Why in old blocks I can't see the miner address using RPC API calls?

Question

So, I'm using Bitcoin Core RPC client version v22.0.0 and Bitcoin Core version v22.0.0.

To get the block with height 1, I call the API like this:

bitcoin-cli -datadir=/Users/dennis/Bitcoin getblock \
00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048 2

You see this block only contains the coinbase transaction. If you check the vout section you won't see any address.

"vin": [
  {
    "coinbase": "04ffff001d0104",
    "sequence": 4294967295
  }
],
"vout": [
  {
    "value": 50.00000000,
    "n": 0,
    "scriptPubKey": {
      "asm": "0496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858ee OP_CHECKSIG",
      "hex": "410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac",
      "type": "pubkey"
    }
  }
]

However, If you make the same call but for a newer block, for example with height 700,000:

bitcoin-cli -datadir=/Users/dennis/Bitcoin getblock \         
0000000000000000000590fc0f3eba193a278534220b2b37e9849e1a770ca959 2

You will see the address of the coinbase transaction:

"vin": [
  {
    "coinbase": "0360ae0a2cfabe6d6d078b52bc69cf0982356d3eb439efe5489aee2c74da629dcc1a8b50a309cc0800100000000212030400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005008a1c0000",
    "txinwitness": [
      "0000000000000000000000000000000000000000000000000000000000000000"
    ],
    "sequence": 0
  }
],
"vout": [
  {
    "value": 6.40388640,
    "n": 0,
    "scriptPubKey": {
      "asm": "0 f3b2d6544de521b5c617fc83ca6d13854f29a8a5",
      "hex": "0014f3b2d6544de521b5c617fc83ca6d13854f29a8a5",
      "address": "bc1q7wedv4zdu5smt3shljpu5mgns48jn299mukymc",
      "type": "witness_v0_keyhash"
    }
  },

Questions:

• It is something related to bitcoin-cli version?
• If so, It's posible to get the coinbase address for older blocks building a parser and directly parsing blk000.dat files?
• If it's not possible, how blockchain.com shows the coinbase address for all blocks?

Answer 1

If you look at this block in a blockchain explorer such as blockchair, it shows the transaction as

{
    "txid": "0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098",
    "hash": "0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098",
    "version": 1,
    "size": 134,
    "vsize": 134,
    "weight": 536,
    "locktime": 0,
    "vin": [
        {
            "coinbase": "04ffff001d0104",
            "sequence": 4294967295
        }
    ],
    "vout": [
        {
            "value": 50,
            "n": 0,
            "scriptPubKey": {
                "asm": "0496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858ee OP_CHECKSIG",
                "hex": "410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac",
                "reqSigs": 1,
                "type": "pubkey",
                "addresses": [
                    "12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX"
                ]
            }
        }
    ]
}

Blockchair shows an address, but Bitcoin Core doesn't.

Note that "Bitcoin address" is an invention that I believe was intended to make it easier for recipients to provide senders with information needed by the sender to construct a transaction script.

Transaction data doesn't ever actually include an address.

Bitcoin core doesn't present an address, probably because they weren't in use at the time P2PK transactions were used. I guess addresses came into use with P2PKH transactions.

Note that many blockchain explorers have their own way of dreiving addresses from more exotic forms of payment such as multisignature payments. Not all software agrees about whether such transaction types can be represented in the form of an address.

Answer 2

The coinbase output (the destination of the mining reward) is freely decided by the miner.

In early block, this destination was Pay to Pubkey(P2PK). Since P2PK is not assigned an address, no address is shown.

The coinbase transaction in the 700,000 height shows the address because the destination is P2WPKH.