Type in which php in your terminal. OSX comes pre installed with php so chances are u aren't using the brew's php and u need to set it to use brew's php and not the default pho that comes with osx

For example I use this in httpd

LoadModule php5_module /usr/local/Cellar/php55/5.5.20/libexec/apache2/libphp5.so

when i type php --ini

Configuration File (php.ini) Path: /usr/local/etc/php/5.6 Loaded Configuration File: /usr/local/etc/php/5.6/php.ini Scan for additional .ini files in: /usr/local/etc/php/5.6/conf.d Additional .ini files parsed: (none)

so how will i use brew php . started when i installed brew

Mcrypt is a php extension. Composer cannot install it for you. In the say way that if you ask for php 5.6 on a php 5.3 system, composer isn't going to install php 5.6 for you.