Since Bitcoin Core developers began proposing a controversial increase to the data storage capacity of a Bitcoin script operation code, the number of node operators protesting that change has hit an all-time high.
Internet-connected full nodes propagating Knots-tagged blocks that reject the proposed increased data limit have doubled since the OP_RETURN war began last month.
Core has 19,662 reachable nodes, while Knots is the second-most popular client at 1,464.
On April 17, Chaincode Labs’ Antoine Poinsot reintroduced Peter Todd’s pull request (PR) 28130 that asked Core contributors to lift the roughly 80-byte restriction on the datacarrier limit OP_RETURN outputs.
As Core contributors indicated their willingness to proceed with the change, software downloads of an alternate full node client, Knots, skyrocketed.
As disagreements divided the Bitcoin community, Peter Todd eventually formalized the request as PR 32359. Despite dozens of reviewers voting “NACK” — shorthand for “negative acknowledgement” — Blockstream engineer and Core contributor Greg Sanders wrote that Core was planning to implement PR 32359 within a few days.
Knots’ default mempool will not lift the datacarrier limit of OP_RETURN, no matter what Core decides. Therefore, the growth of reachable Knots nodes — which reached an all-time high of 6.5% yesterday, according to tracker Coin.dance — is a proxy for measuring the resistance movement.
Corporate interests versus Bitcoin’s preeminence
For the larger data limit camp, increasing OP_RETURN’s datacarrier simply normalizes its on-chain data storage limits with other ways to store arbitrary data in bitcoin transactions, such as witness outputs.
Removing OP_RETURN’s 80-byte cap is a simple, unremarkable upgrade, according to their rhetoric.
For the smaller data limit camp, many of whom run Knots, the proposal is evidence that Bitcoin Core developers are succumbing to corporate and venture capital interests in using Bitcoin’s largest mempool as a distributed database.
Allowing easier proliferation and validation of images, music, games, contracts, and non-transactional data is a slippery slope that undermines bitcoin’s primary purpose of displacing fiat.
Read more: Moderators censor Bitcoin devs as OP_RETURN war rages on
Decision time for Bitcoin’s 2025 OP_RETURN war
A major conference of Bitcoin developers is starting today in Austin. The main topic of discussion will be PR 32359 and mempool policy, with a final decision on the proposal expected momentarily.
New comments are arriving by the hour on the Bitcoin-Dev mailing list, GitHub, StackerNews, and X.
Bitcoin full node operators may choose any software client they wish to validate and propagate transactions. Core is by far the dominant version with 19,662 reachable nodes as of publication time, while Knots is the second-most popular client at 1,464.
Other clients include btcd, Bitcore, and UASF.
Although there are hundreds of thousands of full node operators in the world, it’s impossible to quantify how many full nodes actually exist. Bitcoin is purpose-built to accommodate nodes with intermittent internet access, and nodes are free to join and leave the network at any moment.
Reachable node trackers like Coin.dance, Bitnodes, or Clark Moody use various types of internet monitoring tools to estimate the number of nodes that are reachable at any given moment.
