The long-anticipated transition of Ethereum to proof-of-stake (PoS) — known as The Merge — is now officially scheduled. After years of research, testing, and community collaboration, the Ethereum network is poised for its most significant upgrade yet. This transformation marks the end of energy-intensive proof-of-work (PoW) mining and the beginning of a more sustainable, scalable, and secure blockchain ecosystem.
Understanding The Merge: A Two-Phase Transition
The Merge isn't a single event but a coordinated two-phase upgrade that seamlessly integrates the existing Ethereum mainnet with the Beacon Chain, which has been running parallel since December 2020 under PoS consensus.
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Phase 1: Bellatrix Upgrade – Activating Consensus Change
The first step in The Merge is the Bellatrix upgrade, a consensus-layer (CL) activation on the Beacon Chain. This update prepares the network by enabling the execution layer (EL) to eventually take over block production under PoS rules.
- Scheduled for: September 6, 2022, at 11:34:47 UTC
- Epoch height: Beacon Chain epoch 144896
At this point, the consensus layer begins expecting communication from execution clients. Nodes must be running both CL and EL software to remain synchronized.
Phase 2: Paris Upgrade – Finalizing the PoS Transition
The second phase, known as Paris, occurs when the current PoW chain reaches a predefined terminal total difficulty (TTD) of 58750000000000000000000. At this threshold, mining ceases permanently, and block validation shifts entirely to staked validators.
- Expected timeframe: Between September 10 and September 20, 2022
- Trigger mechanism: TTD (Terminal Total Difficulty), not a fixed timestamp
- Post-TTD process: The first block produced after TTD by a validator marks the official completion of The Merge. Finality is expected within approximately 13 minutes (2 epochs).
Once Paris activates, all new blocks are created by stakers rather than miners. The network continues uninterrupted, preserving account balances, transaction history, and smart contract logic.
Key Technical Updates and Requirements
To support The Merge, both node operators and developers must ensure their infrastructure meets updated specifications.
Required Client Versions
Node operators must run compatible versions of both execution layer (EL) and consensus layer (CL) clients. Running only one will result in chain divergence post-upgrade.
⚠️ Critical Warning: Avoid using Geth v1.10.22 due to severe database corruption issues. Upgrade immediately to v1.10.23 or later.
Clients are distributed across multiple independent implementations to enhance decentralization and resilience. Validators are encouraged to avoid over-concentration in any single client to mitigate systemic risk.
New Communication Protocols
Two core protocols enable seamless interaction between layers:
- Engine API: A secure JSON-RPC interface allowing CL and EL clients to communicate via authenticated ports.
- JWT Authentication: A shared secret token (generated per node) ensures trusted communication between client layers.
Node operators should follow client-specific documentation to generate and configure JWT tokens correctly.
Additionally, the Optimistic Sync mechanism allows CL clients to sync quickly while trusting EL data until full verification is complete.
Security and Stability: Vulnerability Bounty Program
To reinforce network security ahead of the transition, Ethereum launched an elevated Merge Vulnerability Bounty Program:
- 4x reward multiplier applied to all qualifying reports submitted before September 8
- Maximum bounty: $1 million for critical vulnerabilities
This initiative underscores Ethereum’s commitment to proactive security and community-driven auditing.
Frequently Asked Questions (FAQ)
What should node operators do?
You must run both an execution client (e.g., Geth, Nethermind) and a consensus client (e.g., Lighthouse, Teku). Configure them to communicate via the Engine API using a shared JWT token. Ensure both clients are updated to Merge-compatible versions before activation.
Do stakers need to take action?
Yes. Validators already running consensus clients must now also operate an execution client. This enables them to validate transactions and earn priority fees from blocks they propose. Set your fee recipient address in the validator configuration to receive these rewards.
Third-party staking providers may handle this on your behalf — confirm their setup complies with post-Merge requirements.
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Why is the TTD date range so broad?
TTD depends on real-time network hashrate fluctuations. Higher mining activity accelerates progress toward TTD; lower activity delays it. The projected window accounts for uncertainty in miner behavior. In extreme cases, a coordinated TTD override (as seen on Ropsten) could adjust timing if necessary.
How does The Merge affect dApp developers?
Most smart contracts remain unaffected. However, APIs relying on PoW-specific methods (like eth_getWork) will no longer function. Test your dApps on Goerli or Sepolia, both of which have already completed their own merges.
Update frontends, tooling, and CI/CD pipelines accordingly. Note: All pre-Merge testnets (Ropsten, Rinkeby, Kiln) are being deprecated.
As an ETH holder, do I need to act?
No action is required. Whether you hold ETH on exchanges, in wallets, or use DeFi applications, your assets remain safe and fully functional post-Merge. Beware of scams claiming otherwise.
Can I still mine Ethereum after The Merge?
No. Once The Merge completes, Ethereum fully transitions to PoS. Mining becomes obsolete, and GPU-based mining rigs will no longer contribute to the network.
Will I be able to withdraw staked ETH after The Merge?
Not immediately. Withdrawals require a follow-up network upgrade after The Merge stabilizes. Specification work is underway, with withdrawals expected in a future hard fork (later dubbed "Shanghai").
Where can I get more help?
Join the community call on September 9 at 14:00 UTC to ask questions directly to core developers, researchers, and EthStaker contributors.
Core Keywords
Ethereum Merge, proof-of-stake upgrade, The Merge 2025, Ethereum staking, Bellatrix upgrade, Paris upgrade, TTD Ethereum, Ethereum node setup
👉 Explore how Ethereum’s shift to proof-of-stake redefines sustainability in crypto networks.
This historic upgrade represents more than technical evolution — it's a collective achievement shaped by researchers, developers, testers, and advocates worldwide. The path forward remains collaborative, secure, and open.
When will The Merge happen? Sooner than you think — and faster than ever imagined.