: &IdGenerator,
+) -> Option<ValueConstructor> {
+    let info = match builtin {
+        DefaultFunction::AddInteger
+        | DefaultFunction::SubtractInteger
+        | DefaultFunction::MultiplyInteger
+        | DefaultFunction::DivideInteger
+        | DefaultFunction::QuotientInteger
+        | DefaultFunction::RemainderInteger
+        | DefaultFunction::ModInteger => {
+            let tipo = function(vec![int(), int()], int());
 
-                (tipo, 2)
-            }
+            Some((tipo, 2))
+        }
 
-            DefaultFunction::EqualsInteger
-            | DefaultFunction::LessThanInteger
-            | DefaultFunction::LessThanEqualsInteger => {
-                let tipo = function(vec![int(), int()], bool());
+        DefaultFunction::EqualsInteger
+        | DefaultFunction::LessThanInteger
+        | DefaultFunction::LessThanEqualsInteger => {
+            let tipo = function(vec![int(), int()], bool());
 
-                (tipo, 2)
-            }
-            DefaultFunction::AppendByteString => todo!(),
-            DefaultFunction::ConsByteString => todo!(),
-            DefaultFunction::SliceByteString => todo!(),
-            DefaultFunction::LengthOfByteString => todo!(),
-            DefaultFunction::IndexByteString => todo!(),
-            DefaultFunction::EqualsByteString => todo!(),
-            DefaultFunction::LessThanByteString => todo!(),
-            DefaultFunction::LessThanEqualsByteString => todo!(),
-            DefaultFunction::Sha2_256 => todo!(),
-            DefaultFunction::Sha3_256 => todo!(),
-            DefaultFunction::Blake2b_256 => todo!(),
-            DefaultFunction::VerifyEd25519Signature => todo!(),
-            DefaultFunction::VerifyEcdsaSecp256k1Signature => todo!(),
-            DefaultFunction::VerifySchnorrSecp256k1Signature => todo!(),
-            DefaultFunction::AppendString => todo!(),
-            DefaultFunction::EqualsString => todo!(),
-            DefaultFunction::EncodeUtf8 => todo!(),
-            DefaultFunction::DecodeUtf8 => todo!(),
-            DefaultFunction::IfThenElse => todo!(),
-            DefaultFunction::ChooseUnit => todo!(),
-            DefaultFunction::Trace => todo!(),
-            DefaultFunction::FstPair => todo!(),
-            DefaultFunction::SndPair => todo!(),
-            DefaultFunction::ChooseList => todo!(),
-            DefaultFunction::MkCons => todo!(),
-            DefaultFunction::HeadList => todo!(),
-            DefaultFunction::TailList => todo!(),
-            DefaultFunction::NullList => todo!(),
-            DefaultFunction::ChooseData => todo!(),
-            DefaultFunction::ConstrData => todo!(),
-            DefaultFunction::MapData => todo!(),
-            DefaultFunction::ListData => todo!(),
-            DefaultFunction::IData => todo!(),
-            DefaultFunction::BData => todo!(),
-            DefaultFunction::UnConstrData => todo!(),
-            DefaultFunction::UnMapData => todo!(),
-            DefaultFunction::UnListData => todo!(),
-            DefaultFunction::UnIData => todo!(),
-            DefaultFunction::UnBData => todo!(),
-            DefaultFunction::EqualsData => todo!(),
-            DefaultFunction::SerialiseData => todo!(),
-            DefaultFunction::MkPairData => todo!(),
-            DefaultFunction::MkNilData => todo!(),
-            DefaultFunction::MkNilPairData => todo!(),
-        };
+            Some((tipo, 2))
+        }
+        DefaultFunction::AppendByteString => {
+            let tipo = function(vec![byte_array(), byte_array()], byte_array());
 
+            Some((tipo, 2))
+        }
+        DefaultFunction::ConsByteString => {
+            let tipo = function(vec![int(), byte_array()], byte_array());
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::SliceByteString => {
+            let tipo = function(vec![int(), int(), byte_array()], byte_array());
+
+            Some((tipo, 3))
+        }
+        DefaultFunction::LengthOfByteString => {
+            let tipo = function(vec![byte_array()], int());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::IndexByteString => {
+            let tipo = function(vec![byte_array(), int()], int());
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::EqualsByteString
+        | DefaultFunction::LessThanByteString
+        | DefaultFunction::LessThanEqualsByteString => {
+            let tipo = function(vec![byte_array(), byte_array()], bool());
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::Sha2_256 | DefaultFunction::Sha3_256 | DefaultFunction::Blake2b_256 => {
+            let tipo = function(vec![byte_array()], byte_array());
+
+            Some((tipo, 1))
+        }
+
+        DefaultFunction::VerifyEd25519Signature => {
+            let tipo = function(vec![byte_array(), byte_array(), byte_array()], bool());
+
+            Some((tipo, 3))
+        }
+        DefaultFunction::VerifyEcdsaSecp256k1Signature => None,
+        DefaultFunction::VerifySchnorrSecp256k1Signature => None,
+        DefaultFunction::AppendString => {
+            let tipo = function(vec![string(), string()], string());
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::EqualsString => {
+            let tipo = function(vec![string(), string()], bool());
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::EncodeUtf8 => {
+            let tipo = function(vec![string()], byte_array());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::DecodeUtf8 => {
+            let tipo = function(vec![byte_array()], string());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::IfThenElse => None,
+        DefaultFunction::ChooseUnit => None,
+        DefaultFunction::Trace => {
+            let ret = generic_var(id_gen.next());
+
+            let tipo = function(vec![string(), ret.clone()], ret);
+
+            Some((tipo, 2))
+        }
+        DefaultFunction::FstPair => None,
+        DefaultFunction::SndPair => None,
+        DefaultFunction::ChooseList => None,
+        DefaultFunction::MkCons => None,
+        DefaultFunction::HeadList => {
+            let ret = generic_var(id_gen.next());
+
+            let tipo = function(vec![list(ret.clone())], ret);
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::TailList => {
+            let ret = list(generic_var(id_gen.next()));
+
+            let tipo = function(vec![ret.clone()], ret);
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::NullList => {
+            let ret = list(generic_var(id_gen.next()));
+
+            let tipo = function(vec![ret], bool());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::ChooseData => None,
+        DefaultFunction::ConstrData => None,
+        DefaultFunction::MapData => None,
+        DefaultFunction::ListData => None,
+        DefaultFunction::IData => None,
+        DefaultFunction::BData => None,
+        DefaultFunction::UnConstrData => None,
+        DefaultFunction::UnMapData => None,
+        DefaultFunction::UnListData => None,
+        DefaultFunction::UnIData => None,
+        DefaultFunction::UnBData => None,
+        DefaultFunction::EqualsData => {
+            let arg = generic_var(id_gen.next());
+
+            let tipo = function(vec![arg.clone(), arg], bool());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::SerialiseData => {
+            let tipo = function(vec![generic_var(id_gen.next())], byte_array());
+
+            Some((tipo, 1))
+        }
+        DefaultFunction::MkPairData => None,
+        DefaultFunction::MkNilData => None,
+        DefaultFunction::MkNilPairData => None,
+    };
+
+    info.map(|(tipo, arity)| {
         ValueConstructor::public(
             tipo,
             ValueConstructorVariant::ModuleFn {
-                name: builtin.to_string(),
+                name: builtin.to_string().replace("ByteString", "ByteArray"),
                 field_map: None,
                 module: "".to_string(),
                 arity,
@@ -325,7 +400,7 @@ impl From<DefaultFunction> for ValueConstructor {
                 builtin: Some(builtin),
             },
         )
-    }
+    })
 }
 
 pub fn int() -> Arc<Type> {
diff --git a/crates/uplc/Cargo.toml b/crates/uplc/Cargo.toml
index 4e2dcbd2..4f35e214 100644
--- a/crates/uplc/Cargo.toml
+++ b/crates/uplc/Cargo.toml
@@ -27,6 +27,8 @@ thiserror = "1.0.31"
 anyhow = "1.0.57"
 serde = { version = "1.0.144", features = ["derive"] }
 serde_json = "1.0.85"
+strum = "0.24.1"
+strum_macros = "0.24.3"
 
 [dev-dependencies]
 hex = "0.4.3"
diff --git a/crates/uplc/src/builtins.rs b/crates/uplc/src/builtins.rs
index 92872ee9..39eaf625 100644
--- a/crates/uplc/src/builtins.rs
+++ b/crates/uplc/src/builtins.rs
@@ -1,11 +1,13 @@
 use std::{fmt::Display, str::FromStr};
 
+use strum_macros::EnumIter;
+
 use flat_rs::de;
 
 /// All the possible builtin functions in Untyped Plutus Core.
 #[repr(u8)]
 #[allow(non_camel_case_types)]
-#[derive(Debug, Clone, PartialEq, Eq, Copy)]
+#[derive(Debug, Clone, PartialEq, Eq, Copy, EnumIter)]
 pub enum DefaultFunction {
     // Integer functions
     AddInteger = 0,
diff --git a/examples/sample/src/sample/context.ak b/examples/sample/src/sample/context.ak
new file mode 100644
index 00000000..5a07d7e2
--- /dev/null
+++ b/examples/sample/src/sample/context.ak
@@ -0,0 +1,8 @@
+pub type ScriptContext(purpose) {
+    tx_info: TxInfo,
+    script_purpose: purpose
+}
+
+pub type TxInfo {
+    idk: Int
+}
\ No newline at end of file
diff --git a/examples/sample/src/sample/mint.ak b/examples/sample/src/sample/mint.ak
new file mode 100644
index 00000000..2d54a356
--- /dev/null
+++ b/examples/sample/src/sample/mint.ak
@@ -0,0 +1,7 @@
+use sample/context
+
+pub type Mint {
+    currency_symbol: ByteArray
+}
+
+pub type ScriptContext = context.ScriptContext(Mint)
\ No newline at end of file
diff --git a/examples/sample/src/sample/spend.ak b/examples/sample/src/sample/spend.ak
new file mode 100644
index 00000000..1f11f897
--- /dev/null
+++ b/examples/sample/src/sample/spend.ak
@@ -0,0 +1,7 @@
+use sample/context
+
+pub type Spend {
+    idk: Int
+}
+
+pub type ScriptContext = context.ScriptContext(Spend)
\ No newline at end of file
diff --git a/examples/sample/src/sample/syntax.ak b/examples/sample/src/sample/syntax.ak
deleted file mode 100644
index 283b132e..00000000
--- a/examples/sample/src/sample/syntax.ak
+++ /dev/null
@@ -1,13 +0,0 @@
-use aiken/builtin.{addInteger}
-
-pub type ScriptContext {
-  idk: Int
-}
-
-pub fn append(a: ByteArray, b: ByteArray) -> ByteArray {
-  todo
-}
-
-pub fn add(a, b) {
-  addInteger(a, b)
-}
\ No newline at end of file
diff --git a/examples/sample/src/scripts/swap.ak b/examples/sample/src/scripts/swap.ak
index 8b395a43..6893941b 100644
--- a/examples/sample/src/scripts/swap.ak
+++ b/examples/sample/src/scripts/swap.ak
@@ -1,5 +1,5 @@
-use sample
-use sample/syntax.{append}
+use sample/mint
+use sample/spend
 
 pub type Datum {
   something: String,
@@ -10,13 +10,7 @@ pub type Redeemer {
   Sell
 }
 
-pub fn validate(datum: Datum, rdmr: Redeemer, ctx: sample.ScriptContext) -> Bool {
-  let thing = if True {
-    3
-  } else {
-    "thing"
-  }
-
+pub fn spend(datum: Datum, rdmr: Redeemer, ctx: spend.ScriptContext) -> Bool {
   when rdmr is {
     Buy -> True
     Sell -> datum.something == "Aiken"