Validation Harness Design

Overview

Define the smallest repeatable command surface that proves repository changes are safe enough for review.

This skill turns scattered checks into commands agents can run, CI can reuse, and failures can diagnose. For shared harness terms, see ../../references/harness-patterns.md; when validation commands are absent, use references/build-when-missing.md. For setup probes and CI-safe fallbacks, see references/environment-bootstrap.md.

When To Use

• The user wants check_repo_harness.py, doctor.py, a test matrix, or CI gates.
• Existing validation commands are scattered and agents do not know what to run for docs-only, interface, service, logic, or runtime changes.
• JSON, JUnit, or artifact output is needed.

Inputs Needed

• Project shape, main surfaces, existing test commands, and CI configuration.
• Change types and the minimum gate for each type.
• Whether runtime, packaged-environment, external-dependency, or manual checks are needed.