What Is a Consensus Client?
On modern Ethereum, a full node is two programs talking to each other. The execution client (geth, nethermind, besu, erigon) runs transactions and holds state. The consensus client (prysm, lighthouse, teku, nimbus, lodestar) follows the beacon chain, votes, and decides which block is canonical. Together they are the node. Split them in your head or the rest of staking talk will sound like jargon.
How It Actually Works
- The execution engine executes. The consensus engine agrees. A local API (the engine API) is the seam. Home stakers run both, plus a validator key if they propose blocks.
- Client diversity is not a slogan. If most validators run one consensus client and that client has a bug, the chain can finalize the wrong thing or fail to finalize. Minority clients are unpaid insurance.
- This split arrived with the Merge. Bitcoin still uses one-family node software. Different design, different failure modes. See proof of stake.
Risks and Common Mistakes
- Picking software only because a setup guide used it. Check live client-share charts before you copy a majority stack.
- Ignoring the execution client. A consensus vote on bad execution is still a bad block.
- Treating "I use Coinbase" as running a node. You are trusting theirs. That is fine if you know it.
When It Matters
Anyone staking at home, anyone repeating "decentralization" about Ethereum, and anyone reading a client-bug headline. Node-in-a-box links sit in the Resource Library.
Related Terms
Glossary · Learn · Resource Library · Return to Official Home Page
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