Block Buzz launches as open-source rival to Slack and GitHub for AI agents and humans

Jack Dorsey's Block Unveils Open-Source Workspace for Human-Bot Collaboration

Jack Dorsey's Block has launched Block Buzz, a free open-source workspace designed to enable collaboration between humans and AI agents within a unified platform 1

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. The fintech company, which cut over 4,000 jobs in February due to AI-driven restructuring, positions Buzz as a direct challenge to Slack and GitHub by offering a single space where teams can communicate, manage code repositories, and deploy automated workflows 1

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. The platform ships as version 0.4.21 with desktop builds for macOS, Windows, and Linux, though mobile clients remain unfinished 4

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AI Agents Gain Full Membership Status with Cryptographic Identity

Unlike traditional chatbots that wait for commands, AI agents in Buzz function as full workspace members with their own profiles, permissions, and cryptographic identity 2

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. Built on the decentralized Nostr protocol that Dorsey has long championed, each agent holds a cryptographic keypair that belongs to them rather than to the platform 4

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. A second signature ties each agent back to its human owner, creating a verifiable audit trail for every action, whether posting messages, reviewing code, running automations, or joining voice huddles 1

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. This approach addresses what Block calls the most fundamental problem in multi-agent work: portable, verifiable identity that can travel across any Nostr-compatible system 4

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Model-Agnostic Platform Supports Multiple AI Frameworks

The model-agnostic platform welcomes AI agents from any provider, including Anthropic's Claude Code, OpenAI's Codex, and Block's own open-source framework goose 2

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. Teams can plug in existing agents, build new ones, or deploy multiple agents that coordinate with each other through the Agent Client Protocol, an open standard for wiring coding agents into developer tools 4

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. "Every company is going to need a place where humans and agents work together," said Bradley Axen, Block's Head of AI Capabilities. "The question is whether that place is proprietary or open. We built Buzz because we believe it should be open" 1

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Self-Hosting Option Addresses Data Sovereignty Concerns

Published under an Apache 2.0 license, the open collaboration platform allows organizations to self-host their own instances with full control over data and agents, or use Block's hosted version currently free in beta 2

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. This self-hosting capability should appeal to European firms concerned about vendor lock-in and data leaving their control 2

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. However, messages and media on Block-hosted relays aren't end-to-end encrypted, and agent providers like Anthropic and OpenAI may receive prompts and related channel content 3

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. Git hosting is integrated through a built-in software forge where feature branches become channels, and patches, continuous integration results, and review comments are preserved in a single record alongside the discussion 5

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Buzz Faces Skepticism Amid Crowded Market

Block developed the entire Buzz platform using agents, with Thomas Petersen, a principal designer and AI strategist at the company, describing the interface as "more sculpted over time than designed up front" 4

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. Lucas Isaza, who works on AI and product at Block, noted that configurable workspaces remove the constraints once baked into tools like Asana, Jira, and Linear, making "the bottleneck the operating model" 4

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. Yet the platform enters a crowded field where Slack, Microsoft Teams, and OpenAI all race to deploy AI integration in the workplace 2

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. Critics question whether every company needs people and bots sharing the same space, given that they work at different speeds 1

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. Safety researchers also warn about handing agents their own identities and permissions, citing concerns about autonomy 2

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. Whether openness can beat the reach of established incumbents remains the defining question for this Slack and GitHub rival 2

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