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🚧 Development Status: Transaction processing functionality is currently in active development and testing. This documentation describes the planned architecture and workflow. Features will be rolled out progressively as they become production-ready.

Transaction Processing module enables secure transaction creation, simulation, and signing orchestration. It acts as a bridge between transaction intent and blockchain execution, providing a hardware-wallet-like experience with comprehensive pre-execution analysis.

Core Concept

The Transaction Processing module separates transaction logic into three distinct phases:

  1. Creation - Build and validate transaction parameters
  2. Simulation - Preview exactly what will happen before signing
  3. Execution - Coordinate signing and broadcasting

This separation ensures users always understand transaction consequences before committing funds.

How It Works

Your ApplicationVilnaUser DeviceBlockchainCreate transactionBuild & validateSimulate executionReturn simulation resultsPresent simulation to userReview & approveConfirm transactionRequest signingSend for signatureSign locallyReturn signatureBroadcastConfirmationTransaction completeYour ApplicationVilnaUser DeviceBlockchain

Transaction Simulation

The most critical feature is transaction simulation - showing users exactly what will happen before they sign.

What Simulation Provides

Balance Changes:

  • Exact amounts leaving and entering each address
  • Token movements including all affected tokens
  • Gas costs in both native currency and USD

Contract Effects:

  • Smart contract state changes
  • Emitted events
  • Token approvals being granted or consumed

Risk Assessment:

  • Warnings about unusual activity
  • Detection of potentially malicious contracts
  • Slippage calculations for swaps

Simulation Example

For a simple token swap, the simulation would show:

Before Transaction:
- Wallet: 10 ETH, 0 USDC

After Transaction:
- Wallet: 8.95 ETH, 3,500 USDC
- Gas cost: 0.05 ETH ($100)
- Price impact: 0.3%
- Route: ETH → WETH → USDC via Uniswap V3

Supported Transaction Types

Basic Transfers (Planned)

Simple sending of native tokens or ERC-20/BEP-20 tokens between addresses. The system will handle:

  • Optimal gas calculation
  • Nonce management
  • Failed transaction recovery

Token Swaps (In Development)

Integration with major DEX protocols for token exchanges:

  • Automatic routing for best prices
  • Slippage protection
  • MEV protection strategies

Smart Contract Interactions (Future)

General purpose contract calls with:

  • ABI decoding for human-readable actions
  • State change predictions
  • Gas optimization

Batch Operations (Roadmap)

Multiple actions in a single transaction for efficiency:

  • Bulk transfers
  • Complex DeFi strategies
  • Gas cost optimization

Security Architecture

Transaction Integrity

Every transaction follows strict security protocols:

  • Validation - All parameters verified before processing
  • Simulation - Mandatory preview of effects
  • User Confirmation - Explicit approval required
  • Signing Isolation - Private keys never touch Vilna servers

Signing Methods (Planned)

External Wallets:

  • Integration with MetaMask, WalletConnect
  • Hardware wallet support (Ledger, Trezor)
  • Mobile wallet connections

MPC Signing (Future):

  • Threshold signatures using MPC module
  • No single point of failure
  • Audit trail for all signing operations

Real-World Applications

Exchange Withdrawals

Exchanges can use the transaction module to process user withdrawals:

  1. User initiates withdrawal in exchange UI
  2. Exchange creates transaction via Vilna API
  3. Simulation shows exact fees and arrival amount
  4. Multi-signature approval from exchange operators
  5. Automatic broadcasting and confirmation tracking

DeFi Position Management

DeFi platforms can offer safe interaction with protocols:

  1. User wants to add liquidity to a pool
  2. Platform simulates the transaction showing:
    • Tokens being deposited
    • LP tokens received
    • Current pool APY
    • Impermanent loss risks
  3. User approves with full understanding of outcomes

Payment Processing

Payment gateways can offer refunds and payouts:

  1. Merchant initiates refund
  2. System calculates optimal gas settings
  3. Simulation confirms customer will receive exact refund amount
  4. Automatic execution with retry logic

Integration Approach

API-First Design

All transaction operations are available through REST API:

  • Transaction creation with type-specific parameters
  • Simulation endpoint returning detailed previews
  • Signing orchestration with multiple methods
  • Status tracking and confirmation monitoring

Relevant endpoints (when available):

  • POST /transactions/create - Build new transaction
  • POST /transactions/simulate - Get simulation results
  • POST /transactions/sign - Initiate signing flow
  • GET /transactions/{id}/status - Track execution

Event-Driven Updates

Real-time notifications for transaction lifecycle:

  • Creation confirmation
  • Simulation completion
  • Signature collection progress
  • Broadcasting status
  • Blockchain confirmations

Current Limitations

As the module is under development, certain features are not yet available:

  • Direct smart contract interactions are limited
  • Not all DEX protocols are integrated
  • Hardware wallet support is being tested
  • Batch transactions are on the roadmap

Safety Features

Transaction Policies (Planned)

Define rules to prevent accidents and fraud:

  • Daily spending limits
  • Whitelist of allowed recipients
  • Time-based restrictions
  • Multi-approval requirements

Automatic Safeguards

Built-in protections without configuration:

  • Insufficient balance detection
  • Extremely high gas warnings
  • Malicious contract detection
  • Reentrancy attack prevention

Comparison with Direct Blockchain Interaction

Traditional Approach

  • Build raw transaction manually
  • Estimate gas (often incorrectly)
  • Sign without knowing effects
  • Hope transaction succeeds
  • Handle failures manually

With Vilna Transaction Processing

  • Structured transaction creation
  • Accurate gas optimization
  • Preview exact outcomes
  • Confident execution
  • Automatic retry and recovery

Development Roadmap

Currently Available

  • Basic transaction structure
  • Simulation framework
  • Simple transfers (testing)

In Development

  • DEX integrations
  • Enhanced simulation accuracy
  • External wallet connections

Future Plans

  • Full smart contract support
  • Cross-chain transactions
  • Advanced MEV protection
  • Transaction bundling

Getting Started

While the full module is under development, you can:

  1. Contact [email protected] for beta access
  2. Test transaction simulation in sandbox environment
  3. Provide feedback on desired features
  4. Prepare your integration for upcoming release

Key Takeaways

  • Safety First: Every transaction is simulated before execution
  • User Control: Users always see and approve transaction effects
  • No Private Keys: Vilna never has access to signing keys
  • Progressive Release: Features released as they're production-ready

Next Steps