Buzz is a free, open source team workspace built by Block, Jack Dorsey's company. It looks like Slack, but AI agents are team members with their own cryptographic identity, permissions, and audit trail, not integrations or bots. <! article html v1 <p <strong Short answer:</strong Buzz is a free, open source team workspace built by Block (Jack Dorsey's company) and released on July 21, 2026. It looks like Slack: channels, threads, DMs, voice. With one fundamental difference: AI agents aren't integrations or bots. They're <strong team members with their own cryptographic identity, their own permissions, and their own audit trail</strong . It also ships code repositories, which puts it in competition with GitHub too.</p <p If you work with Claude Code, Codex, or goose and you're tired of your project context living scattered across seven browser tabs, this launch matters to you. Here's what it actually is, what works today, what doesn't, and how to try it.</p <hr <h2 id="user content whos behind buzz" Who's behind Buzz</h2 <p Buzz was built by <strong Block, Inc.</strong , the company run by Jack Dorsey (co founder of Twitter and Square/Block). Dorsey describes it as <em "model agnostic, decentralized, self sovereign, and open source."</em </p <p The origin story is refreshingly honest: they built it to <strong reduce their own dependency on Slack and GitHub</strong , then decided to publish it so anyone could do the same. Bradley Axen, Head of AI Capabilities at Block, sums up the thesis: every company is going to need a place where humans and agents work together, and that place should be open.</p <p The code lives at <a href="https://github.com/block/buzz" github.com/block/buzz</a under the <strong Apache 2.0</strong license, written mostly in Rust, and it cleared 16,000 stars within days.</p <hr <h2 id="user content how it actually differs from slack" How it actually differs from Slack</h2 <p The easy take is "Slack with AI bolted on." It goes deeper than that.</p <table <thead <tr <th </th <th Slack</th <th Buzz</th </tr </thead <tbody <tr <td <strong AI agents</strong </td <td Integrations and bots with app tokens</td <td Members with their own keypair, profile, and permissions</td </tr <tr <td <strong Code</strong </td <td You link out to GitHub</td <td Repositories and git hosting inside the platform</td </tr <tr <td <strong Your data</strong </td <td On Slack's infrastructure</td <td On a relay you can self host</td </tr <tr <td <strong AI model</strong </td <td Whatever the vendor picks</td <td Any provider you configure, but subscriptions and API keys aren't interchangeable</td </tr <tr <td <strong License</strong </td <td Proprietary</td <td Apache 2.0, open source</td </tr <tr <td <strong Automation</strong </td <td Proprietary Workflow Builder</td <td YAML workflows on open protocols</td </tr </tbody </table <p The last row is the one that isn't cosmetic. In Slack, wiring up your own app means registering an application on their platform, managing tokens, and learning their structure. In Buzz, because it's built on open protocols, connecting your own tooling is a matter of minutes.</p <p The AI model row deserves a second look too, because it's where a lot of people trip on their first day. Picking an agent that runs on Claude Code or Codex uses the CLI you already log into, so your existing subscription covers it. Choose Anthropic or OpenAI as a provider instead of a harness, though, and Buzz asks for an API key. A Claude Pro or ChatGPT Plus subscription doesn't cover that. Same company, same model family, two different bills. One early tester picked the Claude agent expecting the subscription to carry it, found out otherwise mid setup, and had to switch providers to get anything running.</p <p <img src="https://storage.googleapis.com/4geeks academy website/site 4geeks com/media/03 harness status cards.png" alt="Buzz harness setup screen showing Claude Code, Codex, Goose, and Buzz status cards" loading="lazy" </p <hr <h2 id="user content how buzz works under the hood" How Buzz works under the hood</h2 <p This is what makes the pitch hold together technically. Buzz <strong isn't a chat app with a message database</strong . It's a <strong Nostr</strong relay with a workspace interface on top.</p <p Nostr itself is simpler than it sounds. Your identity is a pair of cryptographic keys, not an account on someone's server. You sign what you send, relays store and forward it, and nobody has to vouch for who you are because the signature already does that. Open an agent's profile in Buzz and you'll see this made concrete: it has its own public key sitting next to yours, not tucked away in a settings panel somewhere. The member count doesn't say three people, one bot. It says four.</p <p <img src="https://storage.googleapis.com/4geeks academy website/site 4geeks com/media/05 fizz honey bumble starter team.png" alt="The three starter agent personas in Buzz: Fizz, Honey, and Bumble" loading="lazy" </p <p T