go-yggdrasil

Single file library for Mojang's Yggdrasil API written in Golang without extra dependencies

Installing

go get github.com/JoshuaDoes/go-yggdrasil

Recommended authentication procedure

Note: This procedure is based on the official Minecraft launcher's authentication logic.

When authenticating with Yggdrasil, you should use *yggdrasil.Client.Authenticate() only if you do not already have an access/client token pair stored somewhere, as Yggdrasil's /authenticate endpoint is severely rate-limited. If you have an access/client token pair, you should use *yggdrasil.Client.Validate() on a pre-initialized *yggdrasil.Client variable to make sure it is still valid. If it is not, you should then use *yggdrasil.Client.Refresh() to get a new access token and have it automatically be stored in the *yggdrasil.Client variable. Should this fail, however, then it is safe to use *yggdrasil.Client.Authenticate() again and store the returned access/client token pair for future use.

Additional notes

When an authentication is successful, your *yggdrasil.Client variable will contain the client's access/client token pair, the current selected profile (changing this is not yet implemented in Yggdrasil), and the current user.

When using any available go-yggdrasil functions, any internal errors will be returned as *yggdrasil.Error.FuncError rather than be classically available as an error type. Any errors returned from Yggdrasil itself will be returned as *yggdrasil.Error.

Authentication example

package main

import "fmt"
import "github.com/JoshuaDoes/yggdrasil"

var yggdrasilClient *yggdrasil.Client

func main() {
	yggdrasilClient = &yggdrasil.Client{ClientToken: "your client token here"}

	//Auth with Minecraft version 1
	authResponse, err := yggdrasilClient.Authenticate("your email/username here", "your password here", "Minecraft", 1)
	if err != nil {
		fmt.Println("Error: " + fmt.Sprintf("%v", err))
	} else {
		//Print access/client token pair
		fmt.Println("Access Token: " + authResponse.AccessToken)
		fmt.Println("Client Token: " + authResponse.ClientToken)
	}
}

Output

> go run main.go
Access Token: 32 char hexadecimal access token
Client Token: specified client token

License

The source code for go-yggdrasil is released under the MIT License. See LICENSE for more details.

Donations

All donations are appreciated and helps me stay awake at night to work on this more. Even if it's not much, it helps a lot in the long run! You can find the donation link here: Donation Link