Centralized crypto exchange OKX launched the public mainnet of X Layer, an Ethereum-based zero-knowledge Layer 2 network that utilizes the Polygon Chain Development Kit, on Monday evening. 

"We envision X Layer and other Layer 2 chains as the highway infrastructure of the Web3 world, with dApps as the marketplaces and self-hosted wallets as the vehicles that take you there,” OKX CMO Haider Rafique said. “In pursuit of this vision, we are building an ecosystem that is as seamless and interoperable as possible."

X Layer, previously dubbed “X1,” launched on testnet in November, with over 50 decentralized applications deploying within a week. Web3 and DeFi apps, including The Graph, Curve, LayerZero, QuickSwap, Galxe and Timeswap, are among those already leveraging the Layer 2 network, according to a statement shared with The Block.

X Layer allows users to deposit and withdraw crypto via OKX, with access to over 170 dapps enabling token swaps, staking and other smart contract applications, the crypto exchange said. OKX’s 50 million global users provide X Layer with a significant potential user base and ample liquidity, it added.

OKX confirmed that its platform token, OKB -1.82% , will serve as X Layer’s native asset to pay transaction fees on the network. 

According to The Block's data dashboard, OKX is currently the second-largest crypto exchange by monthly trading volume behind Binance, generating over $60 billion in trading so far this month.

Utilizing Polygon’s CDK and AggLayer

X Layer is a ZK rollup solution built using Polygon’s CDK. It is designed to increase transaction throughput and reduce costs while retaining the security of the Ethereum network. As X Layer is EVM-compatible, existing Ethereum-based apps can easily be deployed on Layer 2 without requiring significant development work.

Polygon Labs released its CDK software toolkit in August 2023, allowing developers to build Layer 2 chains for Ethereum powered by zero-knowledge proofs.

Multiple projects, such as Immutable, Astar, Canto, Palm Network, Aavegotchi, IDEX, Nubank, and Manta Network, are also using or plan to use the Polygon CDK to develop their Layer 2 networks, with OKX also contributing to the tech stack.

X Layer will be connected to other networks powered by Polygon CDK via its blockchain aggregation layer or “AggLayer,” bolstering the ecosystem’s size and enabling shared state and unified liquidity across multiple chains.

“X Layer is a monumental next step in the industry's ambition to build a truly unified Web3. The X Layer’s connection to the AggLayer solves the fragmentation of liquidity and users across chains on the AggLayer so they can all grow together,” Polygon Labs CEO Marc Boiron said. “OKX’s 50 million users now have an easy path to onboarding to X Layer and all the other chains connected to the AggLayer."