Introduction

downloader.zig is a production-ready HTTP/HTTPS download library for the Zig programming language.

What is downloader.zig?

A lightweight, zero-dependency library that provides:

• HTTP/HTTPS Downloads - Full protocol support via std.http
• Resume Capability - Continue interrupted downloads using Range headers
• Automatic Retries - Configurable retry logic with exponential backoff
• Progress Tracking - Real-time callbacks with speed and ETA
• Smart File Handling - Multiple strategies for existing files
• Update Checker - Automatically check for library updates
• Checksum Verification - Verify file integrity (MD5, SHA-1, SHA-256, SHA-512, CRC32)

Key Features

Zero Dependencies

Built entirely on the Zig standard library. No external C libraries or package dependencies required.

Cross-Platform

Works on Windows, Linux, macOS, and FreeBSD. Supports both 32-bit and 64-bit architectures.

Memory Safe

Designed with Zig's safety guarantees. No hidden allocations. All resources are explicitly managed.

Configurable

Fine-grained control over timeouts, buffer sizes, retry behavior, and file handling.

Use Cases

• CLI download tools
• Package managers
• Asset downloaders for games
• Automated backup systems
• Update distribution

Quick Example

const std = @import("std");
const downloader = @import("downloader");

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();

    try downloader.download(
        gpa.allocator(),
        "https://example.com/file.zip",
        "file.zip"
    );
}

Next Steps

• Getting Started - Installation and first download
• Configuration - Customize download behavior
• API Reference - Full API documentation