API Documentation

The CrawlGrader API returns technology stack, security posture, DNS infrastructure, performance metrics, and SEO signals for any domain.

Base URL

https://crawlgrader-api.p.rapidapi.com

API access is managed through API marketplaces. Subscribe on RapidAPI to get your API key.

Authentication

Include your marketplace API key in the request headers:

X-RapidAPI-Key: your-api-key
X-RapidAPI-Host: crawlgrader-api.p.rapidapi.com

Endpoints

GET /v1/lookup/{domain}

Full lookup for a single domain. Returns all available data.

GET /v1/lookup/stripe.com

Response:

{
  "domain": "stripe.com",
  "scanned_at": "2026-03-28T05:00:00Z",
  "tech_stack": ["Ruby on Rails", "React", "Fastly CDN", "GA4", "Marketo", "Segment"],
  "security": {
    "tls_version": "1.3",
    "cert_issuer": "digicert",
    "cert_type": "EV",
    "hsts": true,
    "hsts_max_age": 31536000,
    "csp": true,
    "x_frame_options": "SAMEORIGIN",
    "x_content_type_options": "nosniff",
    "referrer_policy": "strict-origin-when-cross-origin",
    "permissions_policy": true
  },
  "infrastructure": {
    "dns_provider": "route53",
    "cdn": "fastly",
    "hosting_country": "US",
    "ipv6": true,
    "mx_provider": "google-workspace",
    "spf": true,
    "dmarc": true,
    "san_domains": ["stripe.com", "www.stripe.com"]
  },
  "performance": {
    "ttfb_ms": 95,
    "page_size_kb": 210,
    "compression": "brotli",
    "http2": true,
    "redirects": 1,
    "dns_ms": 8,
    "tcp_ms": 22,
    "tls_ms": 18
  },
  "seo": {
    "robots_txt": true,
    "sitemap": true,
    "sitemap_urls": 1247,
    "canonical": true,
    "hreflang_languages": ["en", "fr", "de", "ja", "es"],
    "schema_types": ["Organization", "WebPage"],
    "last_modified": "2026-03-25",
    "publishing_frequency": "daily"
  },
  "ai_policy": {
    "blocks_gptbot": false,
    "blocks_ccbot": false,
    "blocks_chatgpt_user": false,
    "blocks_google_extended": false,
    "blocks_anthropic": false,
    "crawl_delay": null
  }
}

GET /v1/tech/{domain}

Technology stack only. Lighter response for quick lookups.

{
  "domain": "stripe.com",
  "tech_stack": ["Ruby on Rails", "React", "Fastly CDN", "GA4", "Marketo", "Segment"],
  "detection_sources": {
    "headers": ["Ruby on Rails", "Fastly CDN"],
    "cookies": ["GA4", "Marketo"],
    "dns_txt": ["Segment"],
    "html": ["React"]
  }
}

GET /v1/security/{domain}

Security headers and TLS analysis only.

GET /v1/dns/{domain}

DNS and infrastructure signals only.

POST /v1/bulk

Lookup multiple domains in one request (max 100 per call).

POST /v1/bulk
Content-Type: application/json

{
  "domains": ["stripe.com", "shopify.com", "vercel.com"]
}

Rate limits

Plan	Requests/month	Rate limit
Free	100	10/minute
Basic	5,000	60/minute
Pro	50,000	300/minute
Enterprise	Custom	Custom

Response codes

Code	Meaning
200	Success — data returned
202	Domain queued for scanning — retry in 60 seconds
404	Domain not found or unreachable
429	Rate limit exceeded

Data freshness

Domains are rescanned on a rolling basis. Data is typically no older than 30 days. If you need fresher data, the 202 response triggers an on-demand rescan.

Get access

The API is launching soon on RapidAPI. For early access or enterprise inquiries, email api@crawlgrader.com.