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Migration overview

Horizen migrated all the $ZEN balances from both the old Horizen mainchain and the EON EVM chain to an ERC-20 smart contract on Base (Ethereum L2 Rollup).
Both old chains will be discontinued, and all coin transfers are now managed on Base, via ERC-20 smart contract calls.

Migration was successfully completed on July 23, 2025

What has been migrated?​

  • For EON: all EOA (Externally owned accounts) balances have been automatically migrated to the same address (EON and Base share the same address format, and users can use the same wallet keys).
    The amounts staked by forgers or delegators have also been migrated and moved to the same address in the new chain.
    Smart contracts, ZEN balances locked in smart contracts and stakes delegated by smart contracts have not been migrated.

  • For ZEND Mainchain: the migration covered all $ZEN funds locked in UTXOs of type PayToPubKeyHash (single address) or PayToScriptHash Multisig (multisig address). Note: we estimated that 99% of current UTXOs are part of these groups.
    A simple manual claim of the funds will be required because the address format on the two chains is different (Bitcoin-format in the old Horizen chain, Ethereum format on Base). An automatic migration like the one from EON has not been performed here, because the on-chain UTXO structure does not track the original key/address owning it, making it impossible to map between old and new addresses.

Overview of the process​

  1. A migration point has been fixed on both old chains.
    When reached, Horizen Labs performed dumps of all the relevant data on both chains.

  2. A set of smart contracts have been deployed on BASE to handle the restore:

    • the official ERC-20 smart contract

    • an EONBackupVault, used to store the EON balances and automatically mint them to BASE.

    • A ZENDBackupVault, used to store the ZEND balances and expose methods for manual claiming.

      Horizen Labs was responsible for deploying the contracts and loading the dump data.

  3. A migration check procedure will allow third parties to challenge the fairness of the loaded data.

  4. ZEND owners will be able to claim funds via on-chain calls to the ZENDBackupVault contract.

The next sections of this website will detail all these steps.