Summary: Jack Dorsey announced on July 21, 2026 that Block had open-sourced Buzz, a workspace combining team chat, AI agents, and planned Git hosting. Version 0.4.21 desktop builds shipped under Apache 2.0; agents are workspace members with shared identities and signed events, not separate plugins. Block’s own documentation calls Buzz unfinished, and TechCrunch advised teams not to migrate yet.
Jack Dorsey used X on July 21, 2026 to say that Block — parent of Square, Cash App, Afterpay, and Tidal — had open-sourced Buzz, a workspace holding team chat, AI agents, and Git hosting in one place. He picked his positioning words with care: “model-agnostic, decentralized, self-sovereign, and open source.” His reasoning was plainer: Buzz was “built to reduce our dependency on Slack and GitHub.”
Desktop builds of v0.4.21 arrived from the block/buzz repository that same day, for macOS, Windows, and Linux, released under Apache 2.0. One line is all the repo says about itself on GitHub: “A hive mind communication platform.” TechCrunch reads Buzz as taking on Slack and GitHub at once — human colleagues, AI agents, and the same project’s code and workflows all living in one chat window.
One Open Workspace Against Slack Plus GitHub
Chat basics are fully covered in Buzz: channels, threads, direct messages, shared canvases, media, search, an audit log, and a desktop app, with workflows defined in YAML. The identity model is where it departs from the norm. Employees, AI agents, conversations, and code repositories are all placed behind a single identity system: the same key pairs, channel memberships, and audit trails apply to people and agents without distinction.
That carries a practical payoff. From the very first day, “who said what” and “who changed what” sit on one record, rather than being split between a chat history and a version control system that never talk to each other.
Architecture: Everything Is a Signed Event
Buzz runs on a self-hostable Nostr relay. Every message, reaction, workflow step, code event, and approval is kept as a cryptographically signed event. Sharing an interface is not the extent of it for humans and agents; one event format and one identity structure are common to both.
The word “decentralized” still needs an asterisk. RuntimeWire notes that the relay inside each deployment remains centralized — no peer-to-peer event exchange, no gossip layer, no replication between relays. Self-sovereign, as used here, means that the whole system is yours to own and host, not that deployments federate the way social networks do. The part enterprises lean on is simpler: data and identity stay on infrastructure you control. That alone can justify adopting it.
Agents Are Members, Not Plugins
The AI agents in Buzz are no traditional bots. They are workspace members: able to search discussions, open repositories, submit patches, review code, run workflows, edit canvases, and even create channels. An agent-oriented CLI ships with the product, along with ready-made harnesses for Goose, Codex, and Claude Code, keeping model choice separate from the workspace itself. Swap the model without swapping the tool — a concrete escape hatch for teams wary of single-vendor lock-in.
A Feature Branch Is a Channel
Git hosting remains at the spec stage, though the direction is written down. Standard Git Smart HTTP backs the built-in software forge, and a feature branch can become a channel in its own right: patches, CI results, code reviews, and merge decisions share one record, which in turn shares a search index with discussions and workflow history. “Conversation as the development record” is the design idea. Should it work, the ritual of pasting GitHub links into Slack threads and then excavating the context later disappears from the process altogether.
Why Block Built Its Own
“From Hierarchy to Intelligence,” an essay Dorsey co-wrote with Sequoia’s Roelof Botha, spells out the why: rather than a productivity add-on, AI ought to change how organizations coordinate. Block’s stated assignment for Buzz is to “replace portions of chat, code hosting, workflow automation, project search and agent orchestration with one event system.”
Parallel experiments keep surfacing. A “virtual employee” called Centaur, which lives inside Slack or behind an API, was open-sourced by Paradigm CTO Georgios Konstantopoulos. His argument: “There is a lot of room for improvement for agents that live in Slack.” The overlap says something. Now that agents have become the primary workers inside chat tools, the tool itself has begun to look like the limiting factor.
Reality Check: Not Ready for Migration
The sober notes come first. Buzz is labeled unfinished in Block’s own documentation: mobile clients and push notifications are missing, workflow approval gates lack a completed execution path, and no pricing or adoption figures have been published. TechCrunch’s advice is pragmatic — it is early, and teams should not migrate yet.
The signal, though, is clear enough. When chat, agents, and version control start being designed as one thing, the existing collaboration stack has to re-answer an old question: why three systems?