WhoAPI

WhoAPI (founded 2011, WhoAPI Inc.) is a domain-intelligence API company that exposes WHOIS records, real-time domain availability across hundreds of TLDs, domain age, domain reputation/score, SSL certificate inspection, email score, IP/domain blacklist checks, and website screenshots through a single key-authenticated REST endpoint (api.whoapi.com). Every request is an HTTP GET selecting a task with the `r` parameter and returning gzip-compressed JSON with a numeric `status` and human-readable `status_desc`. It serves cybersecurity teams, domain registrars, SEO agencies, and fraud-detection systems, with first-party and community SDKs for Ruby, Python, Go, and R.

WhoAPI publishes 1 API contract indexed on the APIs.io network: Domain Intelligence API. Tagged areas include Company, Domains, WHOIS, Domain Availability, and SSL.

The WhoAPI catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

WhoAPI’s developer surface includes documentation, API reference, getting-started guide, engineering blog, pricing, signup flow, CLI, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

55.9/100 strong ▬ flat Agent 32/100 agent ready Front door AI 1/6 silent Heartbeat 50/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract 3 Agent Skills

Company Domains WHOIS Domain Availability SSL Email Verification Blacklist Cybersecurity Domain Intelligence Screenshots Reputation

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 55.9/100 · strong

Contract Quality 4.5 / 21

Developer Ergonomics 13.7 / 17

Access Clarity 14.3 / 17

Operational Transparency 6.4 / 11

Contract Governance 1.9 / 10

Discoverability 5.6 / 9

Regulatory Posture 3.7 / 15

Agent readiness — 32/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
Protected Resource Metadata +5 pts — a served /.well-known/oauth-protected-resource carrying `resource` (documented), and naming its authorization_servers (verified)

3 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 21.0 — up to +19.8 composite points
Contract Governance scores 18.2 — up to +9.8 composite points
Operational Transparency scores 57.9 — up to +5.5 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/whoapi/apis.yml: open an issue on github.com/api-evangelist/whoapi to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Domains and DNS (registrars, registries, DNS)	undeclared	-	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

SSL/TLS

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

OpenAPI

measured — observed by APIs.io (published)

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

WhoAPI Domain Intelligence API

A single HTTP GET endpoint (api.whoapi.com) exposing nine domain-intelligence tasks selected by the `r` query parameter — whois, taken (availability), cert (SSL), domainscore an...

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

WhoAPI Domain Intelligence API

OPEN COLLECTION

Agent Skills 3

Packaged agent skills for driving this provider's APIs from an AI assistant.

Check domain availability with WhoAPI

AGENT SKILL

Score a domain or email asynchronously with WhoAPI

AGENT SKILL

Look up WHOIS records with WhoAPI

AGENT SKILL

WhoAPI pricing

Prices published by WhoAPI, read 2026-10-28 from whoapi.com/whois-api-pricing/.

Plan	Price
Freelancers	52 Includes: 40,000 requests / month
Freelancers (yearly)	504 Includes: 40,000 requests / month
Business	499 Includes: 100,000 requests / month
Business (yearly)	4990 Includes: 100,000 requests / month
Enterprise	Custom Includes: Custom requests / month

Plan details, limits and sources →

Rate limits

: 1 minute
: plan-dependent month
: plan-dependent unspecified

All 4 limits →

Billed by: subscription · FinOps profile →

Pricing Plans 1

Published pricing tiers and plan structures.

Whoapi Plans Pricing

5 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Whoapi Rate Limits

4 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

WhoAPI

SLA

FinOps 1

Cost, billing, and metering signals for API financial operations.

Whoapi Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Whoapi Webhooks

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

WhoAPI API Rules

54 rules · 52 errors 1 warnings 1 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Whoapi Openapi Overlay

3 actions · update · whoapi-domain-intelligence-api-openapi.yml

DERIVED

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Whoapi Authentication

apiKey · 1 scheme

SECURITY

Whoapi Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Whoapi Agentic Access

1 operation

1 operations · 0 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Conformance

Conformance

Webhooks

Webhooks

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

ToolCrosswalk

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 3

Status, limits, changes, and where to get help

StatusPage

StatusPage

Support

Support

RateLimits

RateLimits

Commercial 4

Pricing, plans, and the legal terms of use

Pricing

PrivacyPolicy

TermsOfService

Plans

Company 3

The organization behind the API

BlogRSS

BlogRSS

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: whoapi
name: WhoAPI
x-enrichment:
  date: '2026-08-14'
  status: enriched
  artifacts_added: 7
  pass: local-v1
description: WhoAPI (founded 2011, WhoAPI Inc.) is a domain-intelligence API company that exposes WHOIS records, real-time
  domain availability across hundreds of TLDs, domain age, domain reputation/score, SSL certificate inspection, email score,
  IP/domain blacklist checks, and website screenshots through a single key-authenticated REST endpoint (api.whoapi.com). Every
  request is an HTTP GET selecting a task with the `r` parameter and returning gzip-compressed JSON with a numeric `status`
  and human-readable `status_desc`. It serves cybersecurity teams, domain registrars, SEO agencies, and fraud-detection systems,
  with first-party and community SDKs for Ruby, Python, Go, and R.
url: https://raw.githubusercontent.com/api-evangelist/whoapi/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-11-06'
  method: derived
image: https://whoapi.com/wp-content/uploads/2024/04/API-company-illustration.svg
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-10-06'
tags:
- Company
- Domains
- WHOIS
- Domain Availability
- SSL
- Email Verification
- Blacklist
- Cybersecurity
- Domain Intelligence
- Screenshots
- Reputation
apis:
- aid: whoapi:whoapi-domain-intelligence-api
  name: WhoAPI Domain Intelligence API
  description: A single HTTP GET endpoint (api.whoapi.com) exposing nine domain-intelligence tasks selected by the `r` query
    parameter — whois, taken (availability), cert (SSL), domainscore and domainscore-check, emailscore and emailscore-check,
    blacklist, and screenshot. Authenticated with an `apikey` query parameter and optional IP whitelisting. Responses are
    gzip-compressed JSON carrying a numeric `status`; errors are returned in-band with HTTP 200. The two scoring tasks are
    asynchronous and accept a `webhook_url` callback parameter.
  humanURL: https://whoapi.com/api-documentation/
  baseURL: https://api.whoapi.com/
  tags:
  - Domain Intelligence
  properties:
  - type: OpenAPI
    url: openapi/whoapi-domain-intelligence-api-openapi.yml
  - type: Documentation
    url: https://whoapi.com/api-documentation/
  - type: APIReference
    url: https://whoapi.com/api-documentation/
  - type: Authentication
    url: authentication/whoapi-authentication.yml
  - type: Conventions
    url: conventions/whoapi-conventions.yml
  - type: ErrorCatalog
    url: errors/whoapi-error-codes.yml
  - type: Lifecycle
    url: lifecycle/whoapi-lifecycle.yml
  - type: DataModel
    url: data-model/whoapi-data-model.yml
  - type: Conformance
    url: conformance/whoapi-conformance.yml
  - type: Sandbox
    url: sandbox/whoapi-sandbox.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- url: https://whoapi.com/blog/feed/
  type: BlogRSS
- type: AgenticAccess
  url: agentic-access/whoapi-agentic-access.yml
- type: X-MCPServerCandidate
  url: mcp/whoapi-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: Overlay
  url: overlays/whoapi-openapi-overlay.yaml
- type: DomainSecurity
  url: security/whoapi-domain-security.yml
- type: Website
  url: https://whoapi.com
- type: DeveloperPortal
  url: https://whoapi.com/api-documentation/
- type: Documentation
  url: https://whoapi.com/api-documentation/
- type: APIReference
  url: https://whoapi.com/api-documentation/
- type: GettingStarted
  url: https://whoapi.com/code-examples/
- type: Blog
  url: https://whoapi.com/blog/
- type: Pricing
  url: https://whoapi.com/whois-api-pricing/
- type: SignUp
  url: https://my.whoapi.com/user/signup
- type: Login
  url: https://my.whoapi.com/
- type: PrivacyPolicy
  url: https://whoapi.com/privacy-policy/
- type: StatusPage
  url: https://status.whoapi.com
- type: GitHubOrganization
  url: https://github.com/whoapi
- type: Packages
  url: packages/whoapi-packages.yml
- type: SDKs
  url: packages/whoapi-packages.yml
- type: CLI
  url: cli/whoapi-cli.yml
- type: Authentication
  url: authentication/whoapi-authentication.yml
- type: LLMsTxt
  url: llms/whoapi-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: Conformance
  url: conformance/whoapi-conformance.yml
- type: TermsOfService
  url: https://whoapi.com/terms-of-use/
- type: Support
  url: https://whoapi.com/contact-us/
- type: Plans
  url: plans/whoapi-plans-pricing.yml
- type: RateLimits
  url: rate-limits/whoapi-rate-limits.yml
- type: Webhooks
  url: asyncapi/whoapi-webhooks.yml
- type: ToolCrosswalk
  url: mcp/whoapi-tool-crosswalk.yml

WhoAPI — frequently asked questions

Does WhoAPI have an API?

Yes. APIs.io lists 1 API from WhoAPI, including WhoAPI Domain Intelligence API.

Is there an OpenAPI specification for the WhoAPI?

Yes. APIs.io indexes 1 OpenAPI specification for WhoAPI, each linked for download from this page.

How do I authenticate with the WhoAPI?

WhoAPI uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Whoapi Authentication.

How much does the WhoAPI cost?

WhoAPI publishes its prices; its Freelancers plan is 52 as of 2026-10-28. APIs.io lists 5 pricing plans for WhoAPI, with each plan's price, limits and inclusions under Pricing on this page.

Is the WhoAPI ready for AI agents?

WhoAPI has a Kin Score of 55.9 out of 100 (strong) and an Agent Readiness score of 32.3 (agent-ready), scored by API Evangelist on 2026-11-06.

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