1

I am developing an ethereum block explorer in PHP and have established an JSON-RPC communication with my server geth node successfully. Nevertheless, I am kind of stuck when trying to find out the last block in ethereum. I have read the great info at https://ethereum.gitbooks.io/frontier-guide/content/rpc.html but I don't find there any way to ask the ethereum node which one is the last block. Once I had the block hash I see there are endpoints to retrieve full information about the block, but I don't know how to find the latest block hash.

The API endpoint eth_blockNumber is supposed to return the latest block number, but how do I get the hash?

Any help? Thanks in advance!

2

request:

curl -X POST --data '{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["latest", false],"id":1}' localhost:8545

response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "difficulty": "0x31962a3fc82b",
    "extraData": "0x4477617266506f6f6c",
    "gasLimit": "0x47c3d8",
    "gasUsed": "0x0",
    "hash": "0x78bfef68fccd4507f9f4804ba5c65eb2f928ea45b3383ade88aaa720f1209cba",
    "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "miner": "0x2a65aca4d5fc5b5c859090a6c34d164135398226",
    "nonce": "0xa5e8fb780cc2cd5e",
    "number": "0x1e655a",
    "parentHash": "0x8b535592eb3192017a527bbf8e3596da86b3abea51d6257898b2ced9d3a83826",
    "receiptRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
    "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
    "size": "0x20e",
    "stateRoot": "0xdc6ed0a382e50edfedb6bd296892690eb97eb3fc88fd55088d5ea753c48253dc",
    "timestamp": "0x579f4981",
    "totalDifficulty": "0x25cff06a0d96f4bee",
    "transactions": [

    ],
    "transactionsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
    "uncles": [

    ]
  }
}

(I've formatted the results for easier reading).

I've used "latest" to find the latest block. You could also use the result from your eth_blockNumber call.

Source: JSON-RPC - eth_getBlockByNumber.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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