I'm no longer maintaining this repo, check out its forks, or https://store.steampowered.com/account/registerkey
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Add a keys.txt file in the root directory of the binary/script. add 1 key per line and save the file. run the script/program and it will read line per line of the keys.txt file and activate them one by one in steam. After a successful activation it will cancel the game's installation so it does not install.
Do not touch keyboard and or mouse you can press escape at any time to cancel the macro
You can download the latest release over here
This is a script that uses Autohotkey to emulate keyboard and mouse, no reasons to be concerned about VAC. ;)
This script is written in AutoHotKey
http://ahkscript.org/
AutoHotkey (AHK) is a free, open-source macro-creation and automation software for Windows that allows users to automate repetitive tasks. It is driven by a scripting language that was initially aimed at providing keyboard shortcuts, otherwise known as hotkeys, that over time evolved into a full-fledged scripting language.
This is a script that automates the repetitive task of activating steam keys. as this does not inject anything whatsoever you don't have to worry about VAC.
Copyright 2014 colingg (colin.gg)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.