Efforts to introduce Ethereum-style smart contract capabilities to the Bitcoin ecosystem have taken a significant step forward as the OP_CAT proposal has been assigned a ‘BIP number’ – 347. This milestone marks the beginning of substantial discussions and potential implementation of the proposed software upgrade.
Ethan Heilman, one of the co-authors of the proposal alongside Armin Sabouri, emphasized that obtaining a BIP number does not indicate community consensus but rather facilitates organized discourse and development around the proposal.
In essence, the assignment of BIP 347 signals the start of a thorough debate over the contentious proposal’s merits.
The Bitcoin community finds itself divided between those advocating for preserving the network solely for financial transactions and those pushing for the expansion of on-chain capabilities, a faction to which OP_CAT proponents belong.
OP_CAT has a storied history within Bitcoin circles. Originally included as one of the initial op_codes by Satoshi Nakamoto, it was later removed in 2010 due to concerns regarding memory usage and potential vulnerabilities.
However, with the resurgence of developer interest in on-chain solutions, particularly spurred by the Ordinals protocol, proponents have revisited OP_CAT as a means to broaden Bitcoin’s utility. Other proposals, such as Jeremy Rubin’s CTV and scalability solutions like Stacks and Ark, also aim to enrich Bitcoin’s functionality.
Heilman and Sabouri commenced their study of reintroducing OP_CAT in 2022, proposing its implementation via a backward-compatible soft fork on the Bitcoin Mailing List a year later. The approach entails redefining and expanding upon the existing code, ‘OP_SUCCESS126,’ without necessitating a hard fork.
If adopted, OP_CAT covenants could facilitate the development of more complex applications and multi-signature arrangements on Bitcoin by introducing rules, known as ‘covenants,’ to govern transaction behavior.
Heilman explained, “Bitcoin allows users to set rules on who and how their bitcoins can be spent. All CAT does is join two values together. So if you have ‘abc’ and ‘def,’ CAT will join these two values together to make ‘abcdef.’ The CAT is just shorthand for conCATenate.”
He added that, once the software’s functionality is validated, the proposal will undergo scrutiny from the Bitcoin community to determine its acceptance. However, this process could be swift or protracted, depending on community sentiment.
Among OP_CAT’s prominent advocates are the co-founders of the Ordinals project Taproot Wizards, Eric Wall and Udi Wertheimer, who initiated the Quantum Cats inscriptions project to bolster support for Heilman and Sabouri’s proposal.
Despite Quantum Cats’ popularity, OP_CAT faces resistance within the Bitcoin community. Speculation suggests delays in BIP approval, with some attributing this to skepticism among editors like Luke Dashjr, who remains wary of recent on-chain experiments.
However, with the assignment of OP_CAT’s BIP number by the editor ‘Roasbeef,’ the initiative is now in the hands of the broader Bitcoin community to decide its fate.
Heilman expressed his intention to step back from the process, allowing the community to deliberate on the proposal’s merits independently. He emphasized his readiness to address any technical inquiries but refrained from participating in the broader debate.”