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How we built the fastest flashblocks implementation with 5X higher throughput, zero reorgs, and the industry's fastest RPC sync At X Layer, we're building the infrastructure for the next generation of onchain applications. Speed matters — and not just perceived pre-confirmed speed, but real, chainstate finality. In January 2026, we shipped Flashblocks on X Layer mainnet and made X Layer 5X faster, reducing the effective transaction and chainstate finality from 1 second to just 200 milliseconds — while simultaneously achieving the highest flashblocks sequencer throughput among all OP Stack chains . This post is a technical deep dive into the engineering details of Flashblocks. We will provide an in-depth walkthrough of our custom flashblocks builder integration on X Layer sequencers, the zero-reorg protection system that guarantees flashblock finality, and the industry-leading RPC architecture that delivers ultra-low latency chainstate updates to downstream consumers.

X Layer has completed the Jovian network upgrade, setting the minimum base fee to 0.02 Gwei. A standard ERC-20 transfer now costs just $0.0001 — making on-chain transactions virtually free. What Is Jovian?

X Layer is OKX's EVM-compatible Layer 2 network built on the OP Stack. Since its launch, X Layer has undergone two major architectural transitions: an initial migration from Polygon CDK (zkEVM Validium) to the OP Stack, followed by a swap of the execution client from geth to reth. This post covers the second transition — the rationale behind choosing reth and the engineering work required to make it production-ready for X Layer.

X Layer has launched its Hybrid Proof system, combining optimistic proposal with on-demand ZK proving to substantially improve L2 security without sacrificing block production efficiency. Under normal operation, the Proposer submits Output Roots optimistically with no proof generation. When a Challenger disputes a proposal, the system enters a proving window during which the Proposer self-attests via the SP1 zkVM. Compared to interactive Fault Proofs that require many rounds of on-chain bisection, Hybrid Proof reduces dispute resolution to a single ZK verification, sharply cutting both Gas cost and time-to-resolution. The upgrade went live on X Layer testnet on May 6, 2026, shortening the challenge period from the OP Stack default of 7 days to 1 day.This article walks through the design rationale, mechanism, and engineering choices behind X Layer's Hybrid Proof, and examines its impact on developers and users.

X Layer Architecture Migration: From Polygon zkEVM to OP Stack> This article provides a technical deep dive into X Layer's migration from Polygon CDK (zkEVM Validium) to the OP Stack, covering architectural changes, migration rationale, technical comparison, and impact on developers.