How do you find the transaction whose input, vin, is a given output, vout? For example, the following is the JSON representation of the block with height 1000; here the mining reward is locked behind the given scriptPubKey, and I am interested in finding a transaction where this output is referenced as input.

    "hash": "00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09",
    "confirmations": 716370,
    "height": 1000,
    "version": 1,
    "versionHex": "00000001",
    "merkleroot": "fe28050b93faea61fa88c4c630f0e1f0a1c24d0082dd0e10d369e13212128f33",
    "time": 1232346882,
    "mediantime": 1232344831,
    "nonce": 2595206198,
    "bits": "1d00ffff",
    "difficulty": 1,
    "chainwork": "000000000000000000000000000000000000000000000000000003e903e903e9",
    "nTx": 1,
    "previousblockhash": "0000000008e647742775a230787d66fdf92c46a48c896bfbc85cdc8acc67e87d",
    "nextblockhash": "00000000a2887344f8db859e372e7e4bc26b23b9de340f725afbf2edb265b4c6",
    "strippedsize": 216,
    "size": 216,
    "weight": 864,
    "tx": [
            "txid": "fe28050b93faea61fa88c4c630f0e1f0a1c24d0082dd0e10d369e13212128f33",
            "hash": "fe28050b93faea61fa88c4c630f0e1f0a1c24d0082dd0e10d369e13212128f33",
            "version": 1,
            "size": 135,
            "vsize": 135,
            "weight": 540,
            "locktime": 0,
            "vin": [
                    "coinbase": "04ffff001d02fd04",
                    "sequence": 4294967295
            "vout": [
                    "value": 50.00000000,
                    "n": 0,
                    "scriptPubKey": {
                        "asm": "04f5eeb2b10c944c6b9fbcfff94c35bdeecd93df977882babc7f3a2cf7f5c81d3b09a68db7f0e04f21de5d4230e75e6dbe7ad16eefe0d4325a62067dc6f369446a OP_CHECKSIG",
                        "hex": "4104f5eeb2b10c944c6b9fbcfff94c35bdeecd93df977882babc7f3a2cf7f5c81d3b09a68db7f0e04f21de5d4230e75e6dbe7ad16eefe0d4325a62067dc6f369446aac",
                        "type": "pubkey"
            "hex": "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0804ffff001d02fd04ffffffff0100f2052a01000000434104f5eeb2b10c944c6b9fbcfff94c35bdeecd93df977882babc7f3a2cf7f5c81d3b09a68db7f0e04f21de5d4230e75e6dbe7ad16eefe0d4325a62067dc6f369446aac00000000"

1 Answer 1


This information is not stored by Bitcoin Core. Outputs are stored until they are spent, and then removed from the UTXO database. There is no information inside a transaction that indicates where it was spent (in the future), so you would manually have to compile this information yourself by iterating over all transactions in the blockchain.

  • Can't we use the index of transactions created when using the -txindex=1 argument? Iterating through all blocks/transactions is possible but a very expensive operation, leveraging index to some extent could prune some of the processes at least. Commented Jan 6, 2022 at 21:22
  • I don't think txindex=1 would help in this case. I suggest building your own database while parsing which you can make more complicated queries to, like block explorers do. Commented Jan 6, 2022 at 21:32

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