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POST
/
v1
/
rpc
/
submitTransactionReplacement
Submit transaction replacement
curl --request POST \
  --url https://api.kas.fyi/v1/rpc/submitTransactionReplacement \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "transaction": {
    "version": 0,
    "inputs": [
      {
        "previousOutpoint": {
          "transactionId": "fa99f98b8e9b0758100d181eccb35a4c053b8265eccb5a89aadd794e087d9820",
          "index": 1
        },
        "signatureScript": "4123c94e322fd98ce4ba8b2e33b47f2984a2f741ecfea6fb48eb90d209a46b9d58639888a1575a717cb243b006edd720a7153e9a7e63f4539958d0a44eea8bfa9f01",
        "sequence": 0,
        "sigOpCount": 1
      }
    ],
    "outputs": [
      {
        "value": "100000",
        "scriptPublicKey": {
          "version": 0,
          "script": "208b42bec57f9a538f740b067f947a5b29e04043218a37ff1fa7fb5ee850fd3fd3ac"
        }
      }
    ],
    "lockTime": 0,
    "subnetworkId": "0000000000000000000000000000000000000000",
    "gas": "0",
    "payload": ""
  }
}
'
{
  "transactionId": "34e9538fd3225652553930657c3d767d5ccab0fcd545038a69c202e45929dcd6",
  "replacedTransaction": {
    "version": 0,
    "inputs": [
      {
        "previousOutpoint": {
          "transactionId": "fa99f98b8e9b0758100d181eccb35a4c053b8265eccb5a89aadd794e087d9820",
          "index": 1
        },
        "signatureScript": "4123c94e322fd98ce4ba8b2e33b47f2984a2f741ecfea6fb48eb90d209a46b9d58639888a1575a717cb243b006edd720a7153e9a7e63f4539958d0a44eea8bfa9f01",
        "sequence": 0,
        "sigOpCount": 1
      }
    ],
    "outputs": [
      {
        "value": "100000",
        "scriptPublicKey": {
          "version": 0,
          "script": "208b42bec57f9a538f740b067f947a5b29e04043218a37ff1fa7fb5ee850fd3fd3ac"
        }
      }
    ],
    "lockTime": 0,
    "subnetworkId": "0000000000000000000000000000000000000000",
    "gas": "0",
    "payload": ""
  }
}

Documentation Index

Fetch the complete documentation index at: https://docs.kas.fyi/llms.txt

Use this file to discover all available pages before exploring further.

​
Cost

This endpoint costs 0.1 RU (Request Units) per call.

Authorizations

​
x-api-key
string
header
required

API key required for authentication. Get your API key at https://developer.kas.fyi

Body

application/json
​
transaction
object
required

Replacement transaction to submit

Response

200 - application/json

Transaction replacement submitted successfully

​
transactionId
string
required

ID of the replacement transaction

Example:

"34e9538fd3225652553930657c3d767d5ccab0fcd545038a69c202e45929dcd6"

​
replacedTransaction
object
required

The transaction that was replaced