Block has officially launched Buzz, a free, open-source workspace designed to facilitate collaboration between humans and artificial intelligence agents. This innovative platform leverages the decentralized messaging protocol Nostr, renowned for its censorship-resistant architecture, to provide a Slack-like environment where AI agents are treated as first-class participants. The launch marks a significant step for Block in its pursuit of integrating AI into everyday workflows, building upon its previous open-source contributions and internal AI initiatives.
Buzz’s foundation on Nostr is a strategic choice, aligning with Block founder Jack Dorsey’s long-standing support for decentralized technologies. Nostr’s inherent security and privacy features, rooted in cryptographic identity, allow each AI agent to possess its own unique digital signature, cryptographically linked to its human owner. This ensures accountability and transparency within collaborative sessions, a crucial aspect for professional development and team projects.
At its core, Buzz mirrors the familiar functionalities of popular communication tools like Slack and Discord, offering channels, threads, direct messaging, voice and media sharing, and even code repository integration. However, its distinguishing feature is the seamless integration of AI agents as active collaborators, not just passive tools. This allows teams to incorporate a diverse range of AI models and agent harnesses, including Claude Code, Codex, Block’s own "goose" agent framework, or custom-built solutions. The flexibility in agent integration means that development teams can select the AI tools best suited to their specific needs and project requirements, fostering a highly adaptable collaborative ecosystem.
The underlying code for Buzz has been publicly available on GitHub under an Apache 2.0 license since earlier this year, fostering transparency and community contribution. The recent launch signifies Block’s decision to host its own Nostr relay for Buzz, making public signups readily accessible. This move aims to lower the barrier to entry for users who may not wish to manage their own decentralized infrastructure.
The Genesis of Collaborative AI: Bridging the "Second Conversation"
Bradley Axen, Block’s head of AI capabilities, articulated the driving philosophy behind Buzz, emphasizing the often-overlooked "second conversation" in software development and other collaborative efforts. "Everyone misses that second conversation, and at least for building software, that’s where the conversation is really interesting. That’s where you make all the technical decisions," Axen stated in an interview with The New Stack.
He elaborated on the current paradigm, where human-AI collaboration often involves isolated work sessions followed by the manual integration of AI-generated output. "Right now, you’ll make a post, you’ll go work by yourself for an hour with an agent, and then you’ll maybe copy and paste something the agent said back in as if it’s from you," Axen explained. Buzz aims to transform this by enabling a continuous, back-and-forth dialogue between humans and AI agents within a shared workspace, thereby capturing the nuances and critical decision-making processes that occur during these iterative exchanges. This direct integration of AI into the conversational flow is intended to accelerate problem-solving and enhance the quality of collaborative outcomes.
An Identity of Its Own: Decentralized Agents with Human Anchors
The architecture of Buzz on Nostr is built around cryptographic identity. Each participant, whether human or AI agent, is represented by a public-private keypair. Buzz assigns each agent its own unique keypair, establishing it as an independent entity within the network. Crucially, this agent identity is then linked to a human owner through a secondary cryptographic signature.
"It starts like a human. It’s just got its own public key, and it signs events, and then there’s one extra message that we publish on the relay," Axen described. "We’ve got this cryptographic paper trail that neither of us could have done alone that says, okay, this is my agent, and anyone else can review and confirm that that’s true." This verifiable link between an agent and its human owner is fundamental to establishing trust and accountability within the Buzz ecosystem.
This unique identity scheme enables Buzz to enforce granular access controls and permissions. For instance, private channels can be configured to allow only agents owned by specific members to participate, ensuring the security and integrity of sensitive discussions and project data. Block has submitted this proposed identity extension to the Nostr protocol for upstream consideration, aiming to standardize this crucial feature across the decentralized messaging landscape.
The integration of agents into Buzz is facilitated by the Agent Client Protocol (ACP), an open standard introduced by Zed last year. ACP provides a robust framework for connecting coding agents to various tools and applications. Axen’s involvement in the steering committee of the Linux Foundation’s Agentic AI Foundation suggests a potential future where ACP could be adopted and further developed under the foundation’s umbrella, promoting broader interoperability within the agentic AI community.
"A Relay You Own": Decentralized Infrastructure and Hosted Solutions
Buzz’s functionality hinges on Nostr relays, which act as servers for message propagation. While any team can deploy and manage their own Nostr relay, providing complete control over their infrastructure and ensuring no data is routed through Block, the company has also recognized the operational overhead associated with self-hosting.
Axen drew an analogy to Discord servers, highlighting that Buzz offers a similar collaborative space but without a single corporate owner. To cater to the majority of users who prefer a plug-and-play experience, Block has developed a hosted relay option. "I’m really excited that you can [run your own relay], but I think the majority of people just want an off-the-shelf solution," Axen commented.
The hosted relays are being offered free of charge as part of a beta program. While usage limits have not yet been defined, Axen indicated that hosting for small, open-source projects would be cost-effective. However, for organizations seeking a robust replacement for "enterprise-grade Slack," different hosting arrangements and potential pricing models would likely be necessary in the future, reflecting the scalability and resource demands of large-scale deployments. This tiered approach acknowledges the diverse needs of users, from individual developers to large enterprises.
From Goose to BuilderBot: Block’s Evolution in AI Development
Buzz is not Block’s inaugural foray into AI agent development. The company previously open-sourced "goose," its agent framework, in January 2025, which has since garnered significant traction with over 50,000 stars on GitHub. This demonstrates Block’s commitment to fostering open innovation in the AI space.
Internally, Block has also developed "BuilderBot," an AI system that engineers can summon directly within Slack. This sophisticated internal tool reportedly handles over 200,000 operations daily, contributes to the merging of approximately 1,500 pull requests each week, and accounts for roughly 15% of Block’s production code changes. The success of BuilderBot underscores the tangible benefits of integrating AI agents into core development workflows, driving efficiency and accelerating innovation. This internal success story serves as a powerful testament to the potential of agent-based collaboration.
Living Alongside Slack: A Complementary Future for Collaboration Tools
Block acknowledges that it is not alone in its efforts to integrate AI agents into existing team workflows. Companies like Atlassian have begun embedding agents within Jira, and numerous organizations are deploying coding agents within Slack. Block itself continues to utilize Slack internally. Axen posits that Buzz is not necessarily positioned as a direct replacement for Slack but rather as a complementary tool.
"Can it be a full replacement for Slack? We’ll have to see over time, because Slack also encodes a lot of business workflows," Axen noted. "We’ve got a decade of history in Slack." This pragmatic view suggests that Buzz’s initial impact may be in specific use cases, particularly those involving intensive AI collaboration, while Slack continues to serve its role in broader organizational communication and workflow management.
The Buzz repository, though public for some time, has garnered just over 100 stars, indicating it is still in its nascent stages compared to the widespread adoption of "goose." The launch of Buzz occurs against the backdrop of Block’s significant organizational transformation. In February, the company underwent a substantial workforce reduction, cutting over 40% of its employees. CEO Jack Dorsey cited AI as a catalyst for a "new way of working," signaling a strategic pivot towards a more AI-centric operational model. Buzz represents the crucial collaboration layer Block is architecting for this evolving, agent-augmented workforce, aiming to empower a leaner, more agile organization driven by intelligent automation. The platform’s success will likely depend on its ability to demonstrate clear value propositions that differentiate it from established communication tools while fostering a thriving community of developers and users.
