API Style Guides
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.
More than an index entry, but the surface is still mostly links rather than artifacts — the cohort most likely to move a full band from modest, well-targeted work.
API Evangelist profiles API Style Guides the way a machine reads it — 34 machine-readable artifacts across 11 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — API Style Guides scores 24.9/100 (emerging), with a separate agent-readiness read of 2/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-08-17 · rubric v0.11.0
Put this on your own site. The badge is drawn live from API Style Guides's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.
<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/style-guides/"
title="API Style Guides on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/style-guides.svg"
alt="API Style Guides Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/style-guides/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/style-guides/"
title="API Style Guides on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/style-guides/card.svg"
alt="API Style Guides Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile API Style Guides
Each block below is one kind of artifact we hold for API Style Guides. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 11
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
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...
Scroll within the panel for all 11 ·
GraphQL 1
Where a provider ships GraphQL, the schema is the contract. We profile it alongside the REST surface so the whole interface is legible in one place.
GraphQL schemas published by this provider.
API Style Guides GraphQL API
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...
GRAPHQLSemantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Style Guides Context
JSON-LDSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
API Style Guides API Rules
SPECTRALJSON Schema 1
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
API Style Guide Rule
JSON SCHEMAExamples 18
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Adidas Spectral
EXAMPLEAip 131 Get
EXAMPLEAip 158 Pagination
EXAMPLEAip 193 Errors
EXAMPLEAtlassian Uri Conventions
EXAMPLECisco Api Only
EXAMPLEGitlab Summary Verbs
EXAMPLEHeroku Rate Limiting
EXAMPLEHeroku Stability Levels
EXAMPLEKubernetes Spec Status
EXAMPLEMs Azure Idempotency
EXAMPLEMs Azure Versioning
EXAMPLEPaypal Hateoas
EXAMPLEPaypal Idempotency
EXAMPLERfc 9457 Problem Details
EXAMPLERfc 9745 Deprecation
EXAMPLEZalando 100 Api First
EXAMPLEZalando 101 Openapi
EXAMPLEScroll within the panel for all 18 ·
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for API Style Guides — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 1
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 1
Authentication, authorization, and security posture
Other 4
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/style-guides · machine-readable index on apis.io
This is an independent, third-party profile of API Style Guides, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
info@apievangelist.com
·
Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and
you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.