Hybrid dApps are applications that run their core logic on TAC’s EVM Layer while providing a completely native experience for TON users. Unlike traditional cross-chain applications that require users to switch networks or manage multiple wallets, hybrid dApps feel like native TON applications while leveraging the full power of EVM’s mature ecosystem.

What Makes an App “Hybrid”

Traditional dApps exist entirely within one ecosystem. Hybrid dApps span two ecosystems seamlessly:

Backend (EVM Side)

  • Solidity contracts on TAC EVM Layer
  • Complex DeFi primitives and composability
  • Mature tooling and battle-tested code
  • Rich ecosystem of integrations

Frontend (TON Side)

  • TON wallet integration
  • Telegram Mini App interface
  • Native asset handling
  • Familiar TON user flows

Users interact with hybrid dApps exactly like they would with native TON apps, they never know there’s EVM logic running behind the scenes.

The Hybrid dApp Advantage

Hybrid dApps unlock a new paradigm where users and developers enjoy the strengths of both TON and EVM ecosystems—without compromise.

For Users: Native Experience, Expanded Capabilities

No learning curve or new tools:

  • Use existing TON wallet (Tonkeeper, Tonhub, etc.)
  • Access through familiar Telegram Mini Apps
  • Transact with TON tokens directly
  • No network switching or bridge operations

Users get access to sophisticated DeFi without leaving their comfort zone

For Developers: Best of Both Worlds

Hybrid dApp Architecture

Here’s how the different components work together to create a seamless hybrid experience:

User Interface

Native TON experience:

  • Telegram Mini App or web interface
  • TON wallet connection (TON Connect protocol)
  • Familiar TON UX patterns and flows
  • Real-time transaction status updates

Frontend Logic

TAC SDK integration:

  • JavaScript/TypeScript SDK handles cross-chain messaging
  • Automatic transaction routing and status tracking
  • Asset bridging management
  • Error handling and recovery

Cross-Chain Layer

TAC infrastructure:

  • TON Adapter handles secure message routing
  • Automatic asset locking/unlocking operations
  • Sequencer network validates all transactions
  • Proxy contracts translate between ecosystems

Application Logic

EVM smart contracts:

  • Core business logic runs on TAC EVM Layer
  • Complex DeFi operations and state management
  • Integration with other EVM protocols
  • Standard Solidity development patterns

Development Patterns

Hybrid dApps on TAC are designed to feel native to both TON and EVM users, blending familiar interfaces with powerful cross-chain capabilities.

By leveraging TAC’s architecture, developers can build applications that seamlessly connect users, assets, and protocols across ecosystems—without compromising on user experience or security. Below are the key patterns and best practices for building truly hybrid applications.

Frontend Architecture

Most hybrid dApps follow a common frontend pattern:

// 1. Initialize TAC SDK
import { TacSdk, Network } from "@tonappchain/sdk";
const tacSdk = await TacSdk.create({ network: Network.TESTNET });

// 2. Connect TON wallet
import { TonConnectUI } from "@tonconnect/ui";
const tonConnect = new TonConnectUI({
  manifestUrl: "https://yourapp.com/tonconnect-manifest.json",
});

// 3. Create cross-chain transactions
const transactionLinker = await tacSdk.sendCrossChainTransaction(
  {
    evmTargetAddress: "0xYourContract",
    methodName: "yourMethod(bytes,bytes)",
    encodedParameters: encodedParams,
  },
  sender,
  assets
);

// 4. Track transaction status
const tracker = new OperationTracker(Network.TESTNET);
const status = await tracker.getOperationStatus(operationId);

Smart Contract Architecture

EVM-side contracts follow standard patterns with TAC-specific proxy integration:

pragma solidity ^0.8.0;

import "@tac/proxy-contracts/TacProxyV1.sol";

contract HybridDeFiProtocol is TacProxyV1 {
    constructor(address _crossChainLayer) TacProxyV1(_crossChainLayer) {}

    // This function receives cross-chain calls from TON
    function executeSwap(bytes calldata tacHeader, bytes calldata args)
        external
        _onlyCrossChainLayer
    {
        // Decode TAC header to get user info
        TacHeaderV1 memory header = _decodeTacHeader(tacHeader);

        // Decode your application-specific arguments
        SwapParams memory params = abi.decode(args, (SwapParams));

        // Execute your application logic
        performSwap(params);

        // Optionally send results back to TON
        _sendMessageV1(createReturnMessage(header, results));
    }
}

User Journey Example

Let’s follow a TON user interacting with a hybrid DEX:

Discovery

User discovers the DEX through a Telegram Mini App or web interface. The app looks and feels like a native TON application.

Connection

User connects their TON wallet (Tonkeeper) using standard TON Connect. No new wallets or seed phrases required.

Asset Selection

User selects TON tokens to swap. The interface shows familiar token names and balances from their TON wallet.

Transaction

User approves the swap in their TON wallet. Behind the scenes, TAC locks their tokens and sends a message to the EVM DEX contract.

Execution

The DEX executes the swap using sophisticated AMM logic on the EVM side. The user sees real-time status updates in the interface.

Completion

New tokens appear in the user’s TON wallet automatically. The entire process feels like a native TON transaction.

The user never knew they were interacting with an EVM application - it felt completely native to TON.

Best Practices for Hybrid dApps

Common Challenges & Solutions

Building hybrid dApps comes with unique challenges, but TAC provides solutions for each one.

Cross-Chain Latency

Challenge: Cross-chain operations take longer than single-chain transactions Solution: Use optimistic UI updates and clear progress indicators to maintain responsive UX

Asset Complexity

Challenge: Managing token mappings and decimal differences between chains Solution: TAC SDK handles token mapping automatically, with helpers for decimal conversion

Error Handling

Challenge: Failures can occur on either chain with different error types

Solution: Comprehensive error handling in TAC SDK with automatic rollback protection

Testing Complexity

Challenge: Testing requires simulating both TON and EVM environments

Solution: TAC provides testing utilities and local development environments

Ready to Build?

Hybrid dApps represent the future of cross-chain applications - combining the best of both ecosystems while hiding complexity from users.