diff --git a/cli/src/build.ts b/cli/src/build.ts
index e1732f40..00d3388b 100644
--- a/cli/src/build.ts
+++ b/cli/src/build.ts
@@ -219,7 +219,7 @@ async function findUp(dir = process.cwd()): Promise<string | null> {
 }
 
 interface TypeDef {
-  kind: 'fn' | 'struct' | 'impl' | 'enum'
+  kind: 'fn' | 'struct' | 'impl' | 'enum' | 'interface'
   name: string
   def: string
 }
@@ -243,34 +243,27 @@ async function processIntermediateTypeFile(source: string, target: string) {
     const def = JSON.parse(line) as TypeDef
 
     switch (def.kind) {
-      case 'fn':
-      case 'enum':
-        dts += def.def + '\n'
-        break
       case 'struct':
         classes.set(def.name, def.def)
         break
       case 'impl':
         impls.set(def.name, def.def)
+        break
+      case 'interface':
+        dts += `interface ${def.name} {\n${indentLines(def.def, 2)}\n}\n`
+        break
+      default:
+        dts += def.def + '\n'
     }
   })
 
   for (const [name, classDef] of classes.entries()) {
     const implDef = impls.get(name)
 
-    dts += `export class ${name} {
-  ${classDef
-    .split('\n')
-    .map((line) => line.trim())
-    .join('\n  ')}`
+    dts += `export class ${name} {\n${indentLines(classDef, 2)}`
 
     if (implDef) {
-      dts +=
-        '\n  ' +
-        implDef
-          .split('\n')
-          .map((line) => line.trim())
-          .join('\n  ')
+      dts += `\n${indentLines(implDef, 2)}`
     }
 
     dts += '\n}\n'
@@ -279,3 +272,10 @@ async function processIntermediateTypeFile(source: string, target: string) {
   await unlinkAsync(source)
   await writeFileAsync(target, dts, 'utf8')
 }
+
+function indentLines(input: string, spaces: number) {
+  return input
+    .split('\n')
+    .map((line) => ''.padEnd(spaces, ' ') + line.trim())
+    .join('\n')
+}
diff --git a/crates/backend/src/ast.rs b/crates/backend/src/ast.rs
index 6c71303c..2b4dfa93 100644
--- a/crates/backend/src/ast.rs
+++ b/crates/backend/src/ast.rs
@@ -51,7 +51,14 @@ pub struct NapiStruct {
   pub vis: syn::Visibility,
   pub fields: Vec<NapiStructField>,
   pub is_tuple: bool,
-  pub gen_default_ctor: bool,
+  pub kind: NapiStructKind,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum NapiStructKind {
+  None,
+  Constructor,
+  Object,
 }
 
 #[derive(Debug, Clone)]
diff --git a/crates/backend/src/codegen/struct.rs b/crates/backend/src/codegen/struct.rs
index 13d316c4..886feb8a 100644
--- a/crates/backend/src/codegen/struct.rs
+++ b/crates/backend/src/codegen/struct.rs
@@ -5,7 +5,7 @@ use quote::ToTokens;
 
 use crate::{
   codegen::{get_intermediate_ident, get_register_ident},
-  BindgenResult, FnKind, NapiImpl, NapiStruct, TryToTokens,
+  BindgenResult, FnKind, NapiImpl, NapiStruct, NapiStructKind, TryToTokens,
 };
 
 // Generate trait implementations for given Struct.
@@ -53,7 +53,12 @@ fn gen_napi_value_map_impl(name: &Ident, to_napi_val_impl: TokenStream) -> Token
 impl TryToTokens for NapiStruct {
   fn try_to_tokens(&self, tokens: &mut TokenStream) -> BindgenResult<()> {
     let napi_value_map_impl = self.gen_napi_value_map_impl();
-    let class_helper_mod = self.gen_helper_mod();
+
+    let class_helper_mod = if self.kind == NapiStructKind::Object {
+      quote! {}
+    } else {
+      self.gen_helper_mod()
+    };
 
     (quote! {
       #napi_value_map_impl
@@ -72,7 +77,7 @@ impl NapiStruct {
       Span::call_site(),
     );
 
-    let ctor = if self.gen_default_ctor {
+    let ctor = if self.kind == NapiStructKind::Constructor {
       self.gen_default_ctor()
     } else {
       quote! {}
@@ -134,14 +139,20 @@ impl NapiStruct {
   }
 
   fn gen_napi_value_map_impl(&self) -> TokenStream {
-    if !self.gen_default_ctor {
-      return gen_napi_value_map_impl(&self.name, quote! {});
+    match self.kind {
+      NapiStructKind::None => gen_napi_value_map_impl(&self.name, quote! {}),
+      NapiStructKind::Constructor => {
+        gen_napi_value_map_impl(&self.name, self.gen_to_napi_value_ctor_impl())
+      }
+      NapiStructKind::Object => self.gen_to_napi_value_obj_impl(),
     }
+  }
 
+  fn gen_to_napi_value_ctor_impl(&self) -> TokenStream {
     let name = &self.name;
     let js_name_str = &self.js_name;
 
-    let mut fields_conversions = vec![];
+    let mut field_conversions = vec![];
     let mut field_destructions = vec![];
 
     for field in self.fields.iter() {
@@ -150,57 +161,124 @@ impl NapiStruct {
       match &field.name {
         syn::Member::Named(ident) => {
           field_destructions.push(quote! { #ident });
-          fields_conversions.push(quote! { <#ty as ToNapiValue>::to_napi_value(env, #ident)? });
+          field_conversions.push(quote! { <#ty as ToNapiValue>::to_napi_value(env, #ident)? });
         }
         syn::Member::Unnamed(i) => {
           field_destructions.push(quote! { arg#i });
-          fields_conversions.push(quote! { <#ty as ToNapiValue>::to_napi_value(env, arg#i)? });
+          field_conversions.push(quote! { <#ty as ToNapiValue>::to_napi_value(env, arg#i)? });
         }
       }
     }
 
     let destructed_fields = if self.is_tuple {
       quote! {
-        let Self (#(#field_destructions),*)
+        Self (#(#field_destructions),*)
       }
     } else {
       quote! {
-        let Self {#(#field_destructions),*}
+        Self {#(#field_destructions),*}
       }
     };
 
-    gen_napi_value_map_impl(
-      name,
-      quote! {
-        impl ToNapiValue for #name {
-          unsafe fn to_napi_value(env: sys::napi_env, val: #name) -> Result<sys::napi_value> {
-            if let Some(ctor_ref) = get_class_constructor(#js_name_str) {
-              let mut ctor = std::ptr::null_mut();
+    quote! {
+      impl ToNapiValue for #name {
+        unsafe fn to_napi_value(env: sys::napi_env, val: #name) -> Result<sys::napi_value> {
+          if let Some(ctor_ref) = get_class_constructor(#js_name_str) {
+            let mut ctor = std::ptr::null_mut();
 
-              check_status!(
-                sys::napi_get_reference_value(env, ctor_ref, &mut ctor),
-                "Failed to get constructor of class `{}`",
-                #js_name_str
-              )?;
+            check_status!(
+              sys::napi_get_reference_value(env, ctor_ref, &mut ctor),
+              "Failed to get constructor of class `{}`",
+              #js_name_str
+            )?;
 
-              let mut result = std::ptr::null_mut();
-              #destructed_fields = val;
-              let args = vec![#(#fields_conversions),*];
+            let mut result = std::ptr::null_mut();
+            let #destructed_fields = val;
+            let args = vec![#(#field_conversions),*];
 
-              check_status!(
-                sys::napi_new_instance(env, ctor, args.len(), args.as_ptr(), &mut result),
-                "Failed to construct class `{}`",
-                #js_name_str
-              )?;
+            check_status!(
+              sys::napi_new_instance(env, ctor, args.len(), args.as_ptr(), &mut result),
+              "Failed to construct class `{}`",
+              #js_name_str
+            )?;
 
-              Ok(result)
-            } else {
-              Err(Error::new(Status::InvalidArg, format!("Failed to get constructor of class `{}`", #js_name_str)))
-            }
+            Ok(result)
+          } else {
+            Err(Error::new(Status::InvalidArg, format!("Failed to get constructor of class `{}`", #js_name_str)))
           }
         }
-      },
-    )
+      }
+    }
+  }
+
+  fn gen_to_napi_value_obj_impl(&self) -> TokenStream {
+    let name = &self.name;
+    let name_str = self.name.to_string();
+
+    let mut obj_field_setters = vec![];
+    let mut obj_field_getters = vec![];
+    let mut field_destructions = vec![];
+
+    for field in self.fields.iter() {
+      let field_js_name = &field.js_name;
+      let ty = &field.ty;
+
+      match &field.name {
+        syn::Member::Named(ident) => {
+          field_destructions.push(quote! { #ident });
+          obj_field_setters.push(quote! { obj.set(#field_js_name, #ident)?; });
+          obj_field_getters.push(quote! { let #ident: #ty = obj.get(#field_js_name)?.expect(&format!("Field {} should exist", #field_js_name)); });
+        }
+        syn::Member::Unnamed(i) => {
+          field_destructions.push(quote! { arg#i });
+          obj_field_setters.push(quote! { obj.set(#field_js_name, arg#1)?; });
+          obj_field_getters.push(quote! { let arg#i: #ty = obj.get(#field_js_name)?.expect(&format!("Field {} should exist", #field_js_name)); });
+        }
+      }
+    }
+
+    let destructed_fields = if self.is_tuple {
+      quote! {
+        Self (#(#field_destructions),*)
+      }
+    } else {
+      quote! {
+        Self {#(#field_destructions),*}
+      }
+    };
+
+    quote! {
+      impl TypeName for #name {
+        fn type_name() -> &'static str {
+          #name_str
+        }
+      }
+
+      impl ToNapiValue for #name {
+        unsafe fn to_napi_value(env: sys::napi_env, val: #name) -> Result<sys::napi_value> {
+          let env_wrapper = Env::from(env);
+          let mut obj = env_wrapper.create_object()?;
+
+          let #destructed_fields = val;
+          #(#obj_field_setters)*
+
+          Object::to_napi_value(env, obj)
+        }
+      }
+
+      impl FromNapiValue for #name {
+        unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+          let env_wrapper = Env::from(env);
+          let mut obj = Object::from_napi_value(env, napi_val)?;
+
+          #(#obj_field_getters)*
+
+          let val = #destructed_fields;
+
+          Ok(val)
+        }
+      }
+    }
   }
 
   fn gen_default_getters_setters(&self) -> Vec<TokenStream> {
@@ -273,7 +351,7 @@ impl NapiStruct {
     let js_name = &self.js_name;
     let mut props = vec![];
 
-    if self.gen_default_ctor {
+    if self.kind == NapiStructKind::Constructor {
       props.push(quote! { Property::new("constructor").unwrap().with_ctor(constructor) });
     }
 
diff --git a/crates/backend/src/typegen.rs b/crates/backend/src/typegen.rs
index 7dd173f0..33ebe7c3 100644
--- a/crates/backend/src/typegen.rs
+++ b/crates/backend/src/typegen.rs
@@ -5,8 +5,6 @@ mod r#struct;
 use std::collections::HashMap;
 
 use once_cell::sync::Lazy;
-use quote::ToTokens;
-use regex::Regex;
 use syn::Type;
 
 #[derive(Default)]
@@ -29,84 +27,112 @@ pub trait ToTypeDef {
   fn to_type_def(&self) -> TypeDef;
 }
 
-pub static TYPE_REGEXES: Lazy<HashMap<&'static str, Regex>> = Lazy::new(|| {
+static KNOWN_TYPES: Lazy<HashMap<&'static str, &'static str>> = Lazy::new(|| {
   let mut map = HashMap::default();
   map.extend([
-    ("Vec", Regex::new(r"^Vec < (.*) >$").unwrap()),
-    ("Option", Regex::new(r"^Option < (.*) >").unwrap()),
-    ("Result", Regex::new(r"^Result < (.*) >").unwrap()),
-    ("HashMap", Regex::new(r"HashMap < (.*), (.*) >").unwrap()),
+    ("()", "undefined"),
+    ("i8", "number"),
+    ("i16", "number"),
+    ("i32", "number"),
+    ("i64", "number"),
+    ("u8", "number"),
+    ("u16", "number"),
+    ("u32", "number"),
+    ("u64", "BigInt"),
+    ("u128", "BigInt"),
+    ("i128", "BigInt"),
+    ("usize", "BigInt"),
+    ("isize", "BigInt"),
+    ("BigInt", "BigInt"),
+    ("bool", "boolean"),
+    ("String", "string"),
+    ("str", "string"),
+    ("Latin1String", "string"),
+    ("Utf16String", "string"),
+    ("char", "string"),
+    ("Object", "object"),
+    ("Value", "any"),
+    ("Map", "Record<string, any>"),
+    ("HashMap", "Record<{}, {}>"),
+    ("Vec", "Array<{}>"),
+    ("Option", "{} | null"),
+    ("Result", "Error | {}"),
   ]);
 
   map
 });
 
-pub fn ty_to_ts_type(ty: &Type, omit_top_level_result: bool) -> String {
+fn fill_ty(template: &str, args: Vec<String>) -> String {
+  let matches = template.match_indices("{}").collect::<Vec<_>>();
+  if args.len() != matches.len() {
+    return String::from("any");
+  }
+
+  let mut ret = String::from("");
+  let mut prev = 0;
+  matches.into_iter().zip(args).for_each(|((index, _), arg)| {
+    ret.push_str(&template[prev..index]);
+    ret.push_str(&arg);
+    prev = index + 2;
+  });
+
+  ret.push_str(&template[prev..]);
+  ret
+}
+
+pub fn ty_to_ts_type(ty: &Type, is_return_ty: bool) -> String {
   match ty {
-    Type::Reference(r) => ty_to_ts_type(&r.elem, omit_top_level_result),
+    Type::Reference(r) => ty_to_ts_type(&r.elem, is_return_ty),
     Type::Tuple(tuple) => {
-      format!(
-        "[{}]",
-        tuple
-          .elems
-          .iter()
-          .map(|elem| ty_to_ts_type(elem, false))
-          .collect::<Vec<_>>()
-          .join(", ")
-      )
+      if tuple.elems.is_empty() {
+        "undefined".to_owned()
+      } else {
+        format!(
+          "[{}]",
+          tuple
+            .elems
+            .iter()
+            .map(|elem| ty_to_ts_type(elem, false))
+            .collect::<Vec<_>>()
+            .join(", ")
+        )
+      }
+    }
+    Type::Path(syn::TypePath { qself: None, path }) => {
+      let mut ts_ty = None;
+
+      if let Some(syn::PathSegment { ident, arguments }) = path.segments.last() {
+        let rust_ty = ident.to_string();
+        let args = if let syn::PathArguments::AngleBracketed(arguments) = arguments {
+          arguments
+            .args
+            .iter()
+            .filter_map(|arg| match arg {
+              syn::GenericArgument::Type(generic_ty) => Some(ty_to_ts_type(generic_ty, false)),
+              _ => None,
+            })
+            .collect::<Vec<_>>()
+        } else {
+          vec![]
+        };
+
+        if rust_ty == "Result" && is_return_ty {
+          ts_ty = Some(args.first().unwrap().to_owned());
+        } else if let Some(&known_ty) = KNOWN_TYPES.get(rust_ty.as_str()) {
+          if known_ty.contains("{}") {
+            ts_ty = Some(fill_ty(known_ty, args));
+          } else {
+            ts_ty = Some(known_ty.to_owned());
+          }
+        } else {
+          // there should be runtime registered type in else
+          ts_ty = Some(rust_ty);
+        }
+      }
+
+      ts_ty.unwrap_or_else(|| "any".to_owned())
     }
-    Type::Path(syn::TypePath { qself: None, path }) => str_to_ts_type(
-      path.to_token_stream().to_string().as_str(),
-      omit_top_level_result,
-    ),
 
     _ => "any".to_owned(),
   }
 }
-
-pub fn str_to_ts_type(ty: &str, omit_top_level_result: bool) -> String {
-  match ty {
-    "()" => "undefined".to_owned(),
-    "i8" | "i16" | "i32" | "i64" | "u8" | "u16" | "u32" => "number".to_owned(),
-    "i128" | "isize" | "u64" | "u128" | "usize" => "BigInt".to_owned(),
-    "bool" => "boolean".to_owned(),
-    "String" | "str" | "char" => "string".to_owned(),
-    "Object" => "object".to_owned(),
-    // nothing but `& 'lifetime str` could ends with ` str`
-    s if s.ends_with(" str") => "string".to_owned(),
-    s if s.starts_with("Vec") && TYPE_REGEXES["Vec"].is_match(s) => {
-      let captures = TYPE_REGEXES["Vec"].captures(s).unwrap();
-      let inner = captures.get(1).unwrap().as_str();
-
-      format!("Array<{}>", str_to_ts_type(inner, false))
-    }
-    s if s.starts_with("Option") && TYPE_REGEXES["Option"].is_match(s) => {
-      let captures = TYPE_REGEXES["Option"].captures(s).unwrap();
-      let inner = captures.get(1).unwrap().as_str();
-
-      format!("{} | null", str_to_ts_type(inner, false))
-    }
-    s if s.starts_with("Result") && TYPE_REGEXES["Result"].is_match(s) => {
-      let captures = TYPE_REGEXES["Result"].captures(s).unwrap();
-      let inner = captures.get(1).unwrap().as_str();
-
-      if omit_top_level_result {
-        str_to_ts_type(inner, false)
-      } else {
-        format!("Error | {}", str_to_ts_type(inner, false))
-      }
-    }
-    s if TYPE_REGEXES["HashMap"].is_match(s) => {
-      let captures = TYPE_REGEXES["HashMap"].captures(s).unwrap();
-      let key = captures.get(1).unwrap().as_str();
-      let val = captures.get(2).unwrap().as_str();
-
-      format!(
-        "Record<{}, {}>",
-        str_to_ts_type(key, false),
-        str_to_ts_type(val, false)
-      )
-    }
-    s => s.to_owned(),
-  }
-}
diff --git a/crates/backend/src/typegen/struct.rs b/crates/backend/src/typegen/struct.rs
index e20117cb..9943691c 100644
--- a/crates/backend/src/typegen/struct.rs
+++ b/crates/backend/src/typegen/struct.rs
@@ -1,12 +1,16 @@
 use super::{ToTypeDef, TypeDef};
-use crate::{ty_to_ts_type, NapiImpl, NapiStruct};
+use crate::{ty_to_ts_type, NapiImpl, NapiStruct, NapiStructKind};
 
 impl ToTypeDef for NapiStruct {
   fn to_type_def(&self) -> TypeDef {
     TypeDef {
-      kind: "struct".to_owned(),
+      kind: String::from(if self.kind == NapiStructKind::Object {
+        "interface"
+      } else {
+        "struct"
+      }),
       name: self.js_name.to_owned(),
-      def: self.gen_ts_class_fields(),
+      def: self.gen_ts_class(),
     }
   }
 }
@@ -27,7 +31,7 @@ impl ToTypeDef for NapiImpl {
 }
 
 impl NapiStruct {
-  fn gen_ts_class_fields(&self) -> String {
+  fn gen_ts_class(&self) -> String {
     let mut ctor_args = vec![];
     let def = self
       .fields
@@ -40,7 +44,7 @@ impl NapiStruct {
           field_str.push_str("readonly ")
         }
         let arg = format!("{}: {}", &f.js_name, ty_to_ts_type(&f.ty, false));
-        if self.gen_default_ctor {
+        if self.kind == NapiStructKind::Constructor {
           ctor_args.push(arg.clone());
         }
         field_str.push_str(&arg);
@@ -50,7 +54,7 @@ impl NapiStruct {
       .collect::<Vec<_>>()
       .join("\\n");
 
-    if self.gen_default_ctor {
+    if self.kind == NapiStructKind::Constructor {
       format!("{}\\nconstructor({})", def, ctor_args.join(", "))
     } else {
       def
diff --git a/crates/macro/src/parser/attrs.rs b/crates/macro/src/parser/attrs.rs
index c234b281..50723c58 100644
--- a/crates/macro/src/parser/attrs.rs
+++ b/crates/macro/src/parser/attrs.rs
@@ -49,6 +49,7 @@ macro_rules! attrgen {
       (readonly, Readonly(Span)),
       (skip, Skip(Span)),
       (strict, Strict(Span)),
+      (object, Object(Span)),
 
       // impl later
       // (inspectable, Inspectable(Span)),
diff --git a/crates/macro/src/parser/mod.rs b/crates/macro/src/parser/mod.rs
index 712a5a29..1dccac7d 100644
--- a/crates/macro/src/parser/mod.rs
+++ b/crates/macro/src/parser/mod.rs
@@ -10,7 +10,7 @@ use attrs::{BindgenAttr, BindgenAttrs};
 use convert_case::{Case, Casing};
 use napi_derive_backend::{
   BindgenResult, CallbackArg, Diagnostic, FnKind, FnSelf, Napi, NapiEnum, NapiEnumVariant, NapiFn,
-  NapiFnArgKind, NapiImpl, NapiItem, NapiStruct, NapiStructField,
+  NapiFnArgKind, NapiImpl, NapiItem, NapiStruct, NapiStructField, NapiStructKind,
 };
 use proc_macro2::{Ident, TokenStream, TokenTree};
 use quote::ToTokens;
@@ -665,16 +665,22 @@ impl ConvertToAST for syn::ItemStruct {
     );
     let mut fields = vec![];
     let mut is_tuple = false;
-    let gen_default_ctor = opts.constructor().is_some();
+    let struct_kind = if opts.constructor().is_some() {
+      NapiStructKind::Constructor
+    } else if opts.object().is_some() {
+      NapiStructKind::Object
+    } else {
+      NapiStructKind::None
+    };
 
     for (i, field) in self.fields.iter_mut().enumerate() {
       match field.vis {
         syn::Visibility::Public(..) => {}
         _ => {
-          if gen_default_ctor {
+          if struct_kind != NapiStructKind::None {
             errors.push(err_span!(
               field,
-              "#[napi] requires all struct fields to be public to mark struct as constructor\nthis field is not public."
+              "#[napi] requires all struct fields to be public to mark struct as constructor or object shape\nthis field is not public."
             ));
           }
           continue;
@@ -693,7 +699,7 @@ impl ConvertToAST for syn::ItemStruct {
         ),
         None => {
           is_tuple = true;
-          (i.to_string(), syn::Member::Unnamed(i.into()))
+          (format!("field{}", i), syn::Member::Unnamed(i.into()))
         }
       };
 
@@ -719,7 +725,7 @@ impl ConvertToAST for syn::ItemStruct {
         vis,
         fields,
         is_tuple,
-        gen_default_ctor,
+        kind: struct_kind,
       }),
     })
   }
diff --git a/crates/napi/src/bindgen_runtime/callback_info.rs b/crates/napi/src/bindgen_runtime/callback_info.rs
index e85824ae..a7726bea 100644
--- a/crates/napi/src/bindgen_runtime/callback_info.rs
+++ b/crates/napi/src/bindgen_runtime/callback_info.rs
@@ -56,7 +56,6 @@ impl<const N: usize> CallbackInfo<N> {
 
   pub fn construct<T>(&self, js_name: &str, obj: T) -> Result<sys::napi_value> {
     let obj = Box::new(obj);
-    let mut result = std::ptr::null_mut();
     let this = self.this();
 
     unsafe {
@@ -67,7 +66,7 @@ impl<const N: usize> CallbackInfo<N> {
           Box::into_raw(obj) as *mut std::ffi::c_void,
           Some(raw_finalize_unchecked::<T>),
           ptr::null_mut(),
-          &mut result
+          &mut std::ptr::null_mut()
         ),
         "Failed to initialize class `{}`",
         js_name,
diff --git a/crates/napi/src/bindgen_runtime/js_values.rs b/crates/napi/src/bindgen_runtime/js_values.rs
index ee7479db..a2d2301c 100644
--- a/crates/napi/src/bindgen_runtime/js_values.rs
+++ b/crates/napi/src/bindgen_runtime/js_values.rs
@@ -8,6 +8,8 @@ mod map;
 mod nil;
 mod number;
 mod object;
+#[cfg(feature = "serde-json")]
+mod serde;
 mod string;
 
 pub use array::*;
diff --git a/crates/napi/src/bindgen_runtime/js_values/object.rs b/crates/napi/src/bindgen_runtime/js_values/object.rs
index 90f62fb6..2d08c3af 100644
--- a/crates/napi/src/bindgen_runtime/js_values/object.rs
+++ b/crates/napi/src/bindgen_runtime/js_values/object.rs
@@ -2,8 +2,8 @@ use crate::{bindgen_prelude::*, check_status, sys, type_of, ValueType};
 use std::{ffi::CString, ptr};
 
 pub struct Object {
-  env: sys::napi_env,
-  inner: sys::napi_value,
+  pub(crate) env: sys::napi_env,
+  pub(crate) inner: sys::napi_value,
 }
 
 impl Object {
diff --git a/crates/napi/src/bindgen_runtime/js_values/serde.rs b/crates/napi/src/bindgen_runtime/js_values/serde.rs
new file mode 100644
index 00000000..988c239f
--- /dev/null
+++ b/crates/napi/src/bindgen_runtime/js_values/serde.rs
@@ -0,0 +1,95 @@
+use serde_json::{Map, Value};
+
+use crate::{bindgen_runtime::Null, check_status, sys, type_of, Error, Result, Status, ValueType};
+
+use super::{FromNapiValue, Object, ToNapiValue};
+
+impl ToNapiValue for Value {
+  unsafe fn to_napi_value(env: sys::napi_env, val: Self) -> Result<sys::napi_value> {
+    match val {
+      Value::Null => Null::to_napi_value(env, Null),
+      Value::Bool(b) => bool::to_napi_value(env, b),
+      Value::Number(n) => {
+        if n.is_i64() {
+          i64::to_napi_value(env, n.as_i64().unwrap())
+        } else if n.is_f64() {
+          f64::to_napi_value(env, n.as_f64().unwrap())
+        } else {
+          let n = n.as_u64().unwrap();
+          if n > u32::MAX as u64 {
+            todo!("impl BigInt")
+          } else {
+            u32::to_napi_value(env, n as u32)
+          }
+        }
+      }
+      Value::String(s) => String::to_napi_value(env, s),
+      Value::Array(arr) => Vec::<Value>::to_napi_value(env, arr),
+      Value::Object(obj) => Map::to_napi_value(env, obj),
+    }
+  }
+}
+
+impl FromNapiValue for Value {
+  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+    let ty = type_of!(env, napi_val)?;
+    let val = match ty {
+      ValueType::Boolean => Value::Bool(bool::from_napi_value(env, napi_val)?),
+      ValueType::Number => {
+        return Err(Error::new(
+          Status::InvalidArg,
+          "Js Number is not be able to convert to rust.".to_owned(),
+        ));
+      }
+      ValueType::String => Value::String(String::from_napi_value(env, napi_val)?),
+      ValueType::Object => {
+        let mut is_arr = false;
+        check_status!(
+          sys::napi_is_array(env, napi_val, &mut is_arr),
+          "Failed to detect whether given js is an array"
+        )?;
+
+        if is_arr {
+          Value::Array(Vec::<Value>::from_napi_value(env, napi_val)?)
+        } else {
+          Value::Object(Map::<String, Value>::from_napi_value(env, napi_val)?)
+        }
+      }
+      #[cfg(feature = "napi6")]
+      ValueType::Bigint => todo!(),
+      _ => Value::Null,
+    };
+
+    Ok(val)
+  }
+}
+
+impl ToNapiValue for Map<String, Value> {
+  unsafe fn to_napi_value(env: sys::napi_env, val: Self) -> Result<sys::napi_value> {
+    let mut obj = Object::new(env)?;
+
+    for (k, v) in val.into_iter() {
+      obj.set(k, v)?;
+    }
+
+    Object::to_napi_value(env, obj)
+  }
+}
+
+impl FromNapiValue for Map<String, Value> {
+  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+    let obj = Object {
+      env,
+      inner: napi_val,
+    };
+
+    let mut map = Map::new();
+    for key in Object::keys(&obj)?.into_iter() {
+      if let Some(val) = obj.get(&key)? {
+        map.insert(key, val);
+      }
+    }
+
+    Ok(map)
+  }
+}
diff --git a/examples/napi/__test__/typegen.spec.ts.md b/examples/napi/__test__/typegen.spec.ts.md
index b2dd10ea..c4386c50 100644
--- a/examples/napi/__test__/typegen.spec.ts.md
+++ b/examples/napi/__test__/typegen.spec.ts.md
@@ -13,7 +13,6 @@ Generated by [AVA](https://avajs.dev).
     export function sumNums(nums: Array<number>): number␊
     export function getCwd(callback: (arg0: string) => void): void␊
     export function readFile(callback: (arg0: Error | undefined, arg1: string | null) => void): void␊
-    export function readPackageJson(): PackageJson␊
     export enum Kind { Dog = 0, Cat = 1, Duck = 2 }␊
     export enum CustomNumEnum { One = 1, Two = 2, Three = 3, Four = 4, Six = 6, Eight = 8, Nine = 9, Ten = 10 }␊
     export function enumToI32(e: CustomNumEnum): number␊
@@ -23,10 +22,18 @@ Generated by [AVA](https://avajs.dev).
     export function fibonacci(n: number): number␊
     export function listObjKeys(obj: object): Array<string>␊
     export function createObj(): object␊
+    interface PackageJson {␊
+      name: string␊
+      version: string␊
+      dependencies: Record<string, any> | null␊
+      devDependencies: Record<string, any> | null␊
+    }␊
+    export function readPackageJson(): PackageJson␊
+    export function getPackageJsonName(packageJson: PackageJson): string␊
     export function contains(source: string, target: string): boolean␊
     export function concatStr(mutS: string): string␊
-    export function concatUtf16(s: Utf16String): Utf16String␊
-    export function concatLatin1(s: Latin1String): string␊
+    export function concatUtf16(s: string): string␊
+    export function concatLatin1(s: string): string␊
     export class Animal {␊
       readonly kind: Kind␊
       constructor(kind: Kind, name: string)␊
@@ -35,11 +42,4 @@ Generated by [AVA](https://avajs.dev).
       whoami(): string␊
       static getDogKind(): Kind␊
     }␊
-    export class PackageJson {␊
-      name: string␊
-      version: string␊
-      dependencies: Record<string, string> | null␊
-      devDependencies: Record<string, string> | null␊
-      constructor(name: string, version: string, dependencies: Record<string, string> | null, devDependencies: Record<string, string> | null)␊
-    }␊
     `
diff --git a/examples/napi/__test__/typegen.spec.ts.snap b/examples/napi/__test__/typegen.spec.ts.snap
index cf99096f..6a4ff45d 100644
Binary files a/examples/napi/__test__/typegen.spec.ts.snap and b/examples/napi/__test__/typegen.spec.ts.snap differ
diff --git a/examples/napi/__test__/values.spec.ts b/examples/napi/__test__/values.spec.ts
index 643e74e7..f8dfdef9 100644
--- a/examples/napi/__test__/values.spec.ts
+++ b/examples/napi/__test__/values.spec.ts
@@ -21,6 +21,7 @@ import {
   readFile,
   throwError,
   readPackageJson,
+  getPackageJsonName,
 } from '../'
 
 test('number', (t) => {
@@ -68,12 +69,6 @@ test('class', (t) => {
 
   dog.name = '可乐'
   t.is(dog.name, '可乐')
-
-  const packageJson = readPackageJson()
-  t.is(packageJson.name, 'napi-rs')
-  t.is(packageJson.version, '0.0.0')
-  t.is(packageJson.dependencies, null)
-  t.snapshot(Object.keys(packageJson.devDependencies!).sort())
 })
 
 test('callback', (t) => {
@@ -107,3 +102,13 @@ test('Option', (t) => {
 test('Result', (t) => {
   t.throws(() => throwError(), null, 'Manual Error')
 })
+
+test('serde-json', (t) => {
+  const packageJson = readPackageJson()
+  t.is(packageJson.name, 'napi-rs')
+  t.is(packageJson.version, '0.0.0')
+  t.is(packageJson.dependencies, null)
+  t.snapshot(Object.keys(packageJson.devDependencies!).sort())
+
+  t.is(getPackageJsonName(packageJson), 'napi-rs')
+})
diff --git a/examples/napi/__test__/values.spec.ts.md b/examples/napi/__test__/values.spec.ts.md
index a33cc770..1400a0f4 100644
--- a/examples/napi/__test__/values.spec.ts.md
+++ b/examples/napi/__test__/values.spec.ts.md
@@ -4,7 +4,7 @@ The actual snapshot is saved in `values.spec.ts.snap`.
 
 Generated by [AVA](https://avajs.dev).
 
-## class
+## serde-json
 
 > Snapshot 1
 
diff --git a/examples/napi/__test__/values.spec.ts.snap b/examples/napi/__test__/values.spec.ts.snap
index 3004ebd5..97d15dd7 100644
Binary files a/examples/napi/__test__/values.spec.ts.snap and b/examples/napi/__test__/values.spec.ts.snap differ
diff --git a/examples/napi/index.d.ts b/examples/napi/index.d.ts
index 655b8355..0fcfc6d5 100644
--- a/examples/napi/index.d.ts
+++ b/examples/napi/index.d.ts
@@ -3,7 +3,6 @@ export function getNums(): Array<number>
 export function sumNums(nums: Array<number>): number
 export function getCwd(callback: (arg0: string) => void): void
 export function readFile(callback: (arg0: Error | undefined, arg1: string | null) => void): void
-export function readPackageJson(): PackageJson
 export enum Kind { Dog = 0, Cat = 1, Duck = 2 }
 export enum CustomNumEnum { One = 1, Two = 2, Three = 3, Four = 4, Six = 6, Eight = 8, Nine = 9, Ten = 10 }
 export function enumToI32(e: CustomNumEnum): number
@@ -13,10 +12,18 @@ export function add(a: number, b: number): number
 export function fibonacci(n: number): number
 export function listObjKeys(obj: object): Array<string>
 export function createObj(): object
+interface PackageJson {
+  name: string
+  version: string
+  dependencies: Record<string, any> | null
+  devDependencies: Record<string, any> | null
+}
+export function readPackageJson(): PackageJson
+export function getPackageJsonName(packageJson: PackageJson): string
 export function contains(source: string, target: string): boolean
 export function concatStr(mutS: string): string
-export function concatUtf16(s: Utf16String): Utf16String
-export function concatLatin1(s: Latin1String): string
+export function concatUtf16(s: string): string
+export function concatLatin1(s: string): string
 export class Animal {
   readonly kind: Kind
   constructor(kind: Kind, name: string)
@@ -25,10 +32,3 @@ export class Animal {
   whoami(): string
   static getDogKind(): Kind
 }
-export class PackageJson {
-  name: string
-  version: string
-  dependencies: Record<string, string> | null
-  devDependencies: Record<string, string> | null
-  constructor(name: string, version: string, dependencies: Record<string, string> | null, devDependencies: Record<string, string> | null)
-}
diff --git a/examples/napi/src/class.rs b/examples/napi/src/class.rs
index 73321425..444de5ba 100644
--- a/examples/napi/src/class.rs
+++ b/examples/napi/src/class.rs
@@ -1,5 +1,3 @@
-use std::{collections::HashMap, fs};
-
 use napi::bindgen_prelude::*;
 
 use crate::r#enum::Kind;
@@ -47,20 +45,3 @@ impl Animal {
     Kind::Dog
   }
 }
-
-#[napi(constructor)]
-#[derive(Serialize, Deserialize, Debug)]
-struct PackageJson {
-  pub name: String,
-  pub version: String,
-  pub dependencies: Option<HashMap<String, String>>,
-  #[serde(rename = "devDependencies")]
-  pub dev_dependencies: Option<HashMap<String, String>>,
-}
-
-#[napi]
-fn read_package_json() -> Result<PackageJson> {
-  let raw = fs::read_to_string("package.json")?;
-  let p: PackageJson = serde_json::from_str(&raw)?;
-  Ok(p)
-}
diff --git a/examples/napi/src/lib.rs b/examples/napi/src/lib.rs
index f1789ff7..e4d66c0c 100644
--- a/examples/napi/src/lib.rs
+++ b/examples/napi/src/lib.rs
@@ -11,4 +11,5 @@ mod error;
 mod nullable;
 mod number;
 mod object;
+mod serde;
 mod string;
diff --git a/examples/napi/src/serde.rs b/examples/napi/src/serde.rs
new file mode 100644
index 00000000..4ff31c1f
--- /dev/null
+++ b/examples/napi/src/serde.rs
@@ -0,0 +1,25 @@
+use napi::bindgen_prelude::*;
+use serde_json::{Map, Value};
+use std::fs;
+
+#[napi(object)]
+#[derive(Serialize, Deserialize, Debug)]
+struct PackageJson {
+  pub name: String,
+  pub version: String,
+  pub dependencies: Option<Map<String, Value>>,
+  #[serde(rename = "devDependencies")]
+  pub dev_dependencies: Option<Map<String, Value>>,
+}
+
+#[napi]
+fn read_package_json() -> Result<PackageJson> {
+  let raw = fs::read_to_string("package.json")?;
+  let p: PackageJson = serde_json::from_str(&raw)?;
+  Ok(p)
+}
+
+#[napi]
+fn get_package_json_name(package_json: PackageJson) -> String {
+  package_json.name
+}