Overview
ZKsync Gateway is an optional shared proof aggregation layer for ZKsync chains, including both rollups and validiums. It is purpose-built to enhance interoperability, provide proof aggregation, and offer cost efficiencies for chains that choose to operate on top of it.
As a middleware layer between ZKsync chains and Ethereum, ZKsync Gateway collects proofs from multiple chains and submits them to Ethereum for final verification. This reduces gas costs for proof verification while preserving Ethereum as the root of trust.
Assets on Gateway-connected chains remain locked on Ethereum, and all L1-to-L2 interactions—such as deposits—are still executed from Ethereum, not from Gateway.
Key Benefits
- Interoperability: Enables faster communication between ZKsync chains integrated with Gateway, without affecting direct L1–L2 connectivity from Ethereum.
- Proof Aggregation: Reduces costs for users and chains by aggregating multiple proofs into a single proof submitted to Ethereum.
- Cost Efficiency: Offers stable pricing for proof verification compared to direct submission to Ethereum, while still maintaining Ethereum-based asset security.
Governance
ZKsync Gateway was whitelisted as a shared proof aggregation layer in the ZIP-10 governance proposal. This proposal allows chain operators to select ZKsync Gateway as their proof aggregation middleware instead of submitting proofs directly to Ethereum.
Migration to ZKsync Gateway is optional, and chains initially launch with direct Ethereum integration. If desired, operators may later configure their chain to utilize ZKsync Gateway for aggregated proof submission. Switching between direct Ethereum interaction and Gateway is supported at the protocol level, but a chain must first be deployed with Ethereum as its initial point of settlement.
Gateway Network Details
| Environment | Chain ID | Gas Token | Explorer |
|---|---|---|---|
| Testnet | 32657 | $ZK | Testnet Explorer |
| Mainnet | 9075 | $ZK | Mainnet Explorer |