Most marketers using AI are still typing prompts from scratch every time. Open a chat, describe the task, hope you remembered all the context, fix what comes back. Same effort, every time.
There's a better way that almost nobody outside engineering circles knows about: marketing prompt libraries on GitHub. These are free, public collections of ready-made instructions, written by people who do marketing for a living, that you can load into Claude, Codex, or any AI assistant. Once they're in, the AI already knows how to run a CRO audit or write a cold email the way a good marketer would, without you re-explaining it each time.
Here are the ones worth knowing, what each is good for, and how to actually use them.
What these actually are
A "skill" or "prompt library" is just a set of text files containing instructions. When you add them to your AI tool, the AI reads them before it works and follows the framework inside. Think of it as handing a new hire your standard operating procedures instead of explaining every task by hand. You set it up once, and it sticks.
You don't need to be technical to use them. Most install with a single command, and some you can upload straight into the Claude app.
One question people always ask: once a skill is installed, do you have to call it, or does the AI just use it? Mostly the second. A well-built skill has a description telling the AI when it applies, so when you ask something like "audit this landing page for conversions," the AI recognises the task and pulls in the right skill on its own. You don't have to name it. If you want to be sure it's using a specific one, you can also just say "use the CRO skill" and it will. So it's automatic by default, with the option to call it directly when you want control.
The seven worth your time
1. Corey Haines' Marketing Skills. The most-used marketing skill pack right now, and the one to start with. Corey runs the Conversion Factory agency and the Swipe Files community, and he turned years of his agency's standard operating procedures into a free GitHub repo with around 40 skills. It covers CRO, copywriting, SEO, analytics, email sequences, ads, and more. Each skill is a real process he uses with clients, not something assembled for show. Works with Claude Code, Codex, Cursor, and Windsurf. The home page with install instructions is at marketing-skills.com.
How to use it: if a task keeps recurring in your week (writing landing page copy, auditing a page for conversions), grab the matching skill and let it run. Start with the copywriting and CRO ones, which are the most immediately useful.
A practical workflow visual for the ideas in this article.
2. His "Coding for Marketers" companion guide. Not a prompt library exactly, but the on-ramp if the GitHub side feels intimidating. Corey wrote it specifically for marketers who've never touched a terminal. If posts 3 to 5 in this series got you curious about building, this is where to go next. Linked from his site at corey.co.
3. The marketing skills roundups on Composio. Composio keeps a running list of strong marketing skills for Claude, Codex, and similar tools, organised by job: research, writing, design, analytics, CRO. Useful as a directory when you want to see what exists for a specific task rather than installing one big pack.
4. Ads-focused skill packs. There are dedicated skills for auditing ad accounts (Google, Meta, Microsoft) that score your account against current benchmarks and hand back a prioritised fix list. If you run your own ads, these are worth a look. The Composio roundup above points to several, including Daniel Agrici's ads skills on GitHub.
5. AEO and GEO skills. As more people search through ChatGPT and Perplexity instead of Google, getting cited by AI matters. Several free skills now optimise content to get picked up by AI answers. Corey's pack includes one, and the Composio directory lists others.
6. Hook and copywriting skill files. Smaller, single-purpose skills that generate headlines and hooks using proven frameworks, labelling each output by the framework it used so you know what you're testing. Good for ad headlines, subject lines, and social openers. Corey's pack covers most of this through its copywriting skill, and the Composio marketing skills directory lists standalone hook and copy skills if you want something more focused. Start with what's in Corey's pack before hunting for a separate one.
7. The mysticaltech fork of Corey's pack. A version of Corey's repo with pre-built files you can upload directly into the Claude app under Settings, Skills, Upload Custom Skill. Handy if you'd rather not run an install command at all.
How to start without overthinking it
Pick one. Corey Haines' pack is the obvious first choice because it's broad and well-made. Install it, then the next time you sit down to write copy or audit a page, let the skill do the first pass. You'll feel the difference immediately: the AI stops being generic and starts working like someone who knows marketing.
You don't need all seven. You need one that saves you time this week. Add more only when you hit a task the first one doesn't cover.
One thing that trips people up: the install instructions on these GitHub pages look technical. Don't let that stop you. If you're not sure how to install one, copy the link, paste it into Claude Code or whatever AI tool you're using, and ask it to install the skill for you. It'll walk you through it or just do it. The same trick works for anything in this series that involves installing from GitHub.
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