Adam Back supports Bitcoin Core v30 despite increased data limits

Adam Back, the Satoshi-era Bitcoin dev, has sided with the release of Bitcoin Core v30, including the data limit increase in the OP_RETURN function.

Yesterday, Bitcoin developers shared the latest Core version on X, along with the release notes. But that post received heavy criticism from Bitcoin enthusiasts, especially Knots supporters. 

Core v30 is attacked heavily

Bitcoin Core received a ton of negative comments.

One user wrote, “Bitcoin Core v30 is a mistake. Removing OP_RETURN limits opens the door to endless junk data…” Another person discouraged node operators from downloading the new Core version. “Bitcoin core developers have bent the knee to spammers. The OP_RETURN change is senseless,” said a third user.

The Bitcoin Knots community didn’t hold back either. For context, Bitcoin Knots is a software fork of Bitcoin Core, led by Luke Dashjr, a Bitcoin developer from the early 2010s. Bitcoin Knots is fully compatible with Bitcoin Core, but it has more policy-level and optional features than Core. 

The Knots community kept pushing the narrative that OP_RETURN spam could include CSAM, which would lead to legal trouble for BTC miners and node operators. 

A Knots supporter said, “Run knots be humble mark core malware.” Another said, “Since core team is making it easier and cheaper to spam the #bitcoin network with non-monetary data, my trust in them is broken and I’m gonna continue running knots.”

Crypto Twitter — or crypto X, in this case — was a mess. But Adam Back didn’t hold back. He pushed for Bitcoin Core v30, replied to people, and shared supportive posts. 

Back fully supports Bitcoin Core v30

Back has supported Bitcoin Core v30 before its release. He said he “will be running Bitcoin v30.”

A user by the name of Chris Guida asked Back if he’s going to run Bitcoin Core v30, Bitcoin Knots v30, or even something else. Back replied, “Ha you spotted what most did not.”  He continued to explain that there’s no difference between Core 30 and Knots 30 since both have the same Bitcoin v30 codebase.

Back stated that having a data size carrier equivalent to 100kB has been a consensus valid since its inception in 2014. He added that miners and nodes already allow and confirm these kinds of large transactions. It’s not something new that v30 will suddenly introduce. Also, adding data to Bitcoin is 4 times expensive, so it will be difficult to abuse the network. Blaming Core v30 is pointless because people can already add spam to the network.

Back explained earlier in October that it’s possible to hide data in scripts. This is applicable to all programming languages. He wrote, “We can’t really stop that. What do you think say limiting tapscript to 4kb instead of 400kb will do? Via policy or soft fork even? (Hint it will do nothing, spammers will chop their spam up into 100 parts.)”

After the release of Core v30, Adam Back said Bitcoin will have far worse problems if the community fails to make rational changes. He added, “Socially attacking, urging rejection of security & robustness fixes from 200 most skilled people on the planet is itself an attack on Bitcoin. There are security fixes in v30.”

If we socially lose the ability to make rational changes, Bitcoin has far worse problems. Socially attacking, urging rejection of security & robustness fixes from 200 most skilled people on the planet is itself an attack on Bitcoin. There are security fixes in v30.

— Adam Back (@adam3us) October 12, 2025

According to an earlier report by Cryptopolitan, Bitcoin Core v30 added numerous useful changes to the network, including lower default fees, an upgraded wallet and GUI, along with the expanded OP_RETURN data limit.

The smartest crypto minds already read our newsletter. Want in? Join them.