# AI Rook, free: Domain WHOIS API

> WHOIS domain lookup — registrar, registration/expiry dates, nameservers, registrant info.

AI Rook's Free trial plan for the domain WHOIS API costs $0.00 per 1,000 domains. We check each provider's docs for 9 fields. AI Rook's docs list 3: Registrant, Registrar, Name servers.
We haven't run AI Rook through [our domain WHOIS API benchmark](https://datacircle.dev/best-domain-whois-api.txt) yet.
This plan is free. We rank 495 plans for domain WHOIS APIs by price. Half the plans cost $1.575 or less per 1,000 domains. [See the best free domain WHOIS API plan.](https://datacircle.dev/best-domain-whois-api.txt)
[Searchwire's $10 pack](https://datacircle.dev/domain-whois-apis/searchwire/10-pack/llms.txt) is the cheapest paid plan per 1,000 domains. Searchwire's domain WHOIS API costs nothing beyond the plan price. [C99.nl's $25 yearly plan](https://datacircle.dev/domain-whois-apis/c99-nl/25-yearly/llms.txt) costs the least for 10,000 domains a month: $2.08.
[WhoisJSON](https://datacircle.dev/domain-whois-apis/whoisjson/120-monthly/llms.txt), [Enterno](https://datacircle.dev/domain-whois-apis/enterno/free-open-api/llms.txt) and [IPAddress.to](https://datacircle.dev/domain-whois-apis/ipaddress-to/free/llms.txt) are the best domain WHOIS API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/domain-whois-apis/ai-rook/free
- [Domain WHOIS API in 2026: the best of 20+ providers compared](https://datacircle.dev/best-domain-whois-api.txt)
- Get it: https://agents.ai-rook.com/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- Request: `POST https://agents.ai-rook.com/api/whois`
- API key: not needed
- Its API docs: https://agents.ai-rook.com/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing#/paths/~1api~1whois
- Sold by: AI Rook (https://ai-rook.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing)
- Checked: 2026-11-09

## In the answer

- Completeness: 33%
- Registrant: ✓
- Registrar: ✓
- Name servers: ✓

## Price

- $ per 1,000 domains: $0.00
- Per: call
- Billing: free

## Charges

- Also pays for: 74 other calls: one free call each

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: WHOIS domain lookup — registrar, registration/expiry dates, nameservers, registrant info.

## Data

- Keep data: no API terms
- Use data: no API terms

## Plan

- Pay: $0
- You get: 1 request
- Enough for: 1 call, once

## Rate limit

- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: domain
- Method: POST
- Path: /api/whois

## About the plan

- Plan: Free trial
- Who can get it: anyone, one free call per wallet or IP address on each paid endpoint

## The 5 fields the plan's answer can hold

registrar, registered at, expires at, nameservers, registrant

## AI Rook's plans (3)

- [AI Rook, free](https://datacircle.dev/domain-whois-apis/ai-rook/free/llms.txt): $0.00 per 1,000, 33% complete
- [AI Rook, pay as you go](https://datacircle.dev/domain-whois-apis/ai-rook/pay-as-you-go/llms.txt): $2.50 per 1,000, 33% complete
- [AI Rook, $5 pack](https://datacircle.dev/domain-whois-apis/ai-rook/5-pack/llms.txt): $100.00 per 1,000, 33% complete

## AI Rook's calls for this API (1)

- `POST /api/whois`: [AI Rook, free](https://datacircle.dev/domain-whois-apis/ai-rook/free/llms.txt)

## AI Rook's APIs (4)

- [AI Rook: domain WHOIS API pricing, 3 plans](https://datacircle.dev/domain-whois-apis/ai-rook/free/llms.txt)
- [AI Rook: email verification API pricing, 3 plans](https://datacircle.dev/validate-email-apis/ai-rook/free/llms.txt)
- [AI Rook: IP company lookup API pricing, 3 plans](https://datacircle.dev/ip-company-lookup-apis/ai-rook/free/llms.txt)
- [AI Rook: web scraping API pricing, 3 plans](https://datacircle.dev/web-scraping-apis/ai-rook/free/llms.txt)

## AI Rook: domain WHOIS API alternatives

- [Companyfacts, $49 monthly](https://datacircle.dev/domain-whois-apis/companyfacts/49-monthly/llms.txt): $2.45 per 1,000, 67% complete
- [2s.io, pay as you go](https://datacircle.dev/domain-whois-apis/2s-io/pay-as-you-go/llms.txt): $2.50 per 1,000, 56% complete
- [HackerTarget, $250 pack](https://datacircle.dev/domain-whois-apis/hackertarget/250-pack/llms.txt): $2.50 per 1,000, 89% complete, live
- [Vee3, $5 monthly, Starter, GET /v1/domains/lookup](https://datacircle.dev/domain-whois-apis/vee3/5-monthly-starter-get-v1-domains-lookup/llms.txt): $2.50 per 1,000, 78% complete

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-09.

- https://agents.ai-rook.com/.well-known/x402?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://agents.ai-rook.com/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://agents.ai-rook.com/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://ai-rook.com/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing