Tokyo Hardfork Phase 1 — The Merge
Mainnet moves to Proof of Staked Authority
Japan Open Chain Mainnet (Chain ID 81) merges when total difficulty reaches 47,370,500
Estimated: —The Merge triggers at a difficulty threshold, not at a clock time — this estimate is recalculated live from the chain and narrows as the day approaches. The final window will be announced on Nov 26.
Progress to TTD
Live network data
About The Merge
The Merge upgrades Japan Open Chain from Clique PoA to Proof of Staked Authority (PoSA): a consensus layer (the beacon chain) operated by the consortium validators takes over block production, while the execution layer — your transactions, contracts, balances and addresses — carries over unchanged.
No action is required from JOC holders, general users or RPC endpoint users.
If you run your own node, you must change its configuration before The Merge: add a Consensus Client (recommended: Lighthouse) to Geth (v1.13 series) and connect them via the Engine API. Nodes that are not updated will stop following the head of the chain after the Merge. See the Mainnet node connection guide for the steps.
- Why is there no exact time?
- The Merge activates when the chain's accumulated total difficulty reaches 47,370,500 — the same mechanism Ethereum used in September 2022. The arrival time depends on the network's pace, so it can only be estimated: to within a few hours today, and within minutes on the day itself.
- What happens to my tokens and dApps?
- Accounts, balances, contracts, transaction formats and the Chain ID all carry over, and no migration is needed. Note that after the move to PoSA, a very small amount of new JOC is issued as validator rewards (see Impact on supply). Applications that wait for confirmations can start using the safe and finalized block tags after the Merge.