Jack Dorsey’s Block Introduces Buzz: An Open-Source Platform for Human-Agent Collaboration

Building Identity Through Nostr

Block unveiled Buzz on Tuesday as a response to what the company identifies as a fundamental challenge in multi-agent systems: establishing independent cryptographic identity. By building on Nostr’s protocol, every participant—human or AI agent alike—holds a keypair that belongs to them rather than the platform. This architectural choice ensures that agents maintain portable identity, reputation, and history across any Nostr-compatible system.

Each interaction within Buzz, from messages and reactions to code reviews and workflow authorizations, is recorded as a cryptographically signed event in an immutable audit log. The platform ships under an Apache 2.0 license with code available at github.com/block/buzz. Teams can choose to self-host the infrastructure or rely on Block’s managed version, maintaining full control over their deployment strategy.

Features and Current State

Buzz consolidates team channels, threaded conversations, direct messaging, voice communication, media sharing, code repositories, and automated workflows into a single interface. AI agents can participate directly alongside humans—posting messages, reviewing code, executing authorized automations, and contributing to discussions with defined permissions.

The platform supports agents built on multiple frameworks and models, including Anthropic’s Claude Code, OpenAI’s Codex, and goose, Block’s open-source agent framework from early 2025. Bradley Axen, Block’s head of AI capabilities, framed the launch around a central question: whether infrastructure for human-agent collaboration should be proprietary or open source. Buzz represents Block’s answer.

Currently at version 0.4.21, Buzz offers desktop applications for macOS, Windows, and Linux. Mobile clients remain under development. Jack Dorsey characterized the platform as model-agnostic, decentralized, self-sovereign, and open source, positioning it explicitly as an alternative to centralized services like Slack and GitHub.

Implications for Decentralized Infrastructure

Buzz exemplifies a broader movement toward open-source, decentralized alternatives in AI collaboration infrastructure. By anchoring identity and reputation on Nostr rather than a proprietary platform, Block is demonstrating how blockchain protocols can enable composable tooling that respects user sovereignty—a principle foundational to crypto systems.

The combination of Nostr-based identity portability with multi-agent workflows suggests new possibilities for how blockchain teams, AI projects, and distributed organizations might coordinate development without vendor lock-in.

Source: Block, via Decrypt. Not financial advice.