> For the complete documentation index, see [llms.txt](https://bitnet-whitepaper.gitbook.io/developer-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bitnet-whitepaper.gitbook.io/developer-docs/upgrades-overview/hard-fork-upgrades.md).

# Hard Fork Upgrades

### Coordinating Hard Fork Upgrades on BitNet

While traditional governance proposals allow BitNet to schedule upgrades in a decentralized way, they require a full voting period. For **critical updates**, such as emergency patches or security fixes, BitNet supports **Hard Fork Upgrades** to ensure faster execution.

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#### What is a Hard Fork Upgrade?

A **Hard Fork** in BitNet allows validators to pre-agree on a future upgrade height without waiting for a governance vote. It is triggered by a specially crafted patch release that automatically initiates the upgrade logic when the blockchain reaches a defined block height.

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#### Step-by-Step Hard Fork Process

1. **Patch Creation**\
   A private branch is used to fix the vulnerability or apply breaking changes.\
   Example: A patch release like `v8.0.1` includes upgrade logic targeting `v9.0.0`.
2. **Patch Deployment**\
   Validators install the patch release (`v8.0.1`), which contains the hard-coded fork logic set for a specific block height.
3. **Validator Coordination**\
   At least **two-thirds (2/3)** of the validator voting power must upgrade before the fork height to avoid network halts.
4. **Release Distribution**\
   The full major release (`v9.0.0`) is made publicly available **at least one hour** before the scheduled fork to allow:
   * Binary creation (\~30 minutes)
   * Validator testing and Cosmovisor updates

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#### Why Hard Forks Matter

* **Fast Response**: Ideal for critical security fixes
* **No Governance Delay**: Bypasses full voting periods
* **Automated Execution**: Logic executes at `BeginBlock` of upgrade height
* **Validator Participation Required**: If <2/3 voting power upgrades, the fork will fail