README.md

trpc-browser

---

🌐 tRPC for everything in the browser

• Typesafe messaging for extensions
  • between window, content & background scripts
  • ready for Manifest V3.
• Typesafe messaging for windows
  • between window, any other window (eg iframe) or popups

📖 Table of contents

• 🌐 tRPC for everything in the browser
• 📖 Table of contents
• 📦 Installation
• 🧩 Example usage for extensions
• 🕸️ Example usage for windows
• 📔 Requirements
• 📝 Example
• 🆎 Types
  • ChromeLinkOptions
  • WindowLinkOptions
  • PopupLinkOptions
  • CreateChromeHandlerOptions
  • CreateWindowHandlerOptions
• Cross-origin support
• ©️ License
• 🛎️ Contact

📦 Installation

Install trpc-browser.

# npm
npm install trpc-browser
# yarn
yarn add trpc-browser

🧩 Example usage for extensions

1. Add createChromeHandler in your background script.

// background.ts
import { initTRPC } from '@trpc/server';
import { createChromeHandler } from 'trpc-browser/adapter';

const t = initTRPC.create({
  isServer: false,
  allowOutsideOfServer: true,
});

const appRouter = t.router({
  // ...procedures
});

export type AppRouter = typeof appRouter;

createChromeHandler({
  router: appRouter /* 👈 */,
});

2. Add a chromeLink to the client in your content script.

// content.ts
import { createTRPCClient } from '@trpc/client';
import { chromeLink } from 'trpc-browser/link';

import type { AppRouter } from './background';

const port = chrome.runtime.connect();
export const chromeClient = createTRPCProxyClient<AppRouter>({
  links: [/* 👉 */ chromeLink({ port })],
});

3. (extra) If you have an injected window script, hook it up too!.

// inpage.ts
import { createTRPCProxyClient } from '@trpc/client';
import { windowLink } from 'trpc-browser/link';

import type { AppRouter } from './background';

export const windowClient = createTRPCProxyClient<AppRouter>({
  links: [/* 👉 */ windowLink({ window })],
});

// content.ts
import { relay } from 'trpc-browser/relay';

const port = chrome.runtime.connect();
relay(window, port);

🕸️ Example usage for windows

1. Add createWindowHandler in your main window.

// main.ts
import { initTRPC } from '@trpc/server';
import { createWindowHandler } from 'trpc-browser/adapter';

const t = initTRPC.create({
  isServer: false,
  allowOutsideOfServer: true,
});

const appRouter = t.router({
  // ...procedures
});

export type AppRouter = typeof appRouter;

createWindowHandler({
  router: appRouter /* 👈 */,
  window: window /* 👈 */,
});

2. Add a windowLink or popupLink to the client

import { createTRPCProxyClient } from '@trpc/client';
import { popupLink, windowLink } from 'trpc-browser/link';

import type { AppRouter } from './main';

/** iframe */
const iframeEl = document.querySelector('iframe');
export const iframeClient = createTRPCProxyClient<AppRouter>({
  links: [/* 👉 */ windowLink({ window: iframeEl.contentWindow })],
});

/** popup */
export const popupClient = createTRPCProxyClient<AppRouter>({
  links: [
    /* 👉 */ popupLink({
      listenWindow: window,
      createPopup: () => {
        const w = window.open('/example/popup', 'popup', 'width=680,height=520');
        if (!w) {
          throw new Error('Could not open popup');
        }
        return w;
      },
    }),
  ],
});

📔 Requirements

Peer dependencies:

• tRPC Server v10 (@trpc/server) must be installed.
• tRPC Client v10 (@trpc/client) must be installed.

📝 Example

Please see an extension example here. You can also find a window example here.

For advanced use-cases, please find examples in our complete test suite.

🆎 Types

ChromeLinkOptions

Please see full typings here.

Property	Type	Description	Required
port	chrome.runtime.Port	An open web extension port between content & background scripts.	true

WindowLinkOptions

Please see full typings here.

Property	Type	Description	Required
window	Window	A window object which is listened to	true
postWindow	Window	A window object which is posted to (defaults to window)	false
postOrigin	string	The targetOrigin passed to opts.postWindow.postMessage	false

PopupLinkOptions

Please see full typings here.

Property	Type	Description	Required
listenWindow	Window	A window object which is listened to	true
createPopup	Function	A function that returns a window object.	true
postOrigin	string	The targetOrigin passed to popup.postMessage	false

CreateChromeHandlerOptions

Please see full typings here.

Property	Type	Description	Required
router	Router	Your application tRPC router.	true
createContext	Function	Passes contextual (ctx) data to procedure resolvers.	false
onError	Function	Called if error occurs inside handler.	false
chrome	Object	Chrome API object. (default: global.chrome)	false

CreateWindowHandlerOptions

Please see full typings here.

Property	Type	Description	Required
router	Router	Your application tRPC router.	true
createContext	Function	Passes contextual (ctx) data to procedure resolvers.	false
onError	Function	Called if error occurs inside handler.	false
window	Window	Window object to subscribe to	true
postWindow	Window	Window object to post messages to. (default: MessageEvent.source with fallback to opts.window)	false
postOrigin	string	The targetOrigin passed to opts.postWindow.postMessage. If you want to answer to all messages from all origins you should pass '*', by default it will only work on same origin	false

---

Cross-origin support

When posting from a link you can specify the postOrigin option. This will be passed to postMessage as the targetOrigin argument. If you want to answer to all messages from all origins you should pass '*', by default it will only work on same origin.

©️ License

Distributed under the MIT License. See LICENSE for more information.

🛎️ Contact

Janek Rahrt - Follow me on Twitter @0xjanek 💜 James Berry - Follow me on Twitter @jlalmes 💙