World Chain becomes first production L2 to ship streaming Block Access Lists via Flashblocks

World Chain plans on becoming the first production Layer 2 blockchain to stream full EIP-7928 Block Access Lists inside every flashblock, with the feature rolling out on mainnet on Aug. 17, according to an announcement on Wednesday.

The upgrade enables validators to verify blocks in parallel while they are still being built, targeting throughput of up to one gigagas per second without requiring more powerful hardware. (A gigagas is a performance metric representing the processing of one billion gas units.)

“Traditionally, validators must re-execute every transaction in a block sequentially before confirming its validity,” the statement reads. “Full block access lists instead provide a record of the blockchain state each transaction reads and writes, allowing independent transactions to be verified simultaneously across multiple CPU cores rather than one at a time.”

EIP-7928 is an Ethereum Improvement Proposal to add Block-Level Access Lists (aka BALs) that serve as an enforced, block-level record of all accounts and storage slots accessed during a block’s execution, along with post-execution state differences. In the end, this will lead to faster block validation.

Proposed in March 2025, BALs will be included as a headliner update for Ethereum’s Glamsterdam hardfork, planned for the second half of the year.

World Chain, the Optimism-based blockchain used by the World digital identity solution co-founded by OpenAI’s Sam Altman, plans to take BALs a step further by streaming this block builder data incrementally every 200 milliseconds through its flashblock architecture, according to the announcement.

Flashblocks were developed by Flashbots as an extension of their Rollup Boost technology for OP Stack chains. The tech enables partial sub-blocks to be streamed about every 200 milliseconds within a standard 2-second block on OP Stack rollups, enabling near-instant transaction preconfirmations while the full block is still being assembled.

“Instead of waiting until an entire block has been produced, validators begin verifying transactions immediately as the block is assembled, reducing validation latency and spreading verification work throughout the block-building process,” the announcement reads. 

According to World’s test network benchmarks, “validation latency remained effectively stable” even as blockchain throughput increased. “The results suggest that blockchain networks can increase throughput substantially without proportionally increasing the computing resources required to independently verify the chain,” the announcement reads.

World is activating this feature via a runtime flag rather than a hard fork, as will happen on the base layer.

Ethereum co-creator Joseph Lubin previously told The Block that technical upgrades are often tested out in its ecosystem of Layer 2s before introduction on the mainchain, often providing positive feedback from production-level environments.