BNB Chain developers have issued a mandatory update notice ahead of the Osaka/Mendel hard fork, scheduled to go live on BSC mainnet on April 28 at 02:30 UTC. All node operators must upgrade to BSC v1.7.2 before that deadline or risk falling out of sync with the network. The upgrade carries nine protocol-level changes, including a new transaction-level gas cap and a set of Ethereum proposals adopted from the Fusaka roadmap.
What Node Operators Need to Do Before the Deadline
The update procedure is straightforward: operators need to replace their existing binary with BSC v1.7.2 and remove any JournalFileEnabled field from their configuration file. BNB Chain developers flagged that incorrect binary replacement and leftover config fields are the two most common causes of nodes losing sync during hard fork transitions.
The update is non-optional. Nodes that do not complete the upgrade before the fork block will be unable to follow the new chain, effectively disconnecting from the network. The same deadline structure was used for the previous Fermi hard fork, which activated on January 14, 2026 and required all validators to upgrade ahead of time.
The Osaka/Mendel fork was first activated on the BSC testnet on March 24 at block 88,379,325. Developers said the test phase improved block construction, transaction handling at scale, network stability, and execution accuracy before the mainnet rollout.
Gas Cap, Finality, and Nine Protocol Changes in the Upgrade
The most notable addition is BEP-652, which implements a protocol-level gas cap per transaction through EIP-7825. The cap is set at 16,777,216 gas. Under the new rule, all nodes will reject transactions exceeding this limit uniformly, replacing the earlier soft cap model that individual operators could interpret differently. BNB Chain said this approach is more reliable because it eliminates inconsistency at the node level.
Two other proposals address network performance directly. BEP-657 restricts when blob transactions can be included based on block number, adding predictability to how data-heavy transactions flow through the network. BEP-648 targets latency reduction and faster finality, a recurring priority in BNB Chain’s 2026 roadmap.
The upgrade also includes seven Ethereum proposals drawn from the Fusaka upgrade set: six required a hard fork and one was a client-side RPC change. The total package amounts to nine BEPs, making Osaka/Mendel one of the larger single-fork upgrades the chain has shipped.
Consecutive Hard Forks Reflect BNB Chain’s 2026 Scaling Push
The Osaka/Mendel fork is part of a broader infrastructure push BNB Chain has been executing through 2026. The Fermi hard fork earlier this year brought block times down to 0.45 seconds and improved finality stability. The chain’s Layer-2 network, opBNB, also completed the Fourier fork in January, halving its block interval to 250 milliseconds.
BNB Chain’s published 2026 roadmap targets 20,000 transactions per second with sub-second finality, with longer-term plans for a ground-up architecture rebuild aimed at 1 million TPS and sub-150ms finality by 2028. The April 28 upgrade moves the network one step closer to those targets by locking in gas predictability and improving block-level execution.
