The Jenner hardfork, now live on the BNB Smart Chain (BSC) testnet, includes a new feature called Payment Lane. This rule reserves 5% of the gas limit in every block for eligible payment transactions, with a protocol‑wide cap of 10%.
How the reservation works
Payment Lane is enforced during block validation as a gas accounting rule. General transactions are prohibited from using the reserved portion of gas, even when payment demand is low. Eligible payments can draw from the reserved gas and compete for the remaining capacity under the existing fee structure. For example, a block with a 100 million gas limit would set aside 5 million gas for payments, leaving 95 million for other transactions.
Eligible payment transactions
Two types of transactions qualify for the payment class:
- Transfers of non‑zero BNB to accounts that contain no code (code‑free accounts).
- Transactions sent directly to contracts that are listed on a governance‑managed payment‑contract list.
Both routes require a destination address and exclude system transactions. They support transaction types 0x00, 0x01, and 0x02. Contract creation, blob transactions, and type 0x04 transactions are treated as general traffic.
Governance and configuration
Governance controls the payment‑contract list and the reservation ratio. The default reservation is 5%, and the maximum allowed by the protocol is 10%. The payment‑contract list starts empty and can be updated only between blocks, preventing mid‑block reclassification.
Block builders must account for the reserved gas when assembling blocks. Validators reject any block that violates the reservation rule, and violations trigger the builder‑revocation mechanism under the BEP‑675 SendBidBlock flow.
Unused reserved gas
Any reserved gas that is not used in a block remains idle; it is not reassigned to general transactions. Payment Lane does not guarantee transaction inclusion, fixed fees, or free transfers.
Testing and future use
Developers can use the testnet to verify transaction destinations, types, and governance listings before any mainnet deployment. The reservation takes effect in the block immediately following fork activation.
