UML website screenshot

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
31.8/100 thin ▬ flat Agent 23/100 agent aware Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0
AccessFreemium
3 APIs
UMLModelingDiagramsSoftware ArchitectureDesignStandards

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0
Composite quality — 31.8/100 · thin
Contract Quality 14.2 / 25
Developer Ergonomics 1.9 / 20
Access Clarity 3.2 / 20
Operational Transparency 1.7 / 13
Contract Governance 3.5 / 12
Discoverability 7.4 / 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 Surface 0 / 5
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. 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. Want it done for you? Prioritized profiling — $2,500 →

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

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
 GitHubOrg
GitHubOrg
 GitHub
GitHub
 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)

apis.yml Raw ↑ 
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
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

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