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title: Overview - BC Fusion
---


# Overview

**BNB Beacon Chain has been shut down at block height 385,251,927 since December 3, 2024.**

BNB Beacon Chain is a blockchain developed by the BNB Chain community that implements a vision of a decentralized
exchange (DEX) for digital assets. Besides this, Beacon Chain and BSC is a dual-chain structure: Beacon Chain helps to
enhance the security of BSC as a staking and governance layer. With the rise of various other forms of Dex, order-book
based decentralized exchange was decommissioned
in [BEP151](https://github.com/bnb-chain/BEPs/blob/master/BEPs/BEP151.md). With the quick evolution of BSC, the Beacon
Chain has become a burden. The cross-chain bridge that connects the two chains slows down the development iteration and
always exposes BNB to a certain level of security vulnerabilities. It's time to take a step further and migrate the
functionality of Beacon Chain to BSC, **allowing Beacon Chain to retire**.

![img](../assets/bcfusion/phases.png)

There will be several pahses to retrie Beacon Chain:

- **First Sunset Fork** - Some types of Beacon chain transactions will be disabled, for example, TimeLockMsg,
  TimeRelockMsg,
  FreezeMsg, IssueMsg, MintMsg, IssueMiniMsg, HTLTMsg, DepositHTLTMsg, MsgCreateValidatorOpen,
  MsgCreateSideChainValidator, MsgCreateSideChainValidatorWithVoteAddr, MsgEditSideChainValidatorWithVoteAddr,
  MsgSideChainDelegate, MsgSideChainReDelegate. 
- **BSC Feynman Hardfork** - Native validators and staking, native goverenance will be enabled on BNB Smart Chain.
  The BSC validators/delegators can start migrations after the Feynman upgrade.
- **Second Sunset Fork** - More Beacon chain transactions will be disabled, for example,MsgSideChainSubmitProposal. All
  TimeLock and AtomicSwap will automatically be refunded to the user's
  wallet. All the BSC delegation will be undelegated automatically.
- **Final Sunset Fork** - Cross-chain communication between the Beacon Chain and BSC will be completely stopped.
- **Post BC Fusion** - Beacon Chain will be dumped and and a merkle tree will be generated for recover the assets, which
  are binded to BSC however not transffered to BSC yet.

All stakholders (e.g., token holders/owners, validators, project owners) should pay attention BNB Chain blog for
releated annonuncements and take actions proactively.

For more information about BNB Chain fusion, please refer
to [BEP-333](https://github.com/bnb-chain/BEPs/pull/333?ref=bnbchain.ghost.io).

For the roadmap and milestons of BNB Chain fusion, please refer
to [the blog](https://www.bnbchain.org/en/blog/bnb-chain-fusion-roadmap).