github.com/caddyserver/caddy

The github.com/caddyserver/caddy package (v1) was groundbreaking for its automatic HTTPS and simple configuration, but this version is fundamentally deprecated. The last release was in 2020, and the project has completely moved to v2 (github.com/caddyserver/caddy/v2) with breaking API changes. If you're using v1 in production, you're missing critical security updates and bug fixes.

From a DX perspective, v1's Go API is straightforward but limited. Embedding Caddy as a library works, but the plugin architecture is inflexible compared to v2's modular design. Documentation for v1 programmatic usage is sparse - most examples focus on the Caddyfile DSL. Type safety is adequate but error messages when configuring programmatically can be cryptic, often requiring you to dig into source code.

The migration path to v2 is painful - it's essentially a rewrite, not an upgrade. Configuration formats changed significantly, and the Go APIs are completely different. While v1 served its purpose well, continuing to use it means accumulating technical debt.

When using Caddy v1 as an embedded Go library, you're working with a legacy codebase that stopped active development in 2020. The API is straightforward for basic HTTP server needs - you can configure and start a Caddy instance programmatically with reasonable ease. However, the documentation heavily focuses on Caddy as a standalone binary rather than as an embeddable library, which creates friction when you need to integrate it into your Go application.

The plugin architecture works but feels dated compared to modern Go practices. Type safety is adequate for core functionality, but the configuration layer relies heavily on string-based directives that mirror the Caddyfile syntax, making it easy to introduce runtime errors that TypeScript developers would find frustrating. Error messages are generally clear when things go wrong, but IDE support is limited since much of the configuration happens through parsed strings rather than typed structs.

The elephant in the room is that v2 (a complete rewrite) has been the recommended version since 2020, with a completely different API. If you're starting a new project, you should really be looking at caddy/v2 instead of this package.

Using Caddy v1 (1.0.5) as an embeddable Go library is problematic from an operations perspective. The architecture wasn't designed for programmatic control - it's fundamentally built as a standalone server with global state and package-level initialization. Configuration is heavily file-based (Caddyfile format), making runtime reconfiguration awkward and requiring workarounds to manage through code.

Resource management is opaque. Connection pooling happens deep in the HTTP server layer with limited exposure for tuning. Graceful shutdown exists but coordinating it with your application's lifecycle requires careful orchestration. The plugin system uses init() functions and global registration, creating order-dependent behavior that's hard to reason about in production. Error handling often returns generic errors without structured context for logging systems.

Critically, v1 is EOL - Caddy v2 is a complete rewrite with breaking changes. If you're considering embedding Caddy, you should evaluate v2 instead (github.com/caddyserver/caddy/v2), which has a proper API. Staying on v1 means no security patches and an eventual painful migration.