Final week, in a second of uncharacteristically sneaky conduct, 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 lift the info 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 form of bitcoin OP_RETURN warfare.
Mononaut joked that it was akin to forking Bitcoin for quantum resistance, skipping the mailing listing 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. However, supporters mentioned the PR would standardize mempool coverage and modernize transactions that usually catalogue arbitrary information elsewhere, even earlier than this OP_RETURN proposal.
Finally, 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 advantage of Bitcoin.
Devs from this camp defined their proposal with easy language. Permitting customers to stuff giant quantities of information into blocks by way of OP_RETURN was merely standardizing an already frequent follow of storing non-financial information into unconventional elements of bitcoin blocks like Taproot outputs.
From their perspective, customers already retailer random textual content, photographs, laptop code, and different non-financial information in bitcoin blocks anyway. Worse, lots 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 could cut back hurt by normalizing OP_RETURN with different information storage choices.
OP_RETURN ought to be understood as akin to “harm reduction” like offering sterile needles to heroin addicts to scale back the unfold of illness.
OP_RETURN is undesirable however it’s much less dangerous than bloating the UTXO set with information 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, permit 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 response to senior bitcoin developer Peter Todd, must publish 100-byte information packets for sure operations. Sadly, it could publish unprunable outputs as an alternative of the extra fascinating OP_RETURN, because of OP_RETURN’s 83-byte measurement restrict.
Writing completely to the set of unspent transaction outputs (UTXO), Citrea proliferated the variety of UTXOs – requiring full nodes to obtain and use invaluable 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 permit 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 isn’t 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 concerning OP_RETURN’s datacarrier restrict.
In accordance with his cited rationalization, “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 alter this vital default worth of Bitcoin Core software program – to not point out proscribing the flexibility of customers to self-configure that worth as self-sovereign Bitcoin Core node operators – has resulted in a quick form of OP_RETURN warfare amongst bitcoin maintainers this month.
