Block Launches Buzz: Nostr-Based Slack/GitHub Alternative for Humans and AI

Block launches Buzz — a Nostr-based Slack/GitHub alternative built for humans and AI agents Block, the payments and software firm helmed by Jack Dorsey, has unveiled Buzz: a free, open-source group chat and collaboration platform where employees and autonomous AI agents share a single workspace. Announced on Twitter Tuesday, Dorsey described Buzz as “a new groupchat platform for teams of people and agents of all sizes,” designed to reduce Block’s reliance on Slack and GitHub. He called it “model-agnostic, decentralized, self-sovereign, and open source.” What Buzz does - Combines channels, threads, direct messages, voice, media sharing, code repositories and automated workflows in one interface meant to feel familiar to users of modern team chat tools. - Lets agents and humans operate side-by-side: agents can post, review code, run approved automations and contribute to conversations. Multiple humans and multiple agents can share a single workspace and build on each other’s work. - Gives each participant — human or agent — a cryptographic keypair so identity, history and reputation belong to the actor, not the platform. Nostr, identity and auditability Block built Buzz on Nostr to address identity in multi-agent collaboration. Every message, reaction, workflow step, review approval and git event is recorded as a single signed event in a hash-chain style log, allowing an auditable trail whether the author is a person or an automated process. Because identities are keypair-based and portable, an agent’s identity and reputation can travel across Nostr-compatible systems. Model- and agent-agnostic Buzz is intentionally model-agnostic. Teams can deploy agents backed by any LLM or agent framework — Block cites examples such as Anthropic’s Claude Code, OpenAI’s Codex, and goose (Block’s own open source agent framework released in January 2025). Agents can take CLI-level actions, create channels, update their memories and follow channel- or thread-specific rules set by users. Open source and deployment - Code is available under an Apache 2.0 license at github.com/block/buzz. - Teams can self-host or use Block’s managed hosting. - Buzz is at an early release (version 0.4.21) with desktop builds for macOS, Windows and Linux; mobile clients are still unfinished. A notable caveat: although Buzz emphasizes decentralization, each workspace currently runs on a single relay that the project calls its “single source of truth,” which concentrates the canonical state for that workspace. Built by agents, used to change workflows Block says it developed Buzz using agents internally. Bradley Axen, head of AI capabilities at Block, summarized the product’s mission by asking whether the workspace that mixes humans and agents will be proprietary or open. Lucas Isaza, on Block’s AI/product team, has argued that configurable workspaces free companies from tooling-imposed rituals (like sprint-centric Kanban baked into Asana or Jira), shifting the bottleneck to how teams choose to operate. Thomas Petersen, principal designer and AI strategist, said he rejoined Block to reshape the “lonely experience of working with AI agents” and that Buzz’s interface evolved by agent-driven iteration rather than being fully designed up front. Where this fits in Dorsey’s playbook Buzz extends Jack Dorsey’s ongoing push for open protocols and self-sovereign systems. Since leaving the Bluesky board in 2024, Dorsey has backed several Nostr-based and decentralized tools — including Bitchat and other projects he’s personally funded — and has supported nonprofits for open-source social tooling. The Buzz launch also arrives against a backdrop of major changes at Block: the company cut roughly 4,000 jobs in February (about 40% of staff), and Dorsey has framed AI as fundamentally changing how companies are built and run. Separately, Block continues to move deeper into crypto: it disclosed holdings of 28,355 BTC (~$2.2 billion at the time) in its proof-of-reserves report, and Cash App is moving toward integrating stablecoin support into its core flows. What to watch Buzz is early and experimental, but it surfaces several trends important to the crypto and web3 world: keypair-based, portable identities; cryptographically auditable collaboration; and the fusion of open protocols with AI-driven workflows. The single-relay workspace model will likely draw scrutiny from decentralization purists, while teams evaluating Buzz will be weighing the trade-offs between convenience and the degree of decentralization they require. Source: Block / Jack Dorsey / Block’s github repository (github.com/block/buzz).