Cat Facts (catfact.ninja)

aid: cat-facts-catfact
name: Cat Facts (catfact.ninja)
description: Cat Facts is a free, no-authentication community REST API at catfact.ninja that serves random cat trivia and
  a catalog of cat breeds. It exposes three documented endpoints — a single random fact, a paginated list of facts, and a
  paginated list of breeds — and ships a Swagger UI based OpenAPI 3.0 document at /docs. The service is widely used in API
  onboarding tutorials, demos, and sample apps because it requires no API key and returns small, predictable JSON payloads.
url: https://catfact.ninja/
accessModel:
  pricing: unknown
  onboarding: open
  trial: false
  try_now: false
  public: true
  label: Open access
  confidence: medium
  source: []
  generated: '2026-07-22'
  method: derived
image: https://catfact.ninja/docs/asset/favicon-32x32.png
specificationVersion: '0.20'
created: '2026-05-28'
modified: '2026-05-30'
x-source: public-apis/public-apis
x-type: opensource
x-category: Animals
x-tier: 3
x-tier-reason: bulk-registered-from-public-apis
tags:
- Animals
- Cats
- Trivia
- Public APIs
- Community
- No Authentication
- REST
apis:
- aid: cat-facts-catfact:cat-facts-catfact-breeds-api
  name: Cat Facts (catfact.ninja) Breeds API
  description: Catalog of cat breeds with country, origin, coat, and pattern.
  humanURL: https://catfact.ninja/
  baseURL: https://catfact.ninja
  tags:
  - Breeds
  properties:
  - type: OpenAPI
    url: openapi/cat-facts-catfact-breeds-api-openapi.yml
  - type: Documentation
    url: https://catfact.ninja/
  - type: SwaggerUI
    url: https://catfact.ninja/
  - type: OpenAPISource
    url: https://catfact.ninja/docs?api-docs.json
- aid: cat-facts-catfact:cat-facts-catfact-facts-api
  name: Cat Facts (catfact.ninja) Facts API
  description: Random cat trivia, individually or in paginated lists.
  humanURL: https://catfact.ninja/
  baseURL: https://catfact.ninja
  tags:
  - Facts
  properties:
  - type: OpenAPI
    url: openapi/cat-facts-catfact-facts-api-openapi.yml
  - type: Documentation
    url: https://catfact.ninja/
  - type: SwaggerUI
    url: https://catfact.ninja/
  - type: OpenAPISource
    url: https://catfact.ninja/docs?api-docs.json
common:
- type: AgenticAccess
  url: agentic-access/cat-facts-catfact-agentic-access.yml
- type: DomainSecurity
  url: security/cat-facts-catfact-domain-security.yml
- type: Website
  url: https://catfact.ninja/
- type: SwaggerUI
  url: https://catfact.ninja/
- type: OpenAPI
  url: https://catfact.ninja/docs?api-docs.json
- type: ContactEmail
  url: mailto:contact@catfact.ninja
- type: PublicAPIsListing
  url: https://github.com/public-apis/public-apis
- type: Authentication
  title: No Authentication Required
  url: https://catfact.ninja/
- type: Tools
  title: MCP Server (Community — cursethevulgar)
  url: https://github.com/cursethevulgar/catfact-mcp-server
- type: Tools
  title: MCP Server (Community — mtrmarko)
  url: https://github.com/mtrmarko/cat-facts-mcp
- type: Tools
  title: MCP Server (Community — Volspan)
  url: https://github.com/volspan-deployments/cat-facts-mcp
- type: SpectralRules
  url: rules/cat-facts-catfact-rules.yml
- type: Vocabulary
  url: vocabulary/cat-facts-catfact-vocabulary.yml
- type: JSONLDContext
  url: json-ld/cat-facts-catfact-context.jsonld
features:
- name: Free and Open
  description: No API key, no signup, no quota header. Anyone can hit catfact.ninja and start getting JSON back. Ideal for
    first-class onboarding examples in tutorials and SDK quickstarts.
- name: Paginated Listings
  description: The /facts and /breeds endpoints return Laravel-style paginated responses with current_page, last_page, per_page,
    total, and a links array suitable for "next/prev" UI patterns.
- name: Length-Filtered Facts
  description: Both /fact and /facts accept a max_length query parameter, letting clients restrict trivia length for SMS-friendly,
    push-notification-friendly, or banner use cases.
- name: Self-Describing OpenAPI
  description: A live OpenAPI 3.0 document is published at /docs?api-docs.json and rendered as Swagger UI at /docs — usable
    directly by codegen tools, Postman import, and AI agent toolkits.
useCases:
- name: API Onboarding Tutorials
  description: Used in countless "hello-world" REST tutorials because it returns small JSON, requires no auth, and is CORS-friendly.
    A canonical first call for browsers, mobile apps, and SDKs.
- name: SMS and Chatbot Daily Facts
  description: The original Cat Facts service became a meme around texting friends a daily cat fact. catfact.ninja is the
    easiest backend for any "daily fact" bot, including SMS, Discord, and Slack integrations.
- name: Load Testing and Demo Apps
  description: Engineering teams point load generators, screen-recording demos, and observability sample apps at catfact.ninja
    because it tolerates traffic, returns tiny payloads, and never requires credential rotation.
- name: MCP and Agent Tool Demos
  description: Several community Model Context Protocol servers wrap catfact.ninja as a "hello world" tool because the surface
    is small, safe, and read-only — perfect for showing Claude using a tool.
integrations:
- name: Public APIs Index
  description: Listed in the popular public-apis/public-apis index as a free, no-auth Animals API.
- name: Community MCP Servers
  description: At least three community-built MCP servers wrap the catfact.ninja endpoints as Claude tools.
- name: Swagger UI
  description: Ships a live Swagger UI at https://catfact.ninja/ that imports the OpenAPI spec from /docs.
solutions:
- name: Lowest-Friction Demo API
  description: When you need a public, free, no-auth REST API to demo SDK generation, OpenAPI tooling, mock servers, or agent
    tool calls, catfact.ninja is the smallest acceptable surface area.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com