WinSparkle

Plug-and-forget software update library for Windows applications. C API compatible with all Windows compilers. Shares appcast feed format with macOS Sparkle framework.

How to Use This Skill

• Getting started: Read the Quick Start section below for your language (C/C++ or C#/.NET)
• Complete API with all function signatures: Read references/api.md
• Migrating from DSA to EdDSA signing: Read references/eddsa-migration.md

Core Principles

• Configuration before initialization: All configuration functions (set_appcast_url, set_eddsa_public_key, set_app_details, etc.) must be called before win_sparkle_init()
• EdDSA signing required: Updates must be cryptographically signed with Ed25519; unsigned updates will be rejected
• HTTPS everywhere: The appcast URL, release notes links, and download URLs must all use HTTPS to prevent MITM attacks
• Non-blocking checks: All update check functions (check_update_with_ui, check_update_without_ui, etc.) return immediately; UI appears asynchronously on a background thread
• Minimal first-launch footprint: WinSparkle does nothing on first launch to avoid distorting the user's first impression of the app

Quick Start (C/C++)