# RESTful

**Canonical:** https://apis.io/providers/restful/  
**APIs profiled:** 5

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.

## Kin Score — 13.6 / 100 (emerging)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 13.6).

| Facet | Score |
|---|---|
| Discoverability | 55.6 |
| Contract Quality | 10.7 |
| Governance | 9.8 |
| Contract Governance | 9.8 |
| Operational Transparency | 7.9 |
| Developer Ergonomics | 0.0 |
| Commercial Clarity | 15.8 |
| Access Clarity | 15.8 |

## Agent readiness — 2.5 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Freemium — onboarding: unknown, pricing: freemium, trial: no (confidence: medium).

## APIs (5)

- **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...

## Security (1)

- **Restful Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **Restful Plans Pricing**

## Tags

Architecture, HTTP, Web Services

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/restful/). Scores are computed from the provider's own public artifacts under a published rubric.