Harmony Gives Up on Its Layer 1: What Happens to ONE After the Ethereum Move?

Harmony is preparing to end its seven-year run as a standalone Layer 1. The project has proposed shutting down its 2019 mainnet, moving ONE to Ethereum and abandoning the blockchain model it spent years building around sharding and staking.

The proposal follows a brutal August security incident in which attackers forged trillions of ONE and forced Harmony to roll the network back by more than 141,000 blocks. Users are now being urged to exit smart contracts before September 10, while the eventual final block will be used to snapshot balances for an Ethereum airdrop.

Harmony itself is not disappearing. The team wants to redirect ONE and parts of its validator community toward a new AI video business — raising a bigger question than the migration itself: what role does ONE have once there is no Harmony chain left to secure?

Why Harmony Is Shutting Down Its Blockchain

Harmony says the security burden of operating its own Layer 1 has become too great.

The team specifically cited growing threats from state actors and AI agents when proposing the shutdown. That concern is not abstract for Harmony: its Horizon Bridge lost nearly $100 million to North Korea-linked hackers in 2022, and the network suffered another major security failure in August 2026.

But security is only part of the story. Harmony is also shutting down a chain whose economic activity has collapsed from its previous-cycle highs. DeFi TVL once exceeded $1 billion; today it is only a fraction of that level, while daily DEX activity and network revenue have fallen to negligible levels.

Maintaining validators, emissions and a separate security layer makes far less sense when the underlying network attracts little sustained usage. Moving ONE to Ethereum removes that burden while allowing Harmony to preserve the token and redirect its economics toward a new product.

The proposal therefore looks less like a routine chain migration and more like Harmony formally giving up on the Layer 1 thesis that defined the project since 2019.

The 2026 Exploit That Broke the Network

Harmony’s August attack was far larger than the first reports of 4 billion unauthorized ONE suggested.

The initial mint was only the visible part of the exploit. Harmony later reconstructed roughly 3.01 trillion forged ONE, created through a flaw in cross-shard receipt verification that allowed previously valid receipts to be reused.

That scale made normal recovery impossible. The forged supply was around 200 times larger than ONE’s circulating supply, while one attacker-controlled wallet moved roughly 2.4 trillion ONE in less than two minutes.

The incident exposed a deeper problem than a compromised wallet or bridge. It hit the logic used by Harmony’s own cross-shard system — one of the technical foundations of the network.

Harmony Rolled Back More Than 141,000 Blocks

Harmony responded by reverting the chain to a state before the exploit, wiping out both malicious and legitimate activity.

The rollback returned the network to an August 11 checkpoint and discarded 141,628 blocks, including 109,126 normal transactions and hundreds of staking transactions processed after that point.

That restored the pre-attack state, but at a significant cost. Users who had made legitimate transfers or interacted with applications during the affected period saw those actions disappear from canonical chain history.

For a network already operating with limited activity, the rollback became a turning point. Less than a month later, Harmony proposed a more permanent solution: stop maintaining the Layer 1 altogether and move ONE to Ethereum.

How ONE Will Move to Ethereum

Harmony plans to replace native ONE with an ERC-20 version on Ethereum after the network reaches its final block.

At that point, Harmony will snapshot ONE held in wallets, staking delegations, validator rewards, smart contracts and centralized exchanges. New tokens will then be airdropped to the same Ethereum-compatible addresses, with no separate claim required for ordinary holders.

The proposal keeps both ONE’s total supply and emission rate unchanged. What changes is the infrastructure underneath it: ONE would stop being the native asset of an independent Layer 1 and become an Ethereum token.

Harmony has not yet announced the final block date. September 10 is the transition deadline for users and validators, not the confirmed shutdown date.

What ONE Holders Need to Do Before September 10

Simple ONE balances should migrate automatically, but assets locked inside Harmony applications require attention.

Harmony says wallet holders, delegators and validators will not need to manually claim the new ERC-20 ONE. Exchange balances are also expected to be included in the final snapshot.

The main risk is onchain positions that cannot be recreated automatically on Ethereum:

• Wallet ONE balances: included in the snapshot.
• Staked ONE: included, with delegations and rewards moved into the new structure.
• Centralized exchange balances: expected to migrate through exchange coordination.
• Liquidity pools: will not migrate.
• Multisig safes: will not migrate.
• Smart contracts and dApps: will not migrate with the chain state.

Harmony is therefore urging users to exit smart contracts before September 10, 2026. Holding ONE in a wallet is relatively straightforward; leaving assets inside DeFi positions or application contracts creates the bigger migration risk.

What Happens to ONE Without Harmony Chain?

The Ethereum migration removes the original reason ONE existed: securing and operating the Harmony blockchain.

Today, ONE pays gas, supports staking and rewards validators. Those functions disappear once Harmony retires its mainnet. Yet the proposal keeps both the token supply and emission rate intact, meaning ONE will continue to be issued even without an independent network to secure.

Harmony wants those future emissions redirected toward its next business instead. That turns ONE from an L1 utility token into an asset tied to the project’s governance and new AI-focused economy.

For holders, that is a much bigger change than switching networks. Ethereum can provide the infrastructure, but Harmony still needs to create a credible source of demand for ONE after gas and validator staking disappear.

From Blockchain Validators to AI Video Operators

Harmony’s next plan has little to do with running a blockchain: it wants to build an AI video remix economy.

The proposed platform would let creators publish videos, prompts and assets that users can remix with AI. Harmony wants some existing validators to remain as governors, while others could repurpose their infrastructure as GPU operators powering video generation.

A $1.372 million transition pool has been set aside for eligible validators who shut down their nodes, retain their stakes and participate in the new initiative. Payments would be distributed across four quarterly installments.

Harmony also plans to subsidize GPU operators during the first year and introduce an affiliate model paying a recurring 30% commission on referred $10 monthly subscriptions.

It is a radical pivot for a project once built around sharding and decentralized consensus. Rather than trying to revive Harmony as another Layer 1, the team is betting that its token, community and remaining infrastructure can be repurposed around an entirely different product.

Can Harmony Reinvent ONE After Killing Its L1?

Moving to Ethereum solves Harmony’s infrastructure problem, but it does not automatically solve ONE’s utility problem.

The shutdown removes the cost and security burden of maintaining a separate validator network at a time when Harmony’s onchain activity has fallen far below previous-cycle levels. It also avoids another attempt to rebuild confidence in an L1 that has now suffered multiple major security crises.

What comes next is harder. ONE will lose its role as gas and validator collateral, while future emissions are expected to continue. Harmony’s AI video pivot therefore needs to create enough governance, staking or economic demand to justify a token that was originally designed for an entirely different system.

For users managing supported crypto outside centralized platforms, Atomic Wallet provides a self-custodial way to retain control of private keys while holding and managing digital assets.

Harmony spent seven years trying to prove that its own Layer 1 could scale. Its next chapter will test a very different idea: whether ONE can survive after the blockchain behind it is gone.

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