Base has scheduled its Beryl mainnet upgrade for June 25, 2026. The release brings two changes with direct impact on network users and builders: a new chain-native B20 token standard and a shorter standard withdrawal window for moving funds from Base back to Ethereum, reduced from seven days to five.
Second major release after Base moved to independent upgrades
According to the team’s engineering blog, Beryl has already been deployed on the Sepolia testnet, with mainnet activation fixed for June 25. The upgrade follows Azul, which launched in May and was described as Base’s first fully independent release after the network stopped sharing infrastructure with Optimism’s OP Stack in February. That change is part of the reason Base is now shipping major upgrades on a roughly four-week cycle instead of waiting for longer release windows.
B20 runs inside node software instead of as a standard smart contract
The most notable structural change in Beryl is the introduction of B20. Unlike standard ERC-20 tokens that exist as smart contracts deployed onchain, B20 is written in Rust and implemented as a precompile inside Base node software. The goal is not to break compatibility. Base says B20 mirrors the full ERC-20 specification and also adds ERC-2612 permits, which means existing wallets, exchanges, and indexers should be able to support it without extra integration work.
The standard also includes built-in controls for issuers, such as role-based permissions, mint and burn limits, supply caps, transfer restrictions, and freeze-and-seize functionality. The article says those features are aimed at regulated stablecoin issuers and tokenized real-world assets. Two versions are set to launch with Beryl: a general-purpose asset token and a stablecoin-focused variant with fixed six-decimal precision.
Standard exits to Ethereum will take five days instead of seven
Beryl also changes the withdrawal process. After the upgrade, the usual exit period from Base to Ethereum will fall from 7 days to 5 days. The older seven-day window came from Base’s original fault-proof design, which kept a long delay in place so challengers had time to dispute a withdrawal before finalization.
The report notes that Azul’s Multiproofs system had already created a same-day withdrawal path when both a trusted execution environment and a zero-knowledge proof confirmed a transaction. That route has seen limited use because generating the ZK proof is expensive. Beryl focuses on the slower and much more common single-proof path used by most bridges, narrowing the mechanism to detecting a faulty prover rather than preserving the full dispute window.
Reth V2 arrives with Beryl, while Cobalt is planned for September
The upgrade also includes Reth V2, a new version of the Rust-based execution client Base has used exclusively since Azul. Based on the source material, Reth V2 reduces disk usage across full, minimal, and archive nodes. It also creates room to raise block gas targets without putting the sequencer or RPC infrastructure under the same level of strain, which translates into more available blockspace for applications on the network.
Base has already named the next release as well: Cobalt, targeted for September. The planned features listed in the source include native account abstraction, protocol-level smart accounts, gas sponsorship, transaction batching, added B20 functionality, and a unified node binary that combines consensus and execution.