getmempoolentry

getmempoolentry is a Bitcoin Core JSON-RPC method that returns the full mempool record for a single unconfirmed BTC transaction. Given a txid that is currently in the node's mempool, it reports detailed metadata: virtual size and weight, the time it was first seen, the block height at entry, ancestor and descendant counts and sizes, the depends and spentby links to neighbouring transactions, the bip125-replaceable flag, and a fees object whose base, modified, ancestor, and descendant amounts are denominated in BTC (1 BTC = 100,000,000 satoshis). Send the request to https://bitcoin.therpc.io/YOUR_API_KEY with the txid as the single positional parameter.

Use cases

• Read the base fee and vsize of a pending transaction to derive its sat/vB fee rate and estimate how it ranks against the rest of the mempool.
• Inspect the ancestor and descendant fee and size totals before a child-pays-for-parent (CPFP) or replace-by-fee (RBF) bump, so the bump targets the true package fee rather than the single transaction.
• Confirm whether a transaction can be replaced by checking the bip125-replaceable flag before you attempt an RBF replacement.

Parameters

Response

Example request

1curl https://bitcoin.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5  "jsonrpc": "1.0",
6  "id": "therpc",
7  "method": "getmempoolentry",
8  "params": [
9    "4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"
10  ]
11}'

Errors & troubleshooting

Common pitfalls

• The entry exists only while the transaction is in the mempool. Once it confirms into a block, is evicted under fee pressure, or was never seen, the call returns error code -5 (Transaction not in mempool).
• Every value in the fees object is expressed in BTC, not satoshis. Multiply by 100,000,000 (1e8) to convert to satoshis before doing sat/vB fee-rate math.

Supported networks

• Mainnet
• Testnet

See also

• getrawmempool
• getmempoolancestors
• getmempooldescendants