Gradually, and then suddenly.
This past weekend, many Bitcoin developers across a broad range of camps gave explicit support for a specific soft fork proposal. Could this may mark the beginning of Bitcoin’s next upgrade?
Developer consensus may be converging on a soft fork proposal
Grassroots support for two bitcoin improvement proposals (BIP) appears to be emerging for Bitcoin’s next soft fork, but we’re still a long way from an actual upgrade.
For the uninitiated, Bitcoin Improvement Proposals (BIPs) are formal ways to discuss and track proposed changes to Bitcoin. Theoretically, if a BIP gains sufficient widespread support, it will be added to Bitcoin, either by way of a soft fork or a routine update. Often, these BIPs are referred to by nicknames and multiple BIPs may be included in a soft fork.
Bitcoin’s technical community typically debates these BIPs endlessly. The Taproot Wizards put out a helpful graphic explaining the confusing and seemingly circular process of these discussions. There’s no definitive heuristic for defining what “widespread support” looks like, and Bitcoin consensus is a constantly evolving, moving target.
However, sometimes we can put our finger in the wind and sense a change in its direction. This weekend, we registered a definite shift as numerous developers gave their explicit support for BIPs 119 and 348.
What is the specific proposal?
Many notable bitcoin developers tweeted their support for CTV and CSFS over the weekend.
These initialisms stand for the opcodes OP_CHECKTEMPLATEVERIFY & OP_CHECKSIGFROMSTACK, formally known as BIP 119 and BIP 348. BIP 119/CTV, proposed by Jeremy Rubin, has been around for over half a decade, whereas BIP 348/CSFS was only formalized in November 2024.
Generally speaking, these two BIPs would enable covenants on Bitcoin. A covenant simply restricts the way a wallet can spend bitcoin in future transactions. Covenants proponents generally tout their ability to beef up custody, improve fee management, and enhance existing Bitcoin tech like Lightning, Ark, and DLCs.
Additionally, developers generally consider these two proposals to be “narrowly defined.” In layman’s terms, this means that they only enable a few things and that there is a low probability of users exploiting them for something unexpected if they are activated. The Bitcoin developer community in general prefers to cautiously deliberate any changes to Bitcoin. Speaking to this abundance of caution, even though BIP 119 has remain unchanged for nearly half a decade, there was once a time not long ago when CTV was considered way too aggressive.
A long time coming
Bitcoiners may remember that Rubin’s 2021 and 2022 campaign for CTV received strong pushback from notable tenured Bitcoin developers such as Adam Back and Jimmy Song. Some accused Rubin of “attacking Bitcoin,” although most of those critics have either disappeared or (ironically) become supporters of CTV.
Recent advocacy for the OP_CAT opcode (BIP 347 and/or BIP 420) seems to have widened the Overton window of acceptable Bitcoin proposals, framing CTV & CSFS as the comparatively “conservative” options. It’s important to note that most OP_CAT supporters such as the Taproot Wizards are also in favor of BIPs 119 and 348 (and most proposals in general).
Jeremy stepped back a few years ago and has recently re-engaged with Bitcoin under a private venture but refrained from taking part in any consensus discussion until recently when he posted an official endorsement of a proposal. This kicked off the cascade of developers joining his endorsement this weekend.
Today many of the old critics are gone or won over and we see broad support from notable names across the board: developers at Blocksteam, notable lightning devs, other BIP authors, technical reporters, privacy advocates, a Lightning Lab employee, researchers, and community leaders.
We’re still in the early innings, but it appears that Jeremy Rubin may have finally found rough consensus for CTV — or at least the beginnings of it.
