Serializable

Serializable is a type of shared memory that holds an immutable value that can be serialized and deserialized across different JavaScript Runtimes. It allows passing JavaScript values between Runtimes while ensuring that the data is correctly transferred and reconstructed. The reference cannot be manipulated, as it doesn't represent any standard JavaScript object.

You can't pass JavaScript values to other Runtimes without prior serialization.

Serializable memory model

Type definitions

type SerializableRef<TValue = unknown> = {
  __serializableRef: true;
  __nativeStateSerializableJSRef: TValue;
};

Supported types

Type	Supported
string	yes
number	yes
boolean	yes
object	yes
array	yes
function (non-worklet)	yes
HostObject	yes
worklet	yes
Map	yes
Set	yes
ArrayBuffer	yes
RegExp	yes
Cyclic objects	no
Objects with custom prototype	no

If you want to transfer objects with custom prototypes across Runtimes, you can use registerCustomSerializable to define your own serialization and deserialization logic.

Remarks

• The JavaScript value of a Serializable is a reference wrapper that only holds the C++ side in its jsi::NativeState.
• The prop __nativeStateSerializableJSRef present on the reference doesn't exist in runtime - it's only a TypeScript definition to tell you what type of value is held by the Serializable.
• Functions that aren't worklets are serialized as references to function instances on the respective Runtime, meaning that they can't be invoked on other runtimes, only passed around.