# CCIP Architecture - Overview (TON)
Source: https://docs.chain.link/ccip/concepts/architecture/ton/overview
Last Updated: 2026-04-07

> For the complete documentation index, see [llms.txt](/llms.txt).

CCIP is a cross-chain messaging protocol built on Chainlink and secured by its decentralized oracle networks (DONs). On TON, CCIP provides the following capability:

- **Data Transmission**: Send arbitrary data (i.e., bytes) to a receiving contract.

<Aside>TON currently supports arbitrary message passing only. Token transfers are not yet supported.</Aside>

> \*\*NOTE: Terminology\*\*
>
>
>
> While this documentation references concepts like "smart contracts", the implementation of these ideas varies across different blockchain families. On TON, onchain logic is written in **Tolk** or **FunC** and compiled to the TVM (TON Virtual Machine) instruction set. TON smart contracts are stateful, communicate exclusively through internal and external messages, and cannot call each other's getters synchronously — all cross-contract interaction is asynchronous.

## High-level Architecture

CCIP delivers cross-chain messages from a source chain to a destination chain by combining offchain consensus and onchain execution components. The architecture is composed of two primary layers:

1. **Offchain Architecture**
   - Decentralized Oracle Network (DON) with nodes that perform distinct roles:
     - Commit: Observes and validates source-chain events to build a consensus-based report.
     - Execution: Validates pending messages and optimizes them for execution on the destination chain.

2. **Onchain Architecture**
   - Router:
     - Each blockchain has a single immutable Router contract that serves as the unified interface for users and decentralized applications (dApps).
   - On the source blockchain, onramp functionality consists of:
     - Providing fee estimates.
     - Dispatching the message data.
   - On the destination blockchain, offramping functionality consists of:
     - Accepting and verifying commit reports from the Committing DON.
     - Routing the processed message to the designated receiver.

**Note:** These high-level descriptions outline the core principles of CCIP. The detailed onchain and offchain architectures for TON can be found in the relevant documentation.