Why I Built a Claude Code Playbook for WordPress

I keep my Claude Code rules for WordPress in one public GitHub repo, and every machine I use pulls it at the start of the next session. I built it because my rules kept drifting between projects and costing tokens I didn't need to spend.

This post covers why I made the AI Dev Standards & Playbook, what's in it, and how it changed the way I work with Claude Code.

TL;DR

• One repo holds my coding standards, SEO rules, writing voice, reference docs, slash commands, a reviewer agent and a deploy kit.
• Only one rule is always on, and it's under 1 KB. Everything else loads by file path or when a skill is used.
• A SessionStart hook pulls main and reinstalls on every new Claude Code session, so one merge updates every machine.
• The repo is public and generic. Client facts stay in each project's own CLAUDE.md.
• Repo: github.com/matthummel-pa/ai-dev-standards-playbook
• Docs: matthummel-pa.github.io/ai-dev-standards-playbook

Why did I build a Claude Code playbook?

Two problems.

1. My rules lived inside one theme repo, so they didn't follow me to the next client.
2. They were all always on, so every session paid for every line whether it needed them or not.

When I pulled the rules out of my matthummel.com theme, I had ten always-on rule files. Together they were about 60 KB, loaded into every session. Most of it was WordPress and Sage detail that only matters when I'm editing a PHP or Blade file. Claude Code loads rules at session start, so that 60 KB rode along even when I was writing a blog post.

The fix was to split by trigger. The core rule is now 0.9 KB. The rest only load when Claude touches a matching file or picks a skill. Same standards, a fraction of the context.

What tipped me over was typing the same prompts again and again. Every new session started with me pasting the same security rules, the same accessibility checks and the same "answer first" note. Each of those prompts counted against my credits.

I wanted the rules to already be there, and I wanted the always-on part as small as possible so each session cost less.

How does the playbook load into Claude Code?

Claude Code reads rules, skills and commands from ~/.claude, and a SessionStart hook can run a script before each session. The playbook uses both.

install.sh copies the repo into ~/.claude once and adds the hook. From then on, every new session runs sync.sh, which does a git pull --ff-only and recopies the files. If nothing changed, it prints nothing.

I use copies, not symlinks, on purpose. Symlinks need Developer Mode on Windows, and Claude Code loads ~/.claude/rules/ without an approval prompt when the files are plain copies.

One catch: rules load at session start, so a merge shows up in the session after the one that pulled it. When I want it right away, I run sync.sh by hand and restart.

Here's how the layers fit together:

Layer	Loads	Use it for
rules/core.md	Every session	5 to 10 lines that are true everywhere
Path rules (paths: in frontmatter)	When Claude reads or edits a matching file	Coding standards per file type
Skills (SKILL.md)	Description always; body only when used	Long playbooks: writing, SEO, architecture
Commands (/pb:…)	Only when I type them	Repeatable workflows
Project CLAUDE.md	Every session in that repo	Project facts, commands, hard no's

What's in the repo?

Eight folders. Here's what each one does and when it loads.

Rules

core.md is the only always-on file. It covers:

• Answer first
• Work on a branch
• Read before editing
• Sanitize and escape
• WCAG 2.1 AA
• Never invent metrics
• Verify versioned APIs against official docs

The other rules load by path:

• WordPress rules: *.php, theme.json and block.json
• Sage rules: app/, resources/ and vite.config.js
• SEO rules: Blade templates and SEO code

Skills

A skill is a folder with a SKILL.md that Claude loads on demand. I have six so far:

• doc-references: the official docs for my stack (WordPress Developer Resources, Roots, Tailwind, MDN, the WHATWG HTML spec, W3C and the ARIA APG, web.dev, caniuse, TypeScript, React, Next.js, Node, NestJS) and a rule to check them before writing code against an API I haven't verified that session.
• content-writer: my editorial voice and readability rules for posts and site copy.
• growth-design: landing page, conversion copy and design review guidance.
• portfolio-seo: on-page limits for portfolio and service pages.
• geo-blog-post: blog structure for Google AI Overviews and LLM search.
• sage-architecture: ACF Pro fields registered in PHP, a Customizer dark-mode default, the Tailwind v4 and theme.json token bridge, and CI/CD for built themes.

Commands, agent and hook

I have five slash commands, namespaced so they never shadow a project's own:

• /pb:new-project
• /pb:plan
• /pb:fix
• /pb:review
• /pb:ship

The wp-reviewer agent reads a diff against the WordPress Developer Handbook before I open a pull request.

A PostToolUse hook runs PHPCS on every PHP file Claude edits and sends the errors straight back, so Claude fixes them before moving on.

Project template

/pb:new-project drops a kit into a theme repo:

• A CLAUDE.md under 2 KB
• A .claude/settings.json with safe permissions and a WebFetch allowlist for every doc site in doc-references
• A GitHub Actions workflow that builds the theme, swaps it over SSH, runs a health check and rolls back on failure

How do I use the rules and skills?

I don't call them. Claude Code picks them up from what I'm doing and what I type.

• Rules watch the files. Each rule has a paths: list in its frontmatter. Open a .php file and the WordPress rules are in context. Open a Blade template and the Sage and SEO rules are there. I never mention them.
• Skills watch the prompt. Claude always sees each skill's one-line description and loads the full SKILL.md only when my request matches it. If I say "draft a blog post about X," geo-blog-post and content-writer load. If I say "add an ACF field for the hero," sage-architecture loads. If I ask what wp_insert_post() returns, doc-references loads and Claude fetches the handbook page.
• Commands wait for me. /pb:fix add a skip link to the header runs the fix-and-ship workflow. /pb:review runs the reviewer agent on the branch. Nothing happens until I type the slash.

That's why the descriptions matter more than the bodies. A skill with a vague description never loads, and one with a sharp description loads at the right moment. When a skill isn't firing, I fix the description, not the prompt.

How does it help me develop with Claude Code?

Consistency. Every client site gets the same security checks, the same accessibility bar and the same review before a PR. I don't paste rules into a new CLAUDE.md each time.

Fewer stale answers. The doc-references skill tells Claude to fetch the official page before writing against a hook, a Tailwind v4 feature or a Next.js API. The project settings pre-approve those domains, so the fetch never stops for a permission prompt.

Cheaper sessions. The always-on context went from about 60 KB to under 1 KB, and I stopped re-sending the same rules by hand at the start of each session. Smaller prompts, fewer credits.

One place to fix things. When Claude gets something wrong twice, I change the rule once, open a PR, and the fix lands everywhere the next day. The repo's CI checks frontmatter, the core rule's size budget and a blocklist for private details, so I can't merge a client host name by mistake.

What stays out of the repo?

Anything that names a client. Hosts, paths, plugin lists, logins and product catalogs live in each project's CLAUDE.md and .claude/rules/.

The playbook is public, so validate.py scans every file for patterns like application passwords, GitHub tokens and private keys. It fails the build if one shows up.

Should you build your own?

If you use Claude Code on more than one repo, yes. Start smaller than I did:

1. Put five lines in a core rule.
2. Move one long checklist into a skill.
3. Add the sync hook.

You'll know within a week whether it's worth growing. Anthropic's guide on when to use CLAUDE.md, skills, hooks and subagents is a good overview of how the pieces fit together.

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Originally published on matthummel.com.