Base ships Cobalt upgrade, adding conditional transactions and an admin balance-seizure function

Base, the Coinbase-incubated Ethereum Layer 2, activated its third mainnet upgrade, Cobalt, on Wednesday, September 30, according to The Block, which reported the details from a Base statement shared ahead of the launch.

The headline feature is Validity Transactions: time-bound transactions that stay dormant on-chain until preset conditions are met. Base's example, per The Block, is a swap that only becomes eligible if a pool's price hits a set USDC level before a given block — if it does, Base can include the transaction; if not, it is never included. Base described the API as "neutral infrastructure" that keeps advanced traders' submissions private until they land.

Cobalt also extends the B20 token standard, which launched with Base's Beryl upgrade in June. Three changes, per The Block:

• Composite Policies let asset issuers combine allowlists and blocklists with AND/OR logic — for example, requiring a recipient to sit on both a KYC list and an accreditation list, with transfers failing if either is revoked.
• Schedule Multiplier Updates align the B20 multiplier with the ERC-8056 standard, letting issuers schedule display changes such as stock splits. Existing Beryl integrations keep working.
• seizeWithMemo, a function for B20 assets and stablecoins that lets authorized administrators reassign a holder's balance where seizure has been enabled, recording source, destination, amount, and a memo on-chain. Base's example was moving shares from a frozen account to a recovery wallet.

Base said it plans, over the coming months, to cut block times from 2 seconds to 200 milliseconds, make smart accounts native at the protocol level with gas sponsorship and batching, and adopt a subset of EVM changes from Ethereum's Glamsterdam upgrade.

Key facts

• Cobalt went live on Base mainnet Wednesday, September 30, 2026 — Base's third mainnet upgrade (The Block).
• B20 standard first shipped with the Beryl upgrade in June 2026 (The Block).
• New functions: Validity Transactions, Composite Policies, Schedule Multiplier Updates (aligned to ERC-8056), and seizeWithMemo (The Block).
• Planned next: 2s→200ms block times, native smart accounts with gas sponsorship/batching, partial Glamsterdam EVM support (Base, via The Block).

The real-world read

Every specific in this story traces to Base's own pre-launch statement, relayed by The Block; there is no independent verification of on-chain behavior yet, and Base is an interested party describing its own product. Treat the framing accordingly.

Two things the promotional language glides past. First, "neutral infrastructure" for private, conditional order flow is doing a lot of work — private-until-landed submissions raise the usual questions about ordering advantage and MEV that a marketing quote won't settle. Second, and more pointed: a chain incubated by Coinbase is building in an administrator function (seizeWithMemo) to reassign users' balances, plus reusable KYC/sanctions policy tooling. That is a deliberate move toward permissioned, compliance-gated assets — reasonable for tokenized securities and regulated stablecoins, but worth naming plainly rather than filing under "user control." Whether seizure is enabled is set per-asset by issuers, not by the holder.

Not financial advice.

Sources

• The Block (Tier 2, secondary), "Base launches Cobalt upgrade with conditional transactions and new B20 asset functions," Sept. 30, 2026 — sole source for all details; its account is based on a statement Base shared ahead of launch, so the specifics and quotes originate with Base's own marketing. No primary Base announcement or on-chain confirmation was available for this item.