Block Launches Buzz, PromptQL Raises $136M to Take on Slack

Block shipped Buzz on July 21, a free, open-source chat app built on the Nostr protocol, per TechCrunch. Dorsey said he built it "to reduce our dependency on slack and github." The stakes: whoever owns agent identity in chat owns which agents can act for a team, not just the workspace.

Two days later PromptQL landed at #4 on Product Hunt under the tagline "Multiplayer AI that replaces Slack." PromptQL is Hasura's pivot, the open-source GraphQL engine team's second act as a shared AI hub connected to databases, SaaS apps, and coding agents. Founder Tanmai Gopal posted that the company raised $136M "to kill Slack," per Product Hunt.

Slack's answer runs the other way. It's turning Slackbot into an MCP client that folds outside AI tools into the workspace instead of sending users elsewhere, per No Jitter.

In Buzz, agents post, review code, and run approved automations as participants, not as integrations firing into a channel. Slack is betting that architecture doesn't matter if nobody leaves the workspace where their coworkers already are. Neither side has won yet.

The same pattern shows up across Product Hunt's July 23 leaderboard. Six of the top ten launches that day replace a category tool with an agent instead of adding AI to one. The list: Teable for spreadsheets, PromptQL for chat, AskCodi for orchestration, RunEvr for project management, Moxie Docs for documentation, and Quaso for automation.

Not one of them pitches "X with AI" anymore. Buzz's open protocol matters more than its fight with Slack: owning agent identity that works across every chat app beats owning one more chat app. Nostr's cryptographic identities are the closest thing on the table to that. Slack has never lost a chat war on architecture, only on where people already are, but this one isn't really about chat. Watch whether Buzz's identity layer gets used outside Buzz itself, since that's the real test, not whether it beats Slack head to head.