polymerdao/x402engine-web

x402engine Web

x402engine provides pay-per-call web scraping and screenshot endpoints. Scrape any URL into clean markdown or capture a full-page screenshot as a base64 image. Through the Polymer Pay proxy, each request is paid individually — no x402engine account or API key required.

Authentication

All requests route through the Polymer Pay proxy. Include your Polymer Pay API key in every request:

{
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  }
}

Base URL: https://pay.polymerlabs.org/proxy/https/x402-gateway-production.up.railway.app

To get an Polymer Pay API key, sign up at https://my.pay.polymerlabs.org/dashboard/api-keys.

Common Operations

Web Scrape

Scrape a single URL and receive clean markdown content. No configuration needed — just pass a URL and get back well-structured markdown extracted from the page.

Pricing: $0.005

{
  "method": "GET",
  "url": "https://pay.polymerlabs.org/proxy/https/x402-gateway-production.up.railway.app/api/web/scrape?url=https://example.com/page",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  }
}

Response: JSON object with the scraped URL and clean markdown content extracted from the page.

Web Screenshot

Capture a full-page screenshot of any URL. The page is rendered in a browser and returned as a base64-encoded PNG image.

Pricing: $0.01

{
  "method": "GET",
  "url": "https://pay.polymerlabs.org/proxy/https/x402-gateway-production.up.railway.app/api/web/screenshot?url=https://example.com/page",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  }
}

Response: JSON object with the URL and a base64-encoded PNG image of the rendered page. Decode the base64 string and save as a .png file to view.

Web Search

Perform a neural web search with highlighted snippets. Returns relevant results with context for a given query.

Pricing: $0.01

{
  "method": "POST",
  "url": "https://pay.polymerlabs.org/proxy/https/x402-gateway-production.up.railway.app/api/search/web",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  },
  "body": {
    "query": "x402 payment protocol"
  }
}

Response: JSON object with search results, each containing title, URL, snippet, and relevance score.

Extract Web Contents

Extract clean text content from up to 10 URLs in a single request. Useful for batch content extraction.

Pricing: $0.005

{
  "method": "POST",
  "url": "https://pay.polymerlabs.org/proxy/https/x402-gateway-production.up.railway.app/api/search/contents",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  },
  "body": {
    "urls": ["https://example.com/page1", "https://example.com/page2"]
  }
}

Response: JSON object with extracted text content for each provided URL.

When to Use

• Quick single-page scrape — Fastest and simplest way to get markdown from a URL with zero configuration.
• Webpage screenshots — Capture how a page looks in a browser for visual verification or archiving.
• Batch content extraction — Extract clean text from multiple URLs in a single request with /api/search/contents.
• Budget-conscious scraping — At $0.005/scrape and $0.01/screenshot, x402engine is one of the cheapest options.

Best Practices

• Use for simple pages — x402engine web scrape works well for straightforward content pages. For anti-bot protected sites, use Zyte instead.
• Save screenshots properly — The screenshot response is a base64-encoded image. Decode it with base64 -d > screenshot.png to save as a viewable file.
• Batch with contents endpoint — When you have multiple URLs to extract, use /api/search/contents (up to 10 URLs) instead of calling /api/web/scrape repeatedly.
• Prefer Firecrawl for complex scraping — For multi-page crawls, structured extraction, or site mapping, Firecrawl is more capable.
• Use scrape for LLM input — The markdown output from /api/web/scrape is clean and token-efficient, ideal for feeding into LLM prompts or RAG pipelines.
• For errors — See @skills/polymer-pay-api-errors/SKILL.md for complete error code reference and troubleshooting