Numbers API website screenshot

Numbers API

Free REST API providing interesting mathematical facts, trivia, dates, and year facts about numbers for educational and fun applications. Returns short, readable facts about any number or date across four categories: trivia, mathematical properties, notable years, and day-of-year historical events. No authentication or API key required.

Numbers API publishes 6 APIs on the APIs.io network, including Date API, Math API, Numbers API API, and 3 more. Tagged areas include Numbers, Trivia, Math, Facts, and Education.

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

Numbers API’s developer surface includes documentation, engineering blog, pricing, and 10 more developer resources.

🌐 Visit website 📡 Source on GitHub
42.4/100 developing ▬ flat Agent 28/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreeOpen⚡ Free to try
6 APIs
NumbersTriviaMathFactsEducationFreeNo Auth

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 42.4/100 · developing
Contract Quality 15.1 / 25
Developer Ergonomics 2.2 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 2.7 / 13
Governance 7.0 / 12
Discoverability 7.4 / 10
Agent readiness — 28/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 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 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/numbers-api: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

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

Numbers API Date API

The Date API from Numbers API — 1 operation(s) for date.

Numbers API Math API

The Math API from Numbers API — 1 operation(s) for math.

Numbers API Numbers API API

The Numbers API API from Numbers API — 1 operation(s) for numbers api.

Numbers API Random API

The Random API from Numbers API — 4 operation(s) for random.

Numbers API Trivia API

The Trivia API from Numbers API — 1 operation(s) for trivia.

Numbers API Year API

The Year API from Numbers API — 1 operation(s) for year.

Pricing Plans 1

Published pricing tiers and plan structures.

Numbers Api Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Numbers Api Rate Limits

0 limits

RATE LIMITS

FinOps 1

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

Numbers Api Finops

FINOPS

Semantic Vocabularies 1

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

Numbers Api Context

5 classes · 6 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Numbers API API Rules

4 rules · 3 warnings 1 info

SPECTRAL

JSON Schema 1

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

NumberFact

6 properties

JSON SCHEMA

Examples 5

Example request and response payloads for these APIs.

Batch Facts Json

4 fields

EXAMPLE

Date Fact Json

5 fields

EXAMPLE

Math Fact Json

4 fields

EXAMPLE

Trivia Fact Json

4 fields

EXAMPLE

Year Fact Json

5 fields

EXAMPLE

Security Posture 1

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

Numbers Api Domain Security

TLSv1.3 · HSTS

SECURITY

Agentic Access 1

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

Numbers Api Agentic Access

9 operations

9 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 2

Status, limits, changes, and where to get help

StatusPage
StatusPage
 RateLimits
RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

Website
Website
 LinkedIn
LinkedIn
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

X
X

Source (apis.yml)

apis.yml Raw ↑ 
aid: numbers-api
name: Numbers API
description: 'Free REST API providing interesting mathematical facts, trivia, dates, and year facts about numbers for educational
  and fun applications. Returns short, readable facts about any number or date across four categories: trivia, mathematical
  properties, notable years, and day-of-year historical events. No authentication or API key required.

  '
accessModel:
  pricing: free
  onboarding: open
  trial: false
  try_now: true
  public: true
  label: Free · Open access
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/numbers-api.png
url: https://raw.githubusercontent.com/api-evangelist/numbers-api/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.19'
type: Index
tags:
- Numbers
- Trivia
- Math
- Facts
- Education
- Free
- No Auth
apis:
- aid: numbers-api:numbers-api-date-api
  name: Numbers API Date API
  description: The Date API from Numbers API — 1 operation(s) for date.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Date
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-date-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
- aid: numbers-api:numbers-api-math-api
  name: Numbers API Math API
  description: The Math API from Numbers API — 1 operation(s) for math.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Math
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-math-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
- aid: numbers-api:numbers-api-numbers-api-api
  name: Numbers API Numbers API API
  description: The Numbers API API from Numbers API — 1 operation(s) for numbers api.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Numbers API
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-numbers-api-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
- aid: numbers-api:numbers-api-random-api
  name: Numbers API Random API
  description: The Random API from Numbers API — 4 operation(s) for random.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Random
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-random-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
- aid: numbers-api:numbers-api-trivia-api
  name: Numbers API Trivia API
  description: The Trivia API from Numbers API — 1 operation(s) for trivia.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Trivia
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-trivia-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
- aid: numbers-api:numbers-api-year-api
  name: Numbers API Year API
  description: The Year API from Numbers API — 1 operation(s) for year.
  humanURL: http://numbersapi.com
  baseURL: http://numbersapi.com
  tags:
  - Year
  properties:
  - type: OpenAPI
    url: openapi/numbers-api-year-api-openapi.yml
  - type: Documentation
    url: http://numbersapi.com/#42
common:
- type: AgenticAccess
  url: agentic-access/numbers-api-agentic-access.yml
- type: DomainSecurity
  url: security/numbers-api-domain-security.yml
- type: Website
  url: http://numbersapi.com
- type: Documentation
  url: http://numbersapi.com/#42
- type: GitHubOrg
  url: https://github.com/divad12
- type: LinkedIn
  url: https://www.linkedin.com/in/davidhu2000/
- type: Blog
  url: http://numbersapi.com
- type: Pricing
  url: http://numbersapi.com
- type: StatusPage
  url: http://numbersapi.com
- type: X
  url: https://x.com/numbersapi
- type: Plans
  url: plans/numbers-api-plans-pricing.yml
- type: RateLimits
  url: rate-limits/numbers-api-rate-limits.yml
- type: FinOps
  url: finops/numbers-api-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com