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This page documents the legacy Whitechain Layer 1 (L1), mainnet chain ID 1875. The L1 is live and producing blocks. It is a separate chain from the Whitechain Layer 2 (L2) documented in the rest of these docs, and it migrates to the L2 at L2 Mainnet launch. For the full migration plan, sunset stages, and milestones, see Migration to L2.
This page covers the L1 to L2 migration from the perspective of the legacy L1. Migration has not happened yet. The L1 mainnet produces blocks and accepts transactions today, and it stops at L2 Mainnet launch, on a date that is not yet announced. For the full migration narrative, the technical comparison table, and the current network details, see Migration to L2.

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What gets migrated

The complete state of the Whitechain L1 mainnet becomes the OP Stack L2 genesis:
  • All account balances, for both externally owned accounts and contracts
  • All smart contract code and storage slots
  • Nonce values for every account
No user action is required. Addresses on the L1 map one to one to the same addresses on the L2, so balances and contract identities are preserved. Transaction history and event logs are not migrated, and pending mempool transactions never execute. Migration applies to Mainnet only. The L1 testnet, chain ID 2625, is not migrated. It is superseded by Whitechain Sepolia, chain ID 1874, which starts from its own genesis. See Scope of the migration.

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L1 state at the cut-over

The L1 sequencers stop at the snapshot block, which is the last block the L1 produces. The full state at that block is exported and transformed into the L2 genesis. After the snapshot block the L1 enters a read-only period. The L1 explorer and the L1 JSON-RPC API answer read methods against L1 state up to the snapshot block, and they refuse the methods that submit a transaction. No new L1 transaction is possible. The length of the read-only period is not yet announced. See What read-only mode means. The snapshot block number and timestamp are published with the L2 Mainnet launch date. No date is announced yet. See Deadlines.

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Endpoints at the cut-over

At L2 Mainnet launch the L1-linked hostnames are reassigned to the L2, and the L1 services move to legacy hostnames. whitechain.io, explorer.whitechain.io, and rpc.whitechain.io serve the L2 from the cut-over onward. Confirm which chain an endpoint serves by calling eth_chainId: the legacy L1 mainnet reports chain ID 1875 (hex 0x753). See Endpoint and domain changes.

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What replaces the L1 components

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L1 decommissioning

The L1 is decommissioned permanently after the read-only period. Its explorer and JSON-RPC API shut down, and L1 transaction history is no longer reachable from any Whitechain endpoint.
L1 transaction history and event logs are not migrated to the L2. Export the L1 history your systems need before decommissioning, from https://explorer.whitechain.io while the L1 is live and from https://legacy-explorer.whitechain.io after the cut-over.
For why Whitechain is moving to L2 and the broader technical comparison, see Migration to L2.