Jack Dorsey Wants AI Agents Sitting in Your Team Chat as Coworkers - Not Just Tools You Open When You Need Them

I've watched Jack Dorsey take swings at entrenched incumbents before — Twitter went after the entire concept of mass media, Cash App went after traditional banking. His newest target is oddly specific and oddly ambitious at once: Slack and GitHub, combined, replaced by a single open-source app where AI agents don't just answer your questions when you ask — they sit in the channel with everyone else, all the time, as full participants. Four days after launch, the reaction ranges from genuine excitement about a new product category to pointed security concerns from people who actually build this stuff for a living. The direct answer: On July 21, 2026, Jack Dorsey's company Block launched Buzz, a free, open-source team chat and collaboration platform that combines messaging, code hosting, and project management into a single workspace where human team members and AI agents participate as equals in the same channels. Built on the decentralized Nostr protocol, Buzz gives AI agents their own cryptographic identities, scoped permissions, and audit trails, and works with multiple AI providers including Claude Code, OpenAI Codex, and Block's own Goose agent. It's a genuine, substantial product from an established company, not a side project — but it launched into real skepticism about the security implications of putting autonomous agents directly into shared team conversations. Quick Facts Detail Info Product Buzz Launched July 21, 2026 Built by Block (Jack Dorsey's company, also behind Square, Cash App, Afterpay, Tidal) Positioned against Slack and GitHub License Free, open-source Underlying protocol Nostr — a decentralized, cryptographically-signed communication protocol Platforms available Desktop apps for macOS, Windows, and Linux AI model compatibility Model-agnostic — supports Claude Code, OpenAI Codex, Block's Goose agent, and others Core pitch Humans and AI agents participate as equals in the same channels and workflows Similar competing product Centaur, from Paradigm CTO Georgios Konstantopoulos, launched independently in May 2026 What Buzz Actually Does Buzz looks, on the surface, like any other team chat app — channels, threads, direct messages, voice, media sharing, and search, the same basic building blocks Slack and Microsoft Teams have used for years. Block has folded code hosting and project management into the same interface too, letting teams move from a conversation directly into planning, coding, and pull requests without switching to a separate tool. Dorsey's own framing on launch day was direct: the goal was reducing Block's own internal dependency on Slack and GitHub by building something model-agnostic, decentralized, self-sovereign, and open source. The genuinely different part is how Buzz treats AI. Most workplace AI tools today function as assistants you summon when needed — you open a separate window, ask a question, get an answer, move on. Buzz's core bet is that AI agents should instead exist as persistent, first-class members of a team's actual workspace: added to channels the way you'd add a colleague, able to read ongoing conversations, respond to messages, perform approved tasks, write and review code, and collaborate directly with other agents, all within the same shared context human teammates are working in. How the Security Model Actually Works This is worth understanding in some detail, because it's also the source of the platform's most pointed criticism. Buzz is built on Nostr, a decentralized protocol that represents all activity — including everything an AI agent does — as cryptographically signed events. In practice, that means every action an agent takes inside Buzz is tied to a specific cryptographic identity, with defined permissions and a full audit trail, rather than operating through a generic, blanket bot token the way many chatbot integrations work today. Block's pitch is that this gives teams meaningfully more visibility and control over what any given agent can actually do, and a clear record of what it did, compared to more opaque bot integrations common on other platforms. Because Buzz is model-agnostic, teams aren't locked into a single AI provider — agents built on Claude Code, OpenAI's Codex, Block's own open-source Goose agent, or custom frameworks can all participate side by side in the same workspace, each carrying their own scoped identity and permission set. Buzz vs. Slack and GitHub: What's Actually Different Aspect Traditional Slack + GitHub Setup Buzz AI agent role External tool, opened separately when needed Persistent participant in shared channels Cost Paid subscriptions for both platforms Free and open-source Agent identity Generic bot tokens Individual cryptographic identities per agent Underlying architecture Centralized, proprietary Decentralized, built on Nostr Model support Varies by integration Model-agnostic — works across multiple AI providers Code hosting and chat Separate platforms Combined in one workspace The Skepticism Is Real, and