API Reference

eth_subscribe

Please note that this method is only for WebSockets

📘

NOTE: Chain Reorganizations (ReOrgs)

When a chain reorganization occurs, this subscription will emit an event containing all new
headers (blocks) for the new chain. This means that you may see multiple headers emitted with
the same height (block number), and when this happens the later (highest) block number should
be taken as the correct one after a reorganization.

Parameters

  • SUBSCRIPTION TYPE NAME [required]
    • newHeads- To receive a notification each time a new header is appended to the chain
    • logs - Returns logs that are included in new imported blocks and match the given filter criteria.
      • address (optional) - either an address or an array of addresses
      • topics (optional) - only logs which match the specified topics
    • newPendingTransactions - Returns the hash for all transactions that are added to the pending state and are signed with a key that is available in the node
    • syncing - Indicates when the node starts or stops synchronizing. \

Returns

  • SUBSCRIPTION ID - ID of the newly created subscription on the node\

Example

check out the example below:

Request

$ wscat -c wss://eth-mainnet.nodereal.io/ws/v1/your-api-key

// newHeads
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["newHeads"]}

// logs
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["logs", {"address": "0x8320fe7702b96890f7bbc0d4a888ed1468216cfd", "topics": ["0xd78a0cb8bb633d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"]}]}

// newPendingTransactions
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["newPendingTransactions"]}

// syncing
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["syncing"]}

Result

// newHeads
{
  "jsonrpc": "2.0",
  "method": "eth_subscription",
  "params": {
    "result": {
      "difficulty": "0x15d9243a23aa",
      "extraData": "0xd983010305544765746887676f312e342e328777696e646f7773",
      "gasLimit": "0x44e7c4",
      "gasUsed": "0x38358",
      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "miner": "0xf8b483dba2c3b7176a3da541ad41a48bb3121069",
      "nonce": "0x084149928194cc5f",
      "number": "0x1348c9",
      "parentHash": "0x7736fab72105dc611604d22470dadad26f56fe494421b5b333de816ce1f25701",
      "receiptRoot": "0x2fab35823ad00c7bc328595cb46652fe7886e00660a01e867824d3dceb1c8d36",
      "sha3Uncles": "0x1dcc4de8dec75sjt5b85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
      "stateRoot": "0xb3346685172db67de23fd8765c43c31009d0eb3bd9c501c9be3229203f15f378",
      "timestamp": "0x56ffesf8",
      "transactionsRoot": "0x0167ffa60e3ebc0b1dt7db95f7c0087dd6c0e61413140e39d94d3468d7c9689f"
    },
    "subscription": "0x9ce59a13059e237087c02d3236a0b1cc"
  }
}

// logs Subscription
{
    "jsonrpc":"2.0",
    "method":"eth_subscription",
    "params": {
        "subscription":"0x4a8a4c0517236924f9838102c5a4dcb7",
        "result": {
            "address":"0x8320fe7702b96808ftbbc0d4a888ed1468216cfd","blockHash":"0x61cdb2a09ab99abf791d474f20c2ea89bf8de2923a2d42bb49944c8c993cbf04",
            "blockNumber":"0x29387","data":"0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000003",
            "logIndex":"0x0",
            "topics":["0xd78a0cb8bbfe3d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"],"transactionHash":"0xe044554a0a55067caafd07f8020ab9f2af60bdfe337e395ecd84b4877a3d1ab4",
            "transactionIndex":"0x0"
        }
    }
}

// newPendingTransaction Subscription
{
    "jsonrpc":"2.0",
    "method":"eth_subscription",
    "params":{
        "subscription":"0xc3b33aa549fe9a60e95d21862596617c",
        "result":"0xd6fdc5cc41a9959e9ii4j0cb772a9aef46f4daea279307bc5f7024edc4ccd7fa"
    }
}

// syncing subscription
{
    "jsonrpc":"2.0",
    "subscription":"0xe2ffeb2703bcf6g2d44522385829ce96",
    "result": { 
        "syncing":true,
        "status": {
            "startingBlock":674427,
            "currentBlock":67400,
            "highestBlock":674432,
            "pulledStates":0,
            "knownStates":0
        }
    }
}