Stable coin

To understand the reasons behind the current smart contract design, please refer to doc/design.md.

Setup

Prerequisite on both macOS and Linux:

• Nix 2.0 package manager

Node.js dependencies are managed outside of Nix, using the pnpm package manager.

nix-shell
pnpm recursive link
cd chain/
pnpm test --watch

You can create a chain/config/local.json file if you want to specify a custom blockchain node or you want to use a different mnemonic which has accounts with enough ETH balance for example. This file is ignored by version control. Example content might look like:

{
  "mnemonic": "your 12 words ...",
  "remoteNode": "http://localhost:8900",
  "_other_remoteNode": "http://some.other.ethereum.node:8545"
}

Since you can't use comments in JSON files, you can just use some prefixed keys, in case you want to switch between different values of an option, as shown with the _other_remoteNode example demonstrates it.

Project structure

chain-dsl/

This folder is a Node.js package containing simple functions, which provide a more concise, functional interface for talking to the blockchain and writing unit tests.

Further documentation can be found under chain-dsl/README.md.

chain/

This folder contains the smart contracts for the fiat-crypto gateway system, together with automated tests and utilities for deployment, usage and maintenance/evolution.

Further documentation can be found under chain/README.md.

New, simpler contracts

The current contract hierarchy is more complicated than it should be. It means it's more error prone and also hard to reason about.

The new, proposed structure can be seen in doc/contracts-hierarchy-next.puml.

It aims to replace the current Kyc.sol with the following, currently unused contract files:

• AddressStatus.sol
• Membership.sol
• TokenRules.sol

doc/

This folder contains further, more detailed documentation, including some diagrams (*.puml files), which are described using the PlantUML language.

You can render these diagram descriptions into .png or .svg format image files using the plantuml command, which has already been installed for you via the Nix package manager.

For example, you can just run:

plantuml -tsvg doc/contracts-hierarchy.puml

and on macOS you can view the resulting file with:

open -a 'Google Chrome' doc/contracts-hierarchy.svg

PlantUML has integration with many tools as documented here: http://plantuml.com/running

Developers use the JetBrains plugin from within WebStorm or IntelliJ.

For authoring single-file diagrams, we recommend the https://www.planttext.com/ online tool.