Developer embeds image on Bitcoin as a single transaction, challenging BIP-110’s core claims

Martin Habovštiak, a Slovak Bitcoin developer who maintains the Rust Bitcoin library, has embedded a 66-kilobyte image file directly in the Bitcoin blockchain as a single contiguous transaction, challenging several foundational claims made by proponents of the “anti-spam” BIP-110 proposal and the Bitcoin Knots node implementation.

The transaction, which is publicly verifiable on the blockchain, can be decoded from its raw hex into a valid TIFF image file viewable by standard image software. The image depicts Knots developer Luke Dashjr, a central proponent of BIP-110 (formerly BIP-444), crying. Habovštiak announced the project on X on Thursday, linking to a detailed write-up that includes step-by-step instructions for independent verification using any Bitcoin full node.

The demonstration is notable for what it did not use: the transaction contains no OP_RETURN opcodes, does not rely on Taproot (using SegWit v0 instead), and contains no OP_IF instructions. These are among the primary vectors that BIP-110 targets for restriction, and Habovštiak argues their absence proves that the proposal’s restrictions can be circumvented without relying on any of them.

The proof-of-concept arrives amid an ongoing and at times bitter dispute between Bitcoin Core and Bitcoin Knots camps over what types of data should be permitted on the Bitcoin network. BIP-110, originally introduced as BIP-444 in October 2025, proposes a temporary one-year soft fork that would cap OP_RETURN outputs at 83 bytes, limit individual data pushes to 256 bytes, and restrict other scripting features that enable large data storage. It was introduced after Bitcoin Core’s v30 release effectively uncapped OP_RETURN data limits earlier that year.

Luke Dashjr, the Bitcoin Core developer who maintains Bitcoin Knots and serves as CTO of Ocean mining pool, has been a vocal proponent of limiting arbitrary data on Bitcoin, calling inscriptions “spam” since 2023. BIP-110 proponents have argued that contiguous data storage creates legal risks for node operators and diverts Bitcoin from its core purpose as money.

In his own posts on X, Dashjr contested the characterization of Habovštiak’s transaction as “contiguous,” writing in one such post, “His spam isn’t and doesn’t contain contiguous images.”

About 8.8% of the network is made up of nodes with BIP-110 support, according to data published by The Bitcoin Portal. The proposal is implemented exclusively through Bitcoin Knots, which has seen its node count grow roughly tenfold since the start of 2025.

Habovštiak, a prolific open-source contributor, also produced a BIP-110-compliant version of the image transaction, tested against Bitcoin Knots’ own regtest environment. The compliant version was reportedly larger than the original, which he argued demonstrates that BIP-110’s restrictions would actually increase the total amount of data stored on the blockchain rather than reduce it.

Habovštiak said the project was a one-time effort and that he would not be publishing his code, explicitly to avoid enabling a new wave of NFT-like activity on Bitcoin. He described himself as an opponent of blockchain spam who was motivated by what he considered “untruths” from the Knots camp.

“There’s something I hate much more than spam: Untruths,” Habovštiak wrote. “I tried arguing about this in the past, showed a contiguous image encoded to fit into witness, and yet, the Knots supporters are still saying the same stuff over and over.” The Block could not reach Habovštiak or Dashjr for comment.