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Free Guide — September 2026

3 Secret Plugins
For Claude

A research engine, a marketing team and a prompt engineer. All three are free, all three were built by other people, and one copy-paste prompt installs the whole set. About 2 minutes.

Start Here

The one prompt

Open Claude Code and paste this. It installs all three, checks each one actually landed, and tells you what to type first to test them.

It also catches the two mistakes that make these look installed when they are not. Those are the reason most people give up on this.

Not in Claude Code? Skip to the manual paths below. Everything works in the browser too, it just takes clicking instead of pasting.

Copy-paste prompt

You are setting up three free, open-source Claude plugins on my machine. Install all three, verify each one, then report back.

Do them in this order, and confirm each one worked before moving to the next.

1) last30days
An agent-led search across Reddit, X, YouTube, TikTok, Hacker News, Polymarket, GitHub and arXiv, scored by what real people actually engaged with.
Repo: https://github.com/mvanhorn/last30days-skill (built by mvanhorn)

Install through the Claude Code marketplace, which handles updates on its own:

  /plugin marketplace add mvanhorn/last30days-skill
  /plugin install last30days

If the marketplace command is not available, use this instead:

  npx skills add mvanhorn/last30days-skill -g -a claude-code

Do not install it both ways. Claude Code does not dedupe across install methods, so /last30days will show up twice and you will not know which one is running.

2) marketing skills
Adds 40+ real marketing skills: conversion optimization, SEO, copywriting, ads, cold email, pricing, analytics, churn.
Repo: https://github.com/coreyhaines31/marketingskills (built by Corey Haines)

Install with:

  npx skills add coreyhaines31/marketingskills -a claude-code

The -a claude-code flag is not optional. Run this from inside an agent session without it and the CLI installs to .agents/skills/, which Claude Code does not read. Everything will look like it worked and nothing will actually load.

If I would rather pick specific skills than install all of them, show me the list first:

  npx skills add coreyhaines31/marketingskills --list

3) prompt master
Writes the prompt for me. I describe what I want in normal words, it asks two or three questions, then hands back the finished prompt built for whichever tool I am using.
Repo: https://github.com/nidhinjs/prompt-master (built by nidhinjs)

Install with:

  mkdir -p ~/.claude/skills
  git clone https://github.com/nidhinjs/prompt-master.git ~/.claude/skills/prompt-master

Once all three are in, verify:

- List what is now installed and confirm each of the three appears exactly once.
- Flag any duplicates and tell me which copy to delete and the command to delete it.
- Give me the exact command or phrase that triggers each one.

Then report back in plain English:

- What installed cleanly.
- What did not, with the specific error and the specific fix.
- The first thing I should type to test each of the three.

Do not tell me something worked unless you actually checked. If an install failed, say so plainly and give me the fix.

The Three

What each one actually does

1

last30days

Built by mvanhorn. View the repo

An agent-led search across Reddit, X, YouTube, TikTok, Hacker News, Polymarket, GitHub and arXiv, scored by what real people actually engaged with instead of what an editor ranked.

Google gives you the LinkedIn profile from 2023. This gives you what someone or something has actually been doing this month, pulled from the places Google never touches.

How you trigger it: /last30days [topic or person]

2

marketing skills

Built by Corey Haines. View the repo

Adds 40+ real marketing skills to Claude: conversion optimization, SEO, copywriting, ads, cold email, pricing, analytics, churn prevention, competitor research.

Ask Claude to fix your landing page without this and it guesses. With this it runs an actual playbook written by someone who has run growth for real companies.

How you trigger it: Ask in plain words: "audit the copy on my landing page"

3

prompt master

Built by nidhinjs. View the repo

Writes your prompt for you. You describe what you want in normal words, it asks two or three questions, then hands back the finished prompt built for whichever tool you are pointing it at.

Stops the loop where you write a vague prompt, get the wrong thing, rewrite, get closer, rewrite again, and finally get it right on the fourth try.

How you trigger it: /prompt-master, or just "write me a prompt for..."

Every Other Way In

If you are not in Claude Code

The prompt above only works where Claude can run commands. If you use Claude in the browser or the desktop app, here is the manual path for each surface.

Claude Code

The prompt above does all three. This is the manual version if you would rather run the commands yourself.

/plugin marketplace add mvanhorn/last30days-skill then /plugin install last30days
npx skills add coreyhaines31/marketingskills -a claude-code
git clone https://github.com/nidhinjs/prompt-master.git ~/.claude/skills/prompt-master

claude.ai in the browser

No terminal, so these are uploads. Go to Sidebar, Customize, Skills, Upload a skill. About 2 minutes for all three.

last30days: download last30days.skill from the repo releases page, then upload it
marketing skills: download the repo as a ZIP and upload the skills you want
prompt master: download the repo as a ZIP and upload it (this is the method its author recommends)

Claude Desktop

Only last30days ships a desktop bundle. The other two run through claude.ai or Claude Code.

Download the .mcpb for your platform from the last30days releases page
Drag it into Settings, Extensions

Read Before You Install

The 5 things that quietly break this

None of these throw an error. They just make the plugins sit there doing nothing while you assume they are working.

The flag everyone forgets

Installing marketing skills without -a claude-code puts it in .agents/skills/, which Claude Code does not read. The install reports success. Nothing loads. This one wastes the most time.

Do not install last30days twice

The marketplace install and the npx skills install can both run, and Claude Code will not dedupe them. You get two /last30days entries and no idea which one is live. Pick one method per machine.

last30days is free on the sources that matter

Reddit, Hacker News, Polymarket and GitHub work the second you install it, no keys. X, YouTube and TikTok need a 30-second setup wizard the first time you run it.

Marketing skills has a foundation file

The product-marketing skill is the one every other skill reads first. Fill that one out about your business before you use the rest, or the other 40 are working blind.

You do not need all 40

Run npx skills add coreyhaines31/marketingskills --list and install only the ones you will use. A smaller set is easier to remember you have.

Credit

I did not build any of these

All three are other people's work, given away free. The only thing here that is mine is the install prompt and the list of things that break.

last30days is by mvanhorn. Marketing skills is by Corey Haines, who has run growth for real companies and released the whole library under MIT. Prompt master is by nidhinjs.

If any of these save you real time, go star the repo. That is the whole payment these people asked for.

Work with Me

Want me on your problem for an hour?

Book a 1:1 call and we build the fix live — the workflow you want automated, the tool you can’t crack, whatever’s stuck. Direct, hands-on, no pitch waiting at the end.

$749 $349 credited back if we keep working together
See how it works

Work with Me

Want me on your problem for an hour?

Book a 1:1 call and we build the fix live — the workflow you want automated, the tool you can’t crack, or nothing pre-planned at all. No pitch waiting at the end.

See how it works

Full refund if we don’t find something worth building.