![3cx 11 myphone 3cx 11 myphone](https://wcdn.3cx.com/wp-content/uploads/2021/08/v18-rc.png)
Take note that the files might change with each 3CX installation, so always update the files after you update 3CX. Why would the build output path have anything to do with whether the API will work? After experimenting, I concluded that changing the build output path is totally unnecessary. What is needed is to just copy the files required by the API ( 3CXPhoneSystem.ini, 3cxpscomcpp2.dll, sl.dll and tcxpscom_native.dll) from the 3CX installation folder to your executable folder, and things should work as per normal. The first thing that captured my attention was the requirement that the build output path has to be set to “C:\Program Files\3CX Phone System\Instance1\Bin” for the API to work under 3CX v15 for Windows, as stated by 3CX. This puzzled me as an experienced. Notwithstanding this, I still find the API to be powerful as it provides in-depth customization of several 3CX features and this article will share some my findings. All there is from 3CX regarding this API is a single blog post that has largely remained the same over the years.
![3cx 11 myphone 3cx 11 myphone](https://media.trustradius.com/product-screenshots/NW/x1/EDXASZIG9JFJ.png)
The last time I did any development work using 3CX Call Control API was in 2013 on version 11 and 3CX has grown a lot since then, providing more useful features, especially the ability to run 3CX on Debian Linux as well as on the cloud. Despite this, the Call Control API is still poorly documented, poorly maintained and officially unsupported by 3CX. I revisited the 3CX Call Control API in one of my latest projects, this time on 3CX version 15.5.