Block launches Buzz, Nostr-based workspace for people and agents

Block unveiled Buzz on Tuesday, a free, open-source workspace built on the Nostr protocol that places employees and AI agents in a shared environment. The platform combines team chat, code repositories and automated workflows in one interface. Block published the source under an Apache 2.0 license at github.com/block/buzz. Teams can self-host or use Block’s managed relay. The current release is version 0.4.21 with desktop clients for macOS, Windows and Linux; mobile apps are under development.

Buzz uses Nostr keypairs so every person and agent holds its own cryptographic identity. The project’s repository describes each message, reaction, workflow step and code event as a signed event recorded in a hash-chain audit log. Although Block describes Buzz as decentralized, each workspace today runs on a single relay the repository calls a “single source of truth.”

Buzz supports multiple model and agent frameworks. Block says teams can deploy agents built on Anthropic’s Claude Code, OpenAI’s Codex, and Block’s open-source agent framework, goose. Agents are assigned permissions to post messages, review code, run approved automations and join conversations. They can act through command-line interfaces, create channels and update their own memories while administrators set channel- or thread-level rules.

Founder Jack Dorsey announced the project on Twitter, calling it “a new groupchat platform for teams of people and agents of all sizes” and describing it as “model-agnostic, decentralized, self-sovereign, and open source.” Bradley Axen, Block’s head of AI capabilities, wrote in a statement that “Every company is going to need a place where humans and agents work together.” Lucas Isaza, who works on AI and product at Block, wrote that a single thread can hold diagnosis, task, fix and surrounding conversation in one record.

Thomas Petersen, a principal designer and AI strategist at Block, wrote that he rejoined the company to change “the lonely experience of working with AI” and that the company used agents to build the platform. Block has tested Buzz internally and invited teams to try the software and contribute to the code.

Block has placed AI at the center of its strategy in recent years. The company cut more than 4,000 jobs in early 2025 during a restructuring in which Jack Dorsey noted that AI “fundamentally changes what it means to build and run a company.”

Block describes the release as an initial version. The repository and Apache 2.0 license let organizations inspect, modify and host the code themselves. Block’s managed relay offers a hosted option for teams that do not want to operate their own relay.