Jack Dorsey's Block launches Buzz, an AI agent rival to Slack

Block launched Buzz on Tuesday. It’s an open source workplace chat app where the employees and their AI agents are in the same channels.

Jack Dorsey, the company’s founder, said it would help teams rely less on Slack and GitHub. Buzz considers AI agents as full participants and caters to startups that use AI agents for their daily tasks.

Dorsey broke the news on X on July 21, calling Buzz “model-agnostic, decentralized, self-sovereign and open source.” The app was built by Block, the payments company behind Square, Cash App, Afterpay and Tidal.

Now it has a free desktop version for macOS, Windows and Linux. The code is hosted on GitHub under the Apache 2.0 license.

Buzz gives agents their own identity

According to Buzz’s website, each human and agent on the platform is assigned a cryptographic identity with its own permissions and activity trail. Agents post in channels, review code, and execute workflows that the team has approved. They collaborate with employees rather than waiting for a call.

Buzz is a product based on Nostr, a decentralized protocol for recording activities as signed events. Messages on the app, reactions, code changes and approvals can all be stored in one searchable audit log.

Buzz also works with agents made on other systems, such as Claude Code from Anthropic, Codex from OpenAI, and Goose from Block. Teams decide what internal databases, files, and codebases each agent can access.

The app also has channels, threads, direct messages, canvases, media sharing, search, an audit log, desktop apps, automated workflows, and a first attempt at Git integration. Buzz will soon include more voice features, approval gates, and mobile apps.

The project is open source, so a team that is missing a feature can write one and ship it against its own instance. Teams can run Block’s hosted version or self-host, keeping control of their data, relay and agents.

Block gobbles up losses, rivals circle Buzz

Georgios Konstantopoulos, partner and CTO at Paradigm, has just launched Centaur, an open source tool he calls a “virtual employee” that lives inside Slack or via an API. “Enterprises will want to self-host those agents for security and continue to use them where staff are already working, inside Slack,” he argued on X.

Block has bigger ambitions. Ultimately, the company says, it wants Buzz to consolidate jobs currently spread across chat apps, code hosting, workflow automation, search and continuous-integration dashboards. And that would give a team one record of how a project was discussed, reviewed and delivered.

Buzz lands as Block works through legal and financial pressure. In July, Block agreed to a $45 million settlement with 46 state attorneys general over allegations it misled Cash App users about safety and failed victims of fraud, Cryptopolitan reported.

It trades on the New York Stock Exchange under the symbol XYZ. It reported a net loss of $308.7 million in the first quarter of 2026 and said it would cut more than 4,000 jobs.

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