> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tac.build/llms.txt
> Use this file to discover all available pages before exploring further.

# TON Adapter

> The distributed messaging system that securely connects TON and TAC EVM blockchains through sequencer consensus

<Info>
  **Current Network Status**: The sequencer network is currently distributed but
  not decentralized. Full decentralization is on the roadmap as the network
  matures.
</Info>

The TON Adapter is the cross-chain messaging backbone of TAC, enabling secure communication between TON and TAC EVM Layer.
Unlike traditional bridges that simply move assets, the TON Adapter is designed specifically for application-level interactions,
allowing TON users to execute complex operations on EVM smart contracts seamlessly.

TON Adapter is tied to the specific set of contracts on both TON and TAC EVM chains to perform its duty.

### Core Functions

The TON Adapter handles the following operations:

<Columns cols={2}>
  <Card title="Message Operations" icon="message-circle">
    * Transaction execution coordination
    * TON and TAC EVM calls
    * Value routing
  </Card>

  <Card title="Consensus Operations" icon="handshake">
    * Merkle tree formation
    * Multi-group validation
    * Economic security enforcement
  </Card>
</Columns>

### Sequencer Network Architecture

<Steps>
  <Step title="Individual Sequencers" icon="server">
    Each sequencer monitors both TON and TAC EVM for relevant events,
    maintaining local databases of transactions and forming independent Merkle
    trees.
  </Step>

  <Step title="Sequencer Groups" icon="users">
    Sequencers organize into groups that must reach 3/5 internal consensus. Each
    group validates transactions independently and stakes collateral as security.
  </Step>

  <Step title="Network Consensus" icon="handshake">
    Multiple groups must submit identical Merkle trees to achieve network-wide
    consensus. This creates multiple validation layers for maximum security.
  </Step>

  <Step title="Execution" icon="play">
    Once consensus is reached, transactions execute on the target chain with
    cryptographic proof of validity.
  </Step>
</Steps>

## Asset Management

The TON Adapter handles two primary types of asset operations as tokens move between chains.

### Lock and Mint Operations

When assets need to be moved from one chain to another, the TON Adapter uses a lock-and-mint mechanism:

* **Asset Locking**: Tokens are locked on their native chain to prevent double-spending while preserving the original asset.
* **Metadata Capture**: The system records key token details, including the name, symbol, decimals, and the original contract address.
* **Token Deployment**: If the token is crossing chains for the first time, the system automatically deploys the corresponding ERC-20 contract on TAC EVM and Jetton contract on TON.
* **Token Minting**: An equivalent amount of tokens is minted on the destination chain to keep supply consistent across both networks.

### Burn and Release Operations

When assets move back, the reverse flow applies:

* **Asset Burning**: ERC-20/Jetton tokens are burned, removing them from circulation on a particular chain.
* **Validation**: Sequencers verify the burn.
* **Asset Release**: The previously locked tokens are released.

### Failure Protection

* **Automatic Rollbacks**: If a transaction fails on the target chain, assets are automatically returned to the sender.

* **Failed Transaction Collection**: Failed transactions are processed through the same consensus mechanism to ensure proper resolution.

## Performance Characteristics

The TON Adapter is designed to balance security with reasonable performance for application-level interactions.

<Tabs>
  <Tab title="Latency">
    Cross-chain transactions typically complete **within 1-3 minutes**.
    The exact timing depends on the number of
    sequencer groups participating in consensus and the current cross-chain activity.
  </Tab>

  <Tab title="Throughput">
    The system can handle **hundreds of cross-chain messages per minute**.
    Each transaction will be finalized but the delay of up to **10 minutes** may be introduced under the peak cross-chain activity.
  </Tab>

  <Tab title="Cost">
    Cross-chain operations require gas fees on both chains plus sequencer fees
    for the messaging service. However, the cost remains reasonable (about `0.05 - 0.20 TON`) for
    transactions like token swaps (TON->TAC->TON type).

    The distributed nature of sequencer operations helps keep fees competitive while maintaining
    security guarantees.
  </Tab>
</Tabs>