Add details for post-anchor dust_limit_satoshis - #1301
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Since the introduction of `option_anchors`, pre-signed HTLC transactions don't include any fees, and thus don't contribute to trimming. This results in HTLC outputs in the commitment transactions that may be forever uneconomical to spend, and will pollute the utxo set. We should use a `dust_limit_satoshis` that is higher than Bitcoin Core's standard values to take into account the cost of these second-stage txs at a reasonable (TM) feerate.
This was referenced Nov 19, 2025
ziggie1984
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Dec 15, 2025
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ACK, had some minor comments.
As requested by @ziggie1984
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@TheBlueMatt @rustyrussell can I go ahead and merge this? |
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Gentle ping @TheBlueMatt @rustyrussell 🙏 |
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Note that LDK still hasn't updated to allow higher dust limits, but happy to see the spec change land...we'll do it at some point.
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Ack! |
This was referenced Mar 6, 2026
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Since the introduction of
option_anchors, pre-signed HTLC transactions don't include any fees, and thus don't contribute to trimming. This results in HTLC outputs in the commitment transactions that may be forever uneconomical to spend, and will pollute the utxo set.We should use a
dust_limit_satoshisthat is higher than Bitcoin Core's standard values to take into account the cost of these second-stage txs at a reasonable (TM) feerate. If we want for example to be able to claim HTLC outputs at20 sat/byte, we need adust_limit_satoshisof around4 000 sats.