testmempoolaccept

Returns result of mempool acceptance tests indicating if raw transaction (serialized, hex-encoded) would be accepted by mempool.

This checks if the transaction violates the consensus or policy rules.

See sendrawtransaction call.

Argument #1 - rawtxs

Type: json array, required

An array of hex strings of raw transactions.

Length must be one for now.

[
  "rawtx",    (string)
  ...
]

Argument #2 - maxfeerate

Type: numeric or string, optional, default=0.10

Reject transactions whose fee rate is higher than the specified value, expressed in BTC/kB

Result

[                               (json array) The result of the mempool acceptance test for each raw transaction in the input array.
                                Length is exactly one for now.
  {                             (json object)
    "txid" : "hex",             (string) The transaction hash in hex
    "allowed" : true|false,     (boolean) If the mempool allows this tx to be inserted
    "vsize" : n,                (numeric) Virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted (only present when 'allowed' is true)
    "fees" : {                  (json object) Transaction fees (only present if 'allowed' is true)
      "base" : n                (numeric) transaction fee in BTC
    },
    "reject-reason" : "str"     (string) Rejection string (only present when 'allowed' is false)
  },
  ...
]

Examples

Create a transaction:

bitcoin-cli createrawtransaction "[{\"txid\" : \"mytxid\",\"vout\":0}]" "{\"myaddress\":0.01}"

Sign the transaction, and get back the hex:

bitcoin-cli signrawtransactionwithwallet "myhex"

Test acceptance of the transaction (signed hex):

bitcoin-cli testmempoolaccept '["signedhex"]'

As a JSON-RPC call:

curl --location --request POST 'https://btc.api.watchdata.io/node/jsonrpc?api_key=your_api_key' \
--header 'x-api-key: your_api_key' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "1.0",
    "id": "curltest",
    "method": "testmempoolaccept",
    "params": [
        [
            "signedhex"
        ]
    ]
}'