Adding sails DEX

contracts/Cargo.toml

@@ -11,6 +11,7 @@ members = [
     "car-races/car-3",
     "car-races",
     "concert",
+    "dex",
     "dynamic-nft",
     "galactic-express",
     "multisig-wallet",

contracts/dex/.gitignore

@@ -0,0 +1,2 @@
+target/
+.binpath

contracts/dex/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "dex"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+dex-app = { path = "app" }
+
+[build-dependencies]
+dex-app = { path = "app" }
+sails-rs = { workspace = true, features = ["wasm-builder"] }
+sails-idl-gen.workspace = true
+extended-vft-client.workspace = true
+
+[dev-dependencies]
+dex = { path = ".", features = ["wasm-binary"] }
+dex-client = { path = "client" }
+sails-rs = { workspace = true, features = ["gtest"] }
+tokio = { workspace = true, features = ["rt", "macros"] }
+extended-vft-client.workspace = true
+
+[features]
+wasm-binary = []

contracts/dex/README.md

@@ -0,0 +1,31 @@
+# DEX
+
+This is a basic implementation of a Decentralized Exchange (DEX) contract designed to showcase fundamental functionality. It includes liquidity management, token swaps, and administrative controls. While simple, this example can serve as a foundation for more complex implementations.
+
+### Opportunities for Extension
+
+This basic DEX implementation can be enhanced with additional features:
+
+- **Fees and Incentives**: Introduce a small fee on swaps (e.g., 0.3%) to reward liquidity providers and create a sustainable ecosystem.  
+- **Decimal Precision**: Replace integer-based calculations with decimal values to enable more precise token management and swaps.  
+- **Dynamic Fees**: Implement adaptive fees based on market conditions or pool activity to optimize user experience.  
+- **Governance Integration**: Add voting mechanisms for liquidity providers to influence key decisions, such as fee rates or token listings.  
+- **Multi-Token Pools**: Expand functionality to support more than two tokens in a liquidity pool, enabling advanced DeFi scenarios.
+
+This example is intentionally simple to highlight the core mechanics of a DEX. It can be tailored to suit a wide range of DeFi use cases, making it a versatile starting point for blockchain developers. By extending its features, this contract could evolve into a powerful tool for decentralized finance.
+
+A detailed description of the project can be found on the [wiki](https://wiki.vara.network/docs/examples/DeFi/dex).
+
+⚙️ **Note**: The project code is developed using the [Sails](https://github.com/gear-tech/sails) framework.
+
+### 🏗️ Building
+
+```sh
+cargo b -r -p "dex"
+```
+
+### ✅ Testing
+
+```sh
+cargo t -r -p "dex"
+```

contracts/dex/app/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "dex-app"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+sails-rs.workspace = true
+extended-vft-client.workspace = true