Escrow Smart contract for renting a book - OpenBooks.

Creating an escrow smart contract for renting books on the Solana blockchain using Rust.

Here's a detailed guide on how to achieve this, including the smart contract code and necessary APIs.

Prerequisities

• Rust programming language.
• Solana development environment.
• Anchor framework for Solana smart contracts.
• Nest.js for the backend API.

Step-by-Step Guide to deploy the Escrow Smart Contract.

1. Set up the Solana development environment.

   Ensure you have the Rust programming language and Solana development tools installed on your system.

   Install Rust

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

   Install Solana CLI

   sh -c "$(curl -sSfL https://release.solana.com/v1.8.2/install)"

   Install Anchor

   cargo install --git https://github.com/project-serum/anchor --tag v0.20.1 anchor-cli

2. Create the Anchor project.

   Create a new Anchor project for the smart contract.

   anchor init open_books

   cd open_books

3. Define the Smart Contract.

   Create a file named lib.rs in the programs/open_books/src/ directory with the following code provided in the lib.rs file.

4. Build and Deploy the Smart Contract.

   Build the Smart Contract

   anchor build

   Deploy the Smart Contract

   anchor deploy

Step-by-Step Guide to create the Backend API.

1. Set up the Nest.js project.

   First, ensure you have Node.js and NestJS CLI installed. If not, install them:

   npm install -g @nestjs/cli

   Create a new Nest.js project:

   nest new open-books-backend

   cd open-books-backend

2. Install Necessary Dependencies.

   Install Solana and Anchor dependencies:

   npm install @solana/web3.js @project-serum/anchor @nestjs/common

3. Create the Books Module.

   Generate the 'books' module, controller and service:

   nest generate module books

   nest generate controller books

   nest generate service books

4. Configure the Books Service.

   Create a service that will handle interactions with the Solana blockchain.

   Check the books.service.ts file for the service code.

5. Create the Books Controllers.

   Check the books.controller.ts file for the service code.

6. Configure the Module.

   Check the books.module.ts file for the service code.

7. Integrate the Module into the Main Application.

   Check the app.module.ts file for the service code.

8. Start your Application.

   Ensure your NestJs Application is running:

   npm run start

9. Environment Variables.

   Ensure you have the necessary environment variables set up in your .env file for things like secret keys:

   RENTER_SECRET_KEY=[your_renter_secret_key_here]

10. Testing Endpoints

    You can use tools like Postman or cURL to test the API endpoints.

    Initialise a Book Rental

    curl -X POST http://localhost:3000/books/initialize -H "Content-Type: application/json" -d '{"rentPricePerDay": 5}'

    Rent a Book

    curl -X POST http://localhost:3000/books/rent -H "Content-Type: application/json" -d '{"renter": "RENTER_PUBLIC_KEY", "days": 7}'

    Return a Book

    curl -X POST http://localhost:3000/books/return -H "Content-Type: application/json" -d '{"renter": "RENTER_PUBLIC_KEY"}'

Summary

This setup provides a basic structure for integrating your NestJS backend with the Solana blockchain, allowing you to manage book rentals using smart contracts. Adjust the details and configurations as needed for your specific requirements.

Conclusion

This smart contract and backend API setup allow users to rent books with customizable pricing and an escrow mechanism, ensuring secure and efficient transactions on the Solana blockchain. This forms the foundation of the OpenBooks decentralized library network, promoting peer-to-peer book sharing and community building.