Cat Facts API

Free REST API providing random cat facts, breed information, and cat-related trivia for developers building fun applications and learning APIs. No authentication required; CORS enabled for frontend use. Endpoints return paginated JSON data with configurable limits and max-length filters.

Cat Facts API publishes 3 API contracts indexed on the APIs.io network: Breeds API, Fact API, and Facts API. Tagged areas include Cat Facts, Trivia, Fun, Learning, and Free.

The Cat Facts API catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Cat Facts API’s developer surface includes documentation and 7 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

23.5/100 emerging ▬ flat Agent 39/100 agent ready Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreeOpen⚡ Free to try

1 published contract 1 MCP Servers

Cat FactsTriviaFunLearning Free

Kin Score

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

Composite quality — 23.5/100 · emerging

Contract Quality 11.3 / 21

Developer Ergonomics 1.6 / 17

Access Clarity 0.9 / 17

Operational Transparency 0.6 / 11

Contract Governance 1.0 / 10

Discoverability 5.1 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 39/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 12 / 12

Machine-Readable Auth 0 / 10

Idempotency 9 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 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/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/catfact/"><img src="https://apis.io/badge/catfact/card.svg" alt="Cat Facts API on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

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

Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
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)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks

5 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 5.3 — up to +18.9 composite points
Developer Ergonomics scores 9.5 — up to +18.1 composite points
Operational Transparency scores 5.3 — up to +12.3 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/catfact/apis.yml: open an issue on github.com/api-evangelist/catfact 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 →

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.

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

OpenAPI

measured — observed by APIs.io (published)

APIs 3

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

Cat Facts API Breeds API

The Breeds API from Cat Facts API — 1 operation(s) for breeds.

Cat Facts API Fact API

The Fact API from Cat Facts API — 1 operation(s) for fact.

Cat Facts API Facts API

The Facts API from Cat Facts API — 1 operation(s) for facts.

Open Collections 3

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

Cat Facts Breeds API

OPEN COLLECTION

Cat Facts Breeds Fact API

OPEN COLLECTION

Cat Breeds Facts API

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Cat Facts API MCP Server

Remote MCP server at catfact.ninja over HTTP; 3 tools listed.

MCP SERVER

Cat Facts API pricing

Not yet checked against Cat Facts API's own pricing page. Compiled by API Evangelist; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free	Free

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

Catfact Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Catfact Rate Limits

0 limits

RATE LIMITS

Service Levels 1

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

Cat Facts API

SLA

FinOps 1

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

Catfact Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

context Context

2 classes · 19 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Cat Facts API — jsonschema rules

5 rules · 4 warnings 1 info

SPECTRAL

JSON Schema 4

Standalone JSON Schema definitions for this provider's data models.

BreedList

12 properties

JSON SCHEMA

Breed

5 properties

JSON SCHEMA

FactList

12 properties

JSON SCHEMA

Fact

2 properties

JSON SCHEMA

Examples 3

Example request and response payloads for these APIs.

Breeds List Response

12 fields

EXAMPLE

Fact Response

2 fields

EXAMPLE

Facts List Response

12 fields

EXAMPLE

Security Posture 1

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

Catfact Domain Security

TLSv1.3

SECURITY

Agentic Access 1

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

Catfact Agentic Access

3 operations

3 operations · 0 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 1

The organization behind the API

Website

Website

Source (apis.yml)

aid: catfact
name: Cat Facts API
description: Free REST API providing random cat facts, breed information, and cat-related trivia for developers building fun
  applications and learning APIs. No authentication required; CORS enabled for frontend use. Endpoints return paginated JSON
  data with configurable limits and max-length filters.
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: free
  onboarding: open
  trial: false
  try_now: true
  public: true
  gated: none
  gated_source:
  - onboarding
  label: Free · Open access
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/catfact.png
url: https://raw.githubusercontent.com/api-evangelist/catfact/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
x-docs-platform: swagger-ui
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-09-21
tags:
- Cat Facts
- Trivia
- Fun
- Learning
- Free
apis:
- aid: catfact:catfact-breeds-api
  name: Cat Facts API Breeds API
  description: The Breeds API from Cat Facts API — 1 operation(s) for breeds.
  humanURL: https://catfact.ninja/
  tags:
  - Breeds
  properties:
  - type: OpenAPI
    url: openapi/catfact-breeds-api-openapi.yml
  - type: Documentation
    url: https://catfact.ninja/
- aid: catfact:catfact-fact-api
  name: Cat Facts API Fact API
  description: The Fact API from Cat Facts API — 1 operation(s) for fact.
  humanURL: https://catfact.ninja/
  tags:
  - Fact
  properties:
  - type: OpenAPI
    url: openapi/catfact-fact-api-openapi.yml
  - type: Documentation
    url: https://catfact.ninja/
- aid: catfact:catfact-facts-api
  name: Cat Facts API Facts API
  description: The Facts API from Cat Facts API — 1 operation(s) for facts.
  humanURL: https://catfact.ninja/
  tags:
  - Facts
  properties:
  - type: OpenAPI
    url: openapi/catfact-facts-api-openapi.yml
  - type: Documentation
    url: https://catfact.ninja/
common:
- type: AgenticAccess
  url: agentic-access/catfact-agentic-access.yml
- type: DomainSecurity
  url: security/catfact-domain-security.yml
- type: Website
  url: https://catfact.ninja/
- type: Documentation
  url: https://catfact.ninja/
- type: GitHubOrg
  url: https://github.com/alexwohlbruck/cat-facts
- type: Plans
  url: plans/catfact-plans-pricing.yml
- type: RateLimits
  url: rate-limits/catfact-rate-limits.yml
- type: FinOps
  url: finops/catfact-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Cat Facts API — frequently asked questions

Does Cat Facts API have an API?

Yes. APIs.io lists 3 APIs from Cat Facts API, including Cat Facts API Breeds API, Cat Facts API Fact API and Cat Facts API Facts API.

Is there an OpenAPI specification for the Cat Facts API?

Yes. APIs.io indexes 3 OpenAPI specifications for Cat Facts API, each linked for download from this page.

How much does the Cat Facts API cost?

APIs.io lists 1 pricing plan for Cat Facts API, with each plan's price, limits and inclusions under Pricing on this page.

Does Cat Facts API have an MCP server?

Yes. APIs.io lists 1 MCP server for Cat Facts API: Remote MCP server at catfact.ninja over HTTP; 3 tools listed.

Is the Cat Facts API ready for AI agents?

Cat Facts API has a Kin Score of 23.5 out of 100 (emerging) and an Agent Readiness score of 39.2 (agent-ready), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/catfact"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/catfact/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/catfact/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.