Block launches Buzz for teams using AI agents

Block has introduced Buzz, a free open-source workspace where employees and AI agents can work in the same project environment. For investors following Block, the launch shows Jack Dorsey’s payments company extending its open-source AI push into workplace software, an area currently dominated by tools such as Slack and GitHub.

Dorsey announced the product Tuesday on X, calling Buzz “a new groupchat platform for teams of people and agents of all sizes” and saying it was built to reduce Block’s dependence on Slack and GitHub. He described the platform as “model-agnostic, decentralized, self-sovereign, and open source.”

Buzz combines several tools that teams often use separately: channels, threaded conversations, direct messages, voice, media sharing, code repositories and automated workflows. Block said the interface should feel familiar to people who have used modern workplace chat apps.

How Buzz treats AI agents

The main twist is that Buzz gives AI agents a formal seat in the workspace. In this context, an agent is software that can take actions on behalf of a user or team, such as reviewing code or running an approved workflow.

Block said agents on Buzz have their own cryptographic identities and permissions. A cryptographic identity uses digital keys to prove who, or what, signed an action. That means an agent can post in conversations, review code, run permitted automations and contribute alongside human team members, according to Block.

Bradley Axen, Block’s head of AI capabilities, said in a company statement that companies will need shared workspaces for humans and agents. “The question is whether that place is proprietary or open,” Axen said.

Buzz is designed to work across AI systems rather than locking teams into one provider. Block said teams can use agents built with Anthropic’s Claude Code, OpenAI’s Codex or goose, Block’s open-source agent framework released in January 2025. In plain English, “model-agnostic” means the product is meant to support multiple large language models, the AI systems trained to generate text, code and other outputs.

Why Block built it on Nostr

Block built Buzz on Nostr, an open protocol for sending signed messages across compatible systems. According to Block, Nostr addresses a core issue in multi-agent work: identity.

Under Buzz’s design, each person and each agent has a keypair that belongs to them rather than to the platform. Block says that lets an agent’s identity, history and reputation move across Nostr-compatible systems.

The project’s GitHub repository says every message, reaction, workflow step, review approval and git event is stored as a signed event in one log. It also describes a hash-chain audit trail, a record structure meant to show the sequence and integrity of actions, whether the actor is a person or a software process.

Buzz’s code is available under the Apache 2.0 license at github.com/block/buzz. Block said teams can either self-host the software or use Block’s managed version.

The product is still early. The repository lists Buzz as version 0.4.21, with desktop builds for macOS, Windows and Linux. Mobile clients are not finished. The repository also says each workspace currently runs on a single relay, which it calls the workspace’s “single source of truth,” even as Block frames the product around decentralized infrastructure.

This story draws on original reporting from Decrypt.