webextension-rpc/example

import { RpcClient, RpcServer } from 'webextension-rpc';
import type { RpcInfo } from 'webextension-rpc';
// Only import the *types* of the remote script’s functions.
import type { contentScriptRpcServer } from './content-script';

// From background to content script.
const contentScriptRpc = new RpcClient<typeof contentScriptRpcServer>({ tabId: 123 });
const setColour = contentScriptRpc.func('setColour');
await setColour('blue');

// From content to background script.
const backgroundScriptRpcServer = new RpcServer({
  async duplicateTab(rpcInfo: RpcInfo, active: boolean) {
    const newTab = await browser.tabs.duplicate(rpcInfo.tab.id, { active });
    return newTab.id;
  },
  async timesTwo(x: number) { return 2 * x },
});
export type { backgroundScriptRpcServer }