How to get internal transactions using JSON-RPC methods

Question

In etherscan I noticed that there are transactions that have "internal transactions" inside of them, see this link: etherscan transaction.

Screenshot of the transaction:

My question is: how can I find these internal transactions using the JSON-RPC methods? I tried both the method 'eth_getBlockByNumber' and the method 'eth_getTransactionReceipt' but I don't see these info:

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_getTransactionReceipt","params":["0x893c428fed019404f704cf4d9be977ed9ca01050ed93dccdd6c169422155586f"],"id":1}' https://cloudflare-eth.com | jq

curl -sX POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["0xC3BF", true]}' https://cloudflare-eth.com | jq

Answer 1

You need to use debug_traceTransaction. This method allows you to get all opcodes executed by the transaction, but if you need only the internal transactions it can be overkill. Luckily you can pass the parameter {"tracer":"callTracer"} to get only those.

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"debug_traceTransaction","params":["0x893c428fed019404f704cf4d9be977ed9ca01050ed93dccdd6c169422155586f", {"tracer":"callTracer"}],"id":1}' https://eth.llamarpc.com | jq

It will print the following result, with the internal transactions listed in "calls":

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "from": "0xfd2605a2bf58fdbb90db1da55df61628b47f9e8c",
    "gas": "0x2bb38",
    "gasUsed": "0x195b2",
    "to": "0x109c4f2ccc82c4d77bde15f306707320294aea3f",
    "input": "0x",
    "calls": [
      {
        "from": "0x109c4f2ccc82c4d77bde15f306707320294aea3f",
        "gas": "0x8fc",
        "gasUsed": "0x0",
        "to": "0x881b0a4e9c55d08e31d8d3c022144d75a454211c",
        "input": "0x",
        "value": "0xde0b6b3a7640000",
        "type": "CALL"
      }
    ],
    "value": "0xde0b6b3a7640000",
    "type": "CALL"
  }
}

Docs: https://geth.ethereum.org/docs/developers/evm-tracing/built-in-tracers#call-tracer