Decentralized Savings & Investment Platform on Stellar

Nestera is a decentralized savings and investment protocol built on Stellar using Soroban smart contracts. It enables individuals and communities to save transparently using stablecoins, with flexible, locked, goal-based, and group savings mechanisms enforced fully on-chain.

The project solves the problem of opaque, centralized savings platforms in emerging markets by providing a non-custodial, transparent alternative where users maintain full control of their funds. Nestera is designed for developers, contributors, and financial communities interested in building open, composable savings infrastructure using low-fee, fast-finality blockchain primitives.

• Non-custodial savings via Soroban smart contracts
• Flexible and locked savings with deterministic interest logic
• Goal-based savings with automated milestones
• Group savings pools with shared rules and governance
• Native USDC-based savings on Stellar testnet
• Web interface for seamless contract interaction

• Frontend (apps/web)
  Next.js application for interacting with Nestera smart contracts. Provides user interface for creating savings accounts, depositing funds, and tracking progress.

• Backend (apps/api)
  Node.js API for off-chain services such as indexing contract events, sending notifications, managing user metadata, and aggregating analytics.

• Smart Contracts (contracts/)
  Soroban smart contracts written in Rust that manage all savings logic, fund custody, interest calculations, and withdrawal rules.

/
├── apps/
│   ├── web/              # Next.js frontend
│   └── api/              # Node.js backend API
├── contracts/            # Soroban smart contracts (Rust)
├── packages/             # Shared utilities and types
├── scripts/              # Deployment and automation scripts
├── tests/                # Integration and E2E tests
└── README.md

Before you begin, ensure you have the following installed:

• Node.js (v18 or higher) - Download
• npm or yarn - Comes with Node.js
• Rust (stable toolchain) - Install
• Soroban CLI - Instructions below
• Stellar testnet account - We'll create this in setup

1. Clone the repository
2. Set up smart contracts
3. Set up backend API
4. Set up frontend
5. Run tests

git clone https://github.com/your-org/nestera.git
cd nestera

cargo install --locked stellar-cli --features opt

Or use the install script:

curl -fsSL https://github.com/stellar/stellar-cli/raw/main/install.sh | sh

Verify installation:

stellar --version

stellar network add --global testnet \
  --rpc-url https://soroban-testnet.stellar.org:443 \
  --network-passphrase "Test SDF Network ; September 2015"

stellar keys generate --global alice --network testnet

Get your address:

stellar keys address alice

Fund your account using Friendbot:

curl "https://friendbot.stellar.org?addr=$(stellar keys address alice)"

Verify balance:

stellar account balance --id alice --network testnet

cd contracts
cargo build --target wasm32-unknown-unknown --release

stellar contract deploy \
  --wasm target/wasm32-unknown-unknown/release/nestera_contract.wasm \
  --source alice \
  --network testnet

Save the contract ID output - you'll need it for frontend and backend setup.

stellar contract invoke \
  --id YOUR_CONTRACT_ID \
  --source alice \
  --network testnet \
  -- initialize \
  --admin $(stellar keys address alice)

cd apps/api
npm install

Create .env in apps/api/:

PORT=3001
NODE_ENV=development

# Stellar Network
STELLAR_NETWORK=testnet
SOROBAN_RPC_URL=https://soroban-testnet.stellar.org
HORIZON_URL=https://horizon-testnet.stellar.org

# Contract
CONTRACT_ID=YOUR_DEPLOYED_CONTRACT_ID

# Database (if using)
DATABASE_URL=postgresql://user:password@localhost:5432/nestera

# Optional
REDIS_URL=redis://localhost:6379

npm run migrate

npm run dev

Backend should now be running at http://localhost:3001

curl http://localhost:3001/health

cd apps/web
npm install

Create .env.local in apps/web/:

# Stellar Network
NEXT_PUBLIC_STELLAR_NETWORK=testnet
NEXT_PUBLIC_SOROBAN_RPC_URL=https://soroban-testnet.stellar.org
NEXT_PUBLIC_HORIZON_URL=https://horizon-testnet.stellar.org

# Contract
NEXT_PUBLIC_CONTRACT_ID=YOUR_DEPLOYED_CONTRACT_ID

# Backend API
NEXT_PUBLIC_API_URL=http://localhost:3001

# Wallet Connect (optional)
NEXT_PUBLIC_WALLET_CONNECT_PROJECT_ID=your_project_id

npm run dev

Frontend should now be running at http://localhost:3000

npm run build
npm start

cd contracts
cargo test

cd apps/api
npm test

Run with coverage:

npm run test:coverage

cd apps/web
npm test

Run E2E tests (requires running backend and deployed contracts):

npm run test:e2e

From project root:

npm run test:integration

• Network Passphrase: Test SDF Network ; September 2015
• RPC URL: https://soroban-testnet.stellar.org:443
• Horizon URL: https://horizon-testnet.stellar.org
• Friendbot: https://friendbot.stellar.org

• Main Savings Contract: CXXXXXX... (Update after deployment)
• USDC Token: CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA

Error: insufficient balance

Solution: Fund your account using Friendbot:

curl "https://friendbot.stellar.org?addr=$(stellar keys address alice)"

Error: Failed to connect wallet

Solution:

1. Ensure you have Freighter wallet installed
2. Switch wallet to Testnet network
3. Check that NEXT_PUBLIC_STELLAR_NETWORK=testnet in .env.local

Error: RPC connection timeout

Solution:

1. Verify RPC URL is correct in .env
2. Check Stellar testnet status: https://status.stellar.org
3. Try alternative RPC: https://soroban-testnet.stellar.org:443

Error: wasm32-unknown-unknown target not found

Solution: Add wasm target:

rustup target add wasm32-unknown-unknown

Error: Network connection error

Solution: Ensure contracts are deployed and environment variables are set correctly in test config.

• Stellar Documentation: developers.stellar.org
• Soroban Docs: soroban.stellar.org/docs
• Off-Chain Oracle Architecture: contracts/README.md
• Soroban Examples: github.com/stellar/soroban-examples

We welcome contributions from the community! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Follow the setup instructions above
4. Make your changes
5. Write/update tests
6. Ensure all tests pass (npm test in relevant directory)
7. Commit your changes (git commit -m 'Add amazing feature')
8. Push to your branch (git push origin feature/amazing-feature)
9. Open a Pull Request

• Rust (Contracts): Follow Rust standard formatting (cargo fmt)
• TypeScript (Frontend/Backend): Use ESLint and Prettier configs provided
• Commits: Use conventional commits (e.g., feat:, fix:, docs:)
• Tests: Write tests for new features and bug fixes

• Provide clear description of changes
• Reference any related issues
• Ensure CI checks pass
• Update documentation if needed
• Add screenshots for UI changes

• GitHub Issues: Bug reports and feature requests
• GitHub Discussions: Questions and general discussion
• Discord: Join our Telegram
• Email: [email protected] (if available)

• ✅ Core savings contract
• ✅ Basic web interface
• 🚧 Group savings pools
• 🚧 Interest calculation optimization

• Goal-based savings UI
• Notification system
• Mobile app (Flutter)
• Mainnet deployment

• Cross-chain savings
• Yield strategies integration
• DAO governance
• Advanced analytics dashboard

This project is licensed under the MIT License - see the LICENSE file for details.

• Stellar Development Foundation for Soroban platform
• Drips Wave for grants and support
• Open-source contributors and testers

Need help? Here's how to get support:

1. Check the Troubleshooting section
2. Search existing issues
3. Open a new issue with detailed information
4. Join our Discord community (if available)

Built with ❤️ on Stellar