BNB Chain has activated its Jenner hardfork on the BNB Smart Chain (BSC) testnet, introducing a default reservation of 5% of each block’s gas capacity for eligible payments. The upgrade also gives smart contracts access to millisecond timestamps and installs support for CAS20, its Compliant Asset Standard.
“Payment Lane and CAS20 will go through governance before being fully enabled,” BNB Chain said in its announcement. The payment-contract list starts empty under the upgrade’s rules, so stablecoins and CAS20 tokens need separate governance approval to qualify for the lane.
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Payment Lane changes how block capacity is allocated, not how transactions are priced or ordered. Previously, payments competed with other traffic for the same undivided block space, according to the specification.
General transactions cannot consume the reserved capacity, even when it sits unused. Eligible payments can use the reservation and compete for the rest of the block. Validators must reject blocks that breach the gas-allocation rule. Governance controls the reservation share, up to a protocol maximum of 10%.
Qualifying traffic includes nonzero BNB transfers to accounts with no code and supported transactions sent directly to governance-listed payment contracts. A transaction sent through an unlisted router does not qualify merely because it later transfers a listed stablecoin, BNB Chain’s Payment Lane guide explains. Fees still apply, and no individual payment is guaranteed inclusion in a particular block.
Finer Timestamps, Separate CAS20 Activation
For application developers, Jenner exposes millisecond timing precision already present in block headers. Contracts must explicitly call the new built-in function; the existing block.timestamp value remains in seconds. The change does not speed up block production or strengthen the timing guarantees of validator-supplied timestamps, according to the upgrade guide.
CAS20 moves token functionality into the protocol rather than relying on separately deployed token code. It provides transfer policies, allowlists, blocklists, pausing and separate mint, burn and seizure roles. It retains BEP-20 interface compatibility, but those technical controls do not themselves establish legal compliance.
The hardfork installs that capability without opening token creation. Under the CAS20 specification, token creation and policy-registry updates start disabled. Governance must appoint an administrator, who then activates those features.
For Chapel testnet operators using Reth, reth-bsc v0.1.3 is a mandatory Jenner update. BNB Chain’s upgrade notice lists late November 2026 as the mainnet window, with the exact activation time still to be announced.