OpenDeFi Library: Decentralized Exchange in Tolk

This repo contains source code for Ton Dex contracts in Tolk and tests/infrastructure for them.

Tests, core logic and environment for this project are reused from the T-Dex, similar project written in Tact. Although, there are some semantic changes, to adapt existing interfaces to Tolk language patterns and idioms.

Project Goals

• Build a fully open-source decentralized exchange (DEX)
• Keep transaction costs low with efficient smart contract design
• Show how to build complex smart contracts using Tolk
• Demonstrate safe patterns for working with Jettons
• Explore Tolk language features in a real production system

This project aims to show core TON smart contract development principles and serve as a foundation for other Jetton-based protocols. We also want to explore how Tolk works for building complex multi-contract systems and what coding patterns and idioms work best.

Project Scope

We follow somewhat common Dex architecture and math - Constant Product Formula Market Maker compatible with Uniswap V2. There is no "protocol fee" implemented since the project is open source, only LP providers fee in pools (however it should be possible to add one).

Dex allows cross-pool and exact-out swaps and implements asset-abstraction model, meaning that the protocol could be extended to allow swaps between any kinds of assets.

How-to and dev docs

Check these docs to learn about how Dex works, its semantics and how to integrate with it.

• How to swap on Dex
• How to manage liquidity
• How to work with Factory, TODO
• How to create new pool and vaults, TODO

Project Setup and Development

To start working, install all dependencies:

yarn install

Build the contracts:

yarn build:tolk

Other useful commands:

Run tests:

yarn test

Lint the code:

yarn lint

Format the code:

yarn fmt

Testing

The project uses Jest for testing. Tests are located in the sources/tests directory and cover various aspects of the T-Dex functionality:

• amm-pool.spec.ts - Tests for the AMM Pool functionality
• liquidity-deposit.spec.ts - Tests for liquidity deposit process
• liquidity-payloads.spec.ts - Tests for payload handling in liquidity operations
• swap-payloads.spec.ts - Tests for payload handling in swap operations

To run all tests:

yarn test

Contract Configuration

TODO: describe Tolk pipeline

License

MIT