Validation Stack

Turn Your MVP into a Working Business

Use your favorite AI builder (v0, Bolt, Replit) or your own IDE. Add our AI-friendly API. Instantly transform a static page into a fully interactive platform with Chat, Email, and Reviews.

  • One-line JS Integration
  • AI-Ready (OpenAPI + llms.txt)
  • Universal Compatibility
Get Your API Key Read Docs 
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>

<!-- That's it. Your site now has: -->
<!-- 1. Email Subscription (Waitlist) -->
<!-- 2. AI Sales Associate -->
<!-- 3. Feedback Collection -->
<!-- 4. Review Display Carousel -->
AI-Powered Quick Start

Build With Your Favorite AI Tool

Copy a prompt, paste it into your AI builder, and get a landing page with X0 Start pre-integrated.

Quick Start: Copy a Prompt for Your AI Builder
Copy this prompt and paste it in Bolt
Open Bolt 
@bolt Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Use React with Tailwind CSS. Make it responsive and add smooth animations.
Copy this prompt and paste it in v0
Open v0 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Use shadcn/ui components and Tailwind CSS. Ensure dark mode support.
Copy this prompt and paste it in Replit
Open Replit 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Create this as a simple HTML/CSS/JS project. Keep dependencies minimal.
Copy this prompt and paste it in Gemini
Open Gemini 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Generate clean, semantic HTML5 with modern CSS. Include accessibility best practices.
Copy this prompt and paste it in Claude
Open Claude 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Create a single-page HTML file with embedded CSS and minimal JavaScript. Focus on performance and clean code.
Copy this prompt and paste it in ChatGPT
Open ChatGPT 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Build this with vanilla HTML, CSS, and JavaScript. Make it lightweight and fast-loading.
Copy this prompt and paste it in Base44
Open Base44 
Build me a modern, professional SaaS landing page. Include:

1. **Hero Section**: Bold headline, compelling subheadline, and a primary CTA button
2. **Features Grid**: 3-4 key features with icons and descriptions
3. **Social Proof**: Testimonials or trust badges section
4. **Pricing**: Simple pricing cards (Free, Pro, Enterprise)
5. **Footer**: Links and newsletter signup

**IMPORTANT - X0 Start Integration:**
Add this script tag in the <head> section:
```html
<script src="https://x0start.com/widget.js?token=YOUR_TOKEN" async></script>
```

This script provides:
āœ“ Floating AI chatbot (appears automatically in bottom-right)
āœ“ Email capture widgets
āœ“ Feedback collection

Add an email capture form in the hero section:
`<div data-domain-widget="email-capture" data-title="Join Our Waitlist"></div>`

Style: Modern, clean, with subtle gradients and shadows. Use a professional color scheme.

Use Base44's component library. Optimize for quick deployment.
Paste the prompt into your AI tool, customize the details, and get a fully integrated landing page!

Complete Validation Toolkit

Everything you need to turn a passive visitor into an active lead. No extra SaaS subscriptions required.

Email Subscription

Smart Email Subscription

Drag-and-drop waitlist forms that connect directly to your cold marketing sequences.

  • Auto-tagging (e.g. "Waitlist")
  • Exit-intent popups
AI Chatbot

AI Sales Associate

A bot that knows your product. Train it on your `llms.txt` and let it sell 24/7.

  • FAQ & Lead Qual
  • Human Handoff
Feedback

Feedback Widget

Capture bug reports, feature requests, and general thoughts directly from your users.

  • Screenshot attachments
  • Sentiment tracking
Social Proof

Social Proof Carousel

Collect and display reviews automatically. Nothing builds trust faster than social proof.

  • Invite & Manage Customer reviews
  • Verified Buyer badges
Analytics

Validation Analytics

Metrics that matter: Goal completion, source attribution, and engagement.

  • Conversion Rates
  • Source Tracking
API

Developer API

Headless ready. Send events, capture users, and trigger workflows via REST API.

  • OpenAPI Spec
  • Webhooks

Built for the AI Future

Is your startup ready for AI agents? X0 Start makes your business machine-readable by default.

  • Auto-Generated OpenAPI

    We generate specs so AI agents know how to subscribe users or submit feedback to your site.

  • llms.txt Standard

    Your site gets an llms.txt file automatically, making it discoverable by models like Claude and Gemini.

Learn about AI Integration ā†’ 
User: "Hey Claude, subscribe me to the X0 Start waitlist."

Claude: "I found their llms.txt. 
Sending request to /api/v1/subscribe..."

System: Configured! User added to 'Waitlist Sequence'.