diff --git a/crates/console/prometeu-vm/src/builtins.rs b/crates/console/prometeu-vm/src/builtins.rs
index b4f2184a..845761b7 100644
--- a/crates/console/prometeu-vm/src/builtins.rs
+++ b/crates/console/prometeu-vm/src/builtins.rs
@@ -109,6 +109,11 @@ impl BuiltinTypeMeta {
         out
     }
 
+    pub fn validate_flat_values(&self, values: &[Value]) -> Result<(), BuiltinValueError> {
+        let layout = self.flatten_layout();
+        validate_values_against_layout(values, &layout)
+    }
+
     fn flatten_into(&self, out: &mut Vec<AbiType>) {
         match self.shape {
             BuiltinTypeShape::Scalar => out.extend_from_slice(self.flat_slot_layout),
@@ -153,6 +158,18 @@ impl BuiltinConstMeta {
             BuiltinConstMaterializer::Hook(_) => None,
         }
     }
+
+    pub fn materialize(&self) -> Result<Vec<Value>, BuiltinValueError> {
+        let values = match self.materializer {
+            BuiltinConstMaterializer::Direct(slots) => {
+                slots.iter().copied().map(BuiltinConstSlotValue::into_value).collect()
+            }
+            BuiltinConstMaterializer::Hook(hook) => hook(),
+        };
+
+        validate_values_against_layout(&values, self.flat_slot_layout)?;
+        Ok(values)
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -161,6 +178,12 @@ pub enum IntrinsicExecutionError {
     TypeMismatch { index: usize, expected: AbiType },
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum BuiltinValueError {
+    ArityMismatch { expected: usize, got: usize },
+    TypeMismatch { index: usize, expected: AbiType },
+}
+
 pub type IntrinsicImplementation = fn(&[Value]) -> Result<Vec<Value>, IntrinsicExecutionError>;
 
 #[derive(Debug, Clone, Copy)]
@@ -207,6 +230,18 @@ impl IntrinsicMeta {
     }
 }
 
+impl BuiltinConstSlotValue {
+    pub fn into_value(self) -> Value {
+        match self {
+            BuiltinConstSlotValue::Int32(value) => Value::Int32(value),
+            BuiltinConstSlotValue::Int64(value) => Value::Int64(value),
+            BuiltinConstSlotValue::Float(value) => Value::Float(value),
+            BuiltinConstSlotValue::Bool(value) => Value::Boolean(value),
+            BuiltinConstSlotValue::NominalBuiltin { carrier, .. } => Value::Int32(carrier),
+        }
+    }
+}
+
 const COLOR: BuiltinTypeKey = BuiltinTypeKey::new("color", 1);
 const VEC2: BuiltinTypeKey = BuiltinTypeKey::new("vec2", 1);
 const PIXEL: BuiltinTypeKey = BuiltinTypeKey::new("pixel", 1);
@@ -345,6 +380,14 @@ pub fn lookup_builtin_constant(
     })
 }
 
+pub fn materialize_builtin_constant(
+    target: &str,
+    name: &str,
+    version: u16,
+) -> Result<Option<Vec<Value>>, BuiltinValueError> {
+    lookup_builtin_constant(target, name, version).map(BuiltinConstMeta::materialize).transpose()
+}
+
 pub fn lookup_intrinsic(owner: &str, name: &str, version: u16) -> Option<&'static IntrinsicMeta> {
     INTRINSICS
         .iter()
@@ -386,6 +429,23 @@ fn value_matches_abi_type(value: &Value, expected: AbiType) -> bool {
     }
 }
 
+fn validate_values_against_layout(
+    values: &[Value],
+    layout: &[AbiType],
+) -> Result<(), BuiltinValueError> {
+    if values.len() != layout.len() {
+        return Err(BuiltinValueError::ArityMismatch { expected: layout.len(), got: values.len() });
+    }
+
+    for (index, (value, expected)) in values.iter().zip(layout.iter()).enumerate() {
+        if !value_matches_abi_type(value, *expected) {
+            return Err(BuiltinValueError::TypeMismatch { index, expected: *expected });
+        }
+    }
+
+    Ok(())
+}
+
 fn vec2_dot(args: &[Value]) -> Result<Vec<Value>, IntrinsicExecutionError> {
     if args.len() != 4 {
         return Err(IntrinsicExecutionError::ArityMismatch { expected: 4, got: args.len() });
@@ -462,6 +522,18 @@ mod tests {
         assert!(lookup_intrinsic("vec2", "zero", 1).is_none());
     }
 
+    #[test]
+    fn builtin_constant_materializes_vec2_zero() {
+        let zero = lookup_builtin_constant("vec2", "zero", 1).expect("vec2.zero must exist");
+        let materialized = zero.materialize().expect("vec2.zero must materialize");
+        assert_eq!(materialized, vec![Value::Float(0.0), Value::Float(0.0)]);
+
+        let looked_up = materialize_builtin_constant("vec2", "zero", 1)
+            .expect("materialization lookup must succeed")
+            .expect("constant must exist");
+        assert_eq!(looked_up, materialized);
+    }
+
     #[test]
     fn intrinsic_metadata_exposes_arg_and_return_layouts() {
         let dot = lookup_intrinsic("vec2", "dot", 1).expect("vec2.dot must exist");
@@ -493,4 +565,13 @@ mod tests {
             .expect("length implementation must execute");
         assert_eq!(result, vec![Value::Float(5.0)]);
     }
+
+    #[test]
+    fn pixel_flat_values_validate_with_color_carrier_slot() {
+        let pixel = lookup_builtin_type("pixel", 1).expect("pixel builtin must exist");
+        let values = vec![Value::Int32(1), Value::Int32(2), Value::Int32(0xF800)];
+        pixel.validate_flat_values(&values).expect("pixel flat values must validate");
+        assert_eq!(pixel.flat_slot_width, 3);
+        assert_eq!(pixel.field("color").map(|field| field.start_slot), Some(2));
+    }
 }
diff --git a/crates/console/prometeu-vm/src/lib.rs b/crates/console/prometeu-vm/src/lib.rs
index aff34942..22489a4d 100644
--- a/crates/console/prometeu-vm/src/lib.rs
+++ b/crates/console/prometeu-vm/src/lib.rs
@@ -17,9 +17,9 @@ mod vm_init_error;
 pub use builtins::{
     AbiType, BuiltinConstKey, BuiltinConstMaterializer, BuiltinConstMeta, BuiltinConstSlotValue,
     BuiltinFieldMeta, BuiltinLayoutType, BuiltinScalarType, BuiltinTypeKey, BuiltinTypeMeta,
-    BuiltinTypeShape, IntrinsicExecutionError, IntrinsicImplementation, IntrinsicKey,
-    IntrinsicMeta, lookup_builtin_constant, lookup_builtin_type, lookup_intrinsic,
-    lookup_intrinsic_by_id,
+    BuiltinTypeShape, BuiltinValueError, IntrinsicExecutionError, IntrinsicImplementation,
+    IntrinsicKey, IntrinsicMeta, lookup_builtin_constant, lookup_builtin_type, lookup_intrinsic,
+    lookup_intrinsic_by_id, materialize_builtin_constant,
 };
 pub use prometeu_hal::{HostContext, HostReturn, NativeInterface, SyscallId};
 pub use virtual_machine::{BudgetReport, LogicalFrameEndingReason, VirtualMachine};