Bitcoin dev proposes excommunication for OP_RETURN ‘garbageman’

In an escalation of the Bitcoin OP_RETURN war, the leader of an initiative to change the world’s most popular software for Bitcoin nodes is proposing an unusual punishment for anybody attempting to slow his upcoming change to the network.

Insisting that Bitcoin Core’s default mempool should accommodate large amounts of corporate data storage and information unrelated to the on-chain movement of bitcoin (BTC), Peter Todd is coding up a severe punishment for node operators filtering large transactions from operators of Libre Relay, Todd’s accommodative creation.

Currently, default mempool settings of Bitcoin Core node software will not relay large OP_RETURN outputs. On the other hand, direct-to-miner mempools like MARA Slipstream will accept these non-standard transactions, as will Todd’s Libre Relay.

However, people who don’t like Todd’s Libre Relay accommodation of corporate data storage have created so-called “garbageman” software that penalizes Libre Relay node operators who propagate such large transactions.

Viewing Libre Relay’s queue of massive transactions unrelated to the on-chain movement of BTC as a sneaky workaround, garbageman nodes attempt to filter out certain transactions by pretending to be Libre Relay nodes and Sybil-attacking their broadcasts.

This drowns out their attempts to broadcast large transactions around the Bitcoin network.

Todd, in response, is working on a counterattack to defend his software.

He wants Bitcoin node operators to be able to drop (disconnect from) garbageman nodes and through complicated mathematics and code stemming from Greg Maxwell’s earlier work, he’s working on reliable ways to estimate that a node is running this garbageman attack.

Bitcoin’s garbageman

For context, the Bitcoin community has been fighting a minor civil war this year over on-chain data storage. Protos has been covering their battles for months.

Specifically, two camps have feuded over the default data storage allowance of Bitcoin Core’s queue of pending transactions or “mempool.”

With tens of thousands of nodes connected to the internet at any moment, Bitcoin Core is the world’s most popular software client to validate and broadcast BTC transactions.

For over a decade, its default settings have prevented transactions with OP_RETURN outputs exceeding 83 bytes from propagating across its mempool.

However, business owners began looking for ways to publish larger-than-83-byte quantities via this OP_RETURN datacarrier.

Earlier this year, a venture capitalist-funded suite of altcoin projects called Citrea prompted Chaincode Labs’ Antoine Poinsot to re-introduce Todd’s proposal to raise that datacarrier limit to nearly 4MB.

In 2023, Todd submitted pull request 28130, which failed to gain consensus. Nevertheless, in 2025, Poinsot resubmitted an even more aggressive version of 28130 as 32359 — raising the default mempool’s OP_RETURN datacarrier limit to nearly 4MB and disallowing Bitcoin Core full node operators from lowering it.

Chaincode Labs and Brink developers friendly with Poinsot and Todd, rallied substantial support for 32359, but opposition to the non-user configurability was too much.

They eventually relented a bit and added configurability into the pull request.

OP_RETURN change scheduled to go live in October

That gesture, plus weeks of meiosis rhetoric on social media, worked.

After months of disagreement that threatened to turn into a civil war, Poinsot and Todd declared victory and scheduled the roll-out for October.

If version 30 Bitcoin Core replaces version 29 on this schedule, the default mempool of the latest version of the most popular full node software will no longer filter OP_RETURN outputs with more than 3.9MB of arbitrary data.

Read more: Samson Mow claims Peter Todd was ‘paid’ for OP_RETURN PR

It will be a massive victory for corporations looking to publish rolled-up data onto the Bitcoin ledger, and a disappointing loss for Bitcoin node operators who wish to limit their hard drives to data related to on-chain BTC movements.

In the meantime, Todd isn’t happy about the tactics of his adversaries, and he is coding a complex punishment for people running “garbageman” filters against his Libre Relay software.