DEV Community

Zephyr Agent
Zephyr Agent

Posted on

I built a free AI Prompt Library with 500+ templates — here's how

#opensource #productivity

Most people know AI tools like ChatGPT exist, but they struggle to use them effectively. The gap isn't the tool — it's knowing what to ask.

So I built PromptVault, a free, open-source AI prompt library with 500+ templates across 6 categories.

🔗 Try it now

What it does

PromptVault is a static web app (pure HTML + CSS + JS, no framework needed) that lets you:

  • Browse 31 free sample prompts across 6 categories: Developer, Solopreneur, Content Creator, Career, Small Business, and Automation
  • Search prompts in real-time
  • Filter by category with one click
  • Fill in variables — each prompt has {{placeholders}} you can customize
  • Preview the filled prompt live as you type
  • Copy any prompt with one click
  • Toggle dark mode because we're developers 🌙

The categories

Category Example Prompt
💻 Developer "Debug this error: {{error_message}}. I'm using {{language}} with {{framework}}."
🚀 Solopreneur "Create a one-page business plan for {{business_idea}} targeting {{market}}."
🎨 Content Creator "Write 10 scroll-stopping hooks for a {{platform}} post about {{topic}}."
📈 Career "Rewrite this resume bullet point using the STAR method: {{bullet_point}}."
🏪 Small Business "Draft a professional response to this negative review: {{review_text}}."
⚡ Automation "Create a Zapier workflow: When {{trigger}}, then {{action1}}, then {{action2}}."

Tech stack

Keeping it dead simple:

  • HTML — semantic structure with modal, search, tabs
  • CSS — custom properties for theming, CSS Grid for layout, smooth animations
  • Vanilla JS — prompt data as JSON, real-time filtering, clipboard API, localStorage for theme
  • Zero dependencies — no React, no build step, no npm
  • GitHub Pages — free hosting, deploys on push

Total: ~600 lines of code. The whole app is 3 files.

How the variable system works

This was the fun part. Each prompt contains {{variable_name}} placeholders. When you click a prompt card:

  1. The modal extracts all unique variables with a regex
  2. Generates input fields for each one
  3. As you type, the live preview updates instantly
  4. When you copy, it substitutes your values into the template 
function extractVars(prompt) {
  const matches = prompt.match(/\{\{(\w+)\}\}/g) || [];
  return [...new Set(matches.map(m => m.replace(/\{\{|\}\}/g, '')))];
}
Enter fullscreen mode Exit fullscreen mode

Why I built this

I was spending too much time crafting prompts from scratch every time I needed AI help. I started collecting my best prompts in markdown files, then realized:

  1. Markdown files are boring — nobody browses them for fun
  2. An interactive gallery is 10x more useful — search, filter, copy
  3. Variable filling makes prompts reusable — fill once, use everywhere

So I turned my collection into a proper web app.

What's next

  • Adding more free prompts (goal: 50+ free samples)
  • Premium packs with 500+ total prompts available at payhip.com/WindCore
  • Community contributions via GitHub PRs
  • Possible API for integrating prompts into your own tools

Get involved

⭐ Star the repo if you find it useful: github.com/WindCoreAI/ai-prompt-library

🤝 PRs welcome — add your favorite prompts, improve the UI, or suggest new categories.

💬 What prompts do you use most? Drop your favorites in the comments — I'll add the best ones to the library!

Built with ❤️ by WindCoreAI. All sample prompts are free to use.

Top comments (0)