> For the complete documentation index, see [llms.txt](https://docs.nexus.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexus.xyz/network/architecture/nexusbft.md). # NexusBFT NexusBFT is the consensus mechanism of the Nexus blockchain, built on CometBFT. #### Single-slot finality Blocks are final when committed. There is no probabilistic finality window. Once >2/3 of validators precommit a block, it is irreversible. #### Consensus rounds 1. **Propose** — A designated proposer assembles a block and broadcasts it 2. **Prevote** — Validators evaluate the block and broadcast a prevote (for the block or nil) 3. **Precommit** — Once >2/3 prevotes are seen for the same block, validators broadcast a precommit 4. **Commit** — Once >2/3 precommits are seen, the block is committed and final If a round fails, the protocol advances to a new round with a new proposer. The system never forks. #### Validators Validators run a Cosmos consensus node (`nexus-cosmos`) and an EVM execution node (`nexus-evm`). **Responsibilities:** * Participate in every consensus round * Maintain high uptime * Run both consensus and execution nodes The validator set is permissioned at launch and will expand over time. Validators will stake $NEX to join the active set in subsequent upgrades. #### Role in the system NexusBFT orders transactions and commits blocks with finality. Today it commits NexusEVM blocks. When NexusCore launches (H2 2026), NexusBFT will also commit exchange execution blocks at a faster cadence. After a block is committed, the Compute Network will generate a validity proof of the execution batch. NexusBFT provides ordering and finality; the Compute Network will provide verifiability. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.nexus.xyz/network/architecture/nexusbft.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.