# Flue

> **TL;DR.** Flue is an open-source TypeScript framework for building autonomous agents, positioned as "The Agent Harness Framework" — not another AI SDK, but infrastructure that wraps models with a programmable harness, virtual sandbox, and deployment pipeline.

- **Category:** AI / Developer Tools / Agent Frameworks
- **Stage:** validating
- **Age:** 46 days
- **Origin date:** 2026-05-01
- **First detected:** 2026-05-02
- **Canonical URL:** https://earlyterms.com/term/flue
- **Sources:** 6 primary URLs

## Definition

Flue is an open-source TypeScript framework for building autonomous agents, positioned as "The Agent Harness Framework" — not another AI SDK, but infrastructure that wraps models with a programmable harness, virtual sandbox, and deployment pipeline.

Astro co-founder [Fred K. Schott](https://x.com/FredKSchott/status/2050274923852210397) launched Flue publicly on May 1, 2026, pitching it as "like Claude Code, but 100% headless and programmable." The [withastro/flue](https://github.com/withastro/flue) GitHub repo reached 1.7k stars within days, touching off debate on Hacker News about how it differs from Mastra and whether the TypeScript agent framework moment has arrived.

## Analogy

Think of it as Next.js but for agents — a conventions-over-configuration runtime, not a bare SDK.

## Why it's emerging now

Cloudflare acquired the Astro team in January 2026, then Fred K. Schott shipped Flue in February (stealth) and went public May 1. The timing follows the broader 2026 agent-framework consolidation: developers want Next.js-style conventions for agent projects, not low-level SDK assembly.

## Related terms

- *parent:* Agent Harness
- *parent:* Agentic Frameworks
- *related:* Managed Agents
- *related:* Claude Code
- *related:* Claude Agent SDK
- *competitor:* Hermes Agent
- *related:* Workspace Agent
- *related:* Coding Agents
- *related:* AGENTS.md
- *competitor:* Mastra

## Sources

1. [withastro/flue — GitHub repository (1.7k stars)](https://github.com/withastro/flue)
2. [Flue official site — The Agent Harness Framework](https://flueframework.com/)
3. [Fred K. Schott on X — Introducing Flue launch announcement](https://x.com/FredKSchott/status/2050274923852210397)
4. [Hacker News — Flue is a TypeScript framework for building the next generation of agents (84 points)](https://news.ycombinator.com/item?id=47988501)
5. [Astro Weekly #123 — Flue: The Sandbox Agent Framework](https://newsletter.astroweekly.dev/p/astro-weekly-123)
6. [Cloudflare Blog — Astro joins Cloudflare (Jan 16, 2026)](https://blog.cloudflare.com/astro-joins-cloudflare/)

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_Generated by EarlyTerms · https://earlyterms.com/term/flue_