Source

File: wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php

public function get_item_schema() {
		if ( $this->schema ) {
			return $this->add_additional_fields_schema( $this->schema );
		}

		$schema = array(
			'$schema'    => 'http://json-schema.org/draft-04/schema#',
			'title'      => 'post_tag' === $this->taxonomy ? 'tag' : $this->taxonomy,
			'type'       => 'object',
			'properties' => array(
				'id'          => array(
					'description' => __( 'Unique identifier for the term.' ),
					'type'        => 'integer',
					'context'     => array( 'view', 'embed', 'edit' ),
					'readonly'    => true,
				),
				'count'       => array(
					'description' => __( 'Number of published posts for the term.' ),
					'type'        => 'integer',
					'context'     => array( 'view', 'edit' ),
					'readonly'    => true,
				),
				'description' => array(
					'description' => __( 'HTML description of the term.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit' ),
				),
				'link'        => array(
					'description' => __( 'URL of the term.' ),
					'type'        => 'string',
					'format'      => 'uri',
					'context'     => array( 'view', 'embed', 'edit' ),
					'readonly'    => true,
				),
				'name'        => array(
					'description' => __( 'HTML title for the term.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'embed', 'edit' ),
					'arg_options' => array(
						'sanitize_callback' => 'sanitize_text_field',
					),
					'required'    => true,
				),
				'slug'        => array(
					'description' => __( 'An alphanumeric identifier for the term unique to its type.' ),
					'type'        => 'string',
					'context'     => array( 'view', 'embed', 'edit' ),
					'arg_options' => array(
						'sanitize_callback' => array( $this, 'sanitize_slug' ),
					),
				),
				'taxonomy'    => array(
					'description' => __( 'Type attribution for the term.' ),
					'type'        => 'string',
					'enum'        => array_keys( get_taxonomies() ),
					'context'     => array( 'view', 'embed', 'edit' ),
					'readonly'    => true,
				),
			),
		);

		$taxonomy = get_taxonomy( $this->taxonomy );

		if ( $taxonomy->hierarchical ) {
			$schema['properties']['parent'] = array(
				'description' => __( 'The parent term ID.' ),
				'type'        => 'integer',
				'context'     => array( 'view', 'edit' ),
			);
		}

		$schema['properties']['meta'] = $this->meta->get_field_schema();

		$this->schema = $schema;

		return $this->add_additional_fields_schema( $this->schema );
	}