I'm trying to understand what happens after the merge, what should my frontend clients do. Should they stick with the execution layer (EL) jsonrpc (they'll still have access to the latest transactions, right?) or should I move my frontend clients to use the Consensus Layer (CL) Rest API?

Testing on kiln shows me that the EL will show synced, even when the consensus layer is still syncing. So given that the 'latest' state of the eth client I'm connected to is on the CL slots, then maybe I should drop jsonrpc altogether?

Also, if I move to the Rest API and I have a $blockNumber, I can't use the api to search for the slot that it's related to (slot with execution_payloads.blockNumber == $blockNumber). So maybe I should definitely stick with jsonrpc?

  • Execution Layer: geth or erigon
  • Consensus Layer: prysm

Currently my front end is getting latest blocks, events and processing receipts/logs from latest blocks, so everything is jsonrpc and research tells me that I need to only use tag finalized (or safe) instead of latest. Research also gives me impression slots on the CL are the canonical 'head'... so swimming back and forward here

2 Answers 2


The merge will involve switching the consensus algorithm from PoW to PoS. If your app uses json-rpc endpoints like geth, infura, etc. then making sure the node supports the merge should be enough.


The Merge is designed to not require changes for most applications, so sticking to the JSON-RPC is expected to work. Still, you are strongly recommended to use a testnet like Ropsten (and Goerli when it is ready) to verify your applications, like frontend clients.

From https://blog.ethereum.org/2022/06/03/ropsten-merge-ttd/

As an application or tooling developer, what should I do?

Now is the time to ensure that your front-end code, tooling, deployment pipeline and other off-chain components work as intended. We strongly recommend that developers run through a complete testing & deployment cycle on Ropsten (or Kiln) and report any issues with tools or dependencies to those projects’ maintainers. If you are unsure where to open an issue, please use this repository.

Additionally, you should note that all testnets aside from Sepolia and Goerli will be deprecated post-merge. If you are a user of Ropsten, Rinkeby or Kiln, you should plan to migrate to Goerli or Sepolia. More information about this can be found here.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.