CheckTemplateVerify Does Not Scale Due to UTXO's Required For Fee Payment

CheckTemplateVerify Does Not Scale Due to UTXO's Required For Fee Payment

Original Postby Peter Todd

Posted on: January 30, 2024 08:40 UTC

Current practices within the Lightning Network reveal that commitment transactions typically incur a fixed, low fee rate that is sufficient for propagation.

Contrary to what might be expected, initiators often do not bear the majority of fees. This trend is expected to continue with the advent of V3 transactions, where commitment transactions will have zero fees, relying entirely on anchor outputs and Child Pays for Parent (CPFP) mechanisms for fee adjustments.

A real-world example highlights the implications of such a design: following an unsuccessful cooperative channel closure due to glitches, a recipient was left with a commitment transaction at a low 10 sat/VB fee rate, significantly below the minrelayfee, let alone a competitive rate. With a balance of around 2 million sats and facing the necessity of a timely transaction, the recipient would need to employ CPFP to raise the fee to approximately 30 sat/VB, thus assuming the majority of the fee costs despite being on the receiving end.

The current model renders the concept of 'initiator pays' moot; instead, a more effective approach could involve negotiating a minimum commitment transaction fee rate deducted from the initiator's balance. However, this idea has not gained traction since recipients are disincentivized from setting anything less than the full fee rate. A CPFP variant would encounter similar issues due to these incentive structures. For further reading on these topics, Peter Todd's insights can be found at, or he can be contacted directly via email at 'peter'[:-1]