# API Style Guides

**Canonical:** https://apis.io/providers/style-guides/  
**Website:** https://developer.apievangelist.com/  
**APIs profiled:** 11

A landscape index of public API style guides published by leading technology companies and standards bodies. API style guides codify conventions for resource modeling, URI design, HTTP method use, status codes, error formats, pagination, versioning, deprecation, idempotency, hypermedia, and security so that APIs across an organization (or an industry) behave consistently. This topic repo catalogs the canonical industry style guides, compares the pillars each one chooses to mandate, and provides a shared vocabulary and JSON Schema for describing individual style guide rules.

## Kin Score — 19.0 / 100 (emerging)

Scored 2026-08-21 under rubric 0.12.0. Trend: flat (+0.0 from 19.0).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 25.4 |
| Governance | 25.0 |
| Contract Governance | 25.0 |
| Operational Transparency | 2.6 |
| Developer Ergonomics | 9.5 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

## Agent readiness — 1.5 (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 | documented |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## APIs (11)

- **Microsoft REST API Guidelines** — Microsoft's organization-wide REST API design guidelines, originally published in 2016 and now maintained as separate Azure and Microsoft Graph guideline documents under the umb...
- **Google API Improvement Proposals (AIPs)** — Google's design review system, modeled on Python PEPs and Rust RFCs. AIPs are numbered, individually reviewable design documents covering resource-oriented design, standard meth...
- **Zalando RESTful API and Event Guidelines** — The canonical open community style guide. Maintained by Zalando's API Guild and widely cited as the reference implementation for an API-First, OpenAPI-based REST and event-drive...
- **PayPal API Design Guidelines** — PayPal's API style guide covering service design principles, HTTP methods, hypermedia, naming, URI structure, JSON schema and types, error handling, versioning, and deprecation....
- **adidas API Guidelines** — adidas group's API guidelines covering general principles, REST conventions, and asynchronous (Kafka / AsyncAPI) event design. Ships with a Spectral ruleset that validates both ...
- **Cisco REST API Design Guide** — Guidelines for Designing REST APIs at Cisco, developed across Cisco DevNet, Collaboration, and the Application Platform Group. Emphasizes "API-only" communication, aesthetic and...
- **Atlassian REST API Design Guidelines** — Atlassian's REST API design guidelines, applied across Jira, Confluence, Crowd, and plugin REST modules. Defines URI conventions (singular resources, versioned paths, expand/sta...
- **Heroku Platform API Design Conventions** — Heroku's design conventions for the Platform API, documented in the Platform API Reference and the API Compatibility Policy. Notable for versioned media types (application/vnd.h...
- **GitLab API Style Guide** — GitLab's developer-facing API style guide for the REST API (v4) and GraphQL API. Mandates Grape DSL parameter validation, Entity-based response payloads, Title Case summary verb...
- **Kubernetes API Conventions** — The Kubernetes API conventions document, maintained by SIG Architecture. Defines the "kind / apiVersion" object envelope, spec/status separation, resourceVersion-based optimisti...
- **IETF HTTPAPI Working Group Drafts and RFCs** — The IETF httpapi Working Group is producing the cross-vendor vocabulary that style guides increasingly cite normatively. Includes RFC 9457 Problem Details for HTTP APIs, RFC 965...

## Security (1)

- **Style Guides Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

API Style Guides, API Design, API Governance, REST, OpenAPI, Conventions, Standards, Documentation

---

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