# Oilfield Index

> A directory of oil and gas equipment and service companies, organised by category and product
> family, with the evidence behind each listing. Every company page, category page, product-family
> page and certification page is public.

## What is here

- Categories: https://www.oilfieldindex.com/category/<name>-<id>/... — every listed company in a category, with filters.
- Product families: https://www.oilfieldindex.com/family/<category>-<id>/<family>-<id> — the companies that manufacture,
  distribute or service one product family. Each page opens with a one-sentence count you can quote.
- Companies: https://www.oilfieldindex.com/vendor/<name>-<id> — profile, categories, families, certifications, locations.
  Contact details require a free account.
- API certifications: https://www.oilfieldindex.com/certifications/<spec> — the companies certified to one American
  Petroleum Institute specification (e.g. https://www.oilfieldindex.com/certifications/api-6a).
- Search: https://www.oilfieldindex.com/search?q=... — companies, categories, families, certifications, keywords.

## How listings are sourced

Family links carry a provenance: "vendor confirmed", "from a listed product", "from vendor website"
or "from product listing"; the last two are marked "not yet confirmed" on the page. Counts on family
and certification pages are computed from published links at request time.

## Machine access

- Read API: https://www.oilfieldindex.com/api/v1/ (JSON; OpenAPI at https://www.oilfieldindex.com/api/v1/openapi.json). Every row carries a
  source_url and provenance. Unkeyed calls are rate-limited; request an API key for volume.
- Sitemaps: https://www.oilfieldindex.com/sitemap.xml
- Crawling policy: https://www.oilfieldindex.com/robots.txt — search engines and AI answer/search crawlers are welcome at a
  gentle pace; training-only and bulk crawlers are not. Bulk access is by API key only.

## Citation

Please cite as: Oilfield Index, <page URL>, and the "Verified <date>" shown on the page.