Jack Dorsey has never been shy about betting against the tools everyone else has settled for. First it was banks, with Square. Then it was the tweet itself, when he stepped back from Twitter's centralised model and started funding open protocols instead. Now it's the workplace stack. On July 21, his company Block released Buzz, a free, open-source workspace built to do what Slack, GitHub, and a handful of project management tools currently split between them, except with AI agents treated as full members of the team rather than bots bolted onto the side.

What Buzz actually is

Buzz combines channels, threads, direct messages, canvases, media sharing, code repositories, and automated workflows in one app. Under the hood, it runs on Nostr, the decentralised, relay-based protocol Dorsey has personally funded for years and already used to build Bitchat, his Bluetooth mesh messenger. Every message, reaction, workflow step, code change, and approval in Buzz exists as a cryptographically signed Nostr event.

That signing is the part worth paying attention to. Every human and every AI agent on Buzz gets its own keypair-based identity. When an agent acts, its signature is tied back to the human who authorised it, creating a verifiable chain of custody for whatever the agent touched. If an agent reviews a pull request, approves a workflow, or edits a file, there's a permanent, auditable record of exactly what happened and who is accountable for it. That's a meaningfully different model from asking a chatbot a question and hoping the answer is right. Agents on Buzz can search discussions, submit patches, review code, and run workflows using the same primitives as any human teammate.

Buzz is also model-agnostic. It already ships with pre-built support for Claude Code, OpenAI's Codex, and Block's own agent framework, goose, which means teams aren't locked into a single AI vendor to use it.

Why self-hosting matters here

Block is offering a hosted version of Buzz, but the software is released under an Apache 2.0 license, and teams can run their own instance instead of depending on Block's servers. That's the decentralisation piece Dorsey keeps hammering: teams control their own data, their own relay, and their own agents rather than routing everything through a third party's infrastructure.

For startups anywhere, but especially for African founders already wrestling with the dollar cost of SaaS subscriptions and the added weight of data residency questions, a self-hostable alternative to Slack and GitHub is worth watching closely. It won't replace either overnight, but the option to own your team's communication and code history outright, rather than renting access to it monthly, is the kind of shift that compounds over a few years.

The catch: it's early

Buzz shipped at version 0.4.21. Git integration is still shallow. Mobile apps, approval gates, and some voice features are listed as still under development. Block is running Buzz internally as its own first customer and is explicit that the product isn't finished. Bradley Axen, Block's head of AI capabilities, framed the bet plainly in the launch announcement: every company will eventually need a place where humans and agents work together, and the real question is whether that place is proprietary or open.

Buzz also isn't launching into an empty field. Paradigm's Georgios Konstantopoulos unveiled a similar AI-native chat platform called Centaur around the same time, and Block itself joined the Linux Foundation's Agentic AI Foundation late last year alongside Anthropic and OpenAI, a sign that agent-native workplace tooling is becoming its own contested category rather than a Block side project.

The bigger picture

This is consistent with everything Dorsey has done since leaving Twitter. He stepped off the Bluesky board in 2024 and has since backed a run of tools that no single company can fully control, most of them sitting on Nostr. Buzz extends that same instinct into the workplace: instead of trusting that Slack and GitHub will build agent-native features on their terms, build the alternative on infrastructure nobody owns.

Whether Buzz becomes a genuine Slack and GitHub killer or stays a niche tool for teams already comfortable self-hosting their software remains to be seen. But the identity and accountability model it's built around, giving AI agents a verifiable trail rather than treating them as black boxes, addresses a real gap that's only going to matter more as more companies let agents touch production code and internal workflows unsupervised. That's the part of this story worth watching past the version number.