Let's use the Realms API to download our world backup!

try_realms_api.sh

#!/bin/bash

# you need httpie (apt-get install httpie)
# you need to replace <these things> with your details
# run with 'source' to export vars to your shell for experimentation

# 1. authenticate to get an access token

auth_server=https://authserver.mojang.com
user=<your login email>
password=<your account password>
client_token=any-constant-string

# log in
response=$(http POST ${auth_server}/authenticate username=${user} password=${password} clientToken=${client_token} agent:='{"name": "Minecraft", "version": 1}')
# strip double quotes
access_token=$(echo ${response} | jq .accessToken | sed 's/"//g')

# 2. Utility: validate an access token is still valid
# http POST ${auth_server}/validate accessToken=${access_token} clientToken=${client_token}

# 3. Utility: refresh the token, getting a new accessToken without having to give password
# http POST ${auth_server}/refresh accessToken=${access_token} clientToken=${client_token}

# 4. access Realms!

# server. Note the real Minecraft client uses pc.realms.minecraft.net
realms_server=https://pc.realms.minecraft.net
# your UUID from https://mcuuid.net, I believe the trimmed version is correct
uuid=<your trimmed UUID>
# your username, e.g. notch
user_id=<your username>
# Minecraft version
version=1.11.2

# is this user allowed to access Realms? see http://wiki.vg/Realms_API
http --verbose GET ${realms_server}/mco/available "Cookie:sid=token:${access_token}:${uuid};user=${user_id};version=${version}"

For those who may want to know, bedrock's endpoint is: https://bedrock.realms.minecraft.net/

Are you sure? I'm getting an ENOTFOUND Error when I try to use that. pocket.realms.minecraft.net however does at least return my requests, so I'd expect this one to be the correct endpoint.

Any way to use this with the recent Microsoft changeover? App passwords or something?