cpfp.me

You built a zero-fee transaction. We get it mined.

Submit your TRUC transaction with a P2A anchor output. Pay the mining fee over Lightning. We broadcast a CPFP child and get you into the next block.

How it works

Version 3 transactions opt into Topologically Restricted Until Confirmed rules. A TRUC parent can have at most one unconfirmed child, preventing transaction pinning and enabling reliable package relay to miners.

Pay to Anchor is a special output script (OP_1 <4e73>) that anyone can spend. Adding a P2A output to your transaction lets a third party — like this service — attach a CPFP child to bump your fee after the fact.

Ephemeral Dust

P2A outputs are typically zero-value, which would normally be rejected as dust. Bitcoin Core's ephemeral dust policy exempts them: a zero-value P2A output is allowed provided it is spent in the same package, keeping the mempool clean.

CPFP

Child-Pays-for-Parent: a child transaction includes enough fee to cover both itself and its low-fee parent. Miners take both transactions together, so the parent gets confirmed without carrying any fee of its own.