Is the Codebase Design skill free?

Yes. The skill itself is free from mxyhi/ok-skills. SkillProof publishes the install command and an independent test verdict at no cost.

What is the Codebase Design SkillProof Score?

9.2/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 8/10, docs & honesty 5/5.

How do I install Codebase Design?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use Codebase Design with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

Codebase Design

Shared vocabulary for designing deep modules: interfaces, seams, adapters, testability

by mxyhi · mxyhi/ok-skills

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 9.2/10
Tested: Jul 21, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · 16620c2

Fetched all three files raw (SKILL.md, DEEPENING.md, DESIGN-IT-TWICE.md all HTTP 200); frontmatter parses with name+description, no scripts, no security smells. Ran a real design task in-context — "design the interface for a rate-limiter guarding a third-party API" — producing a baseline artifact and a skill-following artifact. Concrete difference: baseline exposed a 4-method Redis-coupled class (tryAcquire/getRemaining/reset/setLimit); the skill version collapsed the caller surface to one guard(key, action) entry point, classified Redis as category-2 local-substitutable vs the SMS API as category-4 true-external, and applied "two adapters = real seam" to keep the store port while hiding the clock as an internal seam. The skill body measurably reshaped the design rather than just being quoted back.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 8/10
Docs & honesty 5/5

What Codebase Design does

A vocabulary-and-principles skill for designing deep modules — a lot of behaviour behind a small interface, placed at a clean seam and tested through that interface. It triggers when the user wants to design or improve a module's interface, decide where a seam goes, classify dependencies for testing, or make code more testable. Two supporting files add a deepening workflow (dependency categories, replace-don't-layer testing) and a parallel sub-agent "design it twice" process.

How to install Codebase Design

git clone --depth 1 https://github.com/mxyhi/ok-skills.git /tmp/codebase-design-src
mkdir -p ~/.claude/skills
cp -R /tmp/codebase-design-src/codebase-design ~/.claude/skills/codebase-design
# Pure markdown skill: SKILL.md + DEEPENING.md + DESIGN-IT-TWICE.md. No deps, scripts, or API keys.
# DESIGN-IT-TWICE.md references a project-local CONTEXT.md (your own domain vocab) which is not shipped and is optional.

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger Codebase Design

/codebase-design Shared vocabulary for designing deep modules: interfaces, seams, adapters, testability

It also activates on plain-language prompts like these:

Help me design a deeper interface for this module
Find deepening opportunities in this class
Decide where the seam should go in this code

Frequently asked questions

Is the Codebase Design skill free?: Yes. The skill itself is free from mxyhi/ok-skills. SkillProof publishes the install command and an independent test verdict at no cost.
Does Codebase Design work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 21, 2026. Verdict: Tested · Works. Fetched all three files raw (SKILL.md, DEEPENING.md, DESIGN-IT-TWICE.md all HTTP 200); frontmatter parses with name+description, no scripts, no security smells. Ran a real design task in-context — "design the interface for a rate-limiter guarding a third-party API" — producing a baseline artifact and a skill-following artifact. Concrete difference: baseline exposed a 4-method Redis-coupled class (tryAcquire/getRemaining/reset/setLimit); the skill version collapsed the caller surface to one guard(key, action) entry point, classified Redis as category-2 local-substitutable vs the SMS API as category-4 true-external, and applied "two adapters = real seam" to keep the store port while hiding the clock as an internal seam. The skill body measurably reshaped the design rather than just being quoted back.
What is the Codebase Design SkillProof Score?: 9.2/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 8/10, docs & honesty 5/5.
How do I install Codebase Design?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use Codebase Design with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.