Final week, in a second of uncharacteristically sneaky habits, a small group of builders tried to quietly change the default mempool coverage of Bitcoin Core, the world’s dominant software program for full nodes.
After re-introducing a failed 2023 proposal to boost the information storage functionality of OP_RETURN outputs, critics flagged down the 2025 copycat earlier than it merged into manufacturing. Colloquially, some are referring to the shocking incident as a type of bitcoin OP_RETURN warfare.
Mononaut joked that it was akin to forking Bitcoin for quantum resistance, skipping the mailing record and BIP course of, and leaping straight into merging code into manufacturing.
Critics known as the Peter Todd-written pull request (PR) 32359 chaotic, insane, malicious, no consensus, shenanigans, and vandalizing. Then again, supporters mentioned the PR would standardize mempool coverage and modernize transactions that always catalogue arbitrary knowledge elsewhere, even earlier than this OP_RETURN proposal.
In the end, considerations about censorship of opposing viewpoints, deprioritizing bitcoin’s monetary utility, and undisclosed company pursuits have halted PR 32359 from merging into mainnet.
OP_RETURN warfare for hurt discount
Backfooted, the camp in favor of lifting OP_RETURN’s datacarrier restrict was fast to recast its actions as a valiant try at “harm reduction” for the long-term good thing about Bitcoin.
Devs from this camp defined their proposal with easy language. Permitting customers to stuff giant quantities of knowledge into blocks by way of OP_RETURN was merely standardizing an already widespread observe of storing non-financial knowledge into unconventional components of bitcoin blocks like Taproot outputs.
From their perspective, customers already retailer random textual content, pictures, laptop code, and different non-financial knowledge in bitcoin blocks anyway. Worse, a lot of them reap the benefits of the SegWit witness low cost to pay considerably discounted storage charges.
Why insist on OP_RETURN’s 83 byte limitation when plentiful choices exist elsewhere? Certainly, it will scale back hurt by normalizing OP_RETURN with different knowledge storage choices.
OP_RETURN must be understood as akin to “harm reduction” like offering sterile needles to heroin addicts to cut back the unfold of illness.
OP_RETURN is undesirable however it’s much less dangerous than bloating the UTXO set with knowledge saved in unspendable pretend outputs. pic.twitter.com/9nPVORSEsm
— Warren Togami (@wtogami) April 30, 2025
Gallantly, a few of them claimed that lifting OP_RETURN’s datacarrier restrict was tantamount to “harm reduction.” It might, of their view, enable OP_RETURN payloads of 100 bytes or above “instead of Citrea forging ahead with writing permanently to the UTXO set.”
Citrea’s 100 byte payloads – 17 bytes bigger than OP_RETURN’s restrict
Enterprise capitalist-backed bitcoin mission Citrea, in keeping with senior bitcoin developer Peter Todd, must publish 100-byte knowledge packets for sure operations. Sadly, it will publish unprunable outputs as an alternative of the extra fascinating OP_RETURN, resulting from OP_RETURN’s 83-byte dimension restrict.
Writing completely to the set of unspent transaction outputs (UTXO), Citrea proliferated the variety of UTXOs – requiring full nodes to obtain and use useful computation to validate an ever-increasing amount of Citrea-created UTXOs.
The Chaincode Labs bitcoin developer defined that lifting OP_RETURN’s datacarrier restrict would enable company entities like Citrea to conduct its operations extra effectively – with out requiring full node operators to obtain and validate extreme portions of unprunable UTXOs.
Peter Todd, the creator of PR 32359 on the request of Chaincode Labs’ Antoine Poinsot, affirmed, “ I was asked to open [PR 32359] by an active Core dev because entities like Citrea are using unprunable outputs instead of OP_Return, due to the size limits.”
Jameson Lopp says there is no such thing as a battle of curiosity
Jameson Lopp, a Citrea investor and advocate for PR 32359, denies that his funding in Citrea created a battle of curiosity relating to OP_RETURN’s datacarrier restrict.
Based on his cited clarification, “The Citrea protocol does not benefit from this change at all! We’re just asking them nicely to please use OP_RETURN and not bloat the UTXO set.”
In any case, the request to vary this necessary default worth of Bitcoin Core software program – to not point out limiting the flexibility of customers to self-configure that worth as self-sovereign Bitcoin Core node operators – has resulted in a short type of OP_RETURN warfare amongst bitcoin maintainers this month.
