How to Read and Write YAML in Go (gopkg.in/yaml.v3)

Use yaml.Marshal to convert Go structs to YAML bytes and yaml.Unmarshal to parse YAML bytes back into Go structs.

package main

import (
	"fmt"
	"gopkg.in/yaml.v3"
)

type Config struct {
	Name string `yaml:"name"`
	Port int    `yaml:"port"`
}

func main() {
	// Write YAML
	cfg := Config{Name: "server", Port: 8080}
	data, err := yaml.Marshal(&cfg)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(data))

	// Read YAML
	var newCfg Config
	err = yaml.Unmarshal(data, &newCfg)
	if err != nil {
		panic(err)
	}
	fmt.Printf("%+v\n", newCfg)
}

The gopkg.in/yaml.v3 library lets your Go program save data as human-readable YAML text files and read them back later. It works like a translator that turns your Go code structures into text and vice versa. You use it whenever you need to store settings or configuration in a file that people can easily edit.