swift-log

# SwiftLog

[![](https://img.shields.io/badge/docc-read_documentation-blue)](https://swiftpackageindex.com/apple/swift-log/documentation)
[![](https://img.shields.io/github/v/release/apple/swift-log)](https://github.com/apple/swift-log/releases)
[![](https://img.shields.io/endpoint?url=https%3A%2F%2Fswiftpackageindex.com%2Fapi%2Fpackages%2Fapple%2Fswift-log%2Fbadge%3Ftype%3Dswift-versions)](https://swiftpackageindex.com/apple/swift-log)
[![](https://img.shields.io/endpoint?url=https%3A%2F%2Fswiftpackageindex.com%2Fapi%2Fpackages%2Fapple%2Fswift-log%2Fbadge%3Ftype%3Dplatforms)](https://swiftpackageindex.com/apple/swift-log)

This repository contains a logging API implementation for Swift.
SwiftLog provides a unified, performant, and ergonomic logging API that can be
adopted by libraries and applications across the Swift ecosystem.

- 📚 **Documentation** and **tutorials** are available on the [Swift Package Index](https://swiftpackageindex.com/apple/swift-log)
- 🚀 **Contributions** are welcome, please see [CONTRIBUTING.md](CONTRIBUTING.md)
- 🪪 **License** is Apache 2.0, repeated in [LICENSE.txt](LICENSE.txt)
- 🔒 **Security** issues should be reported via the process in [Security](https://github.com/apple/swift-log?tab=security-ov-file)
- 🔀 **Available Logging Backends**: SwiftLog is an API package - you'll want to
choose from the many
[community-maintained logging backends](#available-log-handler-backends) for production use

## Quick Start

The following snippet shows how to add SwiftLog to your Swift Package:

```swift
// swift-tools-version: 6.2
import PackageDescription

let package = Package(
    name: "YourApp",
    dependencies: [
        .package(url: "https://github.com/apple/swift-log", from: "1.6.0")
    ],
    targets: [
        .target(
            name: "YourApp",
            dependencies: [
                .product(name: "Logging", package: "swift-log")
            ]
        )
    ]
)
```

Then start logging:

```swift
import Logging

// Create a logger
let logger = Logger(label: "com.example.YourApp")

// Log at different levels
logger.info("Application started")
logger.warning("This is a warning")
logger.error("Something went wrong", metadata: ["error": "\(error)"])

// Add metadata for context
var requestLogger = logger
requestLogger[metadataKey: "request-id"] = "\(UUID())"
requestLogger.info("Processing request")
```

## Available log handler backends

The community has built numerous specialized logging backends.

A great way to discover available log backend implementations is searching the
[Swift Package Index](https://swiftpackageindex.com/search?query=swift-log)
for the `swift-log` keyword.

## Building with CMake

While Swift Package Manager (SPM) is the primary build system for development and testing, CMake build support is also available for integrated or mixed build environments if needed. Note that tests are not included in the CMake build, they are managed through Swift Package Manager with `swift test`.