Constituent custom filed list (All constituents) passing an array of categories

Morning all,

First post here. I have been working with the Raisers Edge NXT Sky API for a few days. Have been tasked with pulling a list of constituents and then also data on from the custom fields and education API endpoints.

I am having trouble with the Constituent custom field list (All constituents). I'm using PHP 5 and building my parameter list as so

$params = http_build_query(

array(

'category' => array(

'category 1',

'category 2',

'category 3',

'category 4'

),

'limit' => 5000

)

);

This is failing. Does anyone have any suggestion as to why?

Cheers,

Ben

)

);