diff --git a/src/classes/api/endpoints/class-tainacan-rest-metadatum-mappers-controller.php b/src/classes/api/endpoints/class-tainacan-rest-metadatum-mappers-controller.php
index 7f4512ff9..20b47257d 100644
--- a/src/classes/api/endpoints/class-tainacan-rest-metadatum-mappers-controller.php
+++ b/src/classes/api/endpoints/class-tainacan-rest-metadatum-mappers-controller.php
@@ -68,14 +68,15 @@ class REST_Metadatum_Mappers_Controller extends REST_Controller {
 	}
 
 	/**
-	 * @param \Tainacan\Exposers\Mappers\Mapper $mapper
+	 * @param \Tainacan\Mappers\Mapper $mapper
 	 * @param \WP_REST_Request $request
 	 *map
 	 * @return mixed|\WP_Error|\WP_REST_Response
 	 */
 	public function prepare_item_for_response( $mapper, $request ) {
 
-		$metadatum_arr = $mapper->_toArray();
+		$collection_id = isset($request['collection_id']) && $request['collection_id'] != 'default' ? $request['collection_id'] : null;
+		$metadatum_arr = $mapper->_toArray($collection_id);
 
 		return $metadatum_arr;
 	}
diff --git a/src/classes/mappers/class-tainacan-mapper.php b/src/classes/mappers/class-tainacan-mapper.php
index d9e8f7543..3a6dcc5e5 100644
--- a/src/classes/mappers/class-tainacan-mapper.php
+++ b/src/classes/mappers/class-tainacan-mapper.php
@@ -36,20 +36,24 @@ abstract class Mapper {
 	public $header = false; // API response header or file header to be used with
 	public $show_ui = true; // Show mapper in ui and api calls
 	
-	public function _toArray() {
+	public function _toArray($collection_id = null) {
 		return [
 			'slug' => $this->slug,
 			'name' => $this->name,
 			'description' => $this->description,
 			'allow_extra_metadata' => $this->allow_extra_metadata,
 			'context_url' => $this->context_url,
-			'metadata' => $this->metadata,
+			'metadata' => $this->get_metadata($collection_id),
 			'prefix' => $this->prefix,
 			'sufix' => $this->sufix,
 			'header' => $this->header,
 			'add_meta_form' => ''
 		];
 	}
+
+	public function get_metadata($collection_id = null) {
+		return $this->metadata;
+	}
 	
 	/**
 	 * Gets the semantic URL for a given metadatum of this mapper.
diff --git a/src/classes/mappers/class-tainacan-wiki-data.php b/src/classes/mappers/class-tainacan-wiki-data.php
index 780881c9f..1c8ae8fd9 100644
--- a/src/classes/mappers/class-tainacan-wiki-data.php
+++ b/src/classes/mappers/class-tainacan-wiki-data.php
@@ -20,4 +20,31 @@ class Wiki_Data extends Mapper {
 	public $metadata = [
 		
 	];	
+
+	public function get_metadata($collection_id = null) {
+		if($collection_id == null)
+			return $this->metadata;
+		
+		$metadatum_repository = \tainacan_metadata();
+		$collection = new \Tainacan\Entities\Collection( $collection_id );
+		$args = [
+			'meta_query' => [
+				[
+					'key'     => 'exposer_mapping',
+					'compare' => 'EXISTS',
+				]
+			],
+			'posts_per_page' => -1
+		];
+		$metadata = $metadatum_repository->fetch_by_collection( $collection, $args );
+		$prepared_custom_mapper = [];
+		foreach ( $metadata as $item ) {
+			$exposer_mapping = $item->get_exposer_mapping();
+			if(isset($exposer_mapping[$this->slug])) {
+				$slug = $exposer_mapping[$this->slug]['slug'];
+				$prepared_custom_mapper[$slug] = $exposer_mapping[$this->slug];
+			}
+		}
+		return array_merge( $this->metadata,  $prepared_custom_mapper);
+	}
 }
\ No newline at end of file