A serious attempt to bring an Ethereum-like smart contract feature to Bitcoin called OP_CAT has finally earned a “BIP number:” 347. This is the first step toward actually launching the long-proposed software upgrade .
“Getting a BIP number doesn’t mean any kind of consensus from the community,” Ethan Heilman, one of the co-authors of the proposal alongside Armin Sabouri, said in an interview. the proposal is easier because the proposal now has a unique numerical identifier that everyone agrees on.
In other words, the award of BIP 347 means that debate over the controversial proposal can finally begin in earnest.
On one side are those who wish to reserve the Bitcoin network solely for monetary transactions; on the other, those who want to build new things on-chain, of which OP_CAT supporters are only a fraction.
OP_CAT has a long history in Bitcoin circles. Originally included as one of the first op_codes (essentially programming shortcuts built into Bitcoin), Satoshi Nakamoto removed the feature himself in 2010 after concerns were raised about excessive memory usage and the possibility of introduce vulnerabilities.
But in recent years, particularly after the release of the Ordinals protocol which reinvigorated developers’ desire to build on-chain, proponents have returned to OP_CAT as a possible way to increase the amount of things that can be built using Bitcoin . Other proposals include things like Bitcoin developer Jeremy Rubin’s CTV and feature-rich scaling solutions like Stacks and Ark.
Heilman and Sabouri began studying the reintroduction of OP_CAT in 2022 and first proposed launching it a year later on the Bitcoin mailing list via a backwards compatible soft fork. The idea would be to redefine and expand on existing code called “OP_SUCCESS126”, without having to force the chain.
If the proposal is adopted, the OP_CAT clauses could enable the creation of more sophisticated applications and multi-signature setups on Bitcoin. It works by introducing “clauses” or rules that can be established to determine how a Bitcoin-specific transaction will work.
“Bitcoin allows users to set rules on who and how their bitcoins can be spent. All CAT does is connect two values. So if you have ‘abc’ and ‘def,’ CAT will join those two values to form ‘abcdef,’” Heilman said, adding that such a basic maneuver is not possible today. “CAT is just shorthand for conCATenate.”
“Once the community is convinced that the software works as expected, we will build a PR in Bitcoin-Core. This is where the real fun begins because the question changes from “is the software correct?” to “does the Bitcoin community want OP_CAT?” “,” Heilman said. “It could be a quick process or it could take years.”
Among OP_CAT’s biggest supporters are the co-founders of the popular Ordinals Taproot Wizards project, Eric Wall and Udi Wertheimer, who created the Quantum Cats Inscriptions Project as a sort of marketing campaign for Heilman and Sabouri’s proposal.
Although Quantum Cats is one of the most popular inscription projects to date, OP_CAT itself is far from universally accepted. There is speculation, for example, that although Heilman and Sabouri submitted their BIP proposal several months ago, it was delayed by the approval of BIP’s sole publisher and Bitcoin Core developer, Luke Dashjr, who is not alone in being skeptical of recent developments. on-chain experimentation.
On Monday, the Bitcoin community named five additional BIP editors. According to GitHub, OP_CAT’s BIP number was assigned by a publisher called “Roasbeef”.
Heilman said now that OP_CAT has a BIP number, it’s up to the community to determine whether to move forward.
“Speaking only for myself, at this point I intend to remove myself from the process and let the community debate whether OP_CAT is something they want or not,” he said. “I do not intend to participate in this debate unless it is necessary to clarify technical issues.