A clearer, faster browser-to-browser file handoff app.

cd - Website . Original Sha Project . Source Code

Important

This is a fork of Sha, modified and modernized with a clearer UI, cleaner codebase, and faster transfer behavior. It exists as a separate project to maintain a clean separation from the clunkiness of the old project while preserving the original idea.

What is cd?

cd is a direct browser-to-browser file sharing app. Pick files, get a friendly receive code, share the code or QR link, and keep both browser tabs open while the transfer runs.

Sender Browser -> WebRTC Data Channel -> Receiver Browser
       |                 ^
       |                 |
       +-- PeerJS signaling for connection setup

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Links

Link	Purpose
cd Repository	Modernized fork and active codebase
Original Sha Repository	Source project this fork split from
New main website	Main Cd website, New UI, and Upgraded memes
Vite	Local dev server and production build tool
PeerJS	WebRTC signaling library
QRCode	Sender QR generation
html5-qrcode	Receiver camera QR scanning
Cloudflare Workers Static Assets	Deployment target configured by wrangler.jsonc

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Features

Transfer Flow

Feature	Details
Direct P2P Transfer	Files transfer between browsers over WebRTC data channels
No Server Storage	The hosted app does not intentionally store transferred file contents
Multi-File Batches	Send one file or many files in a single session
Friendly Codes	Human-readable receive words with compact joining
Share Links	Receiver links support ?receive=code deep linking
QR Handoff	Sender generates a QR code for quick joining

Modernization Goals

Area	What Changed
UI	Rebuilt into a sharper, clearer brutalist workbench
Codebase	Moved from loose static scripts into a Vite ES module app
Speed	Uses binary chunks, file streams, and data-channel backpressure
Safety	Avoids CDN script injection and keeps file handling in browser APIs
Deployment	Builds to dist/ for cleaner Cloudflare static asset hosting

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Quick Start

1. Install

npm install

2. Run Locally

npm run dev

Open the local Vite URL in two browser windows or on two devices.

3. Send

1. Choose or drop one or more files.
2. Share the generated code, copy the join link, or show the QR code.
3. Keep the sender tab open until the receiver connects.

4. Receive

1. Switch to Receive, open a receive link, or scan the QR code.
2. Connect with the code.
3. Save streamed files when prompted, or let the browser download Blob fallbacks.

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Developer Setup

Prerequisites

• Node.js 18 or newer
• npm 9 or newer
• Git
• A modern Chromium, Firefox, or Safari browser for WebRTC testing

Clone

git clone https://github.com/YashasVM/cd.git
cd cd

Install Dependencies

npm install

Start Dev Server

npm run dev

Vite prints a local URL, usually http://127.0.0.1:5173/. Open it in two browser windows to test send and receive on one machine.

Build Production Assets

npm run build

The production build is written to dist/.

Run Dependency Audit

npm run audit

Preview Production Build

npm run preview

Deploy Notes

wrangler.jsonc points Cloudflare at ./dist, so deploy after running npm run build. The repo is structured for static asset hosting; no server-side file storage process is required.

Manual QA Checklist

• Send one small file.
• Send multiple files in one batch.
• Receive with manual code entry.
• Receive with a copied receive link.
• Receive by scanning the generated QR code.
• Try an invalid code and an unavailable sender.
• Test at least one large file to watch speed and backpressure behavior.

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Architecture

+-------------------+        PeerJS signaling        +-------------------+
|   Sender Browser  | <----------------------------> | Receiver Browser |
|                   |                                |                  |
| File picker/drop  |                                | Code/QR scanner  |
| Manifest builder  |                                | Manifest reader  |
| Stream reader     |                                | Save/download    |
+---------+---------+                                +---------+--------+
          |                                                    ^
          |              WebRTC data channel                   |
          +----------------------------------------------------+
                         Raw binary chunks

Runtime Defaults

Parameter	Value
App Runtime	Vite vanilla JavaScript with ES modules
Signaling	peerjs@1.5.5
QR Generation	qrcode@1.5.4
QR Scanning	html5-qrcode@2.3.8
Hosting Target	Cloudflare static assets from dist/
Buffer Guard	Data channel backpressure before large buffered queues build up

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Repository Layout

/
|-- index.html              App shell and accessible transfer views
|-- src/
|   |-- main.js             Sender, receiver, WebRTC, QR, and transfer logic
|   `-- style.css           Brutalist responsive interface
|-- favicon.svg             App icon
|-- package.json            Scripts and dependencies
|-- package-lock.json       Locked dependency graph
|-- wrangler.jsonc          Cloudflare static asset config
`-- README.md               Project documentation

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Build and Checks

npm run build
npm run audit

Cloudflare serves the production build from dist/, as configured in wrangler.jsonc.

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Safety Notes

• File contents are sent over WebRTC data channels between connected browsers.
• The hosted app serves static assets and does not intentionally store transferred files.
• PeerJS signaling helps establish the connection, but it is not a file storage layer.
• Share codes are temporary secrets. Send them only to the intended receiver.
• The sender should keep the tab open until the transfer completes.
• Browser support, NAT behavior, VPNs, and local network policies can affect peer connectivity.

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Made by @yashas.vm

A modernized split from Sha: clearer UI, cleaner code, faster handoffs.