webextension-rpc/example

import {
  remoteFunction,
  makeRemotelyCallable,
  injectRpcInfo,
} from 'webextension-rpc';
// Only import the *types* of the remote script’s functions.
import type { backgroundScriptRemoteFunctions } from './background-script';

// From background to content script.
export const contentScriptRemoteFunctions = makeRemotelyCallable({
  async setColour(colour: string) {
    document.body.style.backgroundColor = colour;
  },
});

// From content to background script.
const duplicateMe =
  remoteFunction<typeof backgroundScriptRemoteFunctions.duplicateTab>(
    'duplicateTab',
  );
// The injectRpcInfo placeholder will be replaced by actual info.
const newTabId = await duplicateMe(injectRpcInfo, true);