actionable ai

Free guide

It's not the model. It's the harness.

Everyone obsesses over smarter AI. The people shipping AI that actually works obsess over the harness, the layer around the model that makes it reliable. Here's what it is and how to build one.

  • Why capable agents still fail, and why it's almost never the model
  • The 5 parts of a harness, in plain English
  • Copy-ready templates: CLAUDE.md, progress file, evaluator rubric
  • The free WalkingLabs course + a skill that builds the harness for you

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The full harness playbook: why agents fail, the 5 parts of a harness, the templates to steal, and the free course.

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A look inside

What's inside

01

What You'll Learn

Why capable agents still fail, and why it's almost never the model The 5 parts of a harness, in plain English The exact templates to copy: CLAUDE.md, progress file, evaluator The free course plus a skill that builds the harness for you

02

The Big Idea

An agent is the model plus the harness.

03

Why Your Agent Keeps Failing

It's almost never that the model isn't smart enough.

About the author

Cooper Simson

Founder of Actionable AI. 30,000+ operators read the newsletter.

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No. The guide explains the work in practical steps and calls out technical details only when they matter.

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