docs/object-serialization/kotlin/basic-serialization.md

---
title: Basic Serialization
sidebar_position: 1
id: basic-serialization
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Xlang is the default serialization mode for Fory Kotlin. This page covers the basic serialization API and interoperability rules for that default mode.

## Cross-Language Interoperability

The following sections cover model generation, registration, and cross-language round trips in the default xlang mode.

Kotlin xlang serialization uses the JVM Fory implementation through `ForyKotlin`. Use it when
Kotlin payloads must be read by another supported Fory implementation. Register portable model types with
the same identity and field schema on every peer.

Kotlin data classes, enums, and sealed-class models use the Kotlin integration and generated
serializers where applicable. Exact portable carrier mappings remain defined by the
[xlang type mapping](../../specification/xlang_type_mapping.md).

### Create a Fory Instance

```kotlin
import org.apache.fory.kotlin.ForyKotlin

val fory = ForyKotlin.builder()
    .withXlang(true)
    .build()
```

### First round trip

```kotlin
import org.apache.fory.ThreadSafeFory
import org.apache.fory.kotlin.ForyKotlin

data class Person(val name: String, val age: Int)

fun main() {
    val fory: ThreadSafeFory = ForyKotlin.builder()
        .withXlang(true)
        .requireClassRegistration(true)
        .buildThreadSafeFory()
    fory.register(Person::class.java)

    val bytes = fory.serialize(Person("chaokunyang", 28))
    val result = fory.deserialize(bytes) as Person
    println("${result.name} ${result.age}")
}
```