BTC - Transaction Broadcast Error

When broadcasting a BTC transaction, you may encounter errors looking as follows:

{
    "statusCode": 403,
    "errorCode": "btc.blockchain.broadcast.error",
    "message": "Unable to broadcast transaction.",
    "cause": "Request failed with status code 500"
}

How to troubleshoot

To troubleshoot, you will have to check how was the transaction made with "inputs", "outputs" and "amounts".

Example request:

//Endpoint: "/v3/bitcoin/broadcast"
//Payload:
{
  "txData": "020000000001af4800000000000016001419619f650a88532d25fed24dc06aada4a0cb238d00000000",
  "signatureId": "654cf9d2ca22c5a2a9c###" // Tatum KMS related
}

Take the raw txData and use the Bitcoin RPC method testmempoolaccept.

Example request:

curl -X POST -H "Content-Type: application/json" -d '{
    "id": "1",
    "jsonrpc": "2.0",
    "method": "testmempoolaccept",
    "params": [
        [
            "020000000001af4800000000000016001419619f650a88532d25fed24dc06aada4a0cb238d00000000"
        ]
    ]
}'
//response:
{
    "jsonrpc": "2.0",
    "error": {
        "code": -32000,
        "message": "Server error"
    }
}

Based on the response, the transaction payload was built improperly and the blockchain refuses to accept it. In this case, it is best to review how you built your transaction based on inputs, outputs, and amounts.

Good to know

You may decode the transaction using a reliable blockchain explorer, such as BlockCypher.
Analyze the decoded transaction to ensure its structure and content are correct.