Sign inDemoInstall


Package Overview
File Explorer

Advanced tools

Install Socket

Detect and block malicious and high-risk dependencies



Node.js API (N-API)

Version published
Install size
688 kB

Package description

What is node-addon-api?

The node-addon-api package is a helper library for building Node.js Addons in C++. It provides a C++ API that abstracts away the complexities of working with the low-level V8 and N-API provided by Node.js, making it easier to develop native addons.

What are node-addon-api's main functionalities?

Object Wrapping

Object wrapping allows C++ classes to be represented as JavaScript objects. It provides an easy way to create and manage objects that have a one-to-one relationship with C++ objects.

Napi::ObjectReference MyClass::constructor;

MyClass::MyClass(const Napi::CallbackInfo& info) : Napi::ObjectWrap<MyClass>(info) {
  // constructor implementation

Napi::Object MyClass::Init(Napi::Env env, Napi::Object exports) {
  Napi::HandleScope scope(env);

  Napi::Function func = DefineClass(env, "MyClass", {
    InstanceMethod("myMethod", &MyClass::MyMethod)

  constructor = Napi::Persistent(func);

  exports.Set("MyClass", func);
  return exports;

Function Arguments

The package provides a way to handle function arguments passed from JavaScript to C++ with type checking and conversion utilities.

Napi::Value MyFunction(const Napi::CallbackInfo& info) {
  Napi::Env env = info.Env();
  if (info.Length() < 2) {
    Napi::TypeError::New(env, "Expected at least two arguments").ThrowAsJavaScriptException();

  Napi::String arg0 = info[0].As<Napi::String>();
  double arg1 = info[1].As<Napi::Number>().DoubleValue();

  // function implementation

  return Napi::String::New(env, "result");

Asynchronous Operations

node-addon-api provides utilities for performing asynchronous operations, allowing long-running tasks to be executed without blocking the Node.js event loop.

class MyAsyncWorker : public Napi::AsyncWorker {
  MyAsyncWorker(Napi::Function& callback) : AsyncWorker(callback) {}

  void Execute() override {
    // Do work in another thread

  void OnOK() override {
    Napi::HandleScope scope(Env());
    Callback().Call({Env().Null(), Napi::String::New(Env(), "Success")});

Napi::Value RunAsyncWork(const Napi::CallbackInfo& info) {
  Napi::Function callback = info[0].As<Napi::Function>();
  MyAsyncWorker* worker = new MyAsyncWorker(callback);
  return info.Env().Undefined();

Other packages similar to node-addon-api



2019-04-03 Version 1.6.3, @NickNaso

Notable changes:

  • Added SuppressDestruct method to Napi::AsyncWorker.
  • Added new build targets for debug.
  • Exposed macros that throw errors.
  • Fixed memory leaks caused by callback data when a napi error occurs.
  • Fixed missing void *data usage in Napi::PropertyDescriptors.
  • Some minor corrections all over the documentation.


  • [83b41c2fe4] - Document adding -fvisibility=hidden flag for macOS users (Nicola Del Gobbo) #460
  • [1ed7ad8769] - doc: correct return type of Int32Value to int32_t (Bill Gallafent) #459
  • [b0f6b601aa] - src: add AsyncWorker destruction suppression (Gabriel Schulhof) #407
  • [72b1975cff] - doc: fix links to the Property Descriptor docs (Ryuichi Okumura) #458
  • [fcfc612728] - build: new build targets for debug purposes (Jinho Bang) #186
  • [c629553cd7] - doc: minor doc corrections and clarifications (Bruce A. MacNaughton) #426
  • [7b87e0b999] - doc: update (Bernardo Heynemann) #436
  • [fcf173d2a1] - src: expose macros that throw errors (Gabriel Schulhof) #448
  • [b409a2f987] - package: add npm search keywords (Sam Roberts) #452
  • [0bc7987806] - doc: fix references to Weak and Persistent (Jake Barnes) #428
  • [ad6f569f85] - doc: dix typo (Abhishek Kumar Singh) #435
  • [28df833a49] - Merge pull request #441 from jschlight/master (Jim Schlight)
  • [4921e74d83] - Rearranges names to be alphabetical (Jim Schlight)
  • [48220335b0] - Membership review update (Jim Schlight)
  • [44f0695533] - Merge pull request #394 from NickNaso/create_release (Nicola DelGobbo)
  • [fa49d68416] - doc: fix some Finalizer signatures (Philipp Renoth) #414
  • [020ac4a628] - src: make Object::GetPropertyNames() const (Philipp Renoth)#415
  • [91eaa6f4cb] - src: fix callbackData leaks on error napi status (Philipp Renoth) #417
  • [0b40275752] - src: fix noexcept control flow issues (Philipp Renoth) #420
  • [c1ff2936f9] - src: fix missing void*data usage in PropertyDescriptors (Luciano Martorella) #374



node-addon-api module

This module contains header-only C++ wrapper classes which simplify the use of the C based N-API provided by Node.js when using C++. It provides a C++ object model and exception handling semantics with low overhead.

N-API is an ABI stable C interface provided by Node.js for building native addons. It is independent from the underlying JavaScript runtime (e.g. V8 or ChakraCore) and is maintained as part of Node.js itself. It is intended to insulate native addons from changes in the underlying JavaScript engine and allow modules compiled for one version to run on later versions of Node.js without recompilation.

The node-addon-api module, which is not part of Node.js, preserves the benefits of the N-API as it consists only of inline code that depends only on the stable API provided by N-API. As such, modules built against one version of Node.js using node-addon-api should run without having to be rebuilt with newer versions of Node.js.

It is important to remember that other Node.js interfaces such as libuv (included in a project via #include <uv.h>) are not ABI-stable across Node.js major versions. Thus, an addon must use N-API and/or node-addon-api exclusively and build against a version of Node.js that includes an implementation of N-API (meaning a version of Node.js newer than 6.14.2) in order to benefit from ABI stability across Node.js major versions. Node.js provides an ABI stability guide containing a detailed explanation of ABI stability in general, and the N-API ABI stability guarantee in particular.

As new APIs are added to N-API, node-addon-api must be updated to provide wrappers for those new APIs. For this reason node-addon-api provides methods that allow callers to obtain the underlying N-API handles so direct calls to N-API and the use of the objects/methods provided by node-addon-api can be used together. For example, in order to be able to use an API for which the node-addon-api does not yet provide a wrapper.

APIs exposed by node-addon-api are generally used to create and manipulate JavaScript values. Concepts and operations generally map to ideas specified in the ECMA262 Language Specification.

Current version: 1.6.3

(See for complete Changelog)



API Documentation

The following is the documentation for node-addon-api.


Are you new to node-addon-api? Take a look at our examples


To run the node-addon-api tests do:

npm install
npm test

To avoid testing the deprecated portions of the API run

npm install
npm test --disable-deprecated


To run the node-addon-api tests with --debug option:

npm run-script dev

If you want faster build, you might use the following option:

npm run-script dev:incremental

Take a look and get inspired by our test suite

More resource and info about native Addons

WG Members / Collaborators


NameGitHub Link
Anna Henningsenaddaleax
Arunesh Chandraaruneshchandra
Gabriel Schulhofgabrielschulhof
Hitesh Kanwathirthadigitalinfinity
Jim Schlightjschlight
Michael Dawsonmhdawson
Nicola Del GobboNickNaso
Taylor Wollboingoing


NameGitHub Link
Benjamin Byholmkkoopa
Jason Ginchereaujasongin
Sampson Gaosampsongao

Licensed under MIT



Last updated on 03 Apr 2019

Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.


Related posts

SocketSocket SOC 2 Logo


  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Stay in touch

Get open source security insights delivered straight into your inbox.

  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc