diff --git a/nac3artiq/demo/rpc_kwargs_test.py b/nac3artiq/demo/rpc_kwargs_test.py
index acc86bba..d4a444b2 100644
--- a/nac3artiq/demo/rpc_kwargs_test.py
+++ b/nac3artiq/demo/rpc_kwargs_test.py
@@ -19,23 +19,19 @@ class RpcKwargTest:
     def run(self):
         #1) All positional => a=1, b=2, c=3 -> total=6
         s1 = sum_3(1, 2, 3)
-        if s1 != 6:
-            raise ValueError("sum_3(1,2,3) gave the wrong result.")
+        assert s1 == 6
 
         #2) Use the default b=10, c=20 => a=5 => total=35
         s2 = sum_3(5)
-        if s2 != 35:
-            raise ValueError("sum_3(5) gave the wrong result.")
+        assert s2 == 35
 
         #3) a=1 (positional), b=100 (keyword), omit c => c=20 => total=121
         s3 = sum_3(1, b=100)
-        if s3 != 121:
-            raise ValueError("sum_3(1, b=100) gave the wrong result.")
+        assert s3 == 121
 
         #4) a=2, c=300 => b=10 (default) => total=312
         s4 = sum_3(a=2, c=300)
-        if s4 != 312:
-            raise ValueError("sum_3(a=2, c=300) gave the wrong result.")
+        assert s4 == 312
 
 if __name__ == "__main__":
     RpcKwargTest().run()
\ No newline at end of file
diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index 26916279..9f0211e6 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -1,5 +1,5 @@
 use std::{
-    collections::{hash_map::DefaultHasher, HashMap},
+    collections::hash_map::DefaultHasher,
     hash::{Hash, Hasher},
     iter::once,
     mem,
@@ -79,7 +79,8 @@ pub struct ArtiqCodeGenerator<'a> {
 
     /// The [`ParallelMode`] of the current parallel context.
     ///
-    /// The current parallel context refers to the nearest `with` statement, which is used to determine when and how the timeline should be updated.
+    /// The current parallel context refers to the nearest `with` statement,
+    /// which is used to determine when and how the timeline should be updated.
     parallel_mode: ParallelMode,
 }
 
@@ -372,12 +373,11 @@ impl<'b> CodeGenerator for ArtiqCodeGenerator<'b> {
 fn gen_rpc_tag(
     ctx: &mut CodeGenContext<'_, '_>,
     ty: Type,
-    is_kwarg: bool, // Add this parameter
+    is_kwarg: bool,
     buffer: &mut Vec<u8>,
 ) -> Result<(), String> {
-    // Add kwarg marker if needed
     if is_kwarg {
-        buffer.push(b'k'); // 'k' for keyword argument
+        buffer.push(b'k');
     }
 
     use nac3core::typecheck::typedef::TypeEnum::*;
@@ -408,14 +408,14 @@ fn gen_rpc_tag(
                 buffer.push(b't');
                 buffer.push(ty.len() as u8);
                 for ty in ty {
-                    gen_rpc_tag(ctx, *ty, false, buffer)?; // Pass false for is_kwarg
+                    gen_rpc_tag(ctx, *ty, false, buffer)?;
                 }
             }
             TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
                 let ty = iter_type_vars(params).next().unwrap().ty;
 
                 buffer.push(b'l');
-                gen_rpc_tag(ctx, ty, false, buffer)?; // Pass false for is_kwarg
+                gen_rpc_tag(ctx, ty, false, buffer)?;
             }
             TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                 let (ndarray_dtype, ndarray_ndims) = unpack_ndarray_var_tys(&mut ctx.unifier, ty);
@@ -796,7 +796,7 @@ pub fn rpc_codegen_callback_fn<'ctx>(
     ctx: &mut CodeGenContext<'ctx, '_>,
     obj: Option<(Type, ValueEnum<'ctx>)>,
     fun: (&FunSignature, DefinitionId),
-    mut args: Vec<(Option<StrRef>, ValueEnum<'ctx>)>,
+    args: Vec<(Option<StrRef>, ValueEnum<'ctx>)>,
     generator: &mut dyn CodeGenerator,
     is_async: bool,
 ) -> Result<Option<BasicValueEnum<'ctx>>, String> {
@@ -820,8 +820,6 @@ pub fn rpc_codegen_callback_fn<'ctx>(
     tag.push(b':');
     gen_rpc_tag(ctx, fun.0.ret, false, &mut tag)?;
 
-    use std::collections::hash_map::DefaultHasher;
-    use std::hash::{Hash, Hasher};
     let mut hasher = DefaultHasher::new();
     tag.hash(&mut hasher);
     let hash = format!("rpc_tag_{}", hasher.finish());
@@ -832,12 +830,9 @@ pub fn rpc_codegen_callback_fn<'ctx>(
     } else {
         let tag_len = tag.len();
         let arr_ty = int8.array_type(tag_len as u32);
-        let tag_const = int8.const_array(
-            &tag.iter().map(|&b| int8.const_int(b as u64, false)).collect::<Vec<_>>(),
-        );
-        let arr_gv = ctx
-            .module
-            .add_global(arr_ty, None, &format!("{}.arr", hash));
+        let tag_const = int8
+            .const_array(&tag.iter().map(|&b| int8.const_int(b as u64, false)).collect::<Vec<_>>());
+        let arr_gv = ctx.module.add_global(arr_ty, None, &format!("{}.arr", hash));
         arr_gv.set_linkage(Linkage::Private);
         arr_gv.set_initializer(&tag_const);
 
@@ -860,13 +855,14 @@ pub fn rpc_codegen_callback_fn<'ctx>(
 
     let mut pos_index = 0usize;
 
-    if let Some((obj_ty, obj_val)) = obj {
+    if let Some((_obj_ty, obj_val)) = obj {
         param_map[0] = Some(obj_val);
         pos_index = 1;
     }
-    for (maybe_key, val_enum) in args.drain(..) {
+    for (maybe_key, val_enum) in args {
         if let Some(kw_name) = maybe_key {
-            let param_pos = fun.0
+            let param_pos = fun
+                .0
                 .args
                 .iter()
                 .position(|arg| arg.name == kw_name)
@@ -911,23 +907,18 @@ pub fn rpc_codegen_callback_fn<'ctx>(
     let i32_ty = ctx.ctx.i32_type();
     let arg_array = ctx
         .builder
-        .build_array_alloca(
-            ptr_type,
-            i32_ty.const_int(arg_count, false),
-            "rpc.arg_array",
-        )
+        .build_array_alloca(ptr_type, i32_ty.const_int(arg_count, false), "rpc.arg_array")
         .unwrap();
 
     for (i, (llvm_val, ty)) in real_params.iter().enumerate() {
         let arg_slot_ptr = unsafe {
             ctx.builder.build_gep(
                 arg_array,
-                &[
-                    i32_ty.const_int(i as u64, false),
-                ],
+                &[i32_ty.const_int(i as u64, false)],
                 &format!("rpc.arg_slot_{}", i),
             )
-        }.unwrap();
+        }
+        .unwrap();
         let arg_ptr = format_rpc_arg(generator, ctx, (*llvm_val, *ty, i));
         ctx.builder.build_store(arg_slot_ptr, arg_ptr).unwrap();
     }
@@ -937,7 +928,11 @@ pub fn rpc_codegen_callback_fn<'ctx>(
             ctx.module.add_function(
                 "rpc_send_async",
                 ctx.ctx.void_type().fn_type(
-                    &[int32.into(), tag_ptr_type.into(), ptr_type.ptr_type(AddressSpace::default()).into()],
+                    &[
+                        int32.into(),
+                        tag_ptr_type.into(),
+                        ptr_type.ptr_type(AddressSpace::default()).into(),
+                    ],
                     false,
                 ),
                 None,
@@ -946,11 +941,7 @@ pub fn rpc_codegen_callback_fn<'ctx>(
         ctx.builder
             .build_call(
                 rpc_send_async,
-                &[
-                    service_id.into(),
-                    tag_ptr.into(),
-                    arg_array.into(),
-                ],
+                &[service_id.into(), tag_ptr.into(), arg_array.into()],
                 "rpc.send_async",
             )
             .unwrap();
@@ -961,7 +952,11 @@ pub fn rpc_codegen_callback_fn<'ctx>(
             ctx.module.add_function(
                 "rpc_send",
                 ctx.ctx.void_type().fn_type(
-                    &[int32.into(), tag_ptr_type.into(), ptr_type.ptr_type(AddressSpace::default()).into()],
+                    &[
+                        int32.into(),
+                        tag_ptr_type.into(),
+                        ptr_type.ptr_type(AddressSpace::default()).into(),
+                    ],
                     false,
                 ),
                 None,
@@ -970,11 +965,7 @@ pub fn rpc_codegen_callback_fn<'ctx>(
         ctx.builder
             .build_call(
                 rpc_send,
-                &[
-                    service_id.into(),
-                    tag_ptr.into(),
-                    arg_array.into(),
-                ],
+                &[service_id.into(), tag_ptr.into(), arg_array.into()],
                 "rpc.send",
             )
             .unwrap();