Unreal Engine

Unreal Engine is Epic Games' real-time 3D engine for games, film, broadcast, architecture, simulation, automotive, and live events. The engine is shipped as a downloadable editor, source on GitHub (under the Unreal Engine EULA), and a deep C++ and Blueprint API surface rather than a public REST API. The developer-facing surface includes the Unreal C++ API reference, the Blueprint visual scripting API, the Online Subsystem (OSS) abstraction over platform backends, the Pixel Streaming framework for streaming Unreal apps over WebRTC, the Render Hardware Interface (RHI), the Slate UI framework, and a plugin and Marketplace ecosystem (now Fab). Programmatic backend integration for Unreal-built games is typically delivered via Epic Online Services (EOS), profiled separately. This profile documents Unreal Engine as an SDK and tooling surface rather than as a REST API.

Unreal Engine publishes 6 APIs on the APIs.io network. Tagged areas include 3D, Blueprint, C++, Game Development, and Game Engine.

Unreal Engine’s developer surface includes documentation, engineering blog, release notes, support, YouTube channel, and 15 more developer resources.

22.4/100 emerging ▬ flat Agent 3/100 human only Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFree
6 APIs
3DBlueprintC++Game DevelopmentGame EnginePixel StreamingPluginReal-TimeRenderingRHISDKUnreal EngineWebRTC

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 22.4/100 · emerging
Contract Quality 0.0 / 25
Developer Ergonomics 3.0 / 20
Commercial Clarity 5.8 / 20
Operational Transparency 5.5 / 13
Governance 0.0 / 12
Discoverability 8.2 / 10
Agent readiness — 3/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
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
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/unreal-engine: 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 6

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

Unreal Engine C++ API

The Unreal Engine C++ API is the primary programmatic surface of the engine. It is shipped as engine source on GitHub (under the Unreal Engine EULA) and documented as a per-modu...

Unreal Blueprint Visual Scripting

Blueprints are Unreal Engine's visual scripting system. Blueprint nodes wrap the underlying C++ API, letting designers and programmers build gameplay, UI, and tooling logic with...

Unreal Online Subsystem (OSS / OSSv2)

The Online Subsystem is Unreal's abstraction over platform online backends (Steam, PlayStation, Xbox Live, Nintendo, EOS, Google Play, Apple GameCenter, Discord). It exposes a c...

Unreal Pixel Streaming

Pixel Streaming streams an Unreal Engine application running on a server to remote browser clients over WebRTC. The framework includes a Pixel Streaming plugin in the engine, a ...

Unreal Render Hardware Interface (RHI)

The Render Hardware Interface is Unreal's abstraction over graphics APIs (Direct3D 11/12, Vulkan, Metal, OpenGL ES). Engine and plugin developers write rendering code against th...

Unreal Plugins and Fab Marketplace

Unreal Engine has a first-class plugin architecture and a content and code marketplace. The historical Unreal Engine Marketplace was consolidated into Fab, Epic's unified conten...

Pricing Plans 1

Published pricing tiers and plan structures.

Rate Limits 1

Documented rate limits and quota policies.

Unreal Engine Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Security Posture 2

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

Unreal Engine Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Unreal Engine Vulnerability Disclosure

Hackerone · security.txt · contact published

SECURITY

Resources

Documentation 2

Reference material describing how the API behaves

Build 2

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Learn 2

Tutorials, courses, talks, and written guidance

Operate 5

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Company 4

The organization behind the API

Other 2

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: unreal-engine
name: Unreal Engine
description: Unreal Engine is Epic Games' real-time 3D engine for games, film, broadcast, architecture, simulation, automotive,
  and live events. The engine is shipped as a downloadable editor, source on GitHub (under the Unreal Engine EULA), and a
  deep C++ and Blueprint API surface rather than a public REST API. The developer-facing surface includes the Unreal C++ API
  reference, the Blueprint visual scripting API, the Online Subsystem (OSS) abstraction over platform backends, the Pixel
  Streaming framework for streaming Unreal apps over WebRTC, the Render Hardware Interface (RHI), the Slate UI framework,
  and a plugin and Marketplace ecosystem (now Fab). Programmatic backend integration for Unreal-built games is typically delivered
  via Epic Online Services (EOS), profiled separately. This profile documents Unreal Engine as an SDK and tooling surface
  rather than as a REST API.
accessModel:
  pricing: free
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Free
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/unreal-engine.png
url: https://www.unrealengine.com
created: '2024-01-01'
modified: '2026-05-23'
specificationVersion: '0.19'
type: Index
access: 3rd-Party
tags:
- 3D
- Blueprint
- C++
- Game Development
- Game Engine
- Pixel Streaming
- Plugin
- Real-Time
- Rendering
- RHI
- SDK
- Unreal Engine
- WebRTC
apis:
- aid: unreal-engine:unreal-engine-cpp-api
  name: Unreal Engine C++ API
  description: The Unreal Engine C++ API is the primary programmatic surface of the engine. It is shipped as engine source
    on GitHub (under the Unreal Engine EULA) and documented as a per-module class reference covering Actors, Components, GameFramework,
    Subsystems, Slate, RHI, Renderer, AnimGraph, Niagara, Chaos, AI, and more. Developers extend the engine by writing C++
    classes and modules in their project or as plugins.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/cplusplus-in-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - C++
  - SDK
  - Source
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/cplusplus-in-unreal-engine
  - type: APIReference
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/API
  - type: GitHubRepository
    url: https://github.com/EpicGames/UnrealEngine
- aid: unreal-engine:blueprint-visual-scripting
  name: Unreal Blueprint Visual Scripting
  description: Blueprints are Unreal Engine's visual scripting system. Blueprint nodes wrap the underlying C++ API, letting
    designers and programmers build gameplay, UI, and tooling logic without writing C++. The Blueprint API surface mirrors
    much of the engine's UFUNCTION-exposed C++ surface.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/blueprints-visual-scripting-in-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - Blueprint
  - Scripting
  - Visual Scripting
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/blueprints-visual-scripting-in-unreal-engine
- aid: unreal-engine:online-subsystem
  name: Unreal Online Subsystem (OSS / OSSv2)
  description: The Online Subsystem is Unreal's abstraction over platform online backends (Steam, PlayStation, Xbox Live,
    Nintendo, EOS, Google Play, Apple GameCenter, Discord). It exposes a consistent C++ interface for identity, sessions,
    friends, presence, achievements, leaderboards, voice, store, and entitlements that maps onto platform-specific or EOS-backed
    implementations.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/online-subsystem-in-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - Achievements
  - Cross-Platform
  - Identity
  - Online Services
  - Sessions
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/online-subsystem-in-unreal-engine
- aid: unreal-engine:pixel-streaming
  name: Unreal Pixel Streaming
  description: Pixel Streaming streams an Unreal Engine application running on a server to remote browser clients over WebRTC.
    The framework includes a Pixel Streaming plugin in the engine, a signalling and matchmaker service ("Cirrus" / "Frontend"),
    a UE Pixel Streaming Infrastructure reference deployment, and a JavaScript client library for browser integration. Used
    for in-browser product configurators, automotive, digital twins, and cloud-rendered games.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/pixel-streaming-in-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - Browser
  - Cloud Rendering
  - Pixel Streaming
  - Streaming
  - WebRTC
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/pixel-streaming-in-unreal-engine
  - type: GitHubRepository
    url: https://github.com/EpicGamesExt/PixelStreamingInfrastructure
- aid: unreal-engine:render-hardware-interface
  name: Unreal Render Hardware Interface (RHI)
  description: The Render Hardware Interface is Unreal's abstraction over graphics APIs (Direct3D 11/12, Vulkan, Metal, OpenGL
    ES). Engine and plugin developers write rendering code against the RHI rather than directly against a GPU API, and the
    RHI maps that code onto the active backend at runtime.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/graphics-programming-overview-for-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - D3D12
  - GPU
  - Graphics
  - Metal
  - Rendering
  - RHI
  - Vulkan
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/graphics-programming-overview-for-unreal-engine
- aid: unreal-engine:unreal-plugins-and-fab
  name: Unreal Plugins and Fab Marketplace
  description: Unreal Engine has a first-class plugin architecture and a content and code marketplace. The historical Unreal
    Engine Marketplace was consolidated into Fab, Epic's unified content marketplace for Unreal, Twinmotion, RealityCapture,
    and beyond. Plugins extend the editor and runtime in C++ and Blueprint and ship with their own Plugin Descriptor (.uplugin)
    manifest.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://dev.epicgames.com/documentation/en-us/unreal-engine/plugins-in-unreal-engine
  baseURL: https://dev.epicgames.com/documentation/en-us/unreal-engine
  tags:
  - Fab
  - Marketplace
  - Plugins
  properties:
  - type: Documentation
    url: https://dev.epicgames.com/documentation/en-us/unreal-engine/plugins-in-unreal-engine
  - type: Marketplace
    url: https://www.fab.com
common:
- type: VulnerabilityDisclosure
  url: security/unreal-engine-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/unreal-engine-domain-security.yml
- url: https://www.unrealengine.com
  name: Unreal Engine Website
  type: Website
- url: https://dev.epicgames.com/documentation/en-us/unreal-engine
  name: Unreal Engine Documentation
  type: Documentation
- url: https://dev.epicgames.com/community/unreal-engine
  name: Unreal Engine Community
  type: Community
- url: https://dev.epicgames.com/community/unreal-engine/learning
  name: Unreal Online Learning
  type: Learning
- url: https://forums.unrealengine.com
  name: Unreal Engine Forums
  type: Forums
- url: https://github.com/EpicGames/UnrealEngine
  name: Unreal Engine on GitHub
  type: GitHubRepository
- url: https://github.com/EpicGamesExt
  name: Epic Games Ext on GitHub
  type: GitHubOrganization
- url: https://www.fab.com
  name: Fab Marketplace
  type: Marketplace
- url: https://www.unrealengine.com/marketplace-guidelines
  name: Marketplace Guidelines
  type: Guidelines
- url: https://www.unrealengine.com/eula
  name: Unreal Engine EULA
  type: License
- url: https://www.unrealengine.com/blog
  name: Unreal Engine Blog
  type: Blog
- url: https://www.unrealengine.com/release-notes
  name: Unreal Engine Release Notes
  type: ReleaseNotes
- url: https://issues.unrealengine.com
  name: Unreal Engine Public Issue Tracker
  type: IssueTracker
- url: https://www.unrealengine.com/support
  name: Unreal Engine Support
  type: Support
- url: https://www.youtube.com/@UnrealEngine
  name: Unreal Engine on YouTube
  type: YouTube
- url: https://x.com/UnrealEngine
  name: Unreal Engine on X
  type: X
- url: https://www.facebook.com/UnrealEngine
  name: Unreal Engine on Facebook
  type: Facebook
- url: https://www.linkedin.com/showcase/unreal-engine
  name: Unreal Engine on LinkedIn
  type: LinkedIn
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com