ZetaChain is a Proof of Stake (PoS) blockchain built with the Cosmos SDK (opens in a new tab), the CometBFT (opens in a new tab) consensus engine, and Cosmos EVM (opens in a new tab).

This stack delivers:

• Modularity: via the Cosmos SDK for flexible, upgradeable architecture.
• Fast finality: through CometBFT’s instant consensus mechanism
• Full EVM compatibility: with Cosmos EVM, enabling Ethereum smart contracts to run natively on ZetaChain without modification.

ZetaChain acts as a universal connector between blockchains, offering fast ~4-second blocks, instant finality, and throughput up to hundreds of transactions per second, all on infrastructure purpose-built for secure, seamless cross-chain interactions.

Architecture Overview

Hub-and-Spoke Model

ZetaChain uses a hub-and-spoke architecture:

• Hub: ZetaChain, the main coordination layer for all cross-chain activity.
• Spokes: External blockchains (EVM, Solana, Sui, Ton, and Bitcoin) connected with standardized protocols.

All cross-chain messages and transactions pass through ZetaChain, ensuring consistent handling, easier integration of new chains, and a single point for enforcing security and validation rules.

Validators

ZetaChain’s validator set includes two main roles:

Core Validators

• Run ZetaChain node.
• Participate in CometBFT consensus to produce blocks and maintain state.
• Open to anyone staking the required ZETA tokens.
• Incentivized via transaction fees and rewards; subject to slashing for malicious or negligent behavior.

Observer-Signer Validators

• Run both ZetaChain node and ZetaClient.
• Monitor ZetaChain and connected chains for cross-chain events.
• Vote on event validity; upon majority agreement, coordinate outbound transactions.
• Sign outbound transactions using a Threshold Signature Scheme (TSS) so no single validator controls the signing key.

Modules and Components

ZetaChain's functionality is organized into several key modules, each responsible for specific aspects of cross-chain transaction processing.

CrossChain Module

The CrossChain module manages the state and lifecycle of cross-chain transactions (CCTX), serving as the central ledger for tracking their progress and statuses. It handles the creation of new cross-chain transaction records when inbound events are validated, updates transaction statuses based on events (such as PendingInbound, PendingOutbound, OutboundMined), and stores detailed parameters for both inbound and outbound transactions, including sender and receiver information, asset details, and transaction hashes.

Observer Module

The Observer module handles the operations of the observer set, including validator management, voting mechanisms, and consensus policies. It maintains a list of authorized observers eligible to participate in the consensus process, creates and tracks ballots for each observed event to facilitate the voting process, and defines core parameters such as ballot thresholds, minimum observer delegation, and supported chains.

Fungible Module

The Fungible module facilitates the deployment and management of fungible tokens (ZRC20 tokens) representing assets from connected blockchains on ZetaChain. It handles the deployment of ZRC20 contracts corresponding to foreign coins from connected chains, manages pools and liquidity for these tokens, and provides functions for depositing to and calling omnichain smart contracts on ZetaChain from connected chains.

Emissions Module

The Emissions module orchestrates the distribution of rewards to network participants, including observers, validators, and TSS signers. It calculates rewards based on participation metrics and predefined parameters, distributes rewards from a pre-funded emissions pool, and allows participants to securely withdraw their earned rewards.

Authority Module

The Authority module encapsulates logic for administrative functions and permission checks, ensuring that only authorized entities can perform sensitive actions. It maintains tables for different admin groups and their permissions, validates whether a user or entity has the necessary permissions to execute specific actions, and facilitates changes to admin groups or permissions through governance proposals, ensuring transparent and decentralized decision-making.

Protocol Contracts

To enable interaction between users, applications, and the ZetaChain network, protocol contracts are deployed both on ZetaChain and on connected external chains. These contracts provide standardized entry points for initiating and managing cross-chain transactions, as well as registry data for discovering deployed protocol components.

On ZetaChain

On Connected EVM Chains

On Other Connected Chains (Solana, Sui, TON, etc.)

You can find up-to-date contract addresses for both mainnet and testnet in the Contract Addresses Reference.

Economic Incentives and Bonded Stakes

ZetaChain employs bonded stakes and positive/negative incentives to ensure economic safety and encourage validators to act honestly. Validators are required to stake bonds in the form of ZETA tokens, which are at risk if they act maliciously or negligently. This staking mechanism aligns the interests of validators with the network's health and security.

Validators earn transaction fees and block rewards in return for their services in processing transactions and maintaining network security. Those who act dishonestly or fail to fulfill their duties can have a portion of their staked bonds slashed as a penalty. Positive incentives are provided to encourage validators to remain online and actively participate in consensus and observation processes.

Cross-Chain Transaction Workflow

Cross-chain transactions are at the core of ZetaChain’s functionality, enabling assets and data to move between ZetaChain and connected blockchains.

The process differs for incoming (connected chain → ZetaChain) and outgoing (ZetaChain → connected chain) transactions, but both follow a secure, validator-driven workflow.

Incoming Transactions (Connected Chain → ZetaChain)

1. Initiation: A user interacts with the gateway contract on a connected chain (e.g., deposits assets or makes a cross-chain call).
2. Observation: Observer-Signer Validators detect the emitted event and extract transaction details.
3. Voting: Validators submit and vote on a ballot in ZetaChain; a majority is required for approval.
4. Execution on ZetaChain: Once approved, ZetaChain updates the CCTX record, mints assets (if applicable), and/or calls the target universal contract.

Outgoing Transactions (ZetaChain → Connected Chain)

1. Initiation: A user or contract calls the GatewayZEVM contract on ZetaChain, specifying the target chain, recipient, assets, and payload.

2. Preparation: Validators process the request, validate parameters, and generate the outbound transaction.

3. TSS Signing: A subset of validators collaboratively sign the outbound transaction using Threshold Signature Scheme (TSS), ensuring no single validator holds the private key.

4. Submission: The signed transaction is broadcast to the destination chain.

5. Completion or Revert:

   • On success: Assets or data are delivered, and the CCTX is marked complete.
   • On failure: ZetaChain executes revert logic per developer-defined options (e.g., refund assets, trigger fallback contract calls).

Conclusion

For developers, ZetaChain removes much of the friction of building cross-chain applications. Instead of juggling different SDKs, bridges, and security models, you get a single platform that handles cross-chain messaging, asset movement, and contract calls for you. Fast finality and a unified protocol mean you can focus on application logic, not infrastructure. Whether your app needs to reach EVM chains, Solana, Sui, or even Bitcoin, ZetaChain gives you one place to build and deploy, with security and scalability baked in from the start.