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
46.2/100 developing ▬ flat Agent 29/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemium
3 APIs
UMLModelingDiagramsSoftware ArchitectureDesignStandards

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 46.2/100 · developing
Contract Quality 16.2 / 25
Developer Ergonomics 1.7 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 8.3 / 12
Discoverability 7.4 / 10
Agent readiness — 29/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
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
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 2

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

Kroki Diagram API

OPEN COLLECTION

PlantUML Server 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: '0.19'
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