#Autolink Native Extensions

Autolink helps a Lynx app discover native extension packages from node_modules and register their Android and iOS capabilities automatically. Extension packages declare their native entry points in lynx.ext.json; the host app enables the Autolink build integration once, then uses the generated registry instead of manually wiring each Element, Native Module, or Service.

Autolink currently covers native Android and iOS extensions only. It does not generate Web or HarmonyOS integration code.

#Host App Project Structure

Before enabling Autolink, make sure the host app has a project root that can install npm packages and expose the native app build entry points. A typical host app looks like this:

lynx-app/
├── package.json
├── android/
│   ├── settings.gradle
│   └── app/
│       └── build.gradle
├── ios/
│   └── Podfile
└── src/

• package.json is required so the app can declare Autolink extension packages as dependencies.
• For Android, the project needs a Gradle settings file, such as settings.gradle or settings.gradle.kts, and an Android application build file, such as app/build.gradle or app/build.gradle.kts.
• For iOS, the project needs a CocoaPods entry point, usually Podfile. If your team manages Ruby dependencies with Bundler, keep the cocoapods-lynx-extension gem in Gemfile.

After you install dependencies, Autolink scans the installed npm packages for lynx.ext.json files at package roots. A lockfile such as package-lock.json, pnpm-lock.yaml, or yarn.lock is recommended for reproducible installs, but it is not required by Autolink.

#Set Up Autolink in an App

Set up Autolink once in the host app. After that, installed extension packages can be discovered from node_modules and registered through the generated registry.

plugins {
  id 'org.lynxsdk.extension-settings'
}

plugins {
  id 'com.android.application'
  id 'org.lynxsdk.extension-build'
}

import android.app.Application;
import com.example.app.generated.extensions.ExtensionRegistry;

public final class LynxApp extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    ExtensionRegistry.setupGlobal(this);
  }
}

import com.example.app.generated.extensions.ExtensionRegistry;
import com.lynx.tasm.LynxViewBuilder;

public final class LynxViewFactory {
  public LynxViewBuilder createBuilder() {
    LynxViewBuilder builder = new LynxViewBuilder();
    ExtensionRegistry.setup(builder);
    return builder;
  }
}

plugin 'cocoapods-lynx-extension'

target 'LynxApp' do
  use_lynx_extension!
end

#import "ExtensionRegistry.h"
#import <Lynx/LynxConfig.h>

LynxConfig *config = [[LynxConfig alloc] init];
ExtensionRegistry *registry = [[ExtensionRegistry alloc] init];
[registry setup:config];

#Use an Extension

After the app has set up Autolink, install the extension package in your Lynx app:

npm install @example/lynx-button

Each extension package exposes a lynx.ext.json manifest at the package root. Autolink scans installed npm packages for this file.

{
  "platforms": {
    "android": {
      "packageName": "com.example.button",
      "sourceDir": "android"
    },
    "ios": {
      "sourceDir": "ios",
      "podspecPath": "ios/build.podspec"
    }
  }
}

For Android, platforms.android.packageName is required, and sourceDir defaults to android. For iOS, sourceDir defaults to ios, and podspecPath defaults to the first .podspec found under the iOS source directory.

After installing or updating an extension package, sync/build the Android app and run pod install for iOS so the generated registry and native dependencies are refreshed. You do not need to add per-extension manual registration code in the app.

#Extension Package Role and Structure

An Autolink extension package is an npm package that bundles the JavaScript facade, type declarations, native implementation, and Autolink manifest for one reusable capability. App teams install the package as a normal dependency; the Android Gradle plugins and iOS CocoaPods plugin read lynx.ext.json and link the native code into the host app.

A typical extension package looks like this:

lynx-button/
├── package.json
├── lynx.ext.json
├── types/
│   └── index.d.ts
├── src/
│   └── index.ts
├── generated/
│   └── ButtonModule.ts
├── android/
│   └── src/main/java/com/example/button/
│       ├── ButtonElement.java
│       ├── ButtonModule.java
│       ├── ButtonService.java
│       └── generated/ButtonModuleSpec.java
├── ios/
│   ├── build.podspec
│   └── src/
│       ├── ButtonElement.m
│       ├── ButtonModule.m
│       ├── ButtonService.m
│       └── generated/
│           ├── ButtonModuleSpec.h
│           └── ButtonModuleSpec.m
└── example/

• package.json makes the package installable from npm and usually provides the codegen script.
• lynx.ext.json is the Autolink contract. It tells the host app where Android and iOS source code lives.
• types/index.d.ts describes the Native Module API that codegen uses to create platform specs and the JavaScript facade.
• src/index.ts exports the JavaScript API that app code imports.
• android/ and ios/ contain native implementations and generated native specs.
• example/ is a local app used by the extension author to verify the package.

#Create an Extension

Create a new extension package interactively:

npm create lynx-extension

For scripts and tests, the same scaffold can run without prompts:

npm create lynx-extension -- \
  --dir ./lynx-button \
  --types native-module,element,service \
  --package-name @example/lynx-button \
  --android-package com.example.button \
  --module-name ButtonModule \
  --element-name x-button \
  --service-name ButtonService

The generated package includes:

• package.json with "codegen": "lynx-autolink-codegen"
• lynx.ext.json for Android and iOS Autolink discovery
• types/index.d.ts for Native Module type declarations
• src/index.ts for the JavaScript facade
• android/ and ios/ native source folders
• example/, tsconfig.json, and README.md

Run codegen from the extension root:

npm run codegen

lynx-autolink-codegen reads lynx.ext.json and scans types/**/*.d.ts for @lynxmodule declarations:

/** @lynxmodule */
export declare class ButtonModule {
  getLabel(id: string): string;
  setEnabled(id: string, enabled: boolean): void;
}

It generates:

• generated/<ModuleName>.ts for the JavaScript facade
• Android <ModuleName>Spec.java
• iOS <ModuleName>Spec.h and <ModuleName>Spec.m

The first version supports void, string, number, boolean, and nullable unions with null.

#Write Native APIs

Use the Autolink annotations and markers in extension packages. Native Modules usually extend the spec generated by lynx-autolink-codegen; Elements and Services are discovered from their native markers.

package com.example.button;

import com.example.button.generated.ButtonModuleSpec;
import com.lynx.jsbridge.LynxAutolinkNativeModule;
import com.lynx.jsbridge.LynxMethod;
import com.lynx.tasm.behavior.LynxContext;
import java.util.HashMap;
import java.util.Map;

@LynxAutolinkNativeModule(name = "ButtonModule")
public final class ButtonModule extends ButtonModuleSpec {
  private final Map<String, Boolean> enabledState = new HashMap<>();

  public ButtonModule(LynxContext context) {
    super(context);
  }

  @Override
  @LynxMethod
  public String getLabel(String id) {
    return "Button " + id;
  }

  @Override
  @LynxMethod
  public void setEnabled(String id, boolean enabled) {
    enabledState.put(id, enabled);
  }
}

package com.example.button;

import android.content.Context;
import android.view.Gravity;
import android.widget.TextView;
import com.lynx.tasm.behavior.LynxAutolinkElement;
import com.lynx.tasm.behavior.LynxContext;
import com.lynx.tasm.behavior.LynxProp;
import com.lynx.tasm.behavior.ui.LynxUI;

@LynxAutolinkElement(name = "x-button")
public final class ButtonElement extends LynxUI<TextView> {
  public ButtonElement(LynxContext context) {
    super(context);
  }

  @Override
  protected TextView createView(Context context) {
    TextView view = new TextView(context);
    view.setGravity(Gravity.CENTER);
    view.setText("x-button");
    return view;
  }

  @LynxProp(name = "text")
  public void setText(String text) {
    mView.setText(text == null ? "" : text);
  }
}

package com.example.button;

import android.content.Context;
import com.lynx.tasm.service.IServiceProvider;
import com.lynx.tasm.service.LynxAutolinkService;

@LynxAutolinkService
public final class ButtonService implements IServiceProvider {
  private Context appContext;

  @Override
  public Class<? extends IServiceProvider> getServiceClass() {
    return ButtonService.class;
  }

  @Override
  public void onInitialize(Context context) {
    appContext = context.getApplicationContext();
  }

  public void recordClick(String id) {
    // Send analytics or call platform capabilities here.
  }
}

// ButtonModule.h
#import <Foundation/Foundation.h>
#import <Lynx/LynxModule.h>
#import "generated/ButtonModuleSpec.h"

NS_ASSUME_NONNULL_BEGIN

@LynxAutolinkNativeModule("ButtonModule")
@interface ButtonModule : NSObject <ButtonModuleSpec>

@end

NS_ASSUME_NONNULL_END

// ButtonModule.m
#import "ButtonModule.h"

@implementation ButtonModule {
  NSMutableDictionary<NSString *, NSNumber *> *_enabledState;
}

- (instancetype)init {
  self = [super init];
  if (self) {
    _enabledState = [NSMutableDictionary dictionary];
  }
  return self;
}

- (NSString *)getLabel:(NSString *)buttonId {
  return [NSString stringWithFormat:@"Button %@", buttonId];
}

- (void)setEnabled:(NSString *)buttonId enabled:(BOOL)enabled {
  _enabledState[buttonId] = @(enabled);
}

@end

// ButtonElement.h
#import <UIKit/UIKit.h>
#import <Lynx/LynxUI.h>

NS_ASSUME_NONNULL_BEGIN

@interface ButtonElement : LynxUI<UILabel *>

@end

NS_ASSUME_NONNULL_END

// ButtonElement.m
#import "ButtonElement.h"
#import <Lynx/LynxPropsProcessor.h>

@LynxAutolinkUI("x-button")
@implementation ButtonElement

LYNX_PROP_SETTER("text", setText, NSString *) {
  self.view.text = value ?: @"";
}

- (UILabel *)createView {
  UILabel *label = [[UILabel alloc] init];
  label.textAlignment = NSTextAlignmentCenter;
  label.text = @"x-button";
  return label;
}

@end

// ButtonService.h
#import <Foundation/Foundation.h>
#import <LynxServiceAPI/ServiceAPI.h>

NS_ASSUME_NONNULL_BEGIN

@protocol ButtonServiceProtocol <LynxServiceProtocol>

- (void)recordClick:(NSString *)buttonId;

@end

@interface ButtonService : NSObject <ButtonServiceProtocol>

@end

NS_ASSUME_NONNULL_END

// ButtonService.m
#import "ButtonService.h"

@LynxAutolinkService(ButtonService, ButtonServiceProtocol)
@implementation ButtonService

+ (instancetype)sharedInstance {
  static ButtonService *service;
  static dispatch_once_t onceToken;
  dispatch_once(&onceToken, ^{
    service = [[ButtonService alloc] init];
  });
  return service;
}

- (void)recordClick:(NSString *)buttonId {
  // Send analytics or call platform capabilities here.
}

@end

Autolink uses the LynxAutolink names as its public extension authoring API.

For iOS packages that already use Lynx native registration macros, Autolink also scans existing LYNX_LAZY_REGISTER_UI, LYNX_LAZY_REGISTER_SHADOW_NODE, and @LynxServiceRegister(...) declarations so those packages can be linked without rewriting their native code.