Atomic CSS

Atomic CSS is a utility‑first CSS framework that lets you combine the first letters of CSS properties into concise class names, enabling you to style any element instantly. It works without any configuration or build step – just write classes and see results immediately. The framework emphasizes a minimal, class‑only approach, turning CSS property names into short, memorable utilities for rapid development.

Atomic CSS is listed with 1 API on the APIs.io network. Tagged areas include CSS, utility-first, Framework, atomic, and Open Source.

Atomic CSS’s developer surface includes sandbox, documentation, API reference, getting-started guide, support, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

13.5/100 emerging ▼ -5.6 Agent 9/100 agent aware Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessOpen

1 API 1 MCP Servers

CSSutility-firstFramework atomic Open Source

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 13.5/100 · emerging

Contract Quality 0.0 / 21

Developer Ergonomics 5.7 / 17

Access Clarity 0.0 / 17

Operational Transparency 0.3 / 11

Contract Governance 0.0 / 10

Discoverability 4.8 / 9

Regulatory Posture 2.8 / 15

Agent readiness — 9/100 · agent aware

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 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 4 / 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 Energy & Utilities 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
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
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)
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)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0

10 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 0.0 — up to +25.0 composite points
Access Clarity scores 0.0 — up to +20.0 composite points
Developer Ergonomics scores 33.3 — up to +13.3 composite points

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.

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/atomiccss-dev/apis.yml: open an issue on github.com/api-evangelist/atomiccss-dev 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 2

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.

CSS

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

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

APIs 1

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

Atomic CSS API

Atomic CSS 프레임워크를 소개합니다. 설계 철학, 특징, 동작 방식을 설명합니다.

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Atomic CSS MCP Server

Remote MCP server at mcp.atomiccss.dev.

MCP SERVER

Atomic CSS API pricing

Pricing Plans 1

Published pricing tiers and plan structures.

Atomiccss Dev Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Atomiccss Dev Rate Limits

0 limits

RATE LIMITS

Security Posture 2

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

Atomiccss Dev Authentication

0 schemes

SECURITY

Atomiccss Dev Domain Security

TLSv1.3

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Atomiccss Dev Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Resources

Get Started 3

Portal, sign-up, and the first successful call

Sandbox

Sandbox

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

MCPServer

MCPServer

Build 3

SDKs, sample code, and the tooling you integrate with

SDKs

SDKs

Packages

Packages

GitHubOrganization

GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Hosts

Hosts

Source (apis.yml)

aid: atomiccss-dev
name: Atomic CSS
description: Atomic CSS is a utility‑first CSS framework that lets you combine the first letters of CSS properties into concise
  class names, enabling you to style any element instantly. It works without any configuration or build step – just write
  classes and see results immediately. The framework emphasizes a minimal, class‑only approach, turning CSS property names
  into short, memorable utilities for rapid development.
accessModel:
  pricing: unknown
  onboarding: open
  trial: false
  try_now: false
  public: true
  gated: none
  gated_source:
  - onboarding
  label: Open access
  confidence: low
  probe_state: unreadable
  source:
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://atomiccss.dev/favicon.ico
url: https://artifacts.apis.io/atomiccss-dev/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-02 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-01'
modified: '2026-11-01'
tags:
- CSS
- utility-first
- Framework
- atomic
- Open Source
tags_raw:
- css
- utility-first
- framework
- atomic
- open-source
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: MCPServer
  url: mcp/atomiccss-dev-mcp.yml
- type: Hosts
  url: hosts/atomiccss-dev-hosts.yml
- type: SDKs
  url: packages/atomiccss-dev-packages.yml
- type: Packages
  url: packages/atomiccss-dev-packages.yml
- type: Sandbox
  url: https://atomiccss.dev/playground
- type: DomainSecurity
  url: security/atomiccss-dev-domain-security.yml
- type: Website
  url: https://atomiccss.dev/
- type: DeveloperPortal
  url: https://atomiccss.dev/developer/
- type: Documentation
  url: https://atomiccss.dev/docs/
- type: APIReference
  url: https://atomiccss.dev/docs/
- type: GettingStarted
  url: https://atomiccss.dev/en/docs/introduction
- type: Support
  url: https://atomiccss.dev/support/
- type: Blog
  url: https://atomiccss.dev/blog/
- type: GitHubOrganization
  url: https://github.com/nicecss-com
apis:
- name: Atomic CSS API
  description: Atomic CSS 프레임워크를 소개합니다. 설계 철학, 특징, 동작 방식을 설명합니다.
  humanURL: https://atomiccss.dev/docs/introduction
  aid: atomiccss-dev:atomic-css-api
x-coverage:
  state: unreadable
  reason: no-machine-readable-spec
  detail: Documentation pages are HTML only and no machine‑readable OpenAPI/GraphQL/AsyncAPI spec was found.
  evidence:
  - url: https://atomiccss.dev/openapi.json
    status: 200
  checked: '2026-11-02'
x-enrichment:
  date: '2026-11-02'
  status: enriched
  artifacts_added: 25
  pass: modular-v1
  engine: identity=oss,contract=oss,surfaces=oss,docs=oss,regulatory=oss

Atomic CSS API — frequently asked questions

Does Atomic CSS have an API?

Yes. APIs.io lists 1 API from Atomic CSS, including Atomic CSS API.

How do I authenticate with the Atomic CSS API?

Atomic CSS documents its authentication (0 schemes). The details are profiled on APIs.io as Atomiccss Dev Authentication.

Does Atomic CSS have an MCP server?

Yes. APIs.io lists 1 MCP server for Atomic CSS: Remote MCP server at mcp.atomiccss.dev.

Is the Atomic CSS API ready for AI agents?

Atomic CSS has a Kin Score of 13.5 out of 100 (emerging) and an Agent Readiness score of 8.8 (agent-aware), scored by API Evangelist on 2026-11-06.

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