webext-core - Browser Extension Utilities

When to Use

Apply this skill when:

• package.json has any @webext-core/* dependency
• Code imports defineProxyService, flattenPromise from @webext-core/proxy-service
• Code imports defineExtensionMessaging, defineWindowMessaging from @webext-core/messaging
• Code uses MatchPattern from @webext-core/match-patterns
• Tests use fakeBrowser from @webext-core/fake-browser
• Code uses defineJobScheduler from @webext-core/job-scheduler
• Code uses createIsolatedElement from @webext-core/isolated-element

Quick Reference

Most Common Pattern

// services/counter.ts
import { defineProxyService } from '@webext-core/proxy-service';

const [registerCounter, getCounter] = defineProxyService('CounterService', () => {
  let count = 0;
  return {
    increment: () => ++count,
    getCount: () => count,
  };
});

export { registerCounter, getCounter };

// background.ts — register the real implementation
registerCounter();

// popup or content script — call via proxy (all methods return Promise)
const counter = getCounter();
const newCount = await counter.increment();