How to Use the Go Plugin System (plugin Package)

Use the plugin package to compile code as a shared library with -buildmode=plugin, then load it at runtime using plugin.Open and retrieve symbols with Lookup.

// 1. Build the plugin: go build -buildmode=plugin -o myplugin.so myplugin.go
// 2. Load and use it in your main program:
package main

import (
	"fmt"
	"log"
	"plugin"
)

func main() {
	p, err := plugin.Open("myplugin.so")
	if err != nil {
		log.Fatal(err)
	}

	// Retrieve a symbol (must be exported)
	sym, err := p.Lookup("MyFunction")
	if err != nil {
		log.Fatal(err)
	}

	// Type assert and call
	fn := sym.(func() string)
	fmt.Println(fn())
}

Note: Both the host and plugin must be built with CGO enabled (CGO_ENABLED=1) and share the same module path for common dependencies.

The Go plugin system lets you load code into your running program like a browser extension. You compile a separate piece of code into a shared file, then your main program opens that file and calls functions inside it. This is useful for building systems where you want to add new features without rebuilding the entire application.