eval-harness

Define and run formal evaluation suites for AI-driven code changes.

Updated Aug 27, 2026
One-click install
npx skills add https://github.com/JGcode3675/gcs-os --skill eval-harness-jgcode3675
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: eval-harness
Source: https://github.com/JGcode3675/gcs-os/tree/main/home/james/claude-config/skills/eval-harness
Command: npx skills add https://github.com/JGcode3675/gcs-os --skill eval-harness-jgcode3675

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Provides a structured way to define, run, and track evaluations for Claude Code sessions so teams can catch regressions, measure reliability with pass@k metrics, and require clear success criteria before shipping changes.

Core Features & Use Cases

  • Eval-Driven Development: Define capability and regression evals before implementation to clarify expected behavior.
  • Multi-Modal Grading: Support deterministic code-based graders, model-based graders for open-ended outputs, and human review flags for high-risk changes.
  • Metrics & Reporting: Track pass@k and pass^k over time, store eval definitions and run history, and generate per-feature eval reports for CI and release decisions.
  • Integration Patterns: Create, check, and report evals from developer workflows and store artifacts under .claude/evals for versioning alongside code.

Quick Start

Use the eval harness to define, run, and report evals for feature-xyz and store results in .claude/evals.

Frequently Asked Questions about eval-harness

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I set up regression testing for AI-generated code in Claude Code?

Regression testing for Claude Code is handled by defining formal evaluation suites that validate features and detect regressions. You define capability and regression evals before implementation to clarify expected behavior and track success criteria.

What is eval-driven development and how does it measure AI code reliability?

Eval-driven development defines capability and regression evals before implementation to clarify expected behavior. It measures AI code reliability using pass@k metrics, applying formal evaluation suites to validate changes and track success criteria over time.

How do I run deterministic and model-based graders for code evaluation?

Code evaluation supports multi-modal grading by applying deterministic shell-compatible code-based graders for automated checks, model-based graders for open-ended outputs, and human review flags for high-risk changes to validate AI-driven code.

Can I store evaluation run history and artifacts alongside my code repository?

Yes, evaluation definitions and run history are stored as artifacts under the .claude/evals directory. This allows you to version evals alongside your code and generate per-feature reports for CI and release decisions.

What's the best way to measure pass@k reliability during continuous integration?

The best way to measure pass@k reliability during CI is to run formal evaluation suites that track pass@k and pass^k metrics over time. The framework generates per-feature eval reports to inform automated release decisions.

When should I not use automated grading for AI code changes?

Automated grading should be supplemented or avoided for high-risk changes where deterministic checks are insufficient. The framework supports human review flags to manually grade open-ended outputs that model-based or code-based graders cannot reliably evaluate.