Long-Horizon Agents: A Technical Primer on METR Doubling Trends

agihouse_org · x · 2026-08-21

A Technical Primer on Long-Horizon Agents

The article traces how frontier models' autonomous task length has evolved: in 2022, a frontier model could only handle seconds of human-equivalent work, while today's leading agents sustain tasks that take a person hours — and per METR's measurements, the interval over which that horizon doubles is itself shrinking.

Sequoia's January 2026 essay "2026: This is AGI" (Pat Grady and Sonya Huang) distilled the commercial stakes: an agent that can hold a goal across a workday is an agent you can hire, with coding agents as the first instance and vertical specialists as the template.

Between the measurement and the thesis sits an engineering question: what it takes — in models, infrastructure, and evaluation — for an agent to carry a goal through hours of autonomous work reliably rather than half the time. That is the subject of this primer.

Related event: The Evolution of Long-Horizon AI Agents: From Seconds to Hours(3 posts)→

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