Querying the blockchain

hmy provides several subcommands under the blockchain subcommand which let you query the blockchain.

The Harmony blockchain is a sharded blockchain, therefore some commands depend on which shard you target. The shard you target when querying is controlled by the --node flag. For example, if a transaction is made between shard 0 and shard 1, the transaction receipt must be queried from whichever shard sent the funds - in this case shard 0, so the --node flag would look like this:

--node="https://api.s0.t.hmny.io"

For other shards, please replace the s0 with the appropriate shard number - eg. s1 for shard 1, s2 for shard 2 etc.

List of available commands

By using ./hmy blockchain help command we can see that the following options are available:

  • block-by-number - get a harmony blockchain block by block number

  • current-nonce - current nonce of an account delegation information about delegations

  • known-chains - print out the known chain-ids

  • latest-header - get the latest header

  • median-stake - median stake of top 320 validators with delegations applied stake (pre-epos processing)

  • protocol-version - the version of the Harmony Protocol

  • transaction-by-hash - get transaction by hash

  • transaction-receipt - get information about a finalized transaction validator information about validators

  • pool - get transaction pool information

Here are some examples of the above commands that you will use frequently:

transaction-by-hash

Checking the hash of your transaction to see the transaction data and if the transaction has been completed

Using the Binary:

$ ./hmy blockchain transaction-by-hash <transaction-hash> --node="<endpoint-address>"

Using the Shell Wrapper:

$ ./hmy.sh -- blockchain transaction-by-hash <transaction-hash> --node="<endpoint-address>"

Example:

$ ./hmy blockchain transaction-by-hash 0x75d91100734edcd1497200cb438f0864d2ed4a44a88bf8c87855cb2b3cc54001 --node="https://api.s0.t.hmny.io"
{
"id": "0",
"jsonrpc": "2.0",
"result": {
"blockHash": "0xf9c7e165d5636c7dd8a06bf2c53c364d7597028d7e10a3c5256462adf97b1f73",
"blockNumber": "0xa35",
"from": "one1mrrq665uarrmfur6hptevx9furph4293a37zme",
"gas": "0x5208",
"gasPrice": "0x3b9aca00",
"hash": "0x75d91100734edcd1497200cb438f0864d2ed4a44a88bf8c87855cb2b3cc54001",
"input": "0x",
"nonce": "0xe",
"r": "0x4a17d89f7b1818fe72d480a64fecfede1d73bd7242fcaabf907204a7022be806",
"s": "0x557be1b9c378ecbae972e71ec6fc5d484abfe8cb7961ccd87724865c3a7020bc",
"shardID": 0,
"timestamp": "0x5e1cfcc1",
"to": "one1mrrq665uarrmfur6hptevx9furph4293a37zme",
"toShardID": 1,
"transactionIndex": "0x0",
"v": "0x2a",
"value": "0xde0b6b3a7640000"
}
}

transaction-receipt

Get information about a finalized transaction:

Using the Binary:

$ ./hmy blockchain transaction-receipt <transaction-hash> --node="<endpoint-address>"

Using the Shell Wrapper:

$ ./hmy.sh -- blockchain transaction-receipt <transaction-hash> --node="<endpoint-address>"

Example:

$ ./hmy --node="https://api.s0.t.hmny.io" blockchain transaction-receipt 0x599793f313ee17566f8d09728b9d043b8e26135ddce86beeee13f98767d452f7
{
"id": "0",
"jsonrpc": "2.0",
"result": {
"blockHash": "0x52171a8f3af94f639f1e6044679c4189c3cd088ffe7f1c216ce3089212373af9",
"blockNumber": "0x6177",
"contractAddress": null,
"cumulativeGasUsed": "0x5208",
"from": "0x261fa45c6a09cd3faa277d829e91d9473973357c",
"gasUsed": "0x5208",
"logs": [],
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"shardID": 0,
"status": "0x1",
"to": "0x06916163a17f07ce70e3d43ed37395f05b5738ae",
"transactionHash": "0x599793f313ee17566f8d09728b9d043b8e26135ddce86beeee13f98767d452f7",
"transactionIndex": "0x0"
}
}

latest-header command

Checking the network status, last block, epoch, leaders, based on the shard number:

Using the Binary:

$ ./hmy blockchain latest-header --node="<endpoint-address>"

Using the Shell Wrapper:

$ ./hmy.sh -- blockchain latest-header --node="<endpoint-address>"

Example:

Shard 0
Shard 0
$ ./hmy blockchain latest-header --node=https://api.s0.t.hmny.io
{
"id": "0",
"jsonrpc": "2.0",
"result": {
"blockHash": "0xae23db112d22062be6a0f065ecc3989d4e9559ad6a1f34fe4344d021907e8c2e",
"blockNumber": 415749,
"epoch": 5543,
"lastCommitBitmap": "fffffffffffffffb0f00",
"lastCommitSig": "06efa677bdd327d3d9602fd246c214edb35e447692dccc2219ef08ce2fa026b96f3826fcb5a2a3f724222ecef4af66029f3b5d677e54534519ad2a405ad3b336dd5145dcc083fc2330b9d0bb398affd1745cab274b5019f32cba0287bd5e5a17",
"leader": "one18ahxsrk9g4h4gz5r8ema7nyw6g9zpun5hhp54d",
"shardID": 0,
"timestamp": "2019-12-11 12:18:21 +0000 UTC",
"unixtime": 1576066701,
"viewID": 415745
}
}