UML

UML (Unified Modeling Language) is the standard modeling language for software architecture, system design, and technical documentation. Governed by the Object Management Group (OMG), UML defines a set of notation conventions and diagram types — class, sequence, activity, use case, state, component, deployment, and more — used across the software development lifecycle. This collection profiles the ecosystem of tools, APIs, and services that work with UML diagrams programmatically.

UML publishes 3 APIs on the APIs.io network: Diagrams API, Health API, and Validation API. Tagged areas include UML, Modeling, Diagrams, Software Architecture, and Design.

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

UML’s developer surface includes GitHub presence, documentation, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub

32.7/100 thin ▬ flat Agent 23/100 agent aware Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0

AccessFreemium

2 APIs

UML Modeling Diagrams Software Architecture Design Standards

Kin Score

Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0

Composite quality — 32.7/100 · thin

Contract Quality 12.6 / 23

Developer Ergonomics 3.9 / 18

Access Clarity 2.8 / 18

Operational Transparency 1.5 / 12

Contract Governance 3.1 / 11

Discoverability 6.2 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 23/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 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

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

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 github.com/api-evangelist/uml: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 3

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

UML Diagrams API

Generate diagrams from textual descriptions

UML Health API

Service health check

UML Validation API

Validate PlantUML source syntax

Open Collections 6

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Kroki Diagram API

OPEN COLLECTION

PlantUML Server API

OPEN COLLECTION

Kroki Diagram Diagrams API

OPEN COLLECTION

Kroki Diagram Diagrams Health API

OPEN COLLECTION

Kroki Diagram Diagrams Validation API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Uml Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Uml Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Uml Finops

FINOPS

Semantic Vocabularies 1

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

Uml Context

6 classes · 10 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

UML API Rules

5 rules · 3 warnings 2 info

SPECTRAL

UML API Rules

8 rules · 3 errors 5 warnings

SPECTRAL

JSON Schema 1

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

UML Diagram

12 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Uml Diagram Structure

0 properties

JSON STRUCTURE

Examples 2

Example request and response payloads for these APIs.

Kroki Post Diagram Example

4 fields

EXAMPLE

Plantuml Get Diagram Png Example

5 fields

EXAMPLE

Security Posture 1

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

Uml Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Uml Agentic Access

9 operations · 1 acting

AGENTIC

Resources

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

Documentation

Documentation

JSONSchema

JSONSchema

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Vocabulary

Vocabulary

SpectralRules

SpectralRules

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

GitHub

GitHub

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Standards

Standards

Wikipedia

Wikipedia

Source (apis.yml)

aid: uml
name: UML
description: UML (Unified Modeling Language) is the standard modeling language for software architecture, system design, and
  technical documentation. Governed by the Object Management Group (OMG), UML defines a set of notation conventions and diagram
  types — class, sequence, activity, use case, state, component, deployment, and more — used across the software development
  lifecycle. This collection profiles the ecosystem of tools, APIs, and services that work with UML diagrams programmatically.
url: https://raw.githubusercontent.com/api-evangelist/uml/refs/heads/main/apis.yml
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/uml.png
tags:
- UML
- Modeling
- Diagrams
- Software Architecture
- Design
- Standards
created: '2025-01-01'
modified: '2026-05-19'
specificationVersion: '0.23'
apis:
- aid: uml:uml-diagrams-api
  name: UML Diagrams API
  description: Generate diagrams from textual descriptions
  humanURL: https://plantuml.com/
  baseURL: https://www.plantuml.com/plantuml
  tags:
  - Diagrams
  properties:
  - type: OpenAPI
    url: openapi/uml-diagrams-api-openapi.yml
  - type: Documentation
    url: https://plantuml.com/
  - type: Documentation
    url: https://deepwiki.com/plantuml/plantuml-server/6-api-reference
  - type: Documentation
    url: https://docs.kroki.io/kroki/
  - type: GettingStarted
    url: https://docs.kroki.io/kroki/setup/usage/
- aid: uml:uml-health-api
  name: UML Health API
  description: Service health check
  humanURL: https://plantuml.com/
  baseURL: https://www.plantuml.com/plantuml
  tags:
  - Health
  properties:
  - type: OpenAPI
    url: openapi/uml-health-api-openapi.yml
  - type: Documentation
    url: https://plantuml.com/
  - type: Documentation
    url: https://deepwiki.com/plantuml/plantuml-server/6-api-reference
  - type: Documentation
    url: https://docs.kroki.io/kroki/
  - type: GettingStarted
    url: https://docs.kroki.io/kroki/setup/usage/
- aid: uml:uml-validation-api
  name: UML Validation API
  description: Validate PlantUML source syntax
  humanURL: https://plantuml.com/
  baseURL: https://www.plantuml.com/plantuml
  tags:
  - Validation
  properties:
  - type: OpenAPI
    url: openapi/uml-validation-api-openapi.yml
  - type: Documentation
    url: https://plantuml.com/
  - type: Documentation
    url: https://deepwiki.com/plantuml/plantuml-server/6-api-reference
  - type: Documentation
    url: https://docs.kroki.io/kroki/
  - type: GettingStarted
    url: https://docs.kroki.io/kroki/setup/usage/
common:
- type: AgenticAccess
  url: agentic-access/uml-agentic-access.yml
- type: DomainSecurity
  url: security/uml-domain-security.yml
- type: GitHubOrg
  url: https://github.com/plantuml
- type: GitHubOrg
  url: https://github.com/yuzutech
- type: Website
  url: https://www.omg.org/uml/
- type: Standards
  url: https://www.omg.org/spec/UML/
- type: Wikipedia
  url: https://en.wikipedia.org/wiki/Unified_Modeling_Language
- type: GitHub
  url: https://github.com/plantuml/plantuml
- type: GitHub
  url: https://github.com/yuzutech/kroki
- type: Documentation
  url: https://plantuml.com/
- type: Documentation
  url: https://docs.kroki.io/kroki/
- type: JSONLD
  url: json-ld/uml-context.jsonld
- type: Vocabulary
  url: vocabulary/uml-vocabulary.yml
- type: JSONSchema
  url: json-schema/uml-diagram-schema.json
- type: SpectralRules
  url: rules/uml-rules.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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 →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/uml"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/uml/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/uml/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.