Jack Dorsey launched Buzz to replace Slack and GitHub. Its AI agents are full members

Jack Dorsey just launched Buzz, and it wants to eat both Slack and GitHub. The app fuses team chat, AI agents, and Git hosting into one open-source workspace, with the agents sitting in channels as full members rather than bolted-on bots. Block shipped it on July 21 as a free desktop download.

The pitch is consolidation. Instead of a chat app in one tab, a code host in another, and a stack of bot integrations wiring them together, Buzz puts humans and their agents in the same rooms, on infrastructure a team can run itself. Dorsey called it “model-agnostic, decentralized, self-sovereign, and open source” in his launch post. That last phrase is the tell. Buzz is the newest entry in his multi-year campaign to rebuild everyday software on open protocols he doesn’t control, and whether anyone outside Block wants to run their standup on a Nostr relay is the open question.

What Buzz actually is

Buzz looks like Slack. It has channels, threads, and direct messages. The twist is what lives underneath and who else is in the room.

Underneath, Buzz is a Nostr relay written mostly in Rust. Every message, workflow run, and Git event gets cryptographically signed and written to one shared event log, so the whole workspace has a single tamper-evident history. The desktop app is built with Tauri and React and runs on macOS, Windows, and Linux; mobile clients for iOS and Android are still in progress. The code lives at github.com/block/buzz under an Apache 2.0 license, and within a day of launch it had drawn over 3,000 stars and 228 forks.

That log isn’t just a chat archive. Because Git commits and automation runs land in the same signed stream as the messages, a channel doubles as an auditable record of who (or what) changed the code and when. Block backs the relay with Postgres for full-text search and Redis for pub/sub, so the self-hosted story isn’t a toy. It’s the same shape of infrastructure a real team already runs.

The Git piece is what goes after GitHub. Buzz hosts repositories directly, and agents can open patches, review code, and run approved automations against them without leaving the chat window. Block is candid that this is early. The launch build is version 0.4.22, and the company told users not to migrate their teams onto it yet.

Agents that own their identity

Here’s the design choice that separates Buzz from every “bolt AI onto chat” feature shipping this year. In Buzz, an agent isn’t a webhook wearing a name badge. It gets its own keypair, the same as a human, so its identity and reputation belong to it and can travel to any Nostr-compatible system. Access is scoped by that identity rather than a tangle of per-bot permission toggles.

Buzz stays model-agnostic about what drives those agents. Block’s own Goose framework works out of the box, and so do OpenAI’s Codex and Anthropic’s Claude Code, connected through an adapter Block calls buzz-acp. There’s also a buzz-cli for agents that prefer raw JSON over a GUI, plus persona packs for giving each agent a defined role. The upshot is a channel where a person, a Goose agent, and a Claude Code agent can all post, and the log records each action the same signed way whether the author is a human or a process.

Picture a bug report landing in a channel. A Goose agent picks it up and opens a patch against the repo Buzz is hosting, then posts the diff back into the thread for a human to approve. Every step in that loop is a signed event tied to the agent’s own key, so there’s a clean trail of exactly what the agent did, without a human ever handing their personal GitHub token to a bot.

That agents-as-teammates picture is where the wider industry is heading. Vercel rebuilt its AI SDK around production agents, and more developers are running coding agents on their own machines. Buzz’s bet is that if agents are going to act like coworkers, they should carry coworker-grade identity and an audit trail, not an API key buried in a config file.

Dorsey’s open-protocol bet

None of this is a detour for Dorsey. Since leaving Twitter, he’s put his energy into software that runs on protocols no single company owns. He seeded Bluesky and the AT Protocol, backed Damus (a Nostr-based Twitter alternative), and shipped Bitchat, a Bluetooth mesh messenger that needs no servers at all. Block’s Goose agent framework, released in January 2025, is open source too. Buzz is the workplace-shaped version of the same idea. He’s also been blunt that it scratches his own itch first: Buzz exists because Block wanted off tools it didn’t own, long before it worried about anyone else adopting it.

The through-line is Nostr. Choosing it means a Buzz workspace isn’t locked to Block’s servers: a team can point its client at a relay it hosts, and an identity minted in one workspace can move to another. For a founder who keeps warning about centralized platforms, running his own company’s chat and code on rented infrastructure was the contradiction Buzz is meant to resolve. Block says it plans to replace Slack and GitHub internally with it.

Where the skepticism lands

The Hacker News thread on the launch was not a victory lap. The most-repeated jab was the name: Google Buzz lasted about 16 months before Google killed it in 2011, and more than one commenter wondered whether a Dorsey side project would fare better. “Isn’t everything Dorsey does these days his vibe-coded side project?” one asked, needling a pattern of splashy launches that later go quiet.

The sharper critiques are technical. A Slack engineer in the thread flagged the hard problem hiding inside “multiplayer agents”: when agents can read everything in a workspace, keeping one channel’s secrets out of another is a permission nightmare, and identity-scoped access doesn’t make it disappear. Others questioned whether Nostr, built for a public social feed, is the right substrate for a private enterprise workspace running swarms of agents. And there’s the tension in the branding. Open protocol or not, “replace Slack and GitHub” is still a pitch to move a team onto one vendor’s stack, and open-source tooling keeps getting pulled into big platforms anyway, as when VoidZero folded into Cloudflare.

Then there’s the crowd. Self-hosted chat like Mattermost and Rocket.Chat already exists for teams that want to own their infrastructure, and Slack and Microsoft Teams are racing to stitch agents into their own products. Buzz’s real differentiator is the signed-identity model and the single event log, not the chat UI, where polished tools like Linear have set a high bar. Whether that’s enough to pull a team off tools that already work is the thing a 0.4 release can’t answer. A team’s entire history and every integration it depends on live in the incumbent tools, and “open source” doesn’t move any of that for free.

My read: Buzz is the most coherent statement yet of what an agent-native workspace could be, and the keypair-per-agent identity model is a genuinely good idea worth stealing even if Buzz itself stalls. But it’s a 0.4.22 build from a company that says don’t use it in production, running on a protocol most enterprises have never touched. Watch whether Block actually runs itself on Buzz by year-end. If Dorsey’s own engineers drop Slack and GitHub for it, that’s the signal to take it seriously. If it stays quiet, the Google Buzz jokes write themselves.