Spectral

Spectral is an open-source API style guide enforcer and linter from Stoplight, providing a flexible JSON/YAML linting engine with built-in support for OpenAPI (v3.1, v3.0, v2.0), Arazzo v1.0, and AsyncAPI v2.x. Teams use Spectral to define, share, and enforce API design standards through custom rulesets, integrating into CI/CD pipelines, VS Code, and the Stoplight Platform for real-time style guide feedback.

Spectral is listed with 1 API on the APIs.io network. Tagged areas include API Design, API Linting, API Style Guide, AsyncAPI, and JSON Schema.

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

Spectral’s developer surface includes documentation, GitHub presence, release notes, engineering blog, and 10 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

19.5/100 emerging ▬ flat Agent 1/100 human only self hosted · Apache-2.0 Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemium

1 API

API Design API LintingAPI Style GuideAsyncAPI JSON Schema OpenAPI Quality Assurance

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 19.5/100 · emerging

Contract Quality 4.7 / 21

Developer Ergonomics 2.4 / 17

Access Clarity 1.1 / 17

Operational Transparency 1.3 / 11

Contract Governance 2.8 / 10

Discoverability 5.6 / 9

Regulatory Posture 0.7 / 15

Agent readiness — 1/100 · 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 Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document Ask about this →
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship Ask about this →
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author Ask about this →
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey) Ask about this →
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →

12 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 21.9 — up to +19.5 composite points Ask about this →
Access Clarity scores 6.4 — up to +18.7 composite points Ask about this →
Developer Ergonomics scores 14.3 — up to +17.1 composite points Ask about this →

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/spectral/apis.yml: open an issue on github.com/api-evangelist/spectral to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

AsyncAPI

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

JSON Schema

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

OpenAPI

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

APIs 1

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

Spectral

Spectral is a flexible JSON/YAML linter and style guide enforcer with built-in support for OpenAPI (v3.1, v3.0, v2.0), Arazzo v1.0, and AsyncAPI v2.x. It enables teams to define...

Spectral API pricing

Not yet checked against Spectral's own pricing page. Compiled by API Evangelist on 2026-05-04; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free
Professional paid	Free
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Free Tier Monthly Quota: 1000 requests per month
Professional Tier Default: 100 requests per minute

Compiled by API Evangelist, not yet checked against Spectral's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Spectral Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Spectral Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Spectral Finops

FINOPS

Semantic Vocabularies 1

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

Spectral Context

9 classes · 10 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

Spectral — jsonschema rules

5 rules · 4 warn-severity 1 info-severity

SPECTRAL

Spectral API Rules

4 rules · 2 warn-severity

SPECTRAL

JSON Schema 1

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

Spectral Ruleset

5 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Spectral Ruleset Structure

0 properties

JSON STRUCTURE

Examples 1

Example request and response payloads for these APIs.

Spectral Openapi Ruleset Example

3 fields

EXAMPLE

Security Posture 1

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

Spectral Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Build 3

SDKs, sample code, and the tooling you integrate with

GitHub

GitHub

GitHubOrganization

GitHubOrganization

NPMPackage

NPMPackage

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

RateLimits

RateLimits

ReleaseNotes

ReleaseNotes

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Contributing

Contributing

Source (apis.yml)

aid: spectral
name: Spectral
description: Spectral is an open-source API style guide enforcer and linter from Stoplight, providing a flexible JSON/YAML
  linting engine with built-in support for OpenAPI (v3.1, v3.0, v2.0), Arazzo v1.0, and AsyncAPI v2.x. Teams use Spectral
  to define, share, and enforce API design standards through custom rulesets, integrating into CI/CD pipelines, VS Code, and
  the Stoplight Platform for real-time style guide feedback.
type: Index
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  license_evidence:
    repo: stoplightio/spectral
    spdx: Apache-2.0
    stars: 3216
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: medium
  source:
  - repository-license
  generated: '2026-09-25'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/spectral.png
x-docs-platform: stoplight
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
tags:
- API Design
- API Linting
- API Style Guide
- AsyncAPI
- JSON Schema
- OpenAPI
- Quality Assurance
tags_raw:
- API Design
- API Linting
- API Style Guide
- AsyncAPI
- JSON Schema
- OpenAPI
- Quality Assurance
- JSON-Schema
url: https://raw.githubusercontent.com/api-evangelist/spectral/refs/heads/main/apis.yml
created: '2026-03-25'
modified: '2026-05-02'
specificationVersion: '0.23'
apis:
- aid: spectral:spectral
  name: Spectral
  description: Spectral is a flexible JSON/YAML linter and style guide enforcer with built-in support for OpenAPI (v3.1, v3.0,
    v2.0), Arazzo v1.0, and AsyncAPI v2.x. It enables teams to define custom rulesets to enforce naming conventions, security
    standards, and design consistency across API specifications at scale.
  humanURL: https://stoplight.io/open-source/spectral
  baseURL: https://github.com/stoplightio/spectral
  tags:
  - API Design
  - API Linting
  - API Style Guide
  - AsyncAPI
  - JSON Schema
  - OpenAPI
  - Quality Assurance
  tags_raw:
  - API Design
  - API Linting
  - API Style Guide
  - AsyncAPI
  - JSON Schema
  - OpenAPI
  - Quality Assurance
  - JSON-Schema
  properties:
  - type: Documentation
    url: https://docs.stoplight.io/docs/spectral
  - type: GettingStarted
    url: https://docs.stoplight.io/docs/spectral/674b27b261c3c-overview
  - type: GitHub
    url: https://github.com/stoplightio/spectral
  - type: NPMPackage
    url: https://www.npmjs.com/package/@stoplight/spectral-cli
  - type: ChangeLog
    url: https://github.com/stoplightio/spectral/blob/main/CHANGELOG.md
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/spectral/refs/heads/main/json-schema/spectral-ruleset-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/spectral/refs/heads/main/json-structure/spectral-ruleset-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/spectral/refs/heads/main/json-ld/spectral-context.jsonld
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/spectral/refs/heads/main/vocabulary/spectral-vocabulary.yml
common:
- type: Plans
  url: plans/spectral-plans-pricing.yml
- type: RateLimits
  url: rate-limits/spectral-rate-limits.yml
- type: FinOps
  url: finops/spectral-finops.yml
- type: DomainSecurity
  url: security/spectral-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/spectralcode
- type: Website
  url: https://stoplight.io/open-source/spectral
- type: Documentation
  url: https://docs.stoplight.io/docs/spectral
- type: GitHub
  url: https://github.com/stoplightio/spectral
- type: GitHubOrganization
  url: https://github.com/stoplightio
- type: NPMPackage
  url: https://www.npmjs.com/package/@stoplight/spectral-cli
- type: License
  url: https://github.com/stoplightio/spectral/blob/main/LICENSE
  x-license: Apache-2.0
- type: ReleaseNotes
  url: https://github.com/stoplightio/spectral/releases
- type: Contributing
  url: https://github.com/stoplightio/spectral/blob/main/CONTRIBUTING.md
- type: Integrations
  url: https://stoplight.io/integrations
- url: https://blog.stoplight.io/feed
  type: Blog
integrations:
- name: Azure
- name: GitHub
- name: GitLab
- name: Bitbucket
- name: Single sign-on
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-parent: stoplight
x-relationship: acquisition
x-acquired: 2023

Spectral API — frequently asked questions

Does Spectral have an API?

Yes. APIs.io lists 1 API from Spectral, including Spectral.

How much does the Spectral API cost?

APIs.io lists 3 pricing plans for Spectral, with each plan's price, limits and inclusions under Pricing on this page.

Is the Spectral API ready for AI agents?

Spectral has a Kin Score of 19.5 out of 100 (emerging) and an Agent Readiness score of 0.6 (human-only), scored by API Evangelist on 2026-11-13.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

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How their score was established

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