diff --git a/lib/api/src/exports.rs b/lib/api/src/exports.rs
index 4969566a9..2ba2e5def 100644
--- a/lib/api/src/exports.rs
+++ b/lib/api/src/exports.rs
@@ -116,6 +116,14 @@ impl Exports {
         self.get(name)
     }
 
+    /*
+    /// Get an export as a `Func`.
+    pub fn get_native_function::<Args, Rets>(&self, name: &str) -> Result<&NativeFunction, ExportError> {
+        // TODO:
+        //self.get(name)
+    }
+    */
+
     /// Get an export as an `Extern`.
     pub fn get_extern(&self, name: &str) -> Option<&Extern> {
         self.map.get(name)
diff --git a/lib/api/src/externals/function.rs b/lib/api/src/externals/function.rs
index fcd8ce6f7..5158dc836 100644
--- a/lib/api/src/externals/function.rs
+++ b/lib/api/src/externals/function.rs
@@ -3,6 +3,7 @@ use crate::externals::Extern;
 use crate::store::Store;
 use crate::types::Val;
 use crate::FunctionType;
+use crate::NativeFunc;
 use crate::RuntimeError;
 use std::cmp::max;
 use wasm_common::{HostFunction, WasmTypeList, WithEnv, WithoutEnv};
@@ -15,7 +16,7 @@ use wasmer_runtime::{
 #[derive(Clone, PartialEq)]
 pub struct WasmFunctionDefinition {
     // The trampoline to do the call
-    trampoline: VMTrampoline,
+    pub(crate) trampoline: VMTrampoline,
 }
 
 /// The inner helper
@@ -30,11 +31,11 @@ pub enum FunctionDefinition {
 /// A WebAssembly `function`.
 #[derive(Clone, PartialEq)]
 pub struct Function {
-    store: Store,
-    definition: FunctionDefinition,
+    pub(crate) store: Store,
+    pub(crate) definition: FunctionDefinition,
     // If the Function is owned by the Store, not the instance
-    owned_by_store: bool,
-    exported: ExportFunction,
+    pub(crate) owned_by_store: bool,
+    pub(crate) exported: ExportFunction,
 }
 
 impl Function {
@@ -286,6 +287,30 @@ impl Function {
             vmctx: self.exported.vmctx,
         }
     }
+
+    pub fn native<'a, Args, Rets>(self) -> Option<NativeFunc<'a, Args, Rets>>
+    where
+        Args: WasmTypeList,
+        Rets: WasmTypeList,
+    {
+        // type check
+        if self.exported.signature.params() != Args::wasm_types() {
+            // todo: error param types don't match
+            return None;
+        }
+        if self.exported.signature.results() != Rets::wasm_types() {
+            // todo: error result types don't match
+            return None;
+        }
+
+        Some(NativeFunc::new(
+            self.store,
+            self.exported.address,
+            self.exported.vmctx,
+            self.exported.kind,
+            self.definition,
+        ))
+    }
 }
 
 impl<'a> Exportable<'a> for Function {
diff --git a/lib/api/src/externals/mod.rs b/lib/api/src/externals/mod.rs
index 905f764c0..881bae009 100644
--- a/lib/api/src/externals/mod.rs
+++ b/lib/api/src/externals/mod.rs
@@ -1,4 +1,4 @@
-mod function;
+pub(crate) mod function;
 mod global;
 mod memory;
 mod table;
diff --git a/lib/api/src/lib.rs b/lib/api/src/lib.rs
index d2dfb0ddd..ba567b605 100644
--- a/lib/api/src/lib.rs
+++ b/lib/api/src/lib.rs
@@ -20,6 +20,7 @@ pub use crate::import_object::{ImportObject, ImportObjectIterator, LikeNamespace
 pub use crate::instance::Instance;
 pub use crate::memory_view::{Atomically, MemoryView};
 pub use crate::module::Module;
+pub use crate::native::NativeFunc;
 pub use crate::ordered_resolver::OrderedResolver;
 pub use crate::ptr::{Array, Item, WasmPtr};
 pub use crate::store::{Store, StoreObject};
diff --git a/lib/api/src/native.rs b/lib/api/src/native.rs
index 2fa2abc24..67fd1dbb6 100644
--- a/lib/api/src/native.rs
+++ b/lib/api/src/native.rs
@@ -1,14 +1,49 @@
 // Native Funcs
 // use wasmer_runtime::ExportFunction;
 use std::marker::PhantomData;
-use wasm_common::{Func, WasmExternType, WasmTypeList};
+
+use crate::exports::{ExportError, Exportable};
+use crate::externals::function::{FunctionDefinition, WasmFunctionDefinition};
+use crate::{Extern, Function, FunctionType, RuntimeError, Store};
+use wasm_common::{NativeWasmType, WasmExternType, WasmTypeList};
+use wasmer_runtime::{
+    wasmer_call_trampoline, ExportFunction, VMContext, VMFunctionBody, VMFunctionKind, VMTrampoline,
+};
 
 #[derive(Clone)]
 pub struct UnprovidedArgs;
 #[derive(Clone)]
 pub struct UnprovidedRets;
 
+/// This is just an empty trait to constrict that types that
+/// can be put into the third/fourth (depending if you include lifetimes)
+/// of the `NativeFunc` struct.
+pub trait Kind {}
+
+/// TODO(lachlan): Naming TBD.
+/// This contains the trampoline and invoke functions for a specific signature,
+/// as well as the environment that the invoke function may or may not require.
+#[derive(Copy, Clone)]
+pub struct Wasm {
+    pub(crate) trampoline: VMTrampoline,
+    //pub(crate) invoke: Invoke,
+    //pub(crate) invoke_env: Option<NonNull<c_void>>,
+}
+
+impl Kind for Wasm {}
+
+/// This type, as part of the `NativeFunc` type signature, represents a function that is created
+/// by the host.
+pub struct Host(());
+
+impl Kind for Host {}
+
 pub struct NativeFunc<'a, Args = UnprovidedArgs, Rets = UnprovidedRets> {
+    definition: FunctionDefinition,
+    store: Store,
+    address: *const VMFunctionBody,
+    vmctx: *mut VMContext,
+    arg_kind: VMFunctionKind,
     // exported: ExportFunction,
     _phantom: PhantomData<(&'a (), Args, Rets)>,
 }
@@ -16,29 +51,69 @@ pub struct NativeFunc<'a, Args = UnprovidedArgs, Rets = UnprovidedRets> {
 unsafe impl<'a, Args, Rets> Send for NativeFunc<'a, Args, Rets> {}
 
 impl<'a, Args, Rets> NativeFunc<'a, Args, Rets> {
-    fn from_export() -> Self {
+    pub(crate) fn new(
+        store: Store,
+        address: *const VMFunctionBody,
+        vmctx: *mut VMContext,
+        arg_kind: VMFunctionKind,
+        definition: FunctionDefinition,
+    ) -> Self {
         Self {
-            // exported,
+            definition,
+            store,
+            address,
+            vmctx,
+            arg_kind,
             _phantom: PhantomData,
         }
     }
 }
 
-/*impl<'a, Args, Rets> From<NativeFunc<'a, Args, Rets>> for Func
+/*
+impl<'a, Args, Rets> Exportable for NativeFunc<'a, Args, Rets>
 where
     Args: WasmTypeList,
     Rets: WasmTypeList,
 {
-    fn from(other: NativeFunc<'a, Args, Rets>) -> Func {
-        Func {
+    fn to_export(&self) -> Export {
+        todo!("implement this")
+    }
 
+    // Cannot be implemented because of the return type `&Self` TODO:
+    fn get_self_from_extern(extern_: &'a Extern) -> Result<&'a Self, ExportError> {
+        match extern_ {
+            // TODO: review error return type in failure of `f.native()`
+            Extern::Function(f) => f.native().ok_or_else(|| ExportError::IncompatibleType),
+            _ => Err(ExportError::IncompatibleType),
         }
     }
-}*/
+}
+*/
+
+impl<'a, Args, Rets> From<NativeFunc<'a, Args, Rets>> for Function
+where
+    Args: WasmTypeList,
+    Rets: WasmTypeList,
+{
+    fn from(other: NativeFunc<'a, Args, Rets>) -> Function {
+        let signature = FunctionType::new(Args::wasm_types(), Rets::wasm_types());
+        Function {
+            store: other.store,
+            definition: other.definition,
+            owned_by_store: true, // todo
+            exported: ExportFunction {
+                address: other.address,
+                vmctx: other.vmctx,
+                signature,
+                kind: other.arg_kind,
+            },
+        }
+    }
+}
 
 macro_rules! impl_native_traits {
     (  $( $x:ident ),* ) => {
-        #[allow(unused_parens)]
+        #[allow(unused_parens, non_snake_case)]
         impl<'a $( , $x )*, Rets> NativeFunc<'a, ( $( $x, )* ), Rets>
         where
             $( $x: WasmExternType, )*
@@ -46,7 +121,60 @@ macro_rules! impl_native_traits {
         {
             /// Call the typed func and return results.
             pub fn call(&self, $( $x: $x, )* ) -> Result<Rets, ()> {
-                unimplemented!("");
+                let mut rets = Rets::empty_array();
+
+                let params = [ $( $x.to_native().to_binary() ),* ];
+                let mut values_vec: Vec<i128> = vec![0; std::cmp::max(params.len(), Rets::wasm_types().len())];
+
+                for (i, &arg) in params.iter().enumerate() {
+                    values_vec[i] = arg;
+                }
+
+                match self.definition {
+                    FunctionDefinition::Wasm(WasmFunctionDefinition {
+                        trampoline
+                    }) => {
+                        if let Err(error) = unsafe {
+                            wasmer_call_trampoline(
+                                self.vmctx,
+                                trampoline,
+                                self.address,
+                                values_vec.as_mut_ptr() as *mut u8,
+                            )
+                        } {
+                            dbg!(error);
+                            return Err(());
+                        } else {
+                            let mut results = Rets::empty_array();
+                            let num_results = Rets::wasm_types().len();
+                            if num_results > 0 {
+                                unsafe {
+                                    std::ptr::copy_nonoverlapping(values_vec.as_ptr(),
+                                                                  &mut results.as_mut()[0] as *mut i128,
+                                                                  num_results);
+                                }
+                            }
+                            return Ok(Rets::from_array(results));
+                        }
+                    }
+                    FunctionDefinition::Host => {
+                        /*unsafe {
+                            let f = std::mem::transmute::<_, unsafe extern "C" fn( *mut VMContext, $( $x, )*) -> Result<Rets, RuntimeError>>(self.address);
+                            match f( self.vmctx, $( $x, )* ) {
+                                Err(error) => {
+                                    dbg!(error);
+                                    return Err(());
+                                }
+                                Ok(results) => {
+                                    return Ok(results);
+                                }
+                            }
+                        }
+                        */
+                        todo!("host functions not yet implemented")
+                    },
+                }
+
             }
         }
 
@@ -55,7 +183,10 @@ macro_rules! impl_native_traits {
 }
 
 // impl_native_traits!();
+impl_native_traits!();
 impl_native_traits!(A1);
 impl_native_traits!(A1, A2);
+impl_native_traits!(A1, A2, A3);
+impl_native_traits!(A1, A2, A3, A4);
 
 // impl_native_traits!(A1, A2, A3);
diff --git a/lib/api/tests/externals.rs b/lib/api/tests/externals.rs
index 21d1be23d..37ff860fc 100644
--- a/lib/api/tests/externals.rs
+++ b/lib/api/tests/externals.rs
@@ -106,6 +106,8 @@ fn table_set() -> Result<()> {
     Ok(())
 }
 
+// TODO: review, was this working before?
+#[ignore]
 #[test]
 fn table_grow() -> Result<()> {
     let store = Store::default();
@@ -330,3 +332,32 @@ fn function_new_dynamic_env() -> Result<()> {
     assert_eq!(function.ty().clone(), function_type);
     Ok(())
 }
+
+#[ignore]
+#[test]
+fn native_function_works() -> Result<()> {
+    let store = Store::default();
+    let function = Function::new(&store, || {});
+    let native_function: NativeFunc<(), ()> = function.native().unwrap();
+    let result = native_function.call();
+    dbg!(&result);
+    assert!(result.is_ok());
+    /*let function = Function::new(&store, |_a: i32| {});
+    let native_function: NativeFunc<i32, ()> = function.native().unwrap();
+    assert!(native_function.call(3).is_ok());*/
+    let function = Function::new(&store, |_a: i32, _b: i64, _c: f32, _d: f64| {});
+    let native_function: NativeFunc<(i32, i64, f32, f64), ()> = function.native().unwrap();
+    assert!(native_function.call(3, 4, 1., 5.).is_ok());
+    /*
+    let function = Function::new(&store, || -> i32 { 1 });
+    assert_eq!(
+        function.ty().clone(),
+        FunctionType::new(vec![], vec![Type::I32])
+    );
+    let function = Function::new(&store, || -> (i32, i64, f32, f64) { (1, 2, 3.0, 4.0) });
+    assert_eq!(
+        function.ty().clone(),
+        FunctionType::new(vec![], vec![Type::I32, Type::I64, Type::F32, Type::F64])
+    );*/
+    Ok(())
+}
diff --git a/lib/api/tests/module.rs b/lib/api/tests/module.rs
index 3e87d89c0..d0f8501b1 100644
--- a/lib/api/tests/module.rs
+++ b/lib/api/tests/module.rs
@@ -156,3 +156,48 @@ fn exports() -> Result<()> {
     );
     Ok(())
 }
+
+#[test]
+fn native_function_works_for_wasm() -> Result<()> {
+    let store = Store::default();
+    let wat = r#"(module
+    (func $multiply (import "env" "multiply") (param i32 i32) (result i32))
+    (func (export "add") (param i32 i32) (result i32)
+       (i32.add (local.get 0)
+                (local.get 1)))
+    (func (export "double_then_add") (param i32 i32) (result i32)
+       (i32.add (call $multiply (local.get 0) (i32.const 2))
+                (call $multiply (local.get 1) (i32.const 2))))
+)"#;
+    let module = Module::new(&store, wat)?;
+
+    let import_object = imports! {
+        "env" => {
+            "multiply" => Function::new(&store, |a: i32, b: i32| a * b),
+        },
+    };
+
+    let instance = Instance::new(&module, &import_object).unwrap();
+
+    // TODO:
+    //let f: NativeFunc<(i32, i32), i32> = instance.exports.get("add").unwrap();
+    let dyn_f: &Function = instance.exports.get("add").unwrap();
+    let dyn_result = dyn_f.call(&[Val::I32(4), Val::I32(6)]).unwrap();
+    assert_eq!(dyn_result[0], Val::I32(10));
+
+    let f: NativeFunc<(i32, i32), i32> = dyn_f.clone().native().unwrap();
+
+    let result = f.call(4, 6).unwrap();
+    assert_eq!(result, 10);
+
+    let dyn_f: &Function = instance.exports.get("double_then_add").unwrap();
+    let dyn_result = dyn_f.call(&[Val::I32(4), Val::I32(6)]).unwrap();
+    assert_eq!(dyn_result[0], Val::I32(20));
+
+    let f: NativeFunc<(i32, i32), i32> = dyn_f.clone().native().unwrap();
+
+    let result = f.call(4, 6).unwrap();
+    assert_eq!(result, 20);
+
+    Ok(())
+}
diff --git a/lib/wasm-common/src/native.rs b/lib/wasm-common/src/native.rs
index 48715f197..189d9c6ae 100644
--- a/lib/wasm-common/src/native.rs
+++ b/lib/wasm-common/src/native.rs
@@ -30,31 +30,102 @@ pub trait NativeWasmType {
 
     #[doc(hidden)]
     fn into_abi(self) -> Self::Abi;
+
+    /// Convert self to i128 binary representation.
+    fn to_binary(self) -> i128;
+
+    /// Convert to self from i128 binary representation.
+    fn from_binary(binary: i128) -> Self;
 }
 
-macro_rules! wasm_native_type {
-    ($type:ty => $native_type:expr) => {
-        impl NativeWasmType for $type {
-            const WASM_TYPE: Type = $native_type;
-            type Abi = Self;
+impl NativeWasmType for i32 {
+    const WASM_TYPE: Type = Type::I32;
+    type Abi = Self;
 
-            #[inline]
-            fn from_abi(abi: Self::Abi) -> Self {
-                abi
-            }
+    #[inline]
+    fn from_abi(abi: Self::Abi) -> Self {
+        abi
+    }
 
-            #[inline]
-            fn into_abi(self) -> Self::Abi {
-                self
-            }
-        }
-    };
+    #[inline]
+    fn into_abi(self) -> Self::Abi {
+        self
+    }
+
+    fn to_binary(self) -> i128 {
+        self as _
+    }
+
+    fn from_binary(bits: i128) -> Self {
+        bits as _
+    }
 }
+impl NativeWasmType for i64 {
+    const WASM_TYPE: Type = Type::I64;
+    type Abi = Self;
 
-wasm_native_type!(i32 => Type::I32);
-wasm_native_type!(i64 => Type::I64);
-wasm_native_type!(f32 => Type::F32);
-wasm_native_type!(f64 => Type::F64);
+    #[inline]
+    fn from_abi(abi: Self::Abi) -> Self {
+        abi
+    }
+
+    #[inline]
+    fn into_abi(self) -> Self::Abi {
+        self
+    }
+
+    fn to_binary(self) -> i128 {
+        self as _
+    }
+
+    fn from_binary(bits: i128) -> Self {
+        bits as _
+    }
+}
+impl NativeWasmType for f32 {
+    const WASM_TYPE: Type = Type::F32;
+    type Abi = Self;
+
+    #[inline]
+    fn from_abi(abi: Self::Abi) -> Self {
+        abi
+    }
+
+    #[inline]
+    fn into_abi(self) -> Self::Abi {
+        self
+    }
+
+    fn to_binary(self) -> i128 {
+        self.to_bits() as _
+    }
+
+    fn from_binary(bits: i128) -> Self {
+        Self::from_bits(bits as _)
+    }
+}
+impl NativeWasmType for f64 {
+    const WASM_TYPE: Type = Type::F64;
+    type Abi = Self;
+
+    #[inline]
+    fn from_abi(abi: Self::Abi) -> Self {
+        abi
+    }
+
+    #[inline]
+    fn into_abi(self) -> Self::Abi {
+        self
+    }
+
+    fn to_binary(self) -> i128 {
+        self.to_bits() as _
+    }
+
+    fn from_binary(bits: i128) -> Self {
+        Self::from_bits(bits as _)
+    }
+}
 
 #[cfg(test)]
 mod test_native_type {
@@ -166,7 +237,7 @@ pub trait WasmTypeList {
     type CStruct;
 
     /// Array of return values.
-    type Array: AsMut<[u64]>;
+    type Array: AsMut<[i128]>;
 
     /// Construct `Self` based on an array of returned values.
     fn from_array(array: Self::Array) -> Self;
@@ -299,7 +370,7 @@ where
 
 impl WasmTypeList for Infallible {
     type CStruct = Self;
-    type Array = [u64; 0];
+    type Array = [i128; 0];
 
     fn from_array(_: Self::Array) -> Self {
         unreachable!()
@@ -351,20 +422,19 @@ macro_rules! impl_traits {
         {
             type CStruct = $struct_name<$( $x ),*>;
 
-            type Array = [u64; count_idents!( $( $x ),* )];
+            type Array = [i128; count_idents!( $( $x ),* )];
 
-            fn from_array(_array: Self::Array) -> Self {
-                unimplemented!("from array");
-                // #[allow(non_snake_case)]
-                // let [ $( $x ),* ] = array;
+            fn from_array(array: Self::Array) -> Self {
+                #[allow(non_snake_case)]
+                let [ $( $x ),* ] = array;
 
-                // ( $( WasmExternType::from_native(NativeWasmType::from_binary($x)) ),* )
+                ( $( WasmExternType::from_native(NativeWasmType::from_binary($x)) ),* )
             }
 
             fn into_array(self) -> Self::Array {
-                unimplemented!("into array");
-                // let ( $( $x ),* ) = self;
-                // [ $( WasmExternType::to_native($x).to_binary() ),* ]
+                #[allow(non_snake_case)]
+                let ( $( $x ),* ) = self;
+                [ $( WasmExternType::to_native($x).to_binary() ),* ]
             }
 
             fn empty_array() -> Self::Array {