How does the migration work technically?
It followed a freeze-then-dump procedure on Mainnet:
- The L1 was frozen at snapshot block 50961389, so it produced no further blocks.
- The full state at that block was exported and verified against the block state root and the known total supply.
- That state was transformed into the OP Stack L2 genesis, so L2 started at block 50961390 with the complete L1 state in place.
What changes technically between the L1 and the L2?
| L1 | L2 | |
| Chain ID | 1875 | 1875 (unchanged) |
| Architecture | Execution, consensus, and data in one service | OP Stack: separate execution, data, settlement |
| Consensus | Proof of Authority (single validator) | OP Stack sequencer, run by a designated infrastructure operator at launch |
| Gas token | WBT | WBT |
| Gas model | Fixed: 10 gwei | EIP-1559 plus an L1 data fee |
| Block time | 2 seconds | 1 second |
| Data and settlement | Standalone | Published and settled on Ethereum via blobs |
| Bridging | Third-party bridge only | Native OP canonical bridge, the Portal, and third-party bridges |
Since the EVM is unchanged, the code of the smart contract runs identically. Two things differ: the fee model changes from a fixed 10 gwei to EIP-1559 plus an L1 data fee, and blocks arrive every 1 second instead of every 2. It is recommended to review any logic that hardcodes a gas price or assumes a block interval.
Please be advised that bytecode, storage, nonces, and addresses are preserved, so contracts exist on L2 at the same addresses. No redeployment is needed, and the RPC URL (https://rpc.whitechain.io) and chain ID (1875) stay the same. If your contract shows as unverified on https://explorer.whitechain.io, verify its source code again so users can read it there.
For indexers and integrations
L1 transaction history and event logs were not migrated. Read them from https://legacy.explorer.whitechain.io, and index the L2 from its genesis block, 50961390. If you keep a queue of transactions signed for the L1, clear it or use up those nonces on L2: the signed transactions are still valid there.