Less than four weeks after an attacker minted unauthorized ONE tokens and forced a chain rollback, Harmony has proposed shutting down its Layer 1 blockchain entirely and issuing ONE as an ERC-20 token on Ethereum.
The proposal, announced on X on Sunday, Sept. 6, would take a final network snapshot and airdrop matching tokens to the same addresses on Ethereum. Validators could begin shutting down nodes from 7 a.m. Pacific on Sept. 10, and users are urged to exit all smart contracts by that date. The sunset notice did not name the August exploit or the 2022 Horizon bridge hack as reasons.
That August attack is the immediate backdrop. On Aug. 11, an attacker exploited a flaw in cross-shard receipt verification, the mechanism that validates transactions between the network’s parallel chain sections, allowing valid receipts to be processed multiple times and new ONE to be minted without a matching debit elsewhere. The team also flagged a bug in its pre-staking quorum-checking system.
How much was minted is disputed. Harmony’s Aug. 12 statement put the unauthorized mint at nearly 4 billion ONE, about 26% of supply. The project’s own later reconstruction found more than 3 trillion ONE across six transactions. An outside account claimed roughly 2.8 billion forged tokens reached exchanges, a figure Harmony had not confirmed.
On Aug. 17, Harmony said it would revert the chain to an Aug. 11 checkpoint, permanently discarding 109,126 regular transactions and 315 staking transactions, a rollback widely described as controversial. The project said investigators had traced nearly all forged tokens to wallets or service boundaries and were working with exchanges, bridges and law enforcement.
Now the repair effort appears to have ended in retirement.
The sunset mechanics would protect plain holders. Wallet balances, staking delegations, validator rewards, smart contracts and centralized exchange listings would be covered by the snapshot, and holders need not claim anything. Delegated stakes and unclaimed rewards would go to individual governor vaults. Multisig safes, liquidity pools and onchain applications cannot be migrated, which is why Harmony set the Sept. 10 deadline for exiting smart contracts.
Harmony has set aside $1.372 million, equal to a year’s validator rewards before the exploit, for validators who shut down on time, sign an agreement, retain their stakes and serve as governors. Validators would otherwise be offered the option to stop their nodes or join the new venture, an AI video business called The Remix Economy that future ONE emissions would fund.
The proposal is explicitly non-binding, and Harmony has not said whether the shutdown will go through validator governance.
