17 August 2026
New AI agent frameworks built around harness from start
- Newer frameworks like Flue and Vercel's eve make the harness, a central control layer for AI agents, their main architectural feature rather than adding it later.
- Older frameworks including Vercel's AI SDK and Cloudflare's Agents SDK added harness functionality after their initial release as an extra component.
- Building the harness in from the beginning changes how developers structure their agent systems, according to observations by Schott.
How it was covered
Latent Spaceswyx & Alessio
Early-stage agent frameworks like Flue and Vercel's eve are treating the harness as a core component rather than an add-on feature, differentiating them from older frameworks like Vercel's AI SDK and Cloudflare's Agents SDK that are adding harnesses after launch. Schott argues this foundational approach matters for how agents are architected.