diff --git a/.swift-version b/.swift-version
deleted file mode 100644
index 538c861..0000000
--- a/.swift-version
+++ /dev/null
@@ -1 +0,0 @@
-wasm-5.8.0
diff --git a/Package.resolved b/Package.resolved
index 06b6b76..16d8cd1 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -5,8 +5,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/omochi/CodableToTypeScript",
       "state" : {
-        "revision" : "5a275e389ae179222568fbdd54a105bc16b1d266",
-        "version" : "2.8.1"
+        "revision" : "8654d6ff35c9823cff38a6f9dd2aa0e6aed2769b",
+        "version" : "2.11.0"
       }
     },
     {
@@ -27,13 +27,22 @@
         "version" : "1.0.4"
       }
     },
+    {
+      "identity" : "swift-extras-json",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/swift-extras/swift-extras-json.git",
+      "state" : {
+        "revision" : "122b9454ef01bf89a4c190b8fd3717ddd0a2fbd0",
+        "version" : "0.6.0"
+      }
+    },
     {
       "identity" : "swift-syntax",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-syntax",
       "state" : {
-        "revision" : "cd793adf5680e138bf2bcbaacc292490175d0dcd",
-        "version" : "508.0.0"
+        "revision" : "74203046135342e4a4a627476dd6caf8b28fe11b",
+        "version" : "509.0.0"
       }
     },
     {
@@ -41,8 +50,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/omochi/SwiftTypeReader",
       "state" : {
-        "revision" : "dca7ae04b1cc71db4fb82ea713982adaa0c0a695",
-        "version" : "2.5.1"
+        "revision" : "d21bbe0e0598d1a9a80718f19ea7081053986e1c",
+        "version" : "2.7.0"
       }
     },
     {
diff --git a/Package.swift b/Package.swift
index 10ec2bc..b52fa0f 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,21 +1,28 @@
-// swift-tools-version: 5.7
+// swift-tools-version: 5.9
 
 import PackageDescription
 
 let package = Package(
     name: "WasmCallableKit",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .library(name: "WasmCallableKit", targets: ["WasmCallableKit"]),
         .executable(name: "codegen", targets: ["Codegen"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-argument-parser", from: "1.2.2"),
-        .package(url: "https://github.com/omochi/CodableToTypeScript", from: "2.8.1"),
-        .package(url: "https://github.com/omochi/SwiftTypeReader", from: "2.5.1"),
+        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.2.2"),
+        .package(url: "https://github.com/omochi/CodableToTypeScript.git", exact: "2.11.0"),
+        .package(url: "https://github.com/omochi/SwiftTypeReader.git", exact: "2.7.0"),
+        .package(url: "https://github.com/swift-extras/swift-extras-json.git", .upToNextMajor(from: "0.6.0")),
     ],
     targets: [
-        .target(name: "WasmCallableKit", dependencies: ["CWasmCallableKit"]),
+        .target(
+            name: "WasmCallableKit",
+            dependencies: [
+                .product(name: "ExtrasJSON", package: "swift-extras-json"),
+                "CWasmCallableKit",
+            ]
+        ),
         .target(name: "CWasmCallableKit"),
         .executableTarget(
             name: "Codegen",
diff --git a/Sources/Codegen/GenerateSwift.swift b/Sources/Codegen/GenerateSwift.swift
index a6c1614..a557059 100644
--- a/Sources/Codegen/GenerateSwift.swift
+++ b/Sources/Codegen/GenerateSwift.swift
@@ -6,7 +6,7 @@ struct GenerateSwift {
     var scanResult: ScanResult
     var outDirectory: URL
 
-    private func buildParamsEntity(params: [ParamDecl]) -> String {
+    private func buildParamsEntity(params: [FuncParamDecl]) -> String {
         return """
 struct Params: Decodable {
 \(params.enumerated().map({ """
@@ -16,8 +16,8 @@ struct Params: Decodable {
 """
     }
 
-    private func buildCallArguments(params: [ParamDecl]) -> String {
-        return params.enumerated().map { (i, decl: ParamDecl) in
+    private func buildCallArguments(params: [FuncParamDecl]) -> String {
+        return params.enumerated().map { (i, decl: FuncParamDecl) in
             if let interfaceName = decl.interfaceName {
                 return "\(interfaceName): args._\(i)"
             } else {
@@ -42,7 +42,7 @@ meta.inits.append { _ in
                     return """
 meta.inits.append { argData in
 \(buildParamsEntity(params: decl.parameters).withIndent(1))
-    let args = try decoder.decode(Params.self, from: argData)
+    let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
     return \(tryToken)\(className)(
 \(buildCallArguments(params: decl.parameters).withIndent(2))
     )
@@ -54,7 +54,7 @@ meta.inits.append { argData in
             let methods = classInfo.methods.map { (decl: FuncDecl) in
                 let tryToken = decl.isThrows ? "try " : ""
                 let returnReceiver = decl.hasOutput ? "ret" : "_"
-                let returnStmt = "return \(decl.hasOutput ? "try encoder.encode(ret)" : "Data()")"
+                let returnStmt = "return \(decl.hasOutput ? "try WasmCallableKit.encodeJSON(ret)" : "[]")"
                 if decl.parameters.isEmpty {
                     return """
 meta.methods.append { `self`, _ in
@@ -66,7 +66,7 @@ meta.methods.append { `self`, _ in
                     return """
 meta.methods.append { `self`, argData in
 \(buildParamsEntity(params: decl.parameters).withIndent(1))
-    let args = try decoder.decode(Params.self, from: argData)
+    let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
     let \(returnReceiver) = \(tryToken)self.\(decl.name)(
 \(buildCallArguments(params: decl.parameters).withIndent(2))
     )
@@ -78,10 +78,6 @@ meta.methods.append { `self`, argData in
 
             return """
 func build\(className)Metadata() -> ClassMetadata<\(className)> {
-    let decoder = JSONDecoder()
-    decoder.dateDecodingStrategy = .millisecondsSince1970
-    let encoder = JSONEncoder()
-    encoder.dateEncodingStrategy = .millisecondsSince1970
     var meta = ClassMetadata<\(className)>()
 \(inits.joined(separator: "\n").withIndent(1))
 \(methods.joined(separator: "\n").withIndent(1))
@@ -90,7 +86,7 @@ func build\(className)Metadata() -> ClassMetadata<\(className)> {
 """
         }
 
-        let imports = Set(["Foundation", "WasmCallableKit"])
+        let imports = Set(["WasmCallableKit"])
             .union(file.imports.map(\.moduleName))
 
         return """
@@ -104,7 +100,7 @@ func build\(className)Metadata() -> ClassMetadata<\(className)> {
         let methods = globalFuncs.map { (decl: FuncDecl) in
             let tryToken = decl.isThrows ? "try " : ""
             let returnReceiver = decl.hasOutput ? "ret" : "_"
-            let returnStmt = "return \(decl.hasOutput ? "try encoder.encode(ret)" : "Data()")"
+            let returnStmt = "return \(decl.hasOutput ? "try WasmCallableKit.encodeJSON(ret)" : "[]")"
             if decl.parameters.isEmpty {
                 return """
 ret.append { _ in
@@ -116,7 +112,7 @@ ret.append { _ in
                 return """
 ret.append { argData in
 \(buildParamsEntity(params: decl.parameters).withIndent(1))
-    let args = try decoder.decode(Params.self, from: argData)
+    let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
     let \(returnReceiver) = \(tryToken)\(decl.name)(
 \(buildCallArguments(params: decl.parameters).withIndent(2))
     )
@@ -126,18 +122,14 @@ ret.append { argData in
             }
         }
 
-        let imports = Set(["Foundation"])
+        let imports = Set(["WasmCallableKit"])
             .union(allImports.map(\.moduleName))
 
         return """
 \(imports.sorted().map { "import \($0)" }.joined(separator: "\n"))
 
-func buildGlobals() -> [(Data) throws -> Data] {
-    let decoder = JSONDecoder()
-    decoder.dateDecodingStrategy = .millisecondsSince1970
-    let encoder = JSONEncoder()
-    encoder.dateEncodingStrategy = .millisecondsSince1970
-    var ret: [(Data) throws -> Data] = []
+func buildGlobals() -> [([UInt8]) throws -> [UInt8]] {
+    var ret: [([UInt8]) throws -> [UInt8]] = []
 \(methods.joined(separator: "\n").withIndent(1))
     return ret
 }
diff --git a/Sources/Codegen/GenerateTS.swift b/Sources/Codegen/GenerateTS.swift
index c9e4a2b..eb73ab9 100644
--- a/Sources/Codegen/GenerateTS.swift
+++ b/Sources/Codegen/GenerateTS.swift
@@ -33,11 +33,11 @@ struct GenerateTS {
         )
     }
 
-    private func buildEncodingParam(params: [ParamDecl]) throws -> any TSExpr {
-        let fields = try params.enumerated().map { (i, decl: ParamDecl) -> TSObjectExpr.Field in
+    private func buildEncodingParam(params: [FuncParamDecl]) throws -> any TSExpr {
+        let fields = try params.enumerated().map { (i, decl: FuncParamDecl) -> TSObjectExpr.Field in
             let converter = try generator.converter(for: decl.interfaceType)
             let hasEncoder = try converter.hasEncode()
-            let argName = decl.syntaxName!
+            let argName = decl.syntaxName
 
             return .named(
                 name: "_\(i)",
@@ -267,11 +267,11 @@ fileprivate enum DateConvertDecls {
     }
 }
 
-extension [ParamDecl] {
+extension [FuncParamDecl] {
     func toTSParams(generator: CodeGenerator) throws -> [TSFunctionType.Param] {
-        try enumerated().map { i, paramDecl in
+        try self.map { paramDecl in
             TSFunctionType.Param(
-                name: paramDecl.syntaxName ?? "_\(i)",
+                name: paramDecl.syntaxName,
                 type: try generator.converter(for: paramDecl.interfaceType).type(for: .entity)
             )
         }
diff --git a/Sources/WasmCallableKit/ClassCaller.swift b/Sources/WasmCallableKit/ClassCaller.swift
index 4e758c6..206ea27 100644
--- a/Sources/WasmCallableKit/ClassCaller.swift
+++ b/Sources/WasmCallableKit/ClassCaller.swift
@@ -1,5 +1,4 @@
 import CWasmCallableKit
-import Foundation
 
 public struct InstanceID: RawRepresentable, Hashable, CustomStringConvertible {
     public init(_ value: CInt) {
@@ -14,17 +13,17 @@ public struct InstanceID: RawRepresentable, Hashable, CustomStringConvertible {
 
 public protocol ClassMetadataProtocol<C> {
     associatedtype C: AnyObject
-    var inits: [(Data) throws -> C] { get }
-    var methods: [(C, Data) throws -> Data] { get }
-    func initAndBind(initializerID: Int, argData: Data) throws -> any ClassBindingProtocol
+    var inits: [([UInt8]) throws -> C] { get }
+    var methods: [(C, [UInt8]) throws -> [UInt8]] { get }
+    func initAndBind(initializerID: Int, argData: [UInt8]) throws -> any ClassBindingProtocol
 }
 
 public struct ClassMetadata<C: AnyObject>: ClassMetadataProtocol {
     public init() {}
-    public var inits: [(Data) throws -> C] = []
-    public var methods: [(C, Data) throws -> Data] = []
+    public var inits: [([UInt8]) throws -> C] = []
+    public var methods: [(C, [UInt8]) throws -> [UInt8]] = []
 
-    public func initAndBind(initializerID: Int, argData: Data) throws -> any ClassBindingProtocol {
+    public func initAndBind(initializerID: Int, argData: [UInt8]) throws -> any ClassBindingProtocol {
         let `init` = inits[initializerID]
         return Binding(
             instance: try `init`(argData),
@@ -35,14 +34,14 @@ public struct ClassMetadata<C: AnyObject>: ClassMetadataProtocol {
 
 public protocol ClassBindingProtocol<C> {
     associatedtype C: AnyObject
-    func send(functionID: Int, argData: Data) throws -> Data
+    func send(functionID: Int, argData: [UInt8]) throws -> [UInt8]
 }
 
 private struct Binding<C: AnyObject>: ClassBindingProtocol {
     var instance: C
     var metadata: ClassMetadata<C>
 
-    func send(functionID: Int, argData: Data) throws -> Data {
+    func send(functionID: Int, argData: [UInt8]) throws -> [UInt8] {
         try metadata.methods[functionID](instance, argData)
     }
 }
@@ -63,13 +62,9 @@ extension WasmCallableKit {
 
 @_cdecl("ck_class_init_impl")
 func ck_class_init_impl(_ classID: CInt, _ initilizerID: CInt, _ argumentBufferLength: CInt) -> CInt {
-    let metadata = classMetadata[Int(classID)]
-
-    let memory = malloc(Int(argumentBufferLength)).assumingMemoryBound(to: UInt8.self)
-    defer { memory.deallocate() }
-    receive_arg(memory)
+    let arg = consumeArgumentBuffer(argumentBufferLength)
 
-    let arg = Data(String(decodingCString: memory, as: UTF8.self).utf8)
+    let metadata = classMetadata[Int(classID)]
     do {
         let binding = try metadata.initAndBind(initializerID: Int(initilizerID), argData: arg)
         let instanceID = takeInstanceID()
@@ -86,9 +81,7 @@ func ck_class_init_impl(_ classID: CInt, _ initilizerID: CInt, _ argumentBufferL
 
 @_cdecl("ck_class_send_impl")
 func ck_class_send_impl(_ instanceID: CInt, _ functionID: CInt, _ argumentBufferLength: CInt) -> CInt {
-    let memory = malloc(Int(argumentBufferLength)).assumingMemoryBound(to: UInt8.self)
-    defer { memory.deallocate() }
-    receive_arg(memory)
+    let arg = consumeArgumentBuffer(argumentBufferLength)
 
     let instanceID = InstanceID(instanceID)
     guard let binding = bindings.first(where: { $0.0 == instanceID })?.1 else {
@@ -99,7 +92,6 @@ func ck_class_send_impl(_ instanceID: CInt, _ functionID: CInt, _ argumentBuffer
         return -1;
     }
 
-    let arg = Data(String(decodingCString: memory, as: UTF8.self).utf8)
     do {
         let ret = try binding.send(functionID: Int(functionID), argData: arg)
         ret.withUnsafeBytes { (p: UnsafeRawBufferPointer) in
diff --git a/Sources/WasmCallableKit/WasmCallableKit.swift b/Sources/WasmCallableKit/WasmCallableKit.swift
index a696c19..432a8a4 100644
--- a/Sources/WasmCallableKit/WasmCallableKit.swift
+++ b/Sources/WasmCallableKit/WasmCallableKit.swift
@@ -1,21 +1,17 @@
 import CWasmCallableKit
-import Foundation
 
-private var functionList: [(Data) throws -> Data]!
+private var functionList: [([UInt8]) throws -> [UInt8]]!
 
 public enum WasmCallableKit {
-    public static func setFunctionList(_ functions: [(Data) throws -> Data]) {
+    public static func setFunctionList(_ functions: [([UInt8]) throws -> [UInt8]]) {
         functionList = functions
     }
 }
 
 @_cdecl("ck_send_impl")
 func ck_send_impl(_ functionID: CInt, _ argumentBufferLength: CInt) -> CInt {
-    let memory = malloc(Int(argumentBufferLength)).assumingMemoryBound(to: UInt8.self)
-    defer { memory.deallocate() }
-    receive_arg(memory)
+    let arg = consumeArgumentBuffer(argumentBufferLength)
 
-    let arg = Data(String(decodingCString: memory, as: UTF8.self).utf8)
     do {
         let ret = try functionList[Int(functionID)](arg)
         ret.withUnsafeBytes { (p: UnsafeRawBufferPointer) in
@@ -30,3 +26,12 @@ func ck_send_impl(_ functionID: CInt, _ argumentBufferLength: CInt) -> CInt {
         return -1;
     }
 }
+
+func consumeArgumentBuffer(_ argumentBufferLength: CInt) -> [UInt8] {
+    var arg = Array<UInt8>(repeating: 0, count: Int(argumentBufferLength))
+    arg.withUnsafeMutableBufferPointer { p in
+        receive_arg(p.baseAddress!)
+    }
+    arg.removeLast() // remove null terminator
+    return arg
+}
diff --git a/Sources/WasmCallableKit/json.swift b/Sources/WasmCallableKit/json.swift
new file mode 100644
index 0000000..a41b5c7
--- /dev/null
+++ b/Sources/WasmCallableKit/json.swift
@@ -0,0 +1,13 @@
+import ExtrasJSON
+
+extension WasmCallableKit {
+    @inlinable
+    public static func encodeJSON(_ object: some Encodable) throws -> [UInt8] {
+        return try XJSONEncoder().encode(object)
+    }
+
+    @inlinable
+    public static func decodeJSON<T: Decodable>(_ type: T.Type, from data: some Collection<UInt8>) throws -> T {
+        return try XJSONDecoder().decode(type, from: data)
+    }
+}
diff --git a/example/Package.resolved b/example/Package.resolved
index f37d6d0..16d8cd1 100644
--- a/example/Package.resolved
+++ b/example/Package.resolved
@@ -5,8 +5,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/omochi/CodableToTypeScript",
       "state" : {
-        "revision" : "5a275e389ae179222568fbdd54a105bc16b1d266",
-        "version" : "2.8.1"
+        "revision" : "8654d6ff35c9823cff38a6f9dd2aa0e6aed2769b",
+        "version" : "2.11.0"
       }
     },
     {
@@ -27,13 +27,22 @@
         "version" : "1.0.4"
       }
     },
+    {
+      "identity" : "swift-extras-json",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/swift-extras/swift-extras-json.git",
+      "state" : {
+        "revision" : "122b9454ef01bf89a4c190b8fd3717ddd0a2fbd0",
+        "version" : "0.6.0"
+      }
+    },
     {
       "identity" : "swift-syntax",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-syntax",
       "state" : {
-        "revision" : "cd793adf5680e138bf2bcbaacc292490175d0dcd",
-        "version" : "508.0.0"
+        "revision" : "74203046135342e4a4a627476dd6caf8b28fe11b",
+        "version" : "509.0.0"
       }
     },
     {
@@ -41,8 +50,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/omochi/SwiftTypeReader",
       "state" : {
-        "revision" : "76206f746da09de6386c1acd9a500919d13c5693",
-        "version" : "2.5.0"
+        "revision" : "d21bbe0e0598d1a9a80718f19ea7081053986e1c",
+        "version" : "2.7.0"
       }
     },
     {
diff --git a/example/Package.swift b/example/Package.swift
index 7d0e3bb..baa2380 100644
--- a/example/Package.swift
+++ b/example/Package.swift
@@ -4,7 +4,7 @@ import PackageDescription
 
 let package = Package(
     name: "MySwiftLib",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .executable(name: "MySwiftLib", targets: ["MySwiftLib"]),
     ],
diff --git a/example/Sources/MySwiftLib/Echo.swift b/example/Sources/MySwiftLib/Echo.swift
index 1db635b..7cab2c4 100644
--- a/example/Sources/MySwiftLib/Echo.swift
+++ b/example/Sources/MySwiftLib/Echo.swift
@@ -1,5 +1,3 @@
-import Foundation
-
 public class Echo {
     private var name: String
     public init(name: String) {
@@ -29,10 +27,6 @@ public class Echo {
         }
     }
 
-    public func tommorow(now: Date) -> Date {
-        now.addingTimeInterval(60 * 60 * 24 * 1)
-    }
-
     deinit {
         print("Echo deinit")
     }
diff --git a/example/Sources/MySwiftLib/Gen/Echo.gen.swift b/example/Sources/MySwiftLib/Gen/Echo.gen.swift
index 01fafda..5a2cfe2 100644
--- a/example/Sources/MySwiftLib/Gen/Echo.gen.swift
+++ b/example/Sources/MySwiftLib/Gen/Echo.gen.swift
@@ -1,48 +1,33 @@
-import Foundation
 import WasmCallableKit
 
 func buildEchoMetadata() -> ClassMetadata<Echo> {
-    let decoder = JSONDecoder()
-    decoder.dateDecodingStrategy = .millisecondsSince1970
-    let encoder = JSONEncoder()
-    encoder.dateEncodingStrategy = .millisecondsSince1970
     var meta = ClassMetadata<Echo>()
     meta.inits.append { argData in
         struct Params: Decodable {
             var _0: String
         }
-        let args = try decoder.decode(Params.self, from: argData)
+        let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
         return Echo(
             name: args._0
         )
     }
     meta.methods.append { `self`, _ in
         let ret = self.hello()
-        return try encoder.encode(ret)
+        return try WasmCallableKit.encodeJSON(ret)
     }
     meta.methods.append { `self`, _ in
         let _ = self.sayHello()
-        return Data()
+        return []
     }
     meta.methods.append { `self`, argData in
         struct Params: Decodable {
             var _0: Echo.UpdateKind
         }
-        let args = try decoder.decode(Params.self, from: argData)
+        let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
         let _ = self.update(
             args._0
         )
-        return Data()
-    }
-    meta.methods.append { `self`, argData in
-        struct Params: Decodable {
-            var _0: Date
-        }
-        let args = try decoder.decode(Params.self, from: argData)
-        let ret = self.tommorow(
-            now: args._0
-        )
-        return try encoder.encode(ret)
+        return []
     }
     return meta
 }
\ No newline at end of file
diff --git a/example/Sources/MySwiftLib/Gen/MySwiftLibGlobals.gen.swift b/example/Sources/MySwiftLib/Gen/MySwiftLibGlobals.gen.swift
index 34e8f1f..9ee0853 100644
--- a/example/Sources/MySwiftLib/Gen/MySwiftLibGlobals.gen.swift
+++ b/example/Sources/MySwiftLib/Gen/MySwiftLibGlobals.gen.swift
@@ -1,42 +1,28 @@
-import Foundation
+import WasmCallableKit
 
-func buildGlobals() -> [(Data) throws -> Data] {
-    let decoder = JSONDecoder()
-    decoder.dateDecodingStrategy = .millisecondsSince1970
-    let encoder = JSONEncoder()
-    encoder.dateEncodingStrategy = .millisecondsSince1970
-    var ret: [(Data) throws -> Data] = []
+func buildGlobals() -> [([UInt8]) throws -> [UInt8]] {
+    var ret: [([UInt8]) throws -> [UInt8]] = []
     ret.append { argData in
         struct Params: Decodable {
             var _0: Int
             var _1: Int
         }
-        let args = try decoder.decode(Params.self, from: argData)
+        let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
         let ret = add(
             a: args._0,
             b: args._1
         )
-        return try encoder.encode(ret)
-    }
-    ret.append { argData in
-        struct Params: Decodable {
-            var _0: Date
-        }
-        let args = try decoder.decode(Params.self, from: argData)
-        let ret = yesterday(
-            now: args._0
-        )
-        return try encoder.encode(ret)
+        return try WasmCallableKit.encodeJSON(ret)
     }
     ret.append { argData in
         struct Params: Decodable {
             var _0: Vec2
         }
-        let args = try decoder.decode(Params.self, from: argData)
+        let args = try WasmCallableKit.decodeJSON(Params.self, from: argData)
         let ret = normalize(
             args._0
         )
-        return try encoder.encode(ret)
+        return try WasmCallableKit.encodeJSON(ret)
     }
     return ret
 }
\ No newline at end of file
diff --git a/example/Sources/MySwiftLib/Gen/Types.gen.swift b/example/Sources/MySwiftLib/Gen/Types.gen.swift
index 810b86c..984985c 100644
--- a/example/Sources/MySwiftLib/Gen/Types.gen.swift
+++ b/example/Sources/MySwiftLib/Gen/Types.gen.swift
@@ -1,3 +1,2 @@
-import Foundation
 import WasmCallableKit
 
diff --git a/example/Sources/MySwiftLib/Global.swift b/example/Sources/MySwiftLib/Global.swift
index b7bfbd9..eaa5cd8 100644
--- a/example/Sources/MySwiftLib/Global.swift
+++ b/example/Sources/MySwiftLib/Global.swift
@@ -1,9 +1,3 @@
-import Foundation
-
 public func add(a: Int, b: Int) -> Int {
     a + b
 } 
-
-public func yesterday(now: Date) -> Date {
-    now.addingTimeInterval(-60 * 60 * 24 * 1)
-}
diff --git a/example/Sources/MySwiftLib/Types.swift b/example/Sources/MySwiftLib/Types.swift
index 7551d0b..00abe5f 100644
--- a/example/Sources/MySwiftLib/Types.swift
+++ b/example/Sources/MySwiftLib/Types.swift
@@ -1,4 +1,10 @@
-import Foundation
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
+import Glibc
+#elseif canImport(WASILibc)
+import WASILibc
+#endif
 
 public struct Vec2: Codable {
     public var x: Float
diff --git a/example/package-lock.json b/example/package-lock.json
index 7b38a1d..f6a2bad 100644
--- a/example/package-lock.json
+++ b/example/package-lock.json
@@ -9,15 +9,18 @@
       "version": "1.0.0",
       "license": "MIT",
       "devDependencies": {
-        "@types/node": "^18.11.18",
+        "@types/node": "^20.11.1",
         "typescript": "^4.9.4"
       }
     },
     "node_modules/@types/node": {
-      "version": "18.11.18",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-18.11.18.tgz",
-      "integrity": "sha512-DHQpWGjyQKSHj3ebjFI/wRKcqQcdR+MoFBygntYOZytCqNfkd2ZC4ARDJ2DQqhjH5p85Nnd3jhUJIXrszFX/JA==",
-      "dev": true
+      "version": "20.11.30",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.11.30.tgz",
+      "integrity": "sha512-dHM6ZxwlmuZaRmUPfv1p+KrdD1Dci04FbdEm/9wEMouFqxYoFl5aMkt0VMAUtYRQDyYvD41WJLukhq/ha3YuTw==",
+      "dev": true,
+      "dependencies": {
+        "undici-types": "~5.26.4"
+      }
     },
     "node_modules/typescript": {
       "version": "4.9.4",
@@ -31,20 +34,35 @@
       "engines": {
         "node": ">=4.2.0"
       }
+    },
+    "node_modules/undici-types": {
+      "version": "5.26.5",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
+      "integrity": "sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==",
+      "dev": true
     }
   },
   "dependencies": {
     "@types/node": {
-      "version": "18.11.18",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-18.11.18.tgz",
-      "integrity": "sha512-DHQpWGjyQKSHj3ebjFI/wRKcqQcdR+MoFBygntYOZytCqNfkd2ZC4ARDJ2DQqhjH5p85Nnd3jhUJIXrszFX/JA==",
-      "dev": true
+      "version": "20.11.30",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.11.30.tgz",
+      "integrity": "sha512-dHM6ZxwlmuZaRmUPfv1p+KrdD1Dci04FbdEm/9wEMouFqxYoFl5aMkt0VMAUtYRQDyYvD41WJLukhq/ha3YuTw==",
+      "dev": true,
+      "requires": {
+        "undici-types": "~5.26.4"
+      }
     },
     "typescript": {
       "version": "4.9.4",
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-4.9.4.tgz",
       "integrity": "sha512-Uz+dTXYzxXXbsFpM86Wh3dKCxrQqUcVMxwU54orwlJjOpO3ao8L7j5lH+dWfTwgCwIuM9GQ2kvVotzYJMXTBZg==",
       "dev": true
+    },
+    "undici-types": {
+      "version": "5.26.5",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
+      "integrity": "sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==",
+      "dev": true
     }
   }
 }
diff --git a/example/package.json b/example/package.json
index 3aaf0c0..42d5522 100644
--- a/example/package.json
+++ b/example/package.json
@@ -7,12 +7,12 @@
     "build": "tsc",
     "run": "npm run build && node --expose_gc --experimental-wasi-unstable-preview1 lib/index.js",
     "codegen": "swift package codegen --allow-writing-to-package-directory",
-    "swiftbuild": "swift build --product MySwiftLib -c release --triple wasm32-unknown-wasi"
+    "swiftbuild": "swift build --product MySwiftLib -c release --experimental-swift-sdk 5.9.2-RELEASE-wasm"
   },
   "author": "",
   "license": "MIT",
   "devDependencies": {
-    "@types/node": "^18.11.18",
+    "@types/node": "^20.11.1",
     "typescript": "^4.9.4"
   }
 }
diff --git a/example/src/Gen/Echo.gen.ts b/example/src/Gen/Echo.gen.ts
index 21216d0..d90881e 100644
--- a/example/src/Gen/Echo.gen.ts
+++ b/example/src/Gen/Echo.gen.ts
@@ -1,5 +1,5 @@
 import { SwiftRuntime, globalRuntime } from "./SwiftRuntime.gen.js";
-import { Date_decode, Date_encode, TagRecord } from "./common.gen.js";
+import { TagRecord } from "./common.gen.js";
 
 export class Echo {
     #runtime: SwiftRuntime;
@@ -26,12 +26,6 @@ export class Echo {
             _0: update
         }) as void;
     }
-
-    tommorow(now: Date): Date {
-        return Date_decode(this.#runtime.classSend(this.#id, 3, {
-            _0: Date_encode(now)
-        }) as number);
-    }
 }
 
 export type Echo_UpdateKind = {
diff --git a/example/src/Gen/global.gen.ts b/example/src/Gen/global.gen.ts
index f651f11..e85b9bd 100644
--- a/example/src/Gen/global.gen.ts
+++ b/example/src/Gen/global.gen.ts
@@ -1,10 +1,8 @@
 import { SwiftRuntime } from "./SwiftRuntime.gen.js";
 import { Vec2 } from "./Types.gen.js";
-import { Date_decode, Date_encode } from "./common.gen.js";
 
 export type MySwiftLibExports = {
     add: (a: number, b: number) => number;
-    yesterday: (now: Date) => Date;
     normalize: (vec: Vec2) => Vec2;
 };
 
@@ -14,10 +12,7 @@ export const bindMySwiftLib = (swift: SwiftRuntime): MySwiftLibExports => {
             _0: a,
             _1: b
         }) as number,
-        yesterday: (now: Date) => Date_decode(swift.send(1, {
-            _0: Date_encode(now)
-        }) as number),
-        normalize: (vec: Vec2) => swift.send(2, {
+        normalize: (vec: Vec2) => swift.send(1, {
             _0: vec
         }) as Vec2
     };
diff --git a/example/src/index.ts b/example/src/index.ts
index 3156fc4..e63e623 100644
--- a/example/src/index.ts
+++ b/example/src/index.ts
@@ -6,7 +6,11 @@ import { bindMySwiftLib } from './Gen/global.gen.js';
 import { Echo } from './Gen/Echo.gen.js';
 
 // setup wasm instance
-const wasi = new WASI({ args: argv, env });
+const wasi = new WASI({
+  args: argv,
+  env,
+  version: "preview1",
+});
 const wasm = await WebAssembly.compile(
   await readFile(new URL('../.build/release/MySwiftLib.wasm', import.meta.url)),
 );
@@ -31,9 +35,7 @@ console.log(globals.add(40, 2));
   foo.update({ kind: "name", name: { _0: "Swift" }});
   foo.sayHello();
   
-  console.log(foo.tommorow(new Date()).toDateString());
 })();
 (global as any).gc();
 
-console.log(globals.yesterday(new Date()).toDateString());
 console.log(globals.normalize({ x: 2, y: 1 }));