Astro Creator Ships Flue 2, Agents as React Hooks

Fred Schott shipped Flue 2, the first stable release of his agent framework. In a Latent Space interview published August 15, Schott said there's no agent without a harness. The distinction decides how developers build agents. A harness-first framework lets an agent change its own state and capabilities mid-run, not just call a fixed set of tools.

Schott built Astro, the web framework Cloudflare acquired in January 2026. Flue 2 carries the same instinct into agent tooling.

The design borrows straight from React. Agents in Flue 2 are plain JavaScript functions that re-render on every turn, before each model call goes out. Sixteen built-in TypeScript hooks, including useSkill(), useTool(), and useSubagent(), let an agent manage its state, subscribe to lifecycle events, and attach capabilities while it runs. That's a different mental model than a fixed prompt template that calls tools and waits.

The contrast Schott draws matters more than the hook count. Vercel's AI SDK and Cloudflare's own Agents SDK both started as model-calling libraries and added harness features afterward. Flue 2 starts from the harness and treats the model loop as one piece inside it. If Schott is right, frameworks that added the harness as a layer on top will keep catching up.

Related coverage found five vendors shipping gateways that meter agent traffic between apps and models, and three vendors flipping permission automation from opt-in to default. Harnesses, gateways, and permissions are converging on one question: who controls what an agent does mid-run, not just what it says. Flue 2 answers with hooks instead of middleware.

The interview doesn't say how Flue 2 handles cost or latency when it re-renders every turn. That matters for anyone running agents at scale, not just in a demo.