API Documentation

Rankfill Intelligence gives you links, technology profiles, and page metadata for any domain — from a single API. All three datasets are included in every response.

Authentication

All API requests require an API key passed in the Authorization header:

Authorization: Bearer rf_your_api_key_here

Don't have a key? Request early access.

Base URL

https://api.rankfill.com/v1

Rate Limits

Default: 60 requests per minute. Higher limits available on prepaid plans.

Link Intelligence

GET /v1/links

Returns all links pointing to a domain — both external backlinks and internal links. Includes anchor text, link type, rel attributes, HTTP status, and page context.

Parameters

Parameter	Type	Default	Description
`domain`	string	required	Target domain to query
`type`	string	all	`all`, `external`, or `internal`
`link_tag`	string		Filter by tag: `A`, `SCRIPT`, `LINK`, `IMG`
`limit`	integer	100	Results per page (max 10,000)
`cursor`	string		Pagination cursor from previous response

Example Request

curl https://api.rankfill.com/v1/links?domain=example.com&type=external&limit=10 \
  -H "Authorization: Bearer rf_your_api_key"

Response

{
  "data": [
    {
      "source_domain": "blog.partner.com",
      "source_path": "/review-of-example",
      "source_ip": "104.21.32.1",
      "page_title": "Our Review of Example.com",
      "target_domain": "example.com",
      "target_path": "/pricing",
      "anchor_text": "check out their pricing",
      "rel": "nofollow",
      "link_tag": "A",
      "http_status": 200,
      "server": "nginx",
      "content_type": "text/html",
      "language": "en",
      "crawl_date": "2026-02-15"
    }
  ],
  "meta": {
    "domain": "example.com",
    "total": 142857,
    "has_more": true,
    "cursor": "eyJsYXN0X2lkIjoiMTIzNDU2In0="
  }
}

GET /v1/links/summary

Returns aggregate statistics for a domain's link profile — total links, referring domains, top anchors, and link type distribution.

Parameters

Parameter	Type	Default	Description
`domain`	string	required	Target domain to query

Response

{
  "data": {
    "domain": "example.com",
    "total_links": 142857,
    "external_links": 98432,
    "internal_links": 44425,
    "referring_domains": 12847,
    "link_types": {
      "A": 89234,
      "IMG": 31245,
      "SCRIPT": 15678,
      "LINK": 6700
    },
    "top_anchors": [
      {"text": "example", "count": 4521},
      {"text": "click here", "count": 2103},
      {"text": "example.com", "count": 1876}
    ]
  }
}

Technology Intelligence

GET /v1/technology

Returns technology stack information for a domain — frameworks, CMS platforms, CDNs, analytics tools, and JavaScript libraries detected from the site's resource references.

Parameters

Parameter	Type	Default	Description
`domain`	string	required	Domain to analyze

Example Request

curl https://api.rankfill.com/v1/technology?domain=example.com \
  -H "Authorization: Bearer rf_your_api_key"

Response

{
  "data": {
    "domain": "example.com",
    "technologies": [
      {"category": "framework", "name": "React", "source": "cdn.jsdelivr.net/npm/react@18"},
      {"category": "cdn", "name": "Cloudflare", "source": "cdnjs.cloudflare.com"},
      {"category": "analytics", "name": "Google Analytics", "source": "www.googletagmanager.com/gtag/js"},
      {"category": "cms", "name": "WordPress", "generator": "WordPress 6.4"},
      {"category": "css", "name": "Bootstrap", "source": "cdn.jsdelivr.net/npm/bootstrap@5"}
    ],
    "server": "nginx/1.24.0",
    "language": "en"
  }
}

GET /v1/technology/search

Find all domains using a specific technology. Answer questions like "which sites use React?" or "who runs WordPress?"

Parameters

Parameter	Type	Default	Description
`technology`	string	required	Technology name or keyword (e.g. `react`, `wordpress`)
`limit`	integer	100	Results per page (max 10,000)
`cursor`	string		Pagination cursor

Example Request

curl https://api.rankfill.com/v1/technology/search?technology=react&limit=5 \
  -H "Authorization: Bearer rf_your_api_key"

Response

{
  "data": [
    {"domain": "airbnb.com", "source": "a0.muscache.com/react-18.2.0.js"},
    {"domain": "netflix.com", "source": "assets.nflxext.com/react.production.min.js"},
    {"domain": "dropbox.com", "source": "cfl.dropboxstatic.com/react-dom.js"}
  ],
  "meta": {
    "technology": "react",
    "total": 4821543,
    "has_more": true,
    "cursor": "eyJsYXN0X2lkIjoiNTY3ODkwIn0="
  }
}

Page Intelligence

GET /v1/pages

Returns metadata for pages on a domain — titles, descriptions, language, server, CMS generator, content type, and HTTP status.

Parameters

Parameter	Type	Default	Description
`domain`	string	required	Domain to query
`path`	string		Filter to a specific path prefix
`language`	string		Filter by language code (e.g. `en`, `de`)
`limit`	integer	100	Results per page (max 10,000)
`cursor`	string		Pagination cursor

Example Request

curl https://api.rankfill.com/v1/pages?domain=example.com&limit=5 \
  -H "Authorization: Bearer rf_your_api_key"

Response

{
  "data": [
    {
      "domain": "example.com",
      "path": "/",
      "title": "Example - The best example on the web",
      "description": "We provide the finest examples since 2005.",
      "keywords": "example, demo, sample",
      "language": "en",
      "server": "nginx/1.24.0",
      "generator": "",
      "content_type": "text/html; charset=UTF-8",
      "http_status": 200,
      "ip": "93.184.215.14",
      "crawl_date": "2026-02-15"
    }
  ],
  "meta": {
    "domain": "example.com",
    "total": 8432,
    "has_more": true,
    "cursor": "eyJsYXN0X2lkIjoiOTAxMjM0In0="
  }
}

Errors

The API uses standard HTTP status codes:

Code	Meaning
`200`	Success
`400`	Bad request — missing or invalid parameters
`401`	Unauthorized — invalid or missing API key
`404`	Not found — domain not in our index
`429`	Rate limited — slow down
`500`	Server error — try again

Error responses include a message:

{
  "error": {
    "code": 429,
    "message": "Rate limit exceeded. Retry after 2 seconds."
  }
}

Billing

Every row returned counts as one billable row, regardless of which endpoint you call. A request that returns 50 results costs 50 rows. Pagination does not incur additional charges beyond the rows returned.

There are no per-request fees. A request that returns zero results costs nothing.

Tier	Price / 1K rows	Commitment
On-demand	$0.020	None
Prepaid 10M	$0.015	$150 upfront
Prepaid 100M	$0.010	$1,000 upfront