--- a/bindings/jsonnet/Cargo.toml
+++ b/bindings/jsonnet/Cargo.toml
@@ -11,6 +11,7 @@
 jrsonnet-interner = { path = "../../crates/jrsonnet-interner", version = "0.3.8" }
 jrsonnet-evaluator = { path = "../../crates/jrsonnet-evaluator", version = "0.3.8" }
 jrsonnet-parser = { path = "../../crates/jrsonnet-parser", version = "0.3.8" }
+gc = { version = "0.4.1", features = ["derive"] }
 
 [lib]
 crate-type = ["cdylib"]
--- a/bindings/jsonnet/src/native.rs
+++ b/bindings/jsonnet/src/native.rs
@@ -1,8 +1,14 @@
-use jrsonnet_evaluator::{error::Error, native::NativeCallback, EvaluationState, Val};
+use gc::{unsafe_empty_trace, Finalize, Gc, Trace};
+use jrsonnet_evaluator::{
+	error::{Error, LocError},
+	native::{NativeCallback, NativeCallbackHandler},
+	EvaluationState, Val,
+};
 use jrsonnet_parser::{Param, ParamsDesc};
 use std::{
 	ffi::{c_void, CStr},
 	os::raw::{c_char, c_int},
+	path::PathBuf,
 	rc::Rc,
 };
 
@@ -12,6 +18,39 @@
 	success: *mut c_int,
 ) -> *mut Val;
 
+struct JsonnetNativeCallbackHandler {
+	ctx: *const c_void,
+	cb: JsonnetNativeCallback,
+}
+impl Finalize for JsonnetNativeCallbackHandler {}
+unsafe impl Trace for JsonnetNativeCallbackHandler {
+	unsafe_empty_trace!();
+}
+impl NativeCallbackHandler for JsonnetNativeCallbackHandler {
+	fn call(&self, _from: Option<Rc<PathBuf>>, args: &[Val]) -> Result<Val, LocError> {
+		let mut n_args = Vec::new();
+		for a in args {
+			n_args.push(Some(Box::new(a.clone())));
+		}
+		n_args.push(None);
+		let mut success = 1;
+		let v = unsafe {
+			(self.cb)(
+				self.ctx,
+				&n_args as *const _ as *const *const Val,
+				&mut success,
+			)
+		};
+		let v = unsafe { *Box::from_raw(v) };
+		if success == 1 {
+			Ok(v)
+		} else {
+			let e = v.try_cast_str("native error").expect("error msg");
+			Err(Error::RuntimeError(e).into())
+		}
+	}
+}
+
 /// # Safety
 #[no_mangle]
 pub unsafe extern "C" fn jsonnet_native_callback(
@@ -21,5 +60,23 @@
 	ctx: *const c_void,
 	mut raw_params: *const *const c_char,
 ) {
-	todo!()
+	let name = CStr::from_ptr(name).to_str().expect("utf8 name").into();
+	let mut params = Vec::new();
+	loop {
+		if (*raw_params).is_null() {
+			break;
+		}
+		let param = CStr::from_ptr(*raw_params).to_str().expect("not utf8");
+		params.push(Param(param.into(), None));
+		raw_params = raw_params.offset(1);
+	}
+	let params = ParamsDesc(Rc::new(params));
+
+	vm.add_native(
+		name,
+		Gc::new(NativeCallback::new(
+			params,
+			Box::new(JsonnetNativeCallbackHandler { ctx, cb }),
+		)),
+	)
 }
--- a/bindings/jsonnet/src/val_make.rs
+++ b/bindings/jsonnet/src/val_make.rs
@@ -1,10 +1,10 @@
 //! Create values in VM
 
+use gc::Gc;
 use jrsonnet_evaluator::{ArrValue, EvaluationState, ObjValue, Val};
 use std::{
 	ffi::CStr,
 	os::raw::{c_char, c_double, c_int},
-	rc::Rc,
 };
 
 /// # Safety
@@ -38,7 +38,7 @@
 
 #[no_mangle]
 pub extern "C" fn jsonnet_json_make_array(_vm: &EvaluationState) -> *mut Val {
-	todo!()
+	Box::into_raw(Box::new(Val::Arr(ArrValue::Eager(Gc::new(Vec::new())))))
 }
 
 #[no_mangle]
--- a/bindings/jsonnet/src/val_modify.rs
+++ b/bindings/jsonnet/src/val_modify.rs
@@ -2,7 +2,8 @@
 //! Only tested with variables, which haven't altered by code before appearing here
 //! In jrsonnet every value is immutable, and this code is probally broken
 
-use jrsonnet_evaluator::{EvaluationState, LazyBinding, LazyVal, ObjMember, Val};
+use gc::Gc;
+use jrsonnet_evaluator::{ArrValue, EvaluationState, LazyBinding, LazyVal, ObjMember, Val};
 use jrsonnet_parser::Visibility;
 use std::{ffi::CStr, os::raw::c_char};
 
@@ -22,8 +23,7 @@
 				new.push(item);
 			}
 			new.push(LazyVal::new_resolved(val.clone()));
-			// *arr = Val::Arr(ArrValue::Lazy(Gc::new(new)));
-			todo!()
+			*arr = Val::Arr(ArrValue::Lazy(Gc::new(new)));
 		}
 		_ => panic!("should receive array"),
 	}