---
title: Objective-C Runtime
framework: Objective-C Runtime
role: collection
role_heading: Framework
platforms: [iOS 2.0+, iPadOS 2.0+, Mac Catalyst 13.0+, macOS 10.0+, tvOS 9.0+, visionOS 1.0+, watchOS 2.0+]
path: objectivec
---

# Objective-C Runtime

Gain low-level access to the Objective-C runtime and the Objective-C root types.

## Overview

Overview The Objective-C Runtime module APIs define the base of the Objective-C language. These APIs include: Types such as the NSObject class and the NSObjectProtocol protocol that provide the root functionality of most Objective-C classes Functions and data structures that comprise the Objective-C runtime, which provides support for the dynamic properties of the Objective-C language You typically don’t need to use this module directly.

## Topics

### Classes

- [NSObject](objectivec/nsobject-swift.class.md)
- [Protocol](objectivec/protocol.md)

### Protocols

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

### Reference

- [Objective-C Runtime](objectivec/objective-c-runtime.md)
- [Objective-C Structures](objectivec/objective-c-structures.md)
- [Objective-C Constants](objectivec/objective-c-constants.md)
- [Objective-C Functions](objectivec/objective-c-functions.md)
- [Objective-C Data Types](objectivec/objective-c-data-types.md)
- [Objective-C Macros](objectivec/objective-c-macros.md)
- [Objective-C Enumerations](objectivec/objective-c-enums.md)

### Functions

- [objc_copyImageHeaders(_:)](objectivec/objc_copyimageheaders(_:).md)