RESTful website screenshot

RESTful

Representational State Transfer (REST) is an architectural style for designing networked applications using stateless HTTP communication and uniform interfaces. RESTful describes systems and APIs that conform to the REST constraints: client-server separation, statelessness, cacheability, layered system, uniform interface, and (optionally) code-on-demand. This index covers the RESTful design paradigm including maturity models, API design patterns, documentation formats, and key reference implementations.

RESTful publishes 5 APIs on the APIs.io network. Tagged areas include Architecture, HTTP, and Web Services.

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

📡 Source on GitHub
13.6/100 emerging ▬ flat Agent 3/100 human only Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0
AccessFreemium
5 APIs
ArchitectureHTTPWeb Services

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0
Composite quality — 13.6/100 · emerging
Contract Quality 2.7 / 25
Developer Ergonomics 0.0 / 20
Access Clarity 3.2 / 20
Operational Transparency 1.0 / 13
Contract Governance 1.2 / 12
Discoverability 5.6 / 10
Agent readiness — 3/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
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
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Surface 0 / 5
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/restful: 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 5

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

Richardson Maturity Model

A model by Leonard Richardson that breaks down the maturity of a RESTful API into four levels: Level 0 (The Swamp of POX), Level 1 (Resources), Level 2 (HTTP Verbs), and Level 3...

JSON:API

A specification for building APIs in JSON that standardizes resource representation, relationships, error handling, and metadata. Reduces over-fetching and under-fetching with s...

HAL - Hypertext Application Language

A simple format for including hypermedia links in JSON or XML API responses. HAL uses _links for links and _embedded for embedded resources, providing a consistent way to make R...

OpenAPI Specification

The OpenAPI Specification (OAS) defines a standard, language-agnostic interface for HTTP APIs. OpenAPI 3.x is the most widely-used format for describing RESTful APIs, enabling d...

RFC 9110 - HTTP Semantics

The IETF standard defining HTTP semantics: methods, status codes, header fields, content negotiation, authentication, and request/response message formats. The authoritative ref...

Pricing Plans 1

Published pricing tiers and plan structures.

Restful Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Restful Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Restful Finops

FINOPS

Semantic Vocabularies 1

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

Restful Context

13 classes · 7 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

RESTful API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 1

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

RESTful API Description

10 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Restful Api Description Structure

0 properties

JSON STRUCTURE

Security Posture 1

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

Restful Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Build 1

SDKs, sample code, and the tooling you integrate with

IANA HTTP Status Codes
IANA HTTP Status Codes

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity

Other 3

Properties that don't map to a standard resource type

Roy Fielding REST Dissertation
Roy Fielding REST Dissertation
 IANA Link Relations
IANA Link Relations
 RFC 6570 URI Templates
RFC 6570 URI Templates

Source (apis.yml)

apis.yml Raw ↑ 
aid: restful
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/restful.png
name: RESTful
description: 'Representational State Transfer (REST) is an architectural style for designing networked applications using
  stateless HTTP communication and uniform interfaces. RESTful describes systems and APIs that conform to the REST constraints:
  client-server separation, statelessness, cacheability, layered system, uniform interface, and (optionally) code-on-demand.
  This index covers the RESTful design paradigm including maturity models, API design patterns, documentation formats, and
  key reference implementations.'
type: Index
url: https://raw.githubusercontent.com/api-evangelist/restful/refs/heads/main/apis.yml
tags:
- Architecture
- HTTP
- Web Services
created: '2025-01-01'
modified: '2026-05-02'
specificationVersion: '0.23'
apis:
- aid: restful:richardson-maturity-model
  name: Richardson Maturity Model
  description: 'A model by Leonard Richardson that breaks down the maturity of a RESTful API into four levels: Level 0 (The
    Swamp of POX), Level 1 (Resources), Level 2 (HTTP Verbs), and Level 3 (Hypermedia Controls / HATEOAS). Most modern APIs
    target Level 2.'
  humanURL: https://martinfowler.com/articles/richardsonMaturityModel.html
  tags:
  - Best Practices
  - Design Patterns
  - Maturity Model
  properties:
  - type: Documentation
    url: https://martinfowler.com/articles/richardsonMaturityModel.html
- aid: restful:json-api
  name: JSON:API
  description: A specification for building APIs in JSON that standardizes resource representation, relationships, error handling,
    and metadata. Reduces over-fetching and under-fetching with sparse fieldsets and compound documents.
  humanURL: https://jsonapi.org/
  tags:
  - Hypermedia
  - JSON
  - Standards
  properties:
  - type: Documentation
    url: https://jsonapi.org/format/
  - type: Website
    url: https://jsonapi.org/
- aid: restful:hal-specification
  name: HAL - Hypertext Application Language
  description: A simple format for including hypermedia links in JSON or XML API responses. HAL uses _links for links and
    _embedded for embedded resources, providing a consistent way to make REST APIs navigable.
  humanURL: https://stateless.co/hal_specification.html
  tags:
  - Hypermedia
  - JSON
  - Standards
  properties:
  - type: Documentation
    url: https://stateless.co/hal_specification.html
  - type: IETF Draft
    url: https://datatracker.ietf.org/doc/html/draft-kelly-json-hal
- aid: restful:openapi-specification
  name: OpenAPI Specification
  description: The OpenAPI Specification (OAS) defines a standard, language-agnostic interface for HTTP APIs. OpenAPI 3.x
    is the most widely-used format for describing RESTful APIs, enabling documentation, code generation, and validation.
  humanURL: https://spec.openapis.org/oas/latest.html
  tags:
  - Documentation
  - Standards
  - Tooling
  properties:
  - type: Specification
    url: https://spec.openapis.org/oas/latest.html
  - type: Website
    url: https://www.openapis.org/
- aid: restful:http-rfc-9110
  name: RFC 9110 - HTTP Semantics
  description: 'The IETF standard defining HTTP semantics: methods, status codes, header fields, content negotiation, authentication,
    and request/response message formats. The authoritative reference for RESTful HTTP API design.'
  humanURL: https://datatracker.ietf.org/doc/html/rfc9110
  tags:
  - HTTP
  - RFC
  - Standards
  properties:
  - type: Standards
    url: https://datatracker.ietf.org/doc/html/rfc9110
common:
- type: DomainSecurity
  url: security/restful-domain-security.yml
- type: Roy Fielding REST Dissertation
  url: https://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arch_style.htm
- type: IANA HTTP Status Codes
  url: https://www.iana.org/assignments/http-status-codes/
- type: IANA Link Relations
  url: https://www.iana.org/assignments/link-relations/
- type: RFC 6570 URI Templates
  url: https://datatracker.ietf.org/doc/html/rfc6570
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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