# Harness Engineering

Should be used when designing autonomous agent harnesses: research loops, evaluation...

- Repository: https://github.com/muratcankoylan/Agent-Skills-for-Context-Engineering (18272 stars)
- Category: Design
- License: MIT
- Last updated: 2026-10-12
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add muratcankoylan/Agent-Skills-for-Context-Engineering --skill harness-engineering -g -a claude-code -y`
Codex: `npx skills add muratcankoylan/Agent-Skills-for-Context-Engineering --skill harness-engineering -g -a codex -y`
Cursor: `npx skills add muratcankoylan/Agent-Skills-for-Context-Engineering --skill harness-engineering -g -a cursor -y`
Gemini CLI: `npx skills add muratcankoylan/Agent-Skills-for-Context-Engineering --skill harness-engineering -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add muratcankoylan/Agent-Skills-for-Context-Engineering`

## Description

This skill should be used when designing autonomous agent harnesses: research loops, evaluation scaffolds, locked and editable surfaces, durable logs, novelty gates, pruning, rollback, PR preparation, and human approval boundaries.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Harness Engineering

Harness engineering designs the control system around an agent: what it may edit, how it receives feedback, where it writes state, how failures recover, and who can approve irreversible actions. The harness is the difference between a helpful agent session and an autonomous loop that can run for days without corrupting its objective.

## When to Activate

Activate this skill when:

- Building autonomous research or experimentation loops
- Designing an agent environment with locked metrics and editable code or content
- Creating PR-producing or background agents
- Evaluating whether an agent can safely run without frequent human prompts
- Adding novelty, ablation, pruning, rollback, or durable logging to an agent workflow
- Preventing agents from gaming benchmarks, weakening rubrics, or losing state across compaction

Do not activate this skill for adjacent work owned by other skills:
- General quality gates, regression suites, or outcome metrics without autonomous control surfaces: `evaluation`.
- Tool schemas, response formats, and recovery errors for harness tools: `tool-design`.
- Project-level task-model fit, pipeline shape, and cost planning: `project-development`.
- Remote sandbox, warm-pool, and hosted session infrastructure: `hosted-agents`.

## Core Concepts

### Harness Boundary

Separate the agent from the environment it operates inside. The agent proposes actions; the harness defines allowed surfaces, feedback, persistence, and promotion rules.

Use four surface classes:

The rest: https://github.com/muratcankoylan/Agent-Skills-for-Context-Engineering/blob/HEAD/skills/harness-engineering/SKILL.md