---
id: "anthropic-effective-harnesses-long-running-agents"
title: "Effective harnesses for long-running agents"
creator: "Anthropic"
url: "https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents"
level: "advanced"
category: "agents"
models: ["claude"]
source_date: "2025-11-26"
date_added: "2026-10-18"
---

[Agents and harnesses](/agents/index.md)

# Effective harnesses for long-running agents

by Anthropic

[Read the original →](https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents)

Harness design for agents that work across many context windows.

This article addresses continuity when an agent's work spans multiple context windows. It focuses attention on the surrounding execution setup rather than assuming a larger prompt will solve persistence problems.

Level: [Advanced](/levels/index.md#advanced)
Models: claude
Category: [Agents and harnesses](/agents/index.md)
Tags: [harness](/tags/harness/index.md)
Source date: 2025-11-26
Added: 2026-10-18
Last verified: 2026-10-18
Status: ok

Summary in our own words. All rights with the original creator. Correction or removal: DM on X.