APIs.json website screenshot

APIs.json

APIs.json is an open, machine-readable specification that API providers can use to describe their API operations, similar to how websites use sitemap.xml. The format provides a lightweight means for individuals and organizations to document the location of their APIs, associated descriptions, human and machine-readable specifications, and ancillary information such as licensing, maintainers, and terms of service. It was created by Kin Lane and Steven Willmott in May 2014 and is maintained as an open IETF-style draft. The current stable version is 0.19, published in November 2024. APIs.json files can be placed at the root of any domain as /apis.json or /apis.yml for automated discovery. The specification defines root-level fields (name, description, url, apis, common), API-level fields (aid, humanURL, baseURL, tags, properties), and a comprehensive list of property types covering documentation, authentication, licensing, support, and governance. It is the foundation for the APIs.io search engine and API Commons initiative.

APIs.json publishes 1 API on the APIs.io network. Tagged areas include API Aggregation, API Cataloging, API Commons, API Discovery, and API Governance.

The APIs.json catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

APIs.json’s developer surface includes engineering blog, support, and 10 more developer resources.

36.6/100 thin ▼ -5.7 Agent 3/100 human only Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreemium
1 APIs 8 Features 6 Use Cases
API AggregationAPI CatalogingAPI CommonsAPI DiscoveryAPI GovernanceAPI OperationsMachine ReadableSpecificationStandard

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 36.6/100 · thin
Contract Quality 8.5 / 25
Developer Ergonomics 1.3 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 8.3 / 12
Discoverability 5.9 / 10
Agent readiness — 3/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 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/apis-json: 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 1

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

APIs.json Specification

The APIs.json specification defines a machine-readable JSON or YAML format for describing API operations. Unlike OpenAPI which describes the technical interface of a single API,...

Pricing Plans 1

Published pricing tiers and plan structures.

Rate Limits 1

Documented rate limits and quota policies.

Apis Json Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Features 8

Notable capabilities this provider offers.

Machine-Readable API Operations

Provides a machine-readable format for documenting API operations beyond just the technical interface, covering documentation, pricing, authentication, terms of service, support...

Domain Root Discovery

APIs.json files can be placed at /apis.json or /apis.yml at the root of any domain, enabling automated discovery by search engines and robots without prior knowledge of the API ...

Property Type System

Defines a comprehensive enumerated set of property types (OpenAPI, Documentation, Authentication, Pricing, Support, etc.) enabling consistent machine-readable indexing of API op...

Federation via Include

Supports federated API directories through include references, allowing a root APIs.json to reference other APIs.json files on different servers or domains.

Multiple API Collections

A single APIs.json file can document multiple APIs in the apis array, with shared properties in the common section, enabling organization-wide API catalogs.

Authority and Non-Authority

Defines authoritative (same DNS domain) and non-authoritative entries, with conflict resolution rules giving priority to the most specific authoritative entry.

Overlay Support

Supports overlay specifications that can modify or extend existing APIs.json entries, enabling provider-agnostic enrichment of API metadata.

Version History

Maintained as a versioned specification from 0.11 through current 0.19, with full version history and diff comparisons available on GitHub and apisjson.org.

Scroll for all 8

Semantic Vocabularies 1

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

Apis Json Context

9 classes · 26 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

APIs.json API Rules

6 rules · 4 warnings 2 info

SPECTRAL

APIs.json API Rules

34 rules · 15 errors 12 warnings 7 info

SPECTRAL

JSON Schema 4

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

JSON Schema for APIs.json 0.18

16 properties

JSON SCHEMA

JSON Schema for APIs.json 0.19

18 properties

JSON SCHEMA

JSON Schema for APIs.json 0.20

20 properties

JSON SCHEMA

JSON Structure 4

JSON Structure definitions describing this provider's data shapes.

Apis Json Structure 0.17 Structure

14 properties

JSON STRUCTURE

Apis Json Structure 0.18 Structure

16 properties

JSON STRUCTURE

Apis Json Structure 0.19 Structure

18 properties

JSON STRUCTURE

Apis Json Structure 0.20 Structure

20 properties

JSON STRUCTURE

Examples 2

Example request and response payloads for these APIs.

Apis Json Complete Example

16 fields

EXAMPLE

Apis Json Minimal Example

13 fields

EXAMPLE

Security Posture 1

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

Apis Json Domain Security

TLSv1.3

SECURITY

Use Cases 6

What developers build with this provider.

API Discovery

API providers publish APIs.json files at their domain root so that search engines like APIs.io can automatically discover and index all their APIs without manual submission.

API Governance

Platform teams use APIs.json as a canonical machine-readable index of their API portfolio, enabling automated compliance checking of required operational properties like terms o...

API Portal Generation

Developer portals can be automatically generated from APIs.json files by reading the properties array and presenting documentation, OpenAPI specs, getting started guides, and ot...

API Commons Participation

Organizations publish APIs.json files to participate in the API Commons initiative, making their APIs discoverable and accessible to a wider developer community.

Internal API Catalog

Enterprises use APIs.json as the foundation for internal API catalogs, enabling discoverability of internal, partner, and public APIs using a consistent machine-readable format.

Backstage Integration

Teams use the APIs.json Backstage integration to import API metadata from APIs.json files into Spotify Backstage for internal developer portal use.

Integrations 6

Pre-built integrations with other platforms and tools.

APIs.io

The APIs.io search engine is built entirely on the APIs.json specification, indexing submitted APIs.json files to power its API discovery and search capabilities.

API Commons

API Commons uses APIs.json as its core metadata format for documenting API operations across the open API ecosystem.

OpenAPI

APIs.json references OpenAPI specifications as a core property type, linking machine-readable API interface descriptions to their operations metadata.

Backstage

APIs.json files can be imported into Spotify Backstage using the apis-json/backstage integration tool for enterprise developer portal use.

Spectral

Spectral rulesets can validate APIs.json files against the specification schema and enforce organizational governance rules for API operations.

AsyncAPI

APIs.json supports AsyncAPI as a property type, allowing event-driven and message-based APIs to be documented alongside REST APIs in a single APIs.json file.

Resources

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Build 5

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Company 2

The organization behind the API

Other 1

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: apis-json
name: APIs.json
description: APIs.json is an open, machine-readable specification that API providers can use to describe their API operations,
  similar to how websites use sitemap.xml. The format provides a lightweight means for individuals and organizations to document
  the location of their APIs, associated descriptions, human and machine-readable specifications, and ancillary information
  such as licensing, maintainers, and terms of service. It was created by Kin Lane and Steven Willmott in May 2014 and is
  maintained as an open IETF-style draft. The current stable version is 0.19, published in November 2024. APIs.json files
  can be placed at the root of any domain as /apis.json or /apis.yml for automated discovery. The specification defines root-level
  fields (name, description, url, apis, common), API-level fields (aid, humanURL, baseURL, tags, properties), and a comprehensive
  list of property types covering documentation, authentication, licensing, support, and governance. It is the foundation
  for the APIs.io search engine and API Commons initiative.
type: Index
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/apis-json.png
tags:
- API Aggregation
- API Cataloging
- API Commons
- API Discovery
- API Governance
- API Operations
- Machine Readable
- Specification
- Standard
url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/apis.yml
created: '2026-03-26'
modified: '2026-04-19'
specificationVersion: '0.19'
apis:
- aid: apis-json:apis-json-specification
  name: APIs.json Specification
  description: The APIs.json specification defines a machine-readable JSON or YAML format for describing API operations. Unlike
    OpenAPI which describes the technical interface of a single API, APIs.json describes the surrounding operations of one
    or more APIs — documentation, authentication, pricing, terms of service, support, and other properties. Created by Kin
    Lane and Steven Willmott in May 2014, the specification is maintained as an informal IETF draft at apisjson.org. The current
    stable version is 0.19, published November 6, 2024. APIs.json files are placed at the domain root as /apis.json or /apis.yml
    for automated discovery by robots and search engines.
  humanURL: https://apisjson.org
  tags:
  - API Description
  - API Discovery
  - API Operations
  - Machine Readable
  - Specification
  - Standard
  properties:
  - type: Documentation
    url: https://apisjson.org/schema/
  - type: Specification
    url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/spec/apisjson_0.19.txt
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/json-schema/apis-json-schema-0.19.yaml
    title: Schema v0.19
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/json-schema/apis-json-schema-0.18.yaml
    title: Schema v0.18
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/json-schema/apis-json-schema-0.17.yaml
    title: Schema v0.17
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/json-schema/apis-json-schema-0.20.yaml
    title: Schema v0.20 (Draft)
common:
- type: DomainSecurity
  url: security/apis-json-domain-security.yml
- type: Website
  url: https://apisjson.org
- type: Properties
  url: https://apisjson.org/properties/
- type: Blog
  url: https://apisjson.org/blog/
- type: GitHubOrganization
  url: https://github.com/apis-json
- type: GitHubRepository
  url: https://github.com/apis-json/api-json
  title: Specification Repository
- type: GitHubRepository
  url: https://github.com/apis-json/apis-json-website
  title: Website
- type: GitHubRepository
  url: https://github.com/apis-json/artisanal
  title: Artisanal APIs.json Examples
- type: GitHubRepository
  url: https://github.com/apis-json/backstage
  title: Backstage Integration
- type: Support
  url: https://github.com/apis-json/api-json/issues
- type: SpectralRules
  url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/rules/apis-json-spectral-rules.yml
- type: Vocabulary
  url: https://raw.githubusercontent.com/api-evangelist/apis-json/refs/heads/main/vocabulary/apis-json-vocabulary.yaml
- type: Features
  data:
  - name: Machine-Readable API Operations
    description: Provides a machine-readable format for documenting API operations beyond just the technical interface, covering
      documentation, pricing, authentication, terms of service, support, and governance.
  - name: Domain Root Discovery
    description: APIs.json files can be placed at /apis.json or /apis.yml at the root of any domain, enabling automated discovery
      by search engines and robots without prior knowledge of the API provider.
  - name: Property Type System
    description: Defines a comprehensive enumerated set of property types (OpenAPI, Documentation, Authentication, Pricing,
      Support, etc.) enabling consistent machine-readable indexing of API operations.
  - name: Federation via Include
    description: Supports federated API directories through include references, allowing a root APIs.json to reference other
      APIs.json files on different servers or domains.
  - name: Multiple API Collections
    description: A single APIs.json file can document multiple APIs in the apis array, with shared properties in the common
      section, enabling organization-wide API catalogs.
  - name: Authority and Non-Authority
    description: Defines authoritative (same DNS domain) and non-authoritative entries, with conflict resolution rules giving
      priority to the most specific authoritative entry.
  - name: Overlay Support
    description: Supports overlay specifications that can modify or extend existing APIs.json entries, enabling provider-agnostic
      enrichment of API metadata.
  - name: Version History
    description: Maintained as a versioned specification from 0.11 through current 0.19, with full version history and diff
      comparisons available on GitHub and apisjson.org.
- type: UseCases
  data:
  - name: API Discovery
    description: API providers publish APIs.json files at their domain root so that search engines like APIs.io can automatically
      discover and index all their APIs without manual submission.
  - name: API Governance
    description: Platform teams use APIs.json as a canonical machine-readable index of their API portfolio, enabling automated
      compliance checking of required operational properties like terms of service and authentication.
  - name: API Portal Generation
    description: Developer portals can be automatically generated from APIs.json files by reading the properties array and
      presenting documentation, OpenAPI specs, getting started guides, and other resources.
  - name: API Commons Participation
    description: Organizations publish APIs.json files to participate in the API Commons initiative, making their APIs discoverable
      and accessible to a wider developer community.
  - name: Internal API Catalog
    description: Enterprises use APIs.json as the foundation for internal API catalogs, enabling discoverability of internal,
      partner, and public APIs using a consistent machine-readable format.
  - name: Backstage Integration
    description: Teams use the APIs.json Backstage integration to import API metadata from APIs.json files into Spotify Backstage
      for internal developer portal use.
- type: Integrations
  data:
  - name: APIs.io
    description: The APIs.io search engine is built entirely on the APIs.json specification, indexing submitted APIs.json
      files to power its API discovery and search capabilities.
  - name: API Commons
    description: API Commons uses APIs.json as its core metadata format for documenting API operations across the open API
      ecosystem.
  - name: OpenAPI
    description: APIs.json references OpenAPI specifications as a core property type, linking machine-readable API interface
      descriptions to their operations metadata.
  - name: Backstage
    description: APIs.json files can be imported into Spotify Backstage using the apis-json/backstage integration tool for
      enterprise developer portal use.
  - name: Spectral
    description: Spectral rulesets can validate APIs.json files against the specification schema and enforce organizational
      governance rules for API operations.
  - name: AsyncAPI
    description: APIs.json supports AsyncAPI as a property type, allowing event-driven and message-based APIs to be documented
      alongside REST APIs in a single APIs.json file.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com