Jesse Pollak Says Validity Transactions Coming to Base in Cobalt Upgrade

jessepollak flagged validity transactions as a new primitive coming to base, amplifying a developer breakdown of the feature published by jonroethke.

According to that breakdown, validity transactions will ship as part of Base's Cobalt upgrade, estimated for the end of September 2026. The mechanism covers transactions built to EIP-2930 or EIP-1559 standards that execute only when specified onchain conditions are met, enabling conditional transaction flows.

A demo and technical specifications have been published alongside the disclosure.

The primitive is not entirely new to Base's roadmap. On 2026-09-02, Pollak highlighted Vibenet, a Base test network running 200ms blocks with validity transactions and EIP-8130 native account abstraction, as a testing ground for features headed to mainnet. The Cobalt upgrade would move validity transactions from that test environment toward production.

What to watch

Cobalt is positioned as Base's next network upgrade, with the validity transaction rollout framed as its headline feature. Base, the Ethereum Layer-2 incubated by Coinbase and built on the OP Stack, has no native token — network activity is paid in ETH.

The precise mainnet activation date has not been confirmed. Developers can review the published demo and specifications to assess how conditional execution flows would integrate with existing applications on the network.