Neo X MainNet v0.4.2 Upgrade: Anti-MEV Now Live

We’re excited to announce that Neo X MainNet has been upgraded to v0.4.2 (block height 3,749,760), officially bringing the Anti-MEV function live.

This upgrade follows the successful rollout on TestNet and marks a decisive step toward a fairer blockchain ecosystem. At Neo, we uphold decentralization, censorship-resistance, and user-first values. Anti-MEV is not just a feature — it’s a core part of our vision for the future of Web3.

What is MEV?

MEV (Maximum Extractable Value) refers to the maximum profit a block producer can capture by manipulating transaction order. While some argue that “neutral” forms of MEV exist (such as simple DEX arbitrage), the vast majority are harmful. Toxic MEV acts as a hidden tax on users and represents a form of financial censorship. It undermines security, permissionlessness, and decentralization — the very foundations of blockchain.

Common examples of toxic MEV include:

• Front-running — Exploiting a user’s trade by inserting a competing transaction immediately before it.
• Sandwich attacks — Surrounding a user’s trade with other transactions to manipulate price.
• Block withholding and time-bandit attacks — Reordering or reorganizing blocks to capture value.

These are not harmless strategies — they are deliberate manipulations that subvert user intent and erode trust.

How Neo X Eliminates Toxic MEV

Neo X tackles MEV at the protocol level using a combination of cryptographic and consensus innovations:

• dBFT consensus — Eliminates opportunities and incentives for validator misconduct, safeguarding the block production process from the root.
• Enveloped Transactions — Transaction details remain hidden until inclusion in a block, preventing front-running and ordering manipulation.
• ZK-based Distributed Key Generation (DKG) and Threshold Decryption — Keys are generated via DKG, allowing users to encrypt transactions with a shared public key. Two-thirds of consensus nodes then decrypt using partial private keys, ensuring security and fairness.

Together, these mechanisms enforce fair transaction ordering and eliminate toxic MEV at its root.

Our Vision: MEV Is Not Inevitable

As Neo founder Da Hongfei wrote:

“MEV isn’t inevitable; it’s a choice. Too many treat it as an unavoidable byproduct of blockchains. It is not. MEV is engineered into incentives, and it can be engineered out.”

By tolerating MEV, blockchains allow hidden taxes, censorship, and centralization to erode trust. By eliminating it, we protect users, strengthen decentralization, and create more competitive, investable ecosystems.

At Neo, we believe fairness is not just an ethical imperative, but a strategic necessity for the future of Web3. We are committed to building systems that uphold the original promise of blockchain: trust, transparency, and decentralization without compromise.

Neo X Anti-MEV is live on MainNet. This is not just a technical milestone — it’s a statement of intent. We choose a blockchain future that is fair, censorship-resistant, and truly decentralized.

About Neo

Founded in 2014, Neo is an open-source, community-driven blockchain platform designed to welcome developers into the Smart Economy. By enabling developers to digitize and automate the management of assets through smart contracts, Neo is built to realize the optimized digital world of the future. As the most developer-friendly blockchain, Neo meets developers where they are by integrating seamlessly with the world’s most widely used languages and tools and providing the most feature-complete blockchain platform for building full-stack decentralized applications. With native support for powerful infrastructure including decentralized storage, oracles, and domain name service, Neo is the ideal foundation for developers to build the next generation Internet.

Neo X is Neo’s sidechain. With its MEV resistance and full compatibility with Ethereum tooling, Neo X excels in cross-chain scalability and DeFi applications through its use of the dBFT consensus mechanism and enveloped transactions.

Official Website | X | Discord | Telegram | Facebook | Reddit | YouTube