Community fork of the Cosmos blockchain consensus engine after All in Bits unilaterally archived the Tendermint repository amid governance disputes.
CometBFT implements the Tendermint Byzantine Fault Tolerant (BFT) consensus algorithm in Go. It provides a replication engine for deterministic state machines, forming the consensus and networking layer of the Cosmos SDK. It supports ABCI (Application Blockchain Interface) for connecting application logic to the consensus engine.
Tendermint Core was the Byzantine fault-tolerant consensus engine that powered the Cosmos ecosystem — a network of interconnected blockchains worth billions of dollars. The project was created by Jae Kwon and developed by All in Bits (AiB), the company he founded. But as the Cosmos ecosystem grew, tensions between AiB and the broader community became untenable.
The core dispute was about governance and direction. AiB, which held the Tendermint trademark and controlled the repository, pushed for a more minimal approach to the consensus engine. The broader Cosmos community — including the Interchain Foundation, Informal Systems, and dozens of blockchain teams — wanted more features and faster development. AiB had also removed Informal Systems developers from the repository.
In January 2023, Jae Kwon announced that AiB would no longer support Tendermint Core development and unilaterally archived the repository. This was an extraordinary move — archiving the consensus engine that secured billions in assets across the Cosmos network. The community interpreted it as hostage-taking: develop things my way or lose your infrastructure.
Informal Systems, with backing from the Interchain Foundation and numerous Cosmos stakeholders, forked Tendermint Core into CometBFT. The fork was announced in February 2023, with the name chosen to represent both the celestial Cosmos theme and a fresh start. CometBFT was positioned as the official successor, not a rebel offshoot.
The transition was remarkably smooth given the stakes involved. CometBFT maintained full API compatibility with Tendermint, allowing existing chains to upgrade without breaking changes. The Cosmos SDK quickly adopted CometBFT as its default consensus engine, and within months the fork had effectively replaced Tendermint across the ecosystem.
Jae Kwon announces AiB will stop supporting Tendermint Core development
AiB archives the Tendermint Core repository
Informal Systems announces CometBFT as fork and successor to Tendermint
Cosmos SDK adopts CometBFT as default consensus engine
CometBFT achieves full ecosystem adoption across Cosmos chains
CometBFT demonstrated that even in the high-stakes world of blockchain infrastructure, community governance can prevail over founder control. The fork secured the consensus layer for a multi-billion-dollar ecosystem and established Informal Systems as a trusted steward. It also set a precedent for how blockchain communities can handle hostile actions by project founders.