harness_engineering

Name: harness_engineering
Author: Nicolepcx

Verified

This is the corresponding code for the O'Reilly book: Harness Engineering

113stars

29forks

Jupyter Notebook

Installation

# Add to your Claude Code skills
git clone https://github.com/Nicolepcx/harness_engineering

Getting Started

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Security ReportVerified

Last scanned: 9/4/2026

{
  "issues": [],
  "status": "PASSED",
  "scannedAt": "2026-09-04T08:38:23.578Z",
  "npmAuditRan": true,
  "pipAuditRan": true,
  "promptInjectionRan": true
}

README.md

Frequently Asked Questions

What is harness_engineering?

harness_engineering is an open-source ai agents skill for AI coding assistants such as Claude Code, Codex CLI, and ChatGPT, built by Nicolepcx. This is the corresponding code for the O'Reilly book: Harness Engineering. It has 113 GitHub stars.

Is harness_engineering safe to use?

Yes. harness_engineering passed SkillsLLM's automated security scan — a dependency vulnerability audit plus prompt-injection heuristics — with no high-severity issues. You can read the full report in the Security Report section on this page.

How do I install harness_engineering?

Clone the repository with "git clone https://github.com/Nicolepcx/harness_engineering" and add it to your Claude Code skills directory (see the Installation section above).

What programming language is harness_engineering written in?

harness_engineering is primarily written in Jupyter Notebook. It is open-source under Nicolepcx on GitHub, so you can review or fork the full source.

Are there alternatives to harness_engineering?

Yes. SkillsLLM lists many other AI Agents skills you can browse and compare side by side. Open the AI Agents category from the badge at the top of this page, or use the Related Skills and comparison links further down to weigh harness_engineering against similar tools.

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⚠️ Third-Party Software Notice

This skill is third-party open-source software developed and hosted independently on GitHub. SkillsLLM is an informational directory and does not control or maintain the underlying repository.

Any security checks, ratings, or warnings displayed by SkillsLLM are automated and limited in scope. They do not constitute a security certification or guarantee that the software is safe, error-free, or free from malicious code, vulnerabilities, compromised dependencies, or prompt-injection risks.

Review the source code, permissions, dependencies, and configuration before installing or running any third-party skill. Use is at your own risk. To the maximum extent permitted by applicable law, SkillsLLM is not liable for losses arising from third-party software.

Read the Terms of Service

⭐ If you find this repository helpful, please consider giving it a ⭐ here on GitHub (click the star button in the top right corner) It's a quick way to show support for this openly available code. ⭐

Harness Engineering

This is the corresponding code for the book Harness Engineering: Optimization, Coordination, and Adaptive Agentic Systems.

Chapter 1 Why Harness Engineering Matters
Chapter 2 The Harness as the Agent System Substrate
Chapter 3 Skills, Instructions, and Runtime Scaffolding
Chapter 4 Context-Scoped Skill Compilation
Chapter 5 Agent Identity: The Durable Boundary
Chapter 6 The Action Surface: Tools, Sandboxes, and Capability Scoping
Chapter 7 Coordination as State: Why Multi-Agents Systems Fail at the Handoff Layer
Chapter 8 Observability, Traces, and Harness Telemetry
Chapter 9 Harness Optimization Patterns
Chapter 10 Learning the Harness: RL over Skills, Routes, and Signals
Chapter 11 Teaching the Harness to Evolve: Skill Internalization and Latent Coordination
Chapter 12 Governance, Trust Boundaries, and the Harness in Production

Instructions and Navigation

All of the code is organized into folders. Each folder starts with CH followed by the chapter number. For example, CH01. The notebooks are then organized as follows: ch01_prompt_context_harness_progression.ipynb, where ch01 indicates the chapter and prompt_context_harness_progression what is done in the notebook.

Repo structure

├── LICENSE
├── README.md             <- The top-level README for developers using this project.
├── CH01                  <- Per chapter folder with Jupyter notebooks.
    ├── [name].ipynb      <- Jupyter notebooks with naming as mentioned above.
├── CH02                  <- Per chapter folder with Jupyter notebooks.
...                       <- Same structure for all chapters.
├── utils                 <- Custom classes and functions and utility functions.
├── resources             <- Some miscellaneous resources.

Running the Notebooks

Every notebook can be opened and run on Google Colab directly from the links below. Just click the Open In Colab badge next to the notebook you want to run.

Chapter 1 — Why Harness Engineering Matters

Notebook	Colab
Prompt & Context Harness Progression

Chapter 2 — The Harness as the Agent System Substrate

Notebook	Colab
Harness Components
State Across Execution Boundaries

NOTE: You may need to run the notebooks with a GPU.