Skip to main content

About the Project

The Collaborative CoinJoin project was created from a Flipstarter campaign funded by the Bitcoin Cash community. It approaches the design of a CoinJoin wallet by identifying the five primary design elements. These elements are loosely coupled, so that developers can collaborate and innovate on one element at a time.

Five Design Elements​

There are five design elements that go into a desktop application for generating CoinJoin transactions:

  1. Packaging - This is the desktop app using Electron.js. It will be compiled and tested on Windows, Mac, and Linux. The UI will closely resemble wallet.FullStack.cash.
  2. Back End Infrastructure - This is the part that communicates with the blockchain. It uses the web3 Cash Stack.
  3. HD wallet functionality - This is handled by hd-cli-wallet. It generates new addresses from a 12-word mnemonic, and optimizes UTXO handling to preserve privacy.
  4. p2p coordination - This is largely handled by the ipfs-coord library and the colab-coinjoin-api 'API server'. This design element allows players to coordinate with one another over IPFS, without the need for a centralized server.
  5. CoinJoin protocol - The Collaborative CoinJoin protocol has been developed and adapted from this CoinJoin code example. In the future, better (but harder to develop) CoinJoin protocols like CashShuffle and CashFusion can be swapped in later, without having to change the other four design elements.

Code Repositories​

The following code repositories make up the Collaborative CoinJoin framework:

  • hd-cli-wallet is the HD wallet 'engine'. This library can create new wallets, manage UTXOs within an HD wallet context, and send BCH and tokens. It communicates with the colab-coinjoin-api REST API in order to consolidate UTXOs through CoinJoin. It provides a command-line interface (CLI) for developers, and it also exports its functionality into an npm library that is compiled for use in a web browser. That library is used by the electron-bch-coinjoin-wallet user interface.

  • colab-coinjoin-api is a REST API server. It is embedded in electron-bch-coinjoin-wallet, and it can be operated as a stand-alone webserver. It spins up a go-ipfs node at startup, to provide p2p communication. It also provides a REST API for the desktop UI and the command-line wallet. It also provides a JSON RPC over IPFS, for communicating with other CoinJoin players.

  • electron-bch-coinjoin-wallet is an Electron.js desktop app the wraps the above two code repositories. This is the final desktop app. In addition to the desktop user interface, it includes an embedded copy of go-ipfs for p2p communication, and a copy of colab-coinjoin-api as a back-end REST API. The user interface is based on wallet.fullstack.cash.