Block Releases Buzz Group Chat on Nostr for AI Agent Teams

On July 21, 2026, Jack Dorsey’s fintech company Block launched Buzz, an open-source and decentralized group chat platform designed for mixed teams of humans and AI agents. By integrating chat features with native Git hosting, Buzz aims to reduce corporate reliance on centralized tools like Slack and GitHub. If your engineering team heavily utilizes multi-agent systems, this platform explicitly treats those models as first-class members rather than simple chatbot integrations.

The release aligns with Block’s internal strategy, announced earlier this year, to compress management hierarchies by replacing middle layers with an intelligence layer of AI agents. The software introduces a distinct approach to sovereign workspaces and agent identity.

Decentralized Architecture and Agent Identity

Buzz is built on Nostr, a decentralized social networking protocol, which makes the platform self-sovereign and model-neutral. Every participant, human or machine, is assigned a cryptographic identity via a keypair.

For AI agents, Buzz employs a dual-signature system. This ties every automated action back to the human owner’s identity, creating a verifiable audit trail. Every message, reaction, and code commit is recorded as a signed event on the Nostr protocol. This architecture ensures a tamper-proof, searchable history of how an agent arrived at a decision or code change.

The platform connects coding agents into developer tools using the Agent Client Protocol (ACP) open standard. It is model-agnostic out of the box, supporting frameworks like Block’s own goose, OpenAI’s Codex, and Anthropic’s Claude Code.

Unified Workspace Capabilities

Buzz merges traditional communication channels, threads, direct messaging, and voice with a built-in software forge for Git hosting. This setup creates feature branch channels where code modifications and the discussions surrounding them exist in the same continuous log.

Agents in Buzz do more than respond to prompts. They hold their own accounts and permissions, allowing them to participate in team conversations proactively, review and push code, and trigger automated workflows independently.

This “multiplayer” agent environment has drawn positive initial reactions from developers exploring social building. However, managing data leakage and defining precise permission scopes in shared spaces remains a complex challenge when combining agent skills with cross-functional access.

Hosting and Availability

The software launched at v0.4.22. It provides native desktop applications for macOS, Windows 11, and Linux. Because it is fully open-source, the source code is available on GitHub under the repository block/buzz.

Teams have the option to host their own Nostr relay to maintain complete control over their data, or they can use Block’s hosted beta option, which is currently offered for free.

When evaluating Buzz for your organization, consider the operational overhead of running a Nostr relay versus the auditability benefits of the dual-signature cryptographic identity system. If your agents autonomously push code to production, the tamper-proof Nostr event log provides an essential security mechanism that centralized platforms currently lack.