Full node on sepolia

Question

I want to start testing my smart contract on an ethereum 2.0 testnet.
I know there are different node providers like alchemy or quicknode but using these services I can incurr in rate limiting.

The ONLY solution to this problem (if I understood correctly) is setup a full node on my local machine.
Assuming I understood correctly I have to run a command like:

geth --sepolia --syncmode full --metrics --http --http.api net,eth,personal,web3,engine,admin --authrpc.jwtsecret="C:\Users\myusername\jwt.hex" 

and then configure a consensus node on top of geth.

I have the following questions:

1. It's correcty what I just wrote?
2. Do I really node the consensus node? Aren't JSON-RPC evaluated by execution nodes?
3. the rate limiting of alchemy and similar is related to JSON-RPC call on execution node, correct?
4. how can I setup a development environment that use my local node? Every guide that I read talk about using API keys of providers, but I don't want to... For example with Hardhat Ignition I have to use something like:

module.exports = {
  solidity: "0.8.24",
  networks: {
    sepolia: {
      url: "https://sepolia.infura.io/v3/${INFURA_API_KEY}",
      accounts: [SEPOLIA_PRIVATE_KEY],
    },
  },
};

but what am I supposed to do if I have a local node? I can use the HTTP rpc of my node as URL?

Even if you know the answer to some of the points above is really appreciated!

Thanks

Answer 1

As far as I have experienced you will need a consensus client, as execution client will only start syncing when it connects to a beacon node and will need to be synced before you can compute the result of queries.

Can grab a checkpoint and usually sync within a few hours:

• https://eth-clients.github.io/checkpoint-sync-endpoints/#mainnet

Can use ipc to connect locally, either by accessing ~/.ethereum/geth.ipc as an ipc endpoint, or starting a javascript console with: geth attach ~/.ethereum/geth.ipc