ahhhhh.php

<?php
function slug_tax_update ( $pieces ) {
   //global $post;
   //$post_id = $post->ID;
    $post_id =$pieces[ 'params' ]->id;

   $term_field = $pieces[ 'fields' ][ 'tax' ][ 'value' ];
    //if ( is_array( $term_field) ) {
        $terms = $term_field[ 'slug' ];
        $taxonomy = 'ant';
        $append = FALSE;
        wp_set_object_terms( $post_id, $terms, $taxonomy, $append );
   // }
   return $pieces;
}
//add_filter( 'pods_api_pre_save_pod_item_cpt', 'slug_tax_update' );

    function slug_tax_update_POST ( $pieces ) {
        //global $post;
        //$post_id = $post->ID;
        $post_id =$pieces[ 'params' ]->id;

        $term_field = get_post_meta( $post_id, 'tax', true );
        //if ( is_array( $term_field) ) {
            $terms = $term_field[ 'slug' ];
            $taxonomy = 'ant';
            $append = FALSE;
            wp_set_object_terms( $post_id, $terms, $taxonomy, $append );
        //}
        return $pieces;
    }
add_filter( 'pods_api_pre_save_pod_item_cpt', 'slug_tax_update_POST' );