Vote DApp - Solana Voting Application

A decentralized voting application built on Solana using Anchor framework. Implements token-based voting where users purchase tokens with SOL, register proposals, and cast votes.

Program ID: 3tSg7dX3NRgNsCyFL4fGw6RWzjhWUUeSCvveBVaZ8PB5

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🏗️ Architecture

System Overview

Solana Blockchain
    │
    ├── Vote DApp Program (Anchor)
    │   ├── lib.rs (9 instruction handlers)
    │   ├── contexts.rs (Account validation)
    │   ├── state.rs (Data structures)
    │   ├── errors.rs (Error handling)
    │   └── events.rs (Event emissions)
    │
    └── External Programs (via CPI)
        ├── System Program (SOL transfers)
        ├── Token Program (SPL tokens)
        └── Associated Token Program

Key PDAs

• treasury_config - Treasury configuration
• x_mint - Voting token mint
• sol_vault - Receives SOL from purchases
• proposal_{id} - One per proposal
• voter_{pubkey} - One per voter
• vote_{pubkey}_{id} - One per vote
• winner - Winning proposal tracker

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📁 Project Structure

vote_dapp/
├── programs/vote_dapp/src/
│   ├── lib.rs          # Instruction handlers
│   ├── contexts.rs      # Account contexts
│   ├── state.rs         # On-chain data
│   ├── errors.rs        # Custom errors
│   └── events.rs        # Events
├── tests/
│   └── vote_dapp.ts     # Test suite
└── Anchor.toml          # Config

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🎯 Core Features

1. Token Purchase - Buy voting tokens with SOL
2. Voter Registration - Register as eligible voter
3. Proposal Creation - Create proposals with token deposit
4. Voting - Cast yes/no votes with token commitment
5. Winner Selection - Automatic winner after deadline
6. Account Management - Rent recovery via account closure

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💡 Key Technical Learnings

1. Cross-Program Invocation (CPI)

Used for SOL transfers and token operations:

system_program::transfer(cpi_context, amount)?;

transfer(transfer_ctx, token_amount)?;

2. Program Derived Addresses (PDAs)

Deterministic accounts without private keys:

// Single instance
seeds = [b"treasury_config"], bump

// Per-user
seeds = [b"voter", authority.key().as_ref()], bump

// Per-entity
seeds = [b"proposal", proposal_id.to_le_bytes().as_ref()], bump

3. Anchor Constraints

Declarative security checks:

constraint=treasury_config_account.x_mint == x_mint.key()
constraint=authority.key() == treasury_config_account.authority @ VoteError::UnauthorizedAccess

4. Signer Seeds

PDAs need signer seeds when signing transactions:

let signer_seeds = &[&[b"sol_vault", &[bump]][..]];
CpiContext::new_with_signer(program, accounts, signer_seeds)

5. Account Initialization

Different patterns for different needs:

• init - Always creates new account
• init_if_needed - Creates only if doesn't exist
• Manual checks - Custom validation logic

6. String Size Constraints

#[max_len(64)]
pub proposal_info: String

7. Overflow Protection

proposal_count.checked_add(1)
    .ok_or(VoteError::ProposalCounterOverflow)?;

8. Rent Recovery

#[account(..., close = destination)]
pub proposal_account: Account<'info, Proposal>

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🔄 Main Workflows

Initialization

Authority → initialize() → Create PDAs → Treasury ready

Token Purchase

Buyer → buy_tokens() → Transfer SOL → Mint tokens → Tokens received

Voting

Voter → register_voter() → proposal_to_vote() → Transfer tokens → Vote recorded

Winner Selection

Authority → pick_winner() → Check deadline → Update winner account

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🛠️ Technology Stack

• Solana Blockchain - High-performance blockchain
• Anchor Framework v0.32.1 - Solana development framework
• Rust - Program language
• SPL Token - Token standard
• TypeScript - Tests & client

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🚀 Quick Start

Prerequisites

• Rust, Solana CLI, Anchor CLI, Node.js

Commands

anchor build    # Build program
anchor test     # Run tests
anchor deploy   # Deploy to localnet

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🧪 Unit Tests

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📝 Notes for Recruiters

This project demonstrates:

✅ Solana Expertise - Anchor framework, PDAs, CPI patterns
✅ Security - Validation, overflow protection, authority checks
✅ Code Quality - Modular architecture, type safety
✅ Testing - Comprehensive test coverage

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Built with Anchor Framework on Solana