Jack Dorsey has built a lot of platforms. Buzz might be his most interesting bet yet — because it’s designed for a world where some of your teammates aren’t human.
What Is Buzz?
Released today at buzz.xyz, Buzz is a free, open-source collaboration workspace built on the Nostr protocol. It has the features you’d expect from a modern team communication tool: channels, threads, direct messages, voice, media sharing, and code repositories. The code is live at github.com/block/buzz under the Apache 2.0 license.
But Buzz is built around a premise that Slack, Teams, and Discord weren’t: AI agents are participants, not plugins.
What “First-Class AI Agent” Actually Means
In most collaboration tools, AI is a bolt-on — a bot that responds to commands, a Copilot sidebar, an integration you ping for help. In Buzz, agents have:
- Cryptographic identities — each agent has a Nostr keypair, making them verifiable participants in any workspace
- Defined permissions — explicit scoping of what each agent can see, do, and respond to
- Native presence in channels — agents post, review code, run approved automations, and contribute to conversations alongside humans without being in a separate “bot” category
Multiple agents and multiple humans share a workspace and build on each other’s contributions. From Block’s announcement: “The most productive work doesn’t happen when someone asks AI for help. It happens when humans and agents are in the same room, working on the same thing, with shared context.”
That framing isn’t just marketing. It reflects a genuine architectural difference. If an AI agent in your workspace has a cryptographic identity and permission model, you can audit what it did, hold it accountable to defined scopes, and reason about its role in decisions — the same way you can with human teammates.
Built on Nostr: Why It Matters
Buzz uses Nostr — the same decentralized, signed-event protocol that powers some of the more interesting experiments in censorship-resistant social networking. In the context of a team workspace, this gives Buzz some distinctive properties:
- Self-hostable — you control your data and your infrastructure
- Decentralized — no single vendor controls your workspace history or availability
- Signed messages — every message, from humans and agents alike, is cryptographically signed and attributable
- Interoperable — built on an open protocol rather than a proprietary API
The decentralized aspect is worth dwelling on: if your AI agents are cryptographic participants in a Nostr workspace, their contributions are signed, attributable, and portable. That’s a different trust model than “whatever the bot said, we think.”
Combined Slack + GitHub Positioning
Buzz isn’t just a chat tool. It includes built-in Git hosting — code repositories live inside the same workspace where you discuss them. That’s the “GitHub combined with Slack” pitch, and it’s a deliberate design choice rather than an integration play.
The integrated approach means that when an agent reviews a pull request or flags a security issue in code, it’s doing so in the same environment where the conversation about that code is happening. Context isn’t lost in translation between tools.
Block has positioned Buzz as a challenger to both Slack and GitHub — simultaneously. Given Dorsey’s track record (he co-founded Twitter and Square, both category-defining platforms), dismissing that ambition would be a mistake.
Availability
- Free desktop app for macOS, Windows, and Linux — available now at buzz.xyz
- Source code at github.com/block/buzz (Apache 2.0)
- Model-agnostic and agent-agnostic — no lock-in to specific AI providers
- Self-hostable — full control over your workspace infrastructure
Sources
- Introducing Buzz: where humans and agents work together — Block (July 21, 2026)
- Buzz Official Site
- Buzz GitHub Repository (block/buzz)
- Nostr Protocol
Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260721-2000
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