diff --git a/includes/importer/class-abstract-callable-post-create.php b/includes/importer/class-abstract-callable-post-create.php
new file mode 100644
index 00000000..388eed5a
--- /dev/null
+++ b/includes/importer/class-abstract-callable-post-create.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Custom implementation which provides a mechanism for users to tie into the Newspack Listings Import process.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings\Importer;
+
+use Newspack_Listings\Contracts\Importer_Mode;
+use WP_Post;
+
+/**
+ * Abstract Class which establishes that a callable must be defined and returned.
+ */
+abstract class Abstract_Callable_Post_Create {
+
+	/**
+	 * Constructor to prevent initialization.
+	 */
+	final public function __construct() {
+		// Prevent instantiation.
+	}
+
+	/**
+	 * Abstract function, forcing the child class to create a user-defined function.
+	 *
+	 * @return callable
+	 */
+	abstract protected function get_callable(): callable;
+
+	/**
+	 * Automatically execute Abstract_Callable_Post_create class when instantiated.
+	 *
+	 * @param WP_Post       $listing Newspack Listing Post.
+	 * @param Importer_Mode $importer_mode Newspack Listing Import Mode.
+	 * @param array         $row Row of data from import file.
+	 */
+	public function __invoke( WP_Post $listing, Importer_Mode $importer_mode, array $row = [] ) {
+		$this->get_callable()( $listing, $importer_mode, $row );
+	}
+}
diff --git a/includes/importer/class-abstract-callable-pre-create.php b/includes/importer/class-abstract-callable-pre-create.php
new file mode 100644
index 00000000..055b5c8f
--- /dev/null
+++ b/includes/importer/class-abstract-callable-pre-create.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Custom implementation which provides a mechanism for users to tie into the Newspack Listings Import process.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings\Importer;
+
+use Newspack_Listings\Contracts\Importer_Mode;
+
+/**
+ * Abstract Class which establishes that a callable must be defined and returned.
+ */
+abstract class Abstract_Callable_Pre_Create {
+
+	/**
+	 * Constructor.
+	 */
+	final public function __construct() {
+		// Prevent instantiation.
+	}
+
+	/**
+	 * Abstract function, forcing the child class to create a user-defined function.
+	 *
+	 * @return callable
+	 */
+	abstract protected function get_callable(): callable;
+
+	/**
+	 * Automatically execute Abstract_Callable_Pre_Create class when instantiated.
+	 *
+	 * @param array         $row Row of data from import file.
+	 * @param Importer_Mode $importer_mode Newspack Listing Import Mode.
+	 */
+	public function __invoke( array &$row, Importer_Mode $importer_mode ) {
+		$this->get_callable()( $row, $importer_mode );
+	}
+}
diff --git a/includes/importer/class-abstract-file.php b/includes/importer/class-abstract-file.php
new file mode 100644
index 00000000..fc6edd0d
--- /dev/null
+++ b/includes/importer/class-abstract-file.php
@@ -0,0 +1,112 @@
+<?php
+/**
+ * Abstract class definition of File.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings;
+
+use Exception;
+
+/**
+ * Abstract File class, handles low level loading of file and basic functions.
+ */
+abstract class Abstract_File implements Contracts\File {
+
+	/**
+	 * File's full path.
+	 *
+	 * @var string $path
+	 */
+	protected string $path;
+
+	/**
+	 * The file resource handle.
+	 *
+	 * @var resource $handle
+	 */
+	protected $handle = null;
+
+	/**
+	 * File's name, including file extension.
+	 *
+	 * @var string $name
+	 */
+	protected string $name;
+
+	/**
+	 * File's size in MB.
+	 *
+	 * @var int $size
+	 */
+	protected int $size;
+
+	/**
+	 * Constructor. For now this class expects the file to exist on the system.
+	 *
+	 * @param string $path Full file path.
+	 * @throws Exception If file does not exist.
+	 */
+	public function __construct( string $path ) {
+		if ( ! file_exists( $path ) ) {
+			throw new Exception( 'File does not exist!' );
+		}
+
+		$this->path = $path;
+		$parts = explode( '/', $path );
+		$this->name = array_pop( $parts );
+		$this->size = filesize( $this->path ) / 1024;
+	}
+
+	/**
+	 * Returns the file's full path.
+	 *
+	 * @inheritDoc
+	 */
+	public function get_path(): string {
+		return $this->path;
+	}
+
+
+	/**
+	 * Returns a resource stream to the open file.
+	 *
+	 * @return resource
+	 */
+	public function get_handle() {
+		if ( is_null( $this->handle ) ) {
+			$this->handle = fopen( $this->get_path(), 'r' );
+		}
+
+		return $this->handle;
+	}
+
+	/**
+	 * Returns the file's name, with file extension.
+	 *
+	 * @inheritDoc
+	 */
+	public function get_name(): string {
+		return $this->name;
+	}
+
+	/**
+	 * Returns the file's size, in MB.
+	 *
+	 * @inheritDoc
+	 */
+	public function get_size(): int {
+		return $this->size;
+	}
+
+	/**
+	 * Destructor.
+	 */
+	public function __destruct() {
+		if ( is_resource( $this->handle ) ) {
+			// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_read_fclose
+			fclose( $this->handle );
+		}
+	}
+}
\ No newline at end of file
diff --git a/includes/importer/class-abstract-iterable-file.php b/includes/importer/class-abstract-iterable-file.php
new file mode 100644
index 00000000..b2a05ea5
--- /dev/null
+++ b/includes/importer/class-abstract-iterable-file.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * Abstract implementation of Iterable_File.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings;
+
+use Exception;
+use Newspack_Listings\Contracts\Iterable_File;
+
+/**
+ * Abstract implementation of Iterable File contract.
+ */
+abstract class Abstract_Iterable_File extends Abstract_File implements Contracts\Iterable_File {
+
+	/**
+	 * The row/line the iteration should begin at.
+	 *
+	 * @var int $start Default to 0 for first row/line.
+	 */
+	protected int $start = 0;
+
+	/**
+	 * The row/line at which the iteration should terminate.
+	 *
+	 * @var int $end Default value max integer.
+	 */
+	protected int $end = PHP_INT_MAX;
+
+	/**
+	 * Setter for $start.
+	 *
+	 * @param int $start Row/line to start iteration at.
+	 * @returns Iterable_File
+	 * @throws Exception Thrown if $start is greater than $end.
+	 */
+	public function set_start( int $start = 0 ): Iterable_File {
+		if ( $start > $this->end ) {
+			throw new Exception( 'Start cannot be greater than End.' );
+		}
+
+		$this->start = $start;
+
+		return $this;
+	}
+
+	/**
+	 * Returns the integer value representing the row/line at which iteration should begin.
+	 *
+	 * @returns int
+	 */
+	public function get_start(): int {
+		return $this->start;
+	}
+
+	/**
+	 * Setter for $end.
+	 *
+	 * @param int $end Row/line to end iteration at.
+	 * @returns Iterable_File
+	 * @throws Exception Thrown if $end is less than $start.
+	 */
+	public function set_end( int $end = PHP_INT_MAX ): Iterable_File {
+		if ( $end < $this->start ) {
+			throw new Exception( 'End cannot be less than Start.' );
+		}
+
+		$this->end = $end;
+
+		return $this;
+	}
+
+	/**
+	 * Returns the integer value representing the row/line at which iteration should end.
+	 *
+	 * @returns integer
+	 */
+	public function get_end(): int {
+		return $this->end;
+	}
+}
diff --git a/includes/importer/class-csv-file.php b/includes/importer/class-csv-file.php
new file mode 100644
index 00000000..be753b9e
--- /dev/null
+++ b/includes/importer/class-csv-file.php
@@ -0,0 +1,233 @@
+<?php
+/**
+ * Concrete CSV File Implementation.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings\Importer;
+
+use Exception;
+use Iterator;
+use Newspack_Listings\Abstract_Iterable_File;
+use Newspack_Listings\Contracts\Csv_File as Csv_File_Interface;
+use Newspack_Listings\Contracts\Iterable_File;
+use function Newspack_Listings\Importer_Utils\format_data;
+
+/**
+ * Short description.
+ */
+class Csv_File extends Abstract_Iterable_File implements Csv_File_Interface {
+
+	/**
+	 * CSV start row.
+	 *
+	 * @var int $start
+	 */
+	protected int $start = 1;
+
+	/**
+	 * The separator character to be used for CSV parsing.
+	 *
+	 * @var string $separator
+	 */
+	protected string $separator = ',';
+
+	/**
+	 * The enclosure character to be used for CSV parsing.
+	 *
+	 * @var string $enclosure
+	 */
+	protected string $enclosure = '"';
+
+	/**
+	 * The escape character to be used for CSV parsing.
+	 *
+	 * @var string $escape
+	 */
+	protected string $escape = '\\';
+
+	/**
+	 * Defines the encoding to be used for decoding the CSV file.
+	 *
+	 * @var string|bool $encoding
+	 */
+	protected $encoding = false;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param string $path Full path to CSV File.
+	 * @param string $separator CSV Separator to use.
+	 * @param string $enclosure CSV Enclosure Char to use.
+	 * @param string $escape CSV Escape Char to use.
+	 *
+	 * @throws Exception Throws Exception if file is not found.
+	 */
+	public function __construct( string $path, string $separator = ',', string $enclosure = '"', string $escape = '\\' ) {
+		parent::__construct( $path );
+		$this->set_separator( $separator );
+		$this->set_enclosure( $enclosure );
+		$this->set_escape( $escape );
+
+		$this->encoding = function_exists( 'mb_detect_encoding' ) ?
+			mb_detect_encoding( $path, 'UTF-8, ISO-8859-1', true ) :
+			false;
+	}
+
+	/**
+	 * Returns the very first row in a CSV, the header.
+	 *
+	 * @inheritDoc
+	 * @throws Exception Exception thrown if file does not exist on system.
+	 */
+	public function get_header(): array {
+		return $this->get_row( rewind( $this->get_handle() ) );
+	}
+
+	/**
+	 * The iterator that provides the CSV rows.
+	 *
+	 * @return Iterator
+	 * @throws Exception Exception thrown if file does not exist on system.
+	 */
+	public function getIterator(): Iterator {
+		$handle = $this->get_handle();
+		$header = $this->get_row( $handle );
+		$header = array_map( fn( $column) => trim( $column ), $header );
+
+		$row_count = 1;
+		while ( $row_count < $this->get_start() ) {
+			fgets( $handle ); // Move the file handle to the desired starting position.
+
+			if ( feof( $handle ) ) {
+				yield [];
+				return;
+			}
+
+			$row_count++;
+		}
+
+		while ( $row_count <= $this->get_end() && ! feof( $handle ) ) {
+			$row = array_combine( $header, $this->get_row( $handle ) );
+
+			array_map( fn( $value ) => format_data( $value, $this->get_encoding() ), $row );
+
+			yield $row;
+			$row_count++;
+		}
+	}
+
+
+	/**
+	 * Overriding the default behavior of set_start to ensure we always skip the header CSV row.
+	 *
+	 * @param int $start Starting row position.
+	 *
+	 * @return Iterable_File
+	 * @throws Exception Will throw exception if $start is greater than $max.
+	 */
+	public function set_start( int $start = 1 ): Iterable_File {
+		if ( 1 > $start ) {
+			$start = 1;
+		}
+		return parent::set_start( $start );
+	}
+
+	/**
+	 * Set the separator character to be used for CSV parsing.
+	 *
+	 * @param string $separator Separator character to be used for CSV parsing.
+	 *
+	 * @return Csv_File_Interface
+	 */
+	public function set_separator( string $separator ): Csv_File_Interface {
+		$this->separator = $separator;
+
+		return $this;
+	}
+
+	/**
+	 * Get the separator used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_separator(): string {
+		return $this->separator;
+	}
+
+	/**
+	 * Set the enclosure character to be used for CSV parsing.
+	 *
+	 * @param string $enclosure The enclosure character used for CSV parsing.
+	 *
+	 * @return Csv_File_Interface
+	 */
+	public function set_enclosure( string $enclosure ): Csv_File_Interface {
+		$this->enclosure = $enclosure;
+
+		return $this;
+	}
+
+	/**
+	 * Returns the enclosure character used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_enclosure(): string {
+		return $this->enclosure;
+	}
+
+	/**
+	 * Set the escape character to be used for CSV Parsing.
+	 *
+	 * @param string $escape The escape character used for CSV parsing.
+	 *
+	 * @return Csv_File_Interface
+	 */
+	public function set_escape( string $escape ): Csv_File_Interface {
+		$this->escape = $escape;
+
+		return $this;
+	}
+
+	/**
+	 * Returns the escape character to be used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_escape(): string {
+		return $this->escape;
+	}
+
+	/**
+	 * Convenience function to facilitate obtaining a CSV row.
+	 *
+	 * @param resource $handle The open file handle for the CSV file.
+	 * @throws Exception Exception thrown if $handle is not a resource.
+	 */
+	protected function get_row( $handle ): array {
+		if ( ! is_resource( $handle ) ) {
+			throw new Exception( '$handle is not a resource.' );
+		}
+
+		@ini_set( 'auto_detect_line_endings', true ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
+
+		return fgetcsv(
+			$handle,
+			0,
+			$this->get_separator(),
+			$this->get_enclosure(),
+			$this->get_escape()
+		);
+	}
+
+	/**
+	 * Returns the CSV File encoding. False if unable to detect the encoding.
+	 *
+	 * @return bool|string
+	 */
+	private function get_encoding() {
+		return $this->encoding;
+	}
+}
diff --git a/includes/importer/class-custom-callback-pre-create.php b/includes/importer/class-custom-callback-pre-create.php
new file mode 100644
index 00000000..90a684eb
--- /dev/null
+++ b/includes/importer/class-custom-callback-pre-create.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Newspack_Listings\Importer;
+
+use Newspack_Listings\Contracts\Importer_Mode;
+
+class Custom_Callback_Pre_Create extends Abstract_Callable_Pre_Create {
+
+	protected function get_callable(): callable {
+		return function ( array $row, Importer_Mode $importer_mode ) {
+			$dry_run = $importer_mode->is_dry_run() ? 'Dry Run: Yes' : 'Dry Run: No';
+			$skip = $importer_mode->is_skip() ? 'Skip: Yes' : 'Skip: No';
+			$update = $importer_mode->is_update() ? 'Update: Yes' : 'Update: No';
+			var_dump("THE CUSTOM PRE CREATE HAS BEEN CALLED --- Import Mode => $dry_run | $skip | $update");
+		};
+	}
+}
diff --git a/includes/importer/class-file-import-factory.php b/includes/importer/class-file-import-factory.php
new file mode 100644
index 00000000..3809f822
--- /dev/null
+++ b/includes/importer/class-file-import-factory.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Newspack_Listings;
+
+use Exception;
+use IteratorAggregate;
+use Newspack_Listings\Contracts\Iterable_File;
+use Newspack_Listings\Importer\Csv_File;
+
+class File_Import_Factory {
+	/**
+	 * @throws Exception
+	 */
+	public function get_file( string $file_path ): Iterable_File {
+		if ( str_ends_with( $file_path, 'csv' ) ) {
+			return $this->make_csv( $file_path );
+		}
+
+		if ( str_ends_with( $file_path, 'json' ) ) {
+			return $this->make_json( $file_path );
+		}
+
+		throw new Exception( 'Unsupported File Type.' );
+	}
+
+	/**
+	 * @param string $file_path
+	 *
+	 * @return Csv_File
+	 * @throws Exception
+	 */
+	protected function make_csv( string $file_path ): Csv_File {
+		return new Csv_File( $file_path );
+	}
+
+	/**
+	 * @param string $file_path
+	 *
+	 * @return Iterable_File
+	 * @throws Exception
+	 */
+	protected function make_json( string $file_path ): Iterable_File {
+		return new Json_File( $file_path );
+	}
+}
\ No newline at end of file
diff --git a/includes/importer/class-import-mode.php b/includes/importer/class-import-mode.php
new file mode 100644
index 00000000..e1bd3a97
--- /dev/null
+++ b/includes/importer/class-import-mode.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * Class to encapsulate Import Mode values.
+ *
+ * @package Newspack_Listings;
+ */
+namespace Newspack_Listings;
+
+/**
+ * Pseudo Enum Class.
+ */
+final class Import_Mode {
+	const DRY_RUN = 'dry-run';
+	const SKIP = 'skip';
+	const UPDATE = 'UPDATE';
+
+	/**
+	 * Constructor to prevent initialization.
+	 */
+	public function __construct() {
+		// Prevent initialization.
+	}
+}
\ No newline at end of file
diff --git a/includes/importer/class-importer-mode.php b/includes/importer/class-importer-mode.php
new file mode 100644
index 00000000..6f8ca902
--- /dev/null
+++ b/includes/importer/class-importer-mode.php
@@ -0,0 +1,128 @@
+<?php
+/**
+ * Concrete implementation of @see \Newspack_Listings\Contracts\Importer_Mode.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings;
+
+use Newspack_Listings\Contracts\Importer_Mode as Importer_Mode_Interface;
+
+/**
+ * Concrete implementation of @see Importer_Mode_Interface.
+ */
+class Importer_Mode implements Importer_Mode_Interface {
+
+	/**
+	 * This boolean flag tracks whether records should be created in the database.
+	 *
+	 * @var bool $dry_run Boolean flag used to determine whether records should be created.
+	 */
+	protected bool $dry_run = false;
+
+	/**
+	 * This boolean flag tracks whether records should be updated in the database.
+	 *
+	 * @var bool $update Boolean flag used to determine whether records should be updated.
+	 */
+	protected bool $update = true;
+
+	/**
+	 * This boolean flag tracks whether records found in the database should disregard any updates.
+	 *
+	 * @var bool $skip Boolean flag used to determine whether existing records should be skipped.
+	 */
+	protected bool $skip = false;
+
+	/**
+	 * Set the mode the Importer should run under.
+	 *
+	 * @param string $mode @see \Newspack_Listings\Import_Mode.
+	 *
+	 * @return void
+	 */
+	public function set_mode( string $mode ) {
+		switch ( strtolower( $mode ) ) {
+			case Import_Mode::DRY_RUN:
+				$this->set_dry_run();
+				break;
+			case Import_Mode::SKIP:
+				$this->set_skip();
+				break;
+			case Import_Mode::UPDATE:
+			default:
+				$this->set_update();
+				break;
+		}
+	}
+
+	/**
+	 * Sets the $mode_dry_run flag. No records should be created or updated.
+	 *
+	 * @param bool $dry_run Boolean flag.
+	 */
+	public function set_dry_run( bool $dry_run = true ) {
+		$this->dry_run = $dry_run;
+
+		if ( $this->dry_run ) {
+			$this->set_update( false );
+			$this->set_skip( false );
+		}
+	}
+
+	/**
+	 * Set the $mode_update flag. Determines whether existing records should be updated.
+	 *
+	 * @param bool $update Boolean flag.
+	 */
+	public function set_update( bool $update = true ) {
+		$this->update = $update;
+
+		if ( $this->update ) {
+			$this->set_dry_run( false );
+			$this->set_skip( false );
+		}
+	}
+
+	/**
+	 * Set the $mode_skip flag. Determines whether existing records should disregard updates.
+	 *
+	 * @param bool $skip Boolean flag.
+	 */
+	public function set_skip( bool $skip = true ) {
+		$this->skip = $skip;
+
+		if ( $this->skip ) {
+			$this->set_dry_run( false );
+			$this->set_update( false );
+		}
+	}
+
+	/**
+	 * Flag asserting dry-run mode. No database inserts/updates should be performed.
+	 *
+	 * @return bool
+	 */
+	public function is_dry_run(): bool {
+		return $this->dry_run;
+	}
+
+	/**
+	 * Flag asserting skip mode. Only database inserts should be performed.
+	 *
+	 * @return bool
+	 */
+	public function is_skip(): bool {
+		return $this->skip;
+	}
+
+	/**
+	 * Flag asserting update mode. All database operations are permitted.
+	 *
+	 * @return bool
+	 */
+	public function is_update(): bool {
+		return $this->update;
+	}
+}
diff --git a/includes/importer/class-importer.php b/includes/importer/class-importer.php
index 4b661ebb..803276cf 100644
--- a/includes/importer/class-importer.php
+++ b/includes/importer/class-importer.php
@@ -129,7 +129,7 @@ public static function add_cli_command() {
 		);
 
 		WP_CLI::add_command(
-			'newspack-listings import',
+			'newspack-listings old-import',
 			[ __CLASS__, 'run_cli_command' ],
 			[
 				'shortdesc' => 'Import listings data from a CSV file.',
diff --git a/includes/importer/class-json-file.php b/includes/importer/class-json-file.php
new file mode 100644
index 00000000..3872d9c3
--- /dev/null
+++ b/includes/importer/class-json-file.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Concrete implementation of Abstract_Iterable_File for JSON files.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings;
+
+use Iterator;
+
+/**
+ * Iterable File implementation for JSON file types.
+ */
+class Json_File extends Abstract_Iterable_File {
+
+	/**
+	 * Get the Iterator for JSON files.
+	 *
+	 * @return Iterator
+	 */
+	public function getIterator(): Iterator {
+		$json = json_decode( file_get_contents( $this->get_path() ), true );
+
+		$row_count = 0;
+		while ( $row_count < $this->get_start() ) {
+			array_shift( $json );
+
+			if ( empty( $json ) ) {
+				yield [];
+				return;
+			}
+
+			$row_count++;
+		}
+
+		while ( $row_count <= $this->get_end() && ! empty( $json ) ) {
+			yield array_shift( $json );
+			$row_count++;
+		}
+	}
+}
diff --git a/includes/importer/class-listing-type.php b/includes/importer/class-listing-type.php
new file mode 100644
index 00000000..1c4c972a
--- /dev/null
+++ b/includes/importer/class-listing-type.php
@@ -0,0 +1,25 @@
+<?php
+/**
+ * Class to encapsulate Listing Type values.
+ *
+ * @package Newspack_Listings;
+ */
+
+namespace Newspack_Listings;
+
+/**
+ * Pseudo Enum class.
+ */
+final class Listing_Type {
+	const EVENT = 'newspack_lst_event';
+	const GENERIC = 'newspack_lst_generic';
+	const MARKETPLACE = 'newspack_lst_mktplce';
+	const PLACE = 'newspack_lst_place';
+
+	/**
+	 * Constructor to prevent initialization.
+	 */
+	public function __construct() {
+		// Prevent initialization.
+	}
+}
diff --git a/includes/importer/class-listings-type-mapper.php b/includes/importer/class-listings-type-mapper.php
new file mode 100644
index 00000000..633b1188
--- /dev/null
+++ b/includes/importer/class-listings-type-mapper.php
@@ -0,0 +1,127 @@
+<?php
+/**
+ * Mapper for custom types to Newspack Listings Types.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings;
+
+use Exception;
+use Newspack_Listings\Contracts\Listings_Type_Mapper as Listings_Type_Mapper_Interface;
+
+/**
+ * Concrete implementation of @see Listings_Type_Mapper_Interface.
+ */
+class Listings_Type_Mapper implements Listings_Type_Mapper_Interface {
+
+	/**
+	 * Default Newspack Listings Types Map.
+	 *
+	 * @var array|array[] $listing_types
+	 */
+	protected array $listing_types = [
+		Listing_Type::GENERIC     => [],
+		Listing_Type::PLACE       => [],
+		Listing_Type::MARKETPLACE => [],
+		Listing_Type::EVENT       => [],
+	];
+
+	/**
+	 * Custom listing types mapped to Newspack Listing Types.
+	 *
+	 * @var array $types
+	 */
+	protected array $types = [];
+
+	/**
+	 * Returns custom listing types for a particular Newspack Listing Type.
+	 *
+	 * @param string $listing_type Newspack Listing Type.
+	 *
+	 * @return string[]|array
+	 *
+	 * @throws Exception Throws exception if given an unsupported Newspack Listing Type.
+	 */
+	public function get_types( string $listing_type ): array {
+		$this->check_listing_type( $listing_type );
+
+		return $this->listing_types[ $listing_type ];
+	}
+
+	/**
+	 * Get the Newspack Listing Type from a custom listing type.
+	 *
+	 * @param string $type Custom listing type.
+	 *
+	 * @return string
+	 *
+	 * @throws Exception Throws exception if custom listing type doesn't exist.
+	 */
+	public function get_listing_type( string $type ): string {
+		if ( ! array_key_exists( $type, $this->types ) ) {
+			throw new Exception( "Type '$type' isn't mapped." );
+		}
+
+		return $this->types[ $type ];
+	}
+
+	/**
+	 * Map a set of custom listing types to a Newspack Listing Type.
+	 *
+	 * @param string         $listing_type Newspack Listing type.
+	 * @param string[]|array $types Custom listing types.
+	 *
+	 * @throws Exception Throws exception if given an unsupported Newspack Listing Type.
+	 */
+	public function set_types( string $listing_type, array $types ): Listings_Type_Mapper_Interface {
+		$this->check_listing_type( $listing_type );
+
+		$this->listing_types[ $listing_type ] = $types;
+
+		foreach ( $types as $type ) {
+			$this->types[ $type ] = $listing_type;
+		}
+
+		return $this;
+	}
+
+	/**
+	 * Map an individual custom listing type to a Newspack Listing Type.
+	 *
+	 * @param string $listing_type Newspack Listing Type.
+	 * @param string $type Custom listing type.
+	 *
+	 * @throws Exception Throws exception if given an unsupported Newspack Listing Type.
+	 */
+	public function add_type( string $listing_type, string $type ): Listings_Type_Mapper_Interface {
+		$this->check_listing_type( $listing_type );
+
+		$this->listing_types[ $listing_type ][] = $type;
+		$this->types[ $type ]                   = $listing_type;
+
+		return $this;
+	}
+
+	/**
+	 * Convenience function to determine if a custom mapping exists.
+	 *
+	 * @return bool
+	 */
+	public function has_mapped_types(): bool {
+		return ! empty( $this->types );
+	}
+
+	/**
+	 * Checks provided listing type against supported list of Newspack Listing Types.
+	 *
+	 * @param string $listing_type Listing Type.
+	 *
+	 * @throws Exception Throws exception if given an unsupported Newspack Listing Type.
+	 */
+	private function check_listing_type( string $listing_type ) {
+		if ( ! array_key_exists( $listing_type, $this->listing_types ) ) {
+			throw new Exception( "Listing type '$listing_type' doesn't exist" );
+		}
+	}
+}
diff --git a/includes/importer/class-marketplace-type.php b/includes/importer/class-marketplace-type.php
new file mode 100644
index 00000000..fe174cf4
--- /dev/null
+++ b/includes/importer/class-marketplace-type.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * Class to encapsulate Marketplace Type values.
+ *
+ * @package Newspack_Listings;
+ */
+
+namespace Newspack_Listings;
+
+/**
+ * Pseudo Enum class.
+ */
+final class Marketplace_Type {
+	const CLASSIFIED = 'classified';
+	const REAL_ESTATE = 'real_estate';
+
+	/**
+	 * Constructor to prevent initialization.
+	 */
+	public function __construct() {
+		// Prevent initialization.
+	}
+}
diff --git a/includes/importer/class-newspack-listings-callable-importer.php b/includes/importer/class-newspack-listings-callable-importer.php
new file mode 100644
index 00000000..42b90a0b
--- /dev/null
+++ b/includes/importer/class-newspack-listings-callable-importer.php
@@ -0,0 +1,1140 @@
+<?php
+/**
+ * New class to handle the importing of Newspack Listings.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings\Importer;
+
+use Exception;
+use Iterator;
+use Newspack_Listings\Contracts\Importer_Mode as Importer_Mode_Interface;
+use Newspack_Listings\Contracts\Listings_Type_Mapper as Listings_Type_Mapper_Interface;
+use Newspack_Listings\File_Import_Factory;
+use Newspack_Listings\Importer_Mode;
+use Newspack_Listings\Listing_Type;
+use Newspack_Listings\Listings_Type_Mapper;
+use Newspack_Listings\Marketplace_Type;
+use Newspack_Listings\Core;
+use WP_CLI;
+use WP_Error;
+use WP_Post;
+use WP_Query;
+
+/**
+ * The main benefit of this class is the ability to inject callbacks to
+ * modify CSV row data before and after insertion.
+ *
+ * @class Newspack_Listings_Callable_Importer
+ */
+class Newspack_Listings_Callable_Importer {
+
+	/**
+	 * Singleton instance property.
+	 *
+	 * @var Newspack_Listings_Callable_Importer|null $instance
+	 */
+	protected static ?Newspack_Listings_Callable_Importer $instance = null;
+
+	/**
+	 * Abstract Callable instance property.
+	 *
+	 * @var Abstract_Callable_Pre_Create|null $callable_pre_create
+	 */
+	protected ?Abstract_Callable_Pre_Create $callable_pre_create = null;
+
+	/**
+	 * Need to implement Abstract Callable instance property.
+	 *
+	 * @var callable $callable_post_create
+	 */
+	protected $callable_post_create;
+
+	/**
+	 * Object representing the import mode to be referenced.
+	 *
+	 * @var Importer_Mode_Interface $importer_mode
+	 */
+	protected Importer_Mode_Interface $importer_mode;
+
+	/**
+	 * This interface will facilitate the mapping of Newspack Listings Type to custom listing types.
+	 *
+	 * @var Listings_Type_Mapper_Interface $listings_mapper Custom mapper for Newspack Listings Type and user defined types.
+	 */
+	protected Listings_Type_Mapper_Interface $listings_mapper;
+
+	/**
+	 * This will be the category ID that all listings will be imported under.
+	 *
+	 * @var ?int $category_id Main category for imported listings.
+	 */
+	protected ?int $category_id = null;
+
+	/**
+	 * If a listing type is not found, will default to the below. Can be set during execution.
+	 *
+	 * @var string $default_listing_type Default Listing Post Type.
+	 */
+	protected string $default_listing_type = Listing_Type::GENERIC;
+
+	/**
+	 * List of Newspack Listing Type params.
+	 *
+	 * @var array $listing_params_map
+	 */
+	protected array $listing_params_map = [
+		Listing_Type::GENERIC     => [
+			'template' => [
+				'handle'      => 'generic-listing-template',
+				'description' => 'HTML template used for Newspack Listing Type: ' . Listing_Type::GENERIC,
+			],
+			'mapper'   => [
+				'handle'      => 'generic-listing-types',
+				'description' => 'Custom post types that should be mapped to the Generic Listing Type.',
+			],
+		],
+		Listing_Type::EVENT       => [
+			'template' => [
+				'handle'      => 'event-listing-template',
+				'description' => 'HTML template used for Newspack Listing Type: ' . Listing_Type::EVENT,
+			],
+			'mapper'   => [
+				'handle'      => 'event-listing-types',
+				'description' => 'Custom post types that should be mapped to the Event Listing Type',
+			],
+		],
+		Listing_Type::MARKETPLACE => [
+			'template' => [
+				'handle'      => 'marketplace-listing-template',
+				'description' => 'HTML template used for Newspack Listing Type: ' . Listing_Type::MARKETPLACE,
+			],
+			'mapper'   => [
+				'handle'      => 'marketplace-listing-types',
+				'description' => 'Custom post types that should be mapped to the Marketplace Listing Type.',
+			],
+		],
+		Listing_Type::PLACE       => [
+			'template' => [
+				'handle'      => 'place-listing-template',
+				'description' => 'HTML template used for Newspack Listing Type: ' . Listing_Type::PLACE,
+			],
+			'mapper'   => [
+				'handle'      => 'place-listing-types',
+				'description' => 'Custom post types that should be mapped to the Place Listing Type.',
+			],
+		],
+	];
+
+	/**
+	 * This array should contain Newspack Listing Type => HTML Template pair.
+	 *
+	 * @var array $template_override
+	 */
+	protected array $template_override = [];
+
+	/**
+	 * Return's singleton instance.
+	 *
+	 * @return Newspack_Listings_Callable_Importer
+	 */
+	public static function get_instance(): Newspack_Listings_Callable_Importer {
+
+		if ( is_null( self::$instance ) ) {
+			self::$instance                  = new static();
+			self::$instance->importer_mode   = new Importer_Mode();
+			self::$instance->listings_mapper = new Listings_Type_Mapper();
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Constructor.
+	 *
+	 * @return void
+	 */
+	protected function __construct() {
+		if ( class_exists( 'WP_CLI' ) ) {
+			add_action( 'init', [ __CLASS__, 'add_cli_command' ] );
+		}
+	}
+
+	/**
+	 * Register's CLI command.
+	 */
+	public static function add_cli_command() {
+		$synopsis = [
+			[
+				'type'        => 'positional',
+				'name'        => 'file',
+				'description' => 'Path to file',
+				'optional'    => false,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'start',
+				'description' => 'Row number to start at.',
+				'optional'    => true,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'end',
+				'description' => 'Row number to end at.',
+				'optional'    => true,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'mode',
+				'description' => 'Whether to perform a dry-run (no DB interaction), update, or skip if already imported.',
+				'optional'    => true,
+				'default'     => 'update',
+				'options'     => [ 'dry-run', 'update', 'skip' ],
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'pre-create-callback',
+				'description' => 'Path to custom callback to be executed before Newspack Listing Post creation.',
+				'optional'    => true,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'post-create-callback',
+				'description' => 'Path to custom callback to be executed after Newspack Listing Post creation.',
+				'optional'    => true,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'flag',
+				'name'        => 'use-parent-category',
+				'description' => 'This flag determines whether the listings should be imported under a specific category.',
+				'optional'    => true,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'parent-category',
+				'description' => 'Specify the main category name to use.',
+				'optional'    => true,
+				'repeating'   => false,
+			],
+			[
+				'type'        => 'assoc',
+				'name'        => 'default-listing-type',
+				'description' => 'The default listing type to use, if none found.',
+				'optional'    => true,
+				'default'     => Listing_Type::GENERIC,
+				'options'     => array_keys( self::$instance->listing_params_map ),
+				'repeating'   => false,
+			],
+		];
+
+		// Add Newspack Listing Types params.
+		foreach ( self::$instance->listing_params_map as $values ) {
+			$synopsis[] = [
+				'type'        => 'assoc',
+				'name'        => $values['mapper']['handle'],
+				'description' => $values['mapper']['description'],
+				'optional'    => true,
+				'repeating'   => true,
+			];
+		}
+
+		foreach ( self::$instance->listing_params_map as $values ) {
+			$synopsis[] = [
+				'type'        => 'assoc',
+				'name'        => $values['template']['handle'],
+				'description' => $values['template']['description'],
+				'optional'    => true,
+				'repeating'   => true,
+			];
+		}
+
+		WP_CLI::add_command(
+			'newspack-listings import',
+			[ self::$instance, 'handle_import_command' ],
+			[
+				'shortdesc' => 'Import listings data.',
+				'synopsis'  => $synopsis,
+			],
+		);
+	}
+
+	/**
+	 * Set a callable instance for execution.
+	 *
+	 * @param string|Abstract_Callable_Pre_Create $callable_pre_create TBD.
+	 *
+	 * @return void
+	 * @throws Exception Will throw an exception is class is not found.
+	 */
+	protected function set_callable_pre_create( $callable_pre_create ) {
+		if ( is_string( $callable_pre_create ) ) {
+			if ( str_contains( $callable_pre_create, '.php' ) ) {
+				$callable_pre_create = $this->include_class( $callable_pre_create );
+			}
+
+			$callable_pre_create = new $callable_pre_create();
+		}
+
+		if ( ! ( $callable_pre_create instanceof Abstract_Callable_Pre_Create ) ) {
+			throw new Exception( 'Please provide a valid class of type Abstract_Callable_Pre_Create.' );
+		}
+
+		$this->callable_pre_create = $callable_pre_create;
+	}
+
+	/**
+	 * Get the instance of @return Abstract_Callable_Pre_Create|null
+	 *
+	 * @see Abstract_Callable_Pre_Create that was set.
+	 */
+	protected function get_callable_pre_create(): ?Abstract_Callable_Pre_Create {
+		return $this->callable_pre_create;
+	}
+
+	/**
+	 * Set a callable instance for execution.
+	 *
+	 * @param string|Abstract_Callable_Post_Create $callable_post_create TBD.
+	 *
+	 * @return void
+	 * @throws Exception Will throw an exception is class is not found.
+	 */
+	protected function set_callable_post_create( $callable_post_create ) {
+		if ( is_string( $callable_post_create ) ) {
+			if ( str_contains( $callable_post_create, '.php' ) ) {
+				$callable_post_create = $this->include_class( $callable_post_create );
+			}
+
+			$callable_post_create = new $callable_post_create();
+		}
+
+		if ( ! ( $callable_post_create instanceof Abstract_Callable_Post_Create ) ) {
+			throw new Exception( 'Please provide a valid class of type Abstract_Callable_Post_Create.' );
+		}
+
+		$this->callable_post_create = $callable_post_create;
+	}
+
+	/**
+	 * Get the instance of @return Abstract_Callable_Post_Create|null
+	 *
+	 * @see Abstract_Callable_Post_Create that was set
+	 */
+	protected function get_callable_post_create(): ?Abstract_Callable_Post_Create {
+		return $this->callable_post_create;
+	}
+
+	/**
+	 * Setting this variable will cause a category to be created and be associated with all imported listings.
+	 *
+	 * @param string $category Main category used for imported listings.
+	 */
+	protected function set_category_id( string $category ) {
+		if ( category_exists( $category ) ) {
+			WP_CLI::confirm( "Category: '$category' already exists. Are you sure you want to proceed?" );
+
+			global $wpdb;
+
+			$category_sql = "SELECT * FROM $wpdb->terms t
+    			LEFT JOIN $wpdb->term_taxonomy tt ON t.term_id = tt.term_id
+				WHERE t.name = '$category'
+				AND tt.taxonomy = 'category'";
+
+			$result = $wpdb->get_results( $category_sql );
+			$result = array_shift( $result );
+
+			$this->category_id = $result->term_id;
+		} else {
+			if ( $this->get_importer_mode()->is_update() || $this->get_importer_mode()->is_skip() ) {
+				$this->category_id = wp_create_category( $category );
+			}
+		}
+	}
+
+	/**
+	 * Returns the Category ID set by the import.
+	 *
+	 * @return int|null
+	 */
+	protected function get_category_id(): ?int {
+		return $this->category_id;
+	}
+
+	/**
+	 * Handler for WP CLI execution.
+	 *
+	 * @param array $args Positional CLI arguments.
+	 * @param array $assoc_args Associative CLI arguments.
+	 *
+	 * @throws Exception Thrown if file is not on system.
+	 */
+	public function handle_import_command( $args, $assoc_args ) {
+		if ( array_key_exists( 'pre-create-callback', $assoc_args ) ) {
+			$this->set_callable_pre_create( $assoc_args['pre-create-callback'] );
+		}
+
+		if ( array_key_exists( 'post-create-callback', $assoc_args ) ) {
+			$this->set_callable_post_create( $assoc_args['post-create-callback'] );
+		}
+
+		if ( array_key_exists( 'use-parent-category', $assoc_args ) ) {
+			if ( $assoc_args['use-parent-category'] ) {
+				if ( ! array_key_exists( 'parent-category', $assoc_args ) ) {
+					WP_CLI::error( 'The `--use-parent-category` flag was set, but no parent category was provided.' );
+				}
+
+				$this->set_category_id( $assoc_args['parent-category'] );
+			}
+		}
+
+		$this->get_importer_mode()->set_mode( $assoc_args['mode'] ?? '' );
+
+		$this->set_default_listing_type( $assoc_args['default-listing-type'] ?? Listing_Type::GENERIC );
+
+		$assoc_keys            = array_keys( $assoc_args );
+		$custom_listings_types = array_intersect(
+			array_map( fn( $listing_param ) => $listing_param['mapper']['handle'], $this->listing_params_map ),
+			$assoc_keys
+		);
+
+		$listing_types_by_mapper_handle = [];
+
+		foreach ( $this->listing_params_map as $key => $values ) {
+			$listing_types_by_mapper_handle[ $values['mapper']['handle'] ] = $key;
+		}
+
+		if ( ! empty( $custom_listings_types ) ) {
+			$listings_type_mapper = new Listings_Type_Mapper();
+
+			foreach ( $custom_listings_types as $key ) {
+				$listings_type_mapper->set_types(
+					$listing_types_by_mapper_handle[ $key ],
+					explode( ',', trim( $assoc_args[ $key ] ) )
+				);
+
+				$this->set_listings_type_mapper( $listings_type_mapper );
+			}
+		}
+
+		foreach ( $this->listing_params_map as $key => $values ) {
+			if ( array_key_exists( $values['template']['handle'], $assoc_args ) ) {
+				$this->template_override[ $key ] = $assoc_args[ $values['template']['handle'] ];
+			}
+		}
+
+		$this->import(
+			( new File_Import_Factory() )
+				->get_file( $args[0] )
+				->set_start( $assoc_args['start'] ?? 0 )
+				->set_end( $assoc_args['end'] ?? PHP_INT_MAX )
+				->getIterator()
+		);
+	}
+
+	/**
+	 * Set the default listing type to be used when a listing type can't be found.
+	 *
+	 * @param string $type Listing type.
+	 */
+	protected function set_default_listing_type( string $type ) {
+		// TODO does WP CLI throw an exception/error if a value not in the options list is given?
+		if ( Core::is_listing( $type ) ) {
+			$this->default_listing_type = $type;
+		}
+	}
+
+	/**
+	 * Returns the default listing type to use when no listing type can be found.
+	 *
+	 * @return string
+	 */
+	protected function get_default_listing_type(): string {
+		return $this->default_listing_type;
+	}
+
+	/**
+	 * Get the object representing the mode the importer is running under.
+	 *
+	 * @return Importer_Mode_Interface
+	 */
+	protected function get_importer_mode(): Importer_Mode_Interface {
+		return $this->importer_mode;
+	}
+
+	/**
+	 * Import data rows.
+	 *
+	 * @param Iterator $iterator Cycle through rows.
+	 *
+	 * @throws Exception Throws exception if data row cannot be imported properly.
+	 */
+	public function import( Iterator $iterator ) {
+		do {
+			$row = $iterator->current();
+
+			if ( ! is_null( $this->get_callable_pre_create() ) ) {
+				$this->get_callable_pre_create()( $row, $this->get_importer_mode() );
+			}
+
+			$listing = $this->create_or_update_listing( $row );
+
+			if ( isset( $this->callable_post_create ) ) {
+				$this->get_callable_post_create()( $listing, $this->get_importer_mode(), $row );
+			}
+
+			$iterator->next();
+		} while ( $iterator->valid() );
+	}
+
+	/**
+	 * Will take a row of data and attempt to create or update the corresponding row in the database.
+	 *
+	 * @param array $row Row representing data to be inserted.
+	 *
+	 * @return WP_Post
+	 *
+	 * @throws Exception Throws exception if a data row cannot be processed.
+	 */
+	protected function create_or_update_listing( array $row ): WP_Post {
+		$post_type     = $this->get_listing_type( $row );
+		$existing_post = function_exists( 'wpcom_vip_get_page_by_title' ) ?
+			wpcom_vip_get_page_by_title( $row['wp_post.post_title'], OBJECT, $post_type ) :
+			new WP_Query( [ 'post_type' => $post_type, 'title' => $row['wp_post.post_title'] ] );
+
+		if ( $existing_post instanceof WP_Query ) {
+			if ( $existing_post->found_posts >= 1 ) {
+				$existing_post = $existing_post->posts[0];
+			}
+		}
+
+		$incoming_post_data = [
+			'post_author' => 1, // Default user in case author isn't defined.
+		];
+
+		$other_data = [];
+
+		foreach ( $row as $key => $value ) {
+			if ( str_starts_with( $key, 'wp_post.' ) ) {
+				$incoming_post_data[ str_replace( 'wp_post.', '', $key ) ] = $value;
+			} else {
+				$other_data[ $key ] = $value;
+			}
+		}
+
+		$date_format                        = 'Y-m-d H:i:s';
+		$incoming_post_data['post_type']    = $post_type;
+		$incoming_post_data['post_date']    = isset( $incoming_post_data['post_date'] ) ?
+			gmdate( $date_format, strtotime( $incoming_post_data['post_date'] ) ) :
+			gmdate( $date_format, time() );
+		$incoming_post_data['post_excerpt'] = $incoming_post_data['post_excerpt'] ?? '';
+		$incoming_post_data['post_title']   = $incoming_post_data['post_title'] ?? __( '(no title)', 'newspack-listing' );
+		$incoming_post_data['post_status']  = 'publish';
+		$incoming_post_data['meta_input']['_wp_page_template'] = $incoming_post_data['meta_input']['_wp_page_template'] ?? 'single-wide.php';
+		// Keep featured image position if set, otherwise, featured image is shown in listing content.
+		$incoming_post_data['meta_input']['newspack_featured_image_position'] = $incoming_post_data['meta_input']['newspack_featured_image_position'] ?? 'hidden';
+
+		WP_CLI::log( $incoming_post_data['post_title'] );
+
+		if ( is_string( $incoming_post_data['post_author'] ) ) {
+			$incoming_post_data['post_author'] = $this->handle_post_author( $incoming_post_data['post_author'] );
+		}
+
+		$images = [];
+
+		if ( array_key_exists( 'images', $row ) ) {
+			if ( is_string( $row['images'] ) ) {
+				if ( str_contains( $row['images'], ',' ) ) {
+					$paths          = explode( ',', $row['images'] );
+					$array_of_paths = [];
+					foreach ( $paths as $path ) {
+						$array_of_paths[] = [ 'path' => $path ];
+					}
+					$row['images'] = $array_of_paths;
+				} else {
+					$row['images'] = [ [ 'path' => $row['images'] ] ];
+				}
+			}
+
+			$images = $this->handle_post_images( $row['images'] );
+
+			if ( array_key_exists( 'featured_image', $images ) ) {
+				$incoming_post_data['meta_input']['_thumbnail_id'] = $images['featured_image']['id'];
+			}
+		}
+
+		$incoming_post_data['post_content'] = $this->handle_post_content(
+			$incoming_post_data['post_type'] ?? '',
+			$other_data,
+			$images
+		);
+
+		if ( $this->get_importer_mode()->is_dry_run() ) {
+			if ( $existing_post ) {
+				$diff = array_diff_assoc( $existing_post->to_array(), $incoming_post_data );
+
+				/*var_dump(
+					[
+						'Existing Post' => $existing_post->to_array(),
+						'Updates'       => $diff,
+					]
+				);*/
+
+				return $this->handle_existing_post_properties( $existing_post, $incoming_post_data, $post_type );
+			} else {
+				/*var_dump(
+					[
+						'New Post' => $incoming_post_data,
+					]
+				);*/
+
+				return new WP_Post( (object) $incoming_post_data );
+			}
+		}
+
+		if ( $this->get_importer_mode()->is_skip() ) {
+			$post_exists = $existing_post ? 'exists' : 'does not exist';
+			WP_CLI::line( "Post '{$incoming_post_data['post_title']}' $post_exists" );
+
+			if ( $existing_post ) {
+				$this->handle_category( $other_data, $existing_post->ID );
+				$this->handle_tag( $other_data, $existing_post->ID );
+			}
+		}
+
+		if ( $this->get_importer_mode()->is_update() ) {
+			if ( $existing_post ) {
+				$post_id = wp_insert_post(
+					$this->handle_existing_post_properties( $existing_post, $incoming_post_data, $post_type ),
+					true
+				);
+			} else {
+				$post_id = wp_insert_post( $incoming_post_data, true );
+			}
+
+			if ( $post_id instanceof WP_Error ) {
+				WP_CLI::error( $post_id->get_error_message() );
+			} else {
+				$existing_post = get_post( $post_id );
+			}
+
+			$this->handle_category( $other_data, $post_id );
+			$this->handle_tag( $other_data, $post_id );
+		}
+
+		return $existing_post ?? new WP_Post( (object) $incoming_post_data );
+	}
+
+	/**
+	 * Setter for @see Listings_Type_Mapper.
+	 *
+	 * @param Listings_Type_Mapper_Interface $mapper Custom mapper to handle relationship between custom types and Newspack Listing Types.
+	 */
+	protected function set_listings_type_mapper( Listings_Type_Mapper_Interface $mapper ) {
+		$this->listings_mapper = $mapper;
+	}
+
+	/**
+	 * Getter for @return Listings_Type_Mapper_Interface
+	 *
+	 * @see Listings_Type_Mapper.
+	 */
+	protected function get_listings_type_mapper(): Listings_Type_Mapper_Interface {
+		return $this->listings_mapper;
+	}
+
+	/**
+	 * Convenience function to handle the proper retrieval of Newspack Listing Type.
+	 *
+	 * @param array $row Row of data from file.
+	 *
+	 * @return string
+	 */
+	protected function get_listing_type( array $row ): string {
+		if ( $this->listings_mapper->has_mapped_types() ) {
+			try {
+				return $this->listings_mapper->get_listing_type( $row['wp_post.post_type'] );
+			} catch ( Exception $e ) {
+				return $this->get_default_listing_type();
+			}
+		}
+
+		return $this->get_default_listing_type();
+	}
+
+	/**
+	 * Get or create the Author's ID.
+	 *
+	 * @param string $author_slug URL representing the Author.
+	 *
+	 * @return int
+	 */
+	protected function handle_post_author( string $author_slug ): int {
+		$post_author = get_user_by( 'slug', $author_slug );
+
+		if ( $post_author ) {
+			return $post_author->ID;
+		} else {
+			return wp_create_user( $author_slug, wp_generate_password() );
+		}
+	}
+
+	/**
+	 * Generates a Newspack Listing Block from a template.
+	 *
+	 * @param string $listing_type @see Listing_Type.
+	 * @param array  $data Newspack Listing Post Data.
+	 * @param array  $images Array of images to be inserted into post.
+	 *
+	 * @return string
+	 */
+	protected function handle_post_content( string $listing_type, array $data, array $images = [] ): string {
+		$processed_featured_image = '';
+        $processed_images = '';
+
+        foreach ( $images as $key => $image ) {
+            if ( 'featured_image' === $key ) {
+                $featured_image_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/featured_image.html' );
+                $processed_featured_image = strtr(
+                    $featured_image_template,
+                    [
+                        '{id}'  => $image['id'],
+                        '{url}' => $image['path'],
+                    ]
+                );
+            } else {
+                $image_template = file_get_contents(WP_PLUGIN_DIR . '/newspack-listings/includes/templates/image.html');
+                $processed_images .= strtr(
+                    $image_template,
+                    [
+                        '{id}' => $image['id'],
+                        '{url}' => $image['path'],
+                    ]
+                );
+            }
+        }
+
+		if ( array_key_exists( $listing_type, $this->template_override ) ) {
+			$place_template = file_get_contents( $this->template_override[ $listing_type ] );
+
+			foreach ( $data as $key => $value ) {
+				if ( ! str_starts_with( $key, '{' ) && ! str_ends_with( $key, '}' ) ) {
+					$data[ "{{$key}}" ] = $value;
+					unset( $data[ $key ] );
+				}
+			}
+
+			$data['{featured_image}'] = $processed_featured_image;
+            $data['{processed_images}'] = $processed_images;
+
+			return strtr( $place_template, $data );
+		}
+
+		switch ( $listing_type ) {
+			case Listing_Type::PLACE:
+				$place_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/place/place.html' );
+
+				$content = strtr(
+					$place_template,
+					[
+						'{featured_image}' => $processed_featured_image,
+						'{description}'    => $data['description'] ?? '',
+						'{email}'          => $data['email'] ?? '',
+						'{phone}'          => $data['phone'] ?? '',
+						'{phone_display}'  => $data['phone_display'] ?? '',
+						'{address_street}' => $data['address_street'] ?? '',
+						'{address_city}'   => $data['address_city'] ?? '',
+						'{address_region}' => $data['address_region'] ?? '',
+						'{address_postal}' => $data['address_postal'] ?? '',
+					]
+				);
+				break;
+			case Listing_Type::MARKETPLACE:
+				if ( ! array_key_exists( 'marketplace_type', $data ) ) {
+					WP_CLI::warning( 'Listing Type is ' . Listing_Type::MARKETPLACE . " but no 'marketplace_type' param found." );
+					$content = '';
+					break;
+				}
+
+				if ( Marketplace_Type::CLASSIFIED === strtolower( $data['marketplace_type'] ) ) {
+					$classified_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/marketplace/classified.html' );
+
+					$content = strtr(
+						$classified_template,
+						[
+							'{featured_image}'  => $processed_featured_image,
+							'{price}'           => $data['price'] ?? '',
+							'{formatted_price}' => $data['formatted_price'] ?? '',
+							'{description}'     => $data['description'] ?? '',
+						]
+					);
+				} else {
+					$marketplace_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/marketplace/real_estate.html' );
+
+					$content = strtr(
+						$marketplace_template,
+						[
+							'{featured_image}'   => $processed_featured_image,
+							'{email}'            => $data['email'],
+							'{phone}'            => $data['phone'],
+							'{phone_display}'    => $data['phone_display'] ?? '',
+							'{address_street}'   => $data['address_street'] ?? '',
+							'{address_city}'     => $data['address_city'] ?? '',
+							'{address_region}'   => $data['address_region'] ?? '',
+							'{address_postal}'   => $data['address_postal'] ?? '',
+							'{price}'            => $data['price'] ?? '',
+							'{formatted_price}'  => $data['formatted_price'] ?? '',
+							'{show_decimals}'    => $data['show_decimals'] ?? '',
+							'{bedroom_count}'    => $data['bedroom_count'] ?? '',
+							'{bathroom_count}'   => $data['bathroom_count'] ?? '',
+							'{area}'             => $data['area'] ?? '',
+							'{area_measurement}' => $data['area_measurement'] ?? '',
+							'{description}'      => $data['description'] ?? '',
+							'{property_details}' => $data['property_details'] ?? '',
+							'{year_built}'       => $data['year_built'] ?? '',
+							'{garage}'           => $data['garage'] ?? '',
+							'{basement}'         => $data['basement'] ?? '',
+							'{heating}'          => $data['heating'] ?? '',
+							'{cooling}'          => $data['cooling'] ?? '',
+							'{appliances}'       => $data['appliances'] ?? '',
+						]
+					);
+				}
+				break;
+			case Listing_Type::EVENT:
+				$event_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/event/event.html' );
+
+				$content = strtr(
+					$event_template,
+					[
+						'{featured_image}' => $processed_featured_image,
+						'{start_date}'     => $data['start_date'] ?? '',
+					]
+				);
+				break;
+			case Listing_Type::GENERIC:
+			default:
+				$generic_template = file_get_contents( WP_PLUGIN_DIR . '/newspack-listings/includes/templates/generic.html' );
+
+				$content = strtr(
+					$generic_template,
+					[
+						'{featured_image}' => $processed_featured_image,
+						'{html}'           => $data['html'] ?? '',
+					]
+				);
+		}
+
+		return $content;
+	}
+
+	/**
+	 * Handles properly uploading images.
+	 *
+	 * @param string[]|array $images Array of image paths or URL's.
+	 *
+	 * @return string[]
+	 *
+	 * @throws Exception Random Int generation throws exception.
+	 */
+	protected function handle_post_images( array $images ): array {
+		$uploaded_images  = [];
+		$upload_directory = wp_upload_dir();
+
+		foreach ( $images as $key => $image ) {
+			$image_name   = basename( $image['path'] );
+			$image_exists = function_exists( 'wpcom_vip_get_page_by_title' ) ?
+				wpcom_vip_get_page_by_title( $image_name, OBJECT, 'attachment' ) :
+				new WP_Query( [ 'post_type' => 'attachment', 'title' => $image_name] );
+
+			if ( $image_exists instanceof WP_Query ) {
+				if ( $image_exists->found_posts >= 1 ) {
+					$image_exists = $image_exists->posts[0];
+				}
+			}
+
+			if ( $image_exists ) {
+                $uploads_folder_file_path = get_post_meta( $image_exists->ID, '_wp_attached_file', true );
+                $id = $image_exists->ID;
+                $path = $upload_directory['baseurl'] . '/' . $uploads_folder_file_path;
+
+				if ( is_string( $key ) ) {
+					$uploaded_images[ $key ] = [
+						'id'   => $id,
+						'path' => $path,
+					];
+				} else {
+					if ( ! array_key_exists( 'featured_image', $uploaded_images ) ) {
+						$uploaded_images['featured_image'] = [
+                            'id' => $id,
+                            'path' => $path,
+                        ];
+					} else {
+						$uploaded_images[] = [
+							'id'   => $id,
+							'path' => $path,
+						];
+					}
+				}
+
+				continue;
+			}
+
+			if ( $this->get_importer_mode()->is_dry_run() ) {
+				if ( is_string( $key ) ) {
+					$uploaded_images[ $key ] = $image;
+				} else {
+					if ( ! array_key_exists( 'featured_image', $uploaded_images ) ) {
+						$uploaded_images['featured_image'] = $image;
+					} else {
+						$uploaded_images[] = $image;
+					}
+				}
+			} elseif ( file_exists( $image['path'] ) || filter_var( $image['path'], FILTER_VALIDATE_URL ) ) {
+				$image_data = file_get_contents( $image['path'] );
+				$image_type = wp_check_filetype( $image_name );
+
+				$file_path = '/' . urldecode( $image_name );
+				if ( wp_mkdir_p( $upload_directory['path'] ) ) {
+					$file_path = "{$upload_directory['path']}$file_path";
+				} else {
+					$file_path = "{$upload_directory['basedir']}$file_path";
+				}
+
+				file_put_contents( $file_path, $image_data );
+
+				$attachment = [
+					'post_mime_type' => $image_type['type'],
+					'post_title'     => sanitize_file_name( $image_name ),
+					'post_content'   => '',
+					'post_status'    => 'inherit',
+				];
+
+				$attachment_id = random_int( 5, 5 );
+				$path          = "https://example.com/$attachment_id";
+
+				if ( $this->get_importer_mode()->is_update() ) {
+					$attachment_id = wp_insert_attachment( $attachment, $file_path );
+					require_once ABSPATH . 'wp-admin/includes/image.php';
+					$attachment_data = wp_generate_attachment_metadata( $attachment_id, $file_path );
+					wp_update_attachment_metadata( $attachment_id, $attachment_data );
+					$path = $upload_directory['baseurl'] . '/' . $attachment_data['file'];
+				}
+
+				$uploaded_image = [
+					'id'   => $attachment_id,
+					'path' => $path,
+				];
+
+				if ( is_string( $key ) ) {
+					$uploaded_images[ $key ] = $uploaded_image;
+				} else {
+					if ( ! array_key_exists( 'featured_image', $uploaded_images ) ) {
+						$uploaded_images['featured_image'] = $uploaded_image;
+					} else {
+						$uploaded_images[] = $uploaded_image;
+					}
+				}
+			}
+		}
+
+		return $uploaded_images;
+	}
+
+	/**
+	 * Convenience function to handle the import of categories or category. All categories will
+	 * be imported under a parent category if it's provided.
+	 *
+	 * @param array $data Incoming data from import file.
+	 * @param int   $post_id The ID of the post to associate with the category.
+	 */
+	protected function handle_category( array $data, int $post_id ) {
+		if ( array_key_exists( 'categories', $data ) && ! array_key_exists( 'category', $data ) && ! empty( $data['categories'] ) ) {
+			foreach ( $data['categories'] as $category ) {
+				if ( ! is_array( $category ) ) {
+					$category = [ 'category' => $category ];
+				}
+
+				$this->handle_category_creation_or_update( $category, $post_id );
+			}
+		} elseif ( array_key_exists( 'category', $data ) && ! array_key_exists( 'categories', $data ) ) {
+			$this->handle_category_creation_or_update( $data, $post_id );
+		} else {
+			WP_CLI::warning( 'Either no categories provided, or something wrong with categories.' );
+		}
+	}
+
+	/**
+	 * This function will handle the creation of a category record if necessary or the update.
+	 *
+	 * @param array $data Incoming data from import file.
+	 * @param int   $post_id The ID of the post to associate with the category.
+	 */
+	protected function handle_category_creation_or_update( array $data, int $post_id ) {
+		$category = $data['category'];
+
+		global $wpdb;
+
+		$constraint = '';
+
+		if ( is_string( $category ) ) {
+			$constraint = "t.name = '$category'";
+		} elseif ( is_int( $category ) ) {
+			$constraint = "t.term_id = $category";
+		}
+
+		$category_sql = "SELECT t.term_id, t.name, tt.taxonomy, tt.parent as parent_term_id FROM $wpdb->terms as t
+			LEFT JOIN $wpdb->term_taxonomy tt ON t.term_id = tt.term_id
+			WHERE $constraint AND tt.taxonomy = 'category'";
+		$result       = $wpdb->get_results( $category_sql );
+
+		if ( ! empty( $result ) ) {
+			$category = array_shift( $result );
+
+			if ( $this->get_category_id() !== $category->parent_term_id && $this->can_touch_database() ) {
+				$wpdb->update(
+					$wpdb->term_taxonomy,
+					[
+						'parent' => $this->get_category_id(),
+					],
+					[
+						'term_id'  => $category->term_id,
+						'taxonomy' => 'category',
+					]
+				);
+
+				$this->add_category_to_post( $post_id, $category->term_id );
+			}
+		} else {
+			$parent = $this->get_category_id() ?? 0;
+
+			if ( $this->can_touch_database() ) {
+				$category_id = wp_create_category( $category, $parent );
+
+				$this->add_category_to_post( $post_id, $category_id );
+			}
+		}
+	}
+
+	/**
+	 * Convenience function to handle the importation of a single or multiple tags.
+	 *
+	 * @param array $data Incoming data from import file.
+	 * @param int   $post_id The ID of the post to associate with tag.
+	 */
+	protected function handle_tag( array $data, int $post_id ) {
+		if ( array_key_exists( 'tags', $data ) && ! array_key_exists( 'tag', $data ) && ! empty( $data['tags'] ) ) {
+			foreach ( $data['tags'] as $tag ) {
+				if ( ! is_array( $tag ) ) {
+					$tag = [ 'tag' => $tag ];
+				}
+
+				$this->handle_tag_creation_or_update( $tag, $post_id );
+			}
+		} elseif ( array_key_exists( 'tag', $data ) && ! array_key_exists( 'tags', $data ) ) {
+			$this->handle_tag_creation_or_update( $data, $post_id );
+		} else {
+			WP_CLI::warning( 'Either no tags provided, or something wrong with tags.' );
+		}
+	}
+
+	/**
+	 * This function will handle the creation or update of tags.
+	 *
+	 * @param array $data Incoming data from import file.
+	 * @param int   $post_id The ID of the post to associate with tag.
+	 */
+	protected function handle_tag_creation_or_update( array $data, int $post_id ) {
+		if ( tag_exists( $data['tag'] ) ) {
+			if ( $this->can_touch_database() ) {
+				wp_add_post_tags( $post_id, $data['tag'] );
+			}
+		} else {
+			if ( $this->can_touch_database() ) {
+				$tag = wp_create_tag( $data['tag'] );
+
+				wp_add_post_tags( $post_id, $tag );
+			}
+		}
+	}
+
+	/**
+	 * Includes the file at the given path, and returns the Class name.
+	 *
+	 * @param string $path Path to class/file.
+	 *
+	 * @return string
+	 */
+	private function include_class( string $path ): string {
+		[ $file_path, $class ] = explode( ',', $path );
+
+		require_once $file_path;
+
+		return $class;
+	}
+
+	/**
+	 * This function will sync the $new_params into an existing $post.
+	 *
+	 * @param WP_Post $post Existing post.
+	 * @param array   $new_params New data from file.
+	 * @param string  $post_type Newspack Listing Type.
+	 *
+	 * @return WP_Post
+	 */
+	private function handle_existing_post_properties( WP_Post $post, array $new_params, string $post_type ): WP_Post {
+        unset( $new_params['ID'] );
+        unset( $new_params['id'] );
+		foreach ( $new_params as $key => $value ) {
+			$post->$key = $value;
+		}
+
+		$post->post_type = $post_type;
+
+		return $post;
+	}
+
+	/**
+	 * Convenience function to easily associate a category and a post.
+	 *
+	 * @param int $post_id The post to associate the category to.
+	 * @param int $category_id AKA term_id. The category to be associated with a post.
+	 */
+	private function add_category_to_post( int $post_id, int $category_id ) {
+		global $wpdb;
+
+		$associated_check_sql = "SELECT * FROM $wpdb->term_relationships tr
+			INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
+			WHERE tt.term_id = $category_id AND tt.taxonomy = 'category' AND tr.object_id = $post_id";
+		$result               = $wpdb->get_results( $associated_check_sql );
+
+		if ( empty( $result ) && $this->can_touch_database() ) {
+			$term_taxonomy_sql = "SELECT term_taxonomy_id FROM $wpdb->term_taxonomy WHERE term_id = $category_id AND taxonomy = 'category'";
+			$result            = $wpdb->get_results( $term_taxonomy_sql );
+			$result            = array_shift( $result );
+			$result            = $wpdb->insert(
+				$wpdb->term_relationships,
+				[
+					'object_id'        => $post_id,
+					'term_taxonomy_id' => $result->term_taxonomy_id,
+				]
+			);
+		}
+	}
+
+	/**
+	 * Determines whether the import script is running in a mode that allows DB insertion or update.
+	 *
+	 * @return bool
+	 */
+	private function can_touch_database(): bool {
+		return $this->get_importer_mode()->is_update() || $this->get_importer_mode()->is_skip();
+	}
+}
+
+Newspack_Listings_Callable_Importer::get_instance();
diff --git a/includes/importer/contracts/contract-csv-file.php b/includes/importer/contracts/contract-csv-file.php
new file mode 100644
index 00000000..644fe45a
--- /dev/null
+++ b/includes/importer/contracts/contract-csv-file.php
@@ -0,0 +1,65 @@
+<?php
+/**
+ * Interface for interacting with CSV Files.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings\Contracts;
+
+interface Csv_File extends Iterable_File {
+	/**
+	 * Get the CSV Header Row as an associative array.
+	 *
+	 * @return array
+	 */
+	public function get_header(): array;
+
+	/**
+	 * Sets the separator to be used for CSV parsing.
+	 *
+	 * @param string $separator Separator character to use for CSV parsing.
+	 *
+	 * @return void|Csv_File
+	 */
+	public function set_separator( string $separator );
+
+	/**
+	 * Returns the separator character to be used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_separator(): string;
+
+	/**
+	 * Sets the enclosure character to be used for CSV parsing.
+	 *
+	 * @param string $enclosure Enclosure character to use for CSV parsing.
+	 *
+	 * @return void|Csv_File
+	 */
+	public function set_enclosure( string $enclosure );
+
+	/**
+	 * Returns the enclosure character to be used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_enclosure(): string;
+
+	/**
+	 * Sets the escape character to be used for CSV parsing.
+	 *
+	 * @param string $escape Escape character to use for CSV parsing.
+	 *
+	 * @return void|Csv_File
+	 */
+	public function set_escape( string $escape );
+
+	/**
+	 * Returns the escape character to be used for CSV parsing.
+	 *
+	 * @return string
+	 */
+	public function get_escape(): string;
+}
diff --git a/includes/importer/contracts/contract-file.php b/includes/importer/contracts/contract-file.php
new file mode 100644
index 00000000..37b64445
--- /dev/null
+++ b/includes/importer/contracts/contract-file.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Interface for interacting with files.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings\Contracts;
+
+interface File {
+	/**
+	 * Get the file's full path.
+	 *
+	 * @return string
+	 */
+	public function get_path(): string;
+
+	/**
+	 * Should return the file resource.
+	 *
+	 * @return resource
+	 */
+	public function get_handle();
+
+	/**
+	 * Get the file's name.
+	 *
+	 * @return string
+	 */
+	public function get_name(): string;
+
+	/**
+	 * Get the file's size.
+	 *
+	 * @return int
+	 */
+	public function get_size(): int;
+}
diff --git a/includes/importer/contracts/contract-importer-mode.php b/includes/importer/contracts/contract-importer-mode.php
new file mode 100644
index 00000000..0255fcfc
--- /dev/null
+++ b/includes/importer/contracts/contract-importer-mode.php
@@ -0,0 +1,41 @@
+<?php
+/**
+ * Contract establishing Newspack Listings import mode.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings\Contracts;
+
+interface Importer_Mode {
+
+	/**
+	 * Set the mode the Importer should run under.
+	 *
+	 * @param string $mode @see \Newspack_Listings\Import_Mode.
+	 *
+	 * @return void
+	 */
+	public function set_mode( string $mode );
+
+	/**
+	 * This mode indicates that no DB updates should be made.
+	 *
+	 * @return bool
+	 */
+	public function is_dry_run(): bool;
+
+	/**
+	 * This mode indicates that existing content should not be updated. It should be skipped.
+	 *
+	 * @return bool
+	 */
+	public function is_skip(): bool;
+
+	/**
+	 * This mode indicates that all DB operations are permitted.
+	 *
+	 * @return bool
+	 */
+	public function is_update(): bool;
+}
diff --git a/includes/importer/contracts/contract-iterable-file.php b/includes/importer/contracts/contract-iterable-file.php
new file mode 100644
index 00000000..0cfbe720
--- /dev/null
+++ b/includes/importer/contracts/contract-iterable-file.php
@@ -0,0 +1,45 @@
+<?php
+/**
+ * Contract to define Iterable_File.
+ *
+ * @package Newspack_Listings
+ */
+
+namespace Newspack_Listings\Contracts;
+
+use IteratorAggregate;
+use Newspack_Listings\Contracts\File as File_Interface;
+
+interface Iterable_File extends File_Interface, IteratorAggregate {
+	/**
+	 * Set the row at which iteration should begin.
+	 *
+	 * @param int $start Integer value representing the row at which iteration should begin.
+	 *
+	 * @return Iterable_File|void
+	 */
+	public function set_start( int $start = 0 );
+
+	/**
+	 * Get the row at which iteration should begin.
+	 *
+	 * @return int
+	 */
+	public function get_start(): int;
+
+	/**
+	 * Set the row at which the iteration should end.
+	 *
+	 * @param int $end Integer value representing the row at which the iteration should end.
+	 *
+	 * @return Iterable_File|void
+	 */
+	public function set_end( int $end = PHP_INT_MAX );
+
+	/**
+	 * Get the row at which iteration should end.
+	 *
+	 * @return int
+	 */
+	public function get_end(): int;
+}
diff --git a/includes/importer/contracts/contract-listings-type-mapper.php b/includes/importer/contracts/contract-listings-type-mapper.php
new file mode 100644
index 00000000..1f618d54
--- /dev/null
+++ b/includes/importer/contracts/contract-listings-type-mapper.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Mapper for custom types to Newspack Listings Types.
+ *
+ * @package Newspack_Listings.
+ */
+
+namespace Newspack_Listings\Contracts;
+
+interface Listings_Type_Mapper {
+	/**
+	 * Get custom listing types mapped to a Newspack Listing Type.
+	 *
+	 * @param string $listing_type Post_Type type.
+	 *
+	 * @return string[]
+	 */
+	public function get_types( string $listing_type ): array;
+
+	/**
+	 * Get the Newspack Listing Type from a custom listing type.
+	 *
+	 * @param string $type Custom listing type.
+	 *
+	 * @return string
+	 */
+	public function get_listing_type( string $type ): string;
+
+	/**
+	 * Map a set of custom listing types to a Newspack Listing Type.
+	 *
+	 * @param string   $listing_type Post_Type type.
+	 * @param string[] $types Custom listing types.
+	 *
+	 * @return Listings_Type_Mapper
+	 */
+	public function set_types( string $listing_type, array $types ): Listings_Type_Mapper;
+
+	/**
+	 * Map an individual custom listing type to a Newspack Listing Type.
+	 *
+	 * @param string $listing_type Post_Type type.
+	 * @param string $type Custom listing type.
+	 *
+	 * @return Listings_Type_Mapper
+	 */
+	public function add_type( string $listing_type, string $type ): Listings_Type_Mapper;
+
+	/**
+	 * Convenience function to determine if a custom mapping exists.
+	 *
+	 * @return bool
+	 */
+	public function has_mapped_types(): bool;
+}
diff --git a/includes/templates/event/event.html b/includes/templates/event/event.html
new file mode 100644
index 00000000..f413d746
--- /dev/null
+++ b/includes/templates/event/event.html
@@ -0,0 +1,2 @@
+{featured_image}
+<!-- wp:newspack-listings/event-dates {"startDate":"{start_date}"} /-->
\ No newline at end of file
diff --git a/includes/templates/featured_image.html b/includes/templates/featured_image.html
new file mode 100644
index 00000000..6680cc7c
--- /dev/null
+++ b/includes/templates/featured_image.html
@@ -0,0 +1,9 @@
+<!-- wp:cover {"url":"{url}","id":{id},"focalPoint":{"x":"0.56","y":"0.33"},"align":"full"} -->
+<div class="wp-block-cover alignfull has-background-dim"><img class="wp-block-cover__image-background wp-image-{id}" alt="" src="{url}" style="object-position:56% 33%" data-object-fit="cover" data-object-position="56% 33%"/>
+  <div class="wp-block-cover__inner-container">
+    <!-- wp:paragraph {"align":"center","placeholder":"Write title…","fontSize":"large"} -->
+      <p class="has-text-align-center has-large-font-size"></p>
+    <!-- /wp:paragraph -->
+  </div>
+</div>
+<!-- /wp:cover -->
\ No newline at end of file
diff --git a/includes/templates/generic.html b/includes/templates/generic.html
new file mode 100644
index 00000000..e5d9acb1
--- /dev/null
+++ b/includes/templates/generic.html
@@ -0,0 +1,2 @@
+{featured_image}
+{html}
\ No newline at end of file
diff --git a/includes/templates/marketplace/classified.html b/includes/templates/marketplace/classified.html
new file mode 100644
index 00000000..537f9ac3
--- /dev/null
+++ b/includes/templates/marketplace/classified.html
@@ -0,0 +1,20 @@
+{featured_image}
+<!-- wp:group {"className":"newspack-listings__classified-ads-1"} -->
+<div class="wp-block-group newspack-listings__classified-ads-1"><!-- wp:columns -->
+    <div class="wp-block-columns"><!-- wp:column {"width":"66.66%","className":"newspack-listings__classified-ads-1__images"} -->
+        <div class="wp-block-column newspack-listings__classified-ads-1__images" style="flex-basis:66.66%"><!-- wp:image {"sizeSlug":"large","linkDestination":"none"} -->
+            <figure class="wp-block-image size-large"><img alt=""/></figure>
+            <!-- /wp:image -->
+
+            <!-- wp:jetpack/tiled-gallery {"className":"is-style-square","columns":0,"columnWidths":[["66.75138","33.24862"],["50.00000","50.00000"]],"ids":[]} /--></div>
+        <!-- /wp:column -->
+
+        <!-- wp:column {"width":"33.33%"} -->
+        <div class="wp-block-column" style="flex-basis:33.33%"><!-- wp:newspack-listings/price {"price":{price},"formattedPrice":"{formatted_price}"} /-->
+
+            <!-- wp:paragraph -->
+            <p>{description}</p>
+            <!-- /wp:paragraph --></div>
+        <!-- /wp:column --></div>
+    <!-- /wp:columns --></div>
+<!-- /wp:group -->
\ No newline at end of file
diff --git a/includes/templates/marketplace/real_estate.html b/includes/templates/marketplace/real_estate.html
new file mode 100644
index 00000000..5b323b78
--- /dev/null
+++ b/includes/templates/marketplace/real_estate.html
@@ -0,0 +1,101 @@
+{featured_image}
+<!-- wp:group {"className":"newspack-listings__real-estate-pattern-1"} -->
+<div class="wp-block-group newspack-listings__real-estate-pattern-1"><!-- wp:media-text {"align":"","linkDestination":"none","mediaType":"image","mediaWidth":66,"imageFill":true} -->
+    <div class="wp-block-media-text is-stacked-on-mobile is-image-fill" style="grid-template-columns:66% auto"><figure class="wp-block-media-text__media"><img alt=""/></figure><div class="wp-block-media-text__content"><!-- wp:jetpack/tiled-gallery {"className":"is-style-square","ids":[]} /--></div></div>
+    <!-- /wp:media-text -->
+
+    <!-- wp:columns -->
+    <div class="wp-block-columns"><!-- wp:column {"width":"66.66%"} -->
+        <div class="wp-block-column" style="flex-basis:66.66%"><!-- wp:separator {"className":"is-style-wide"} -->
+            <hr class="wp-block-separator is-style-wide"/>
+            <!-- /wp:separator -->
+
+            <!-- wp:columns {"className":"newspack-listings__real-estate-pattern-1__details"} -->
+            <div class="wp-block-columns newspack-listings__real-estate-pattern-1__details"><!-- wp:column {"width":"40%"} -->
+                <div class="wp-block-column" style="flex-basis:40%"><!-- wp:newspack-listings/price {"price":{price},"formattedPrice":"{formatted_price}","showDecimals":{show_decimals} /-->
+
+                    <!-- wp:paragraph {"fontSize":"small"} -->
+                    <p class="has-small-font-size">Price</p>
+                    <!-- /wp:paragraph --></div>
+                <!-- /wp:column -->
+
+                <!-- wp:column {"width":"20%"} -->
+                <div class="wp-block-column" style="flex-basis:20%"><!-- wp:paragraph {"fontSize":"large"} -->
+                    <p class="has-large-font-size"><strong>{bedroom_count}</strong></p>
+                    <!-- /wp:paragraph -->
+
+                    <!-- wp:paragraph {"fontSize":"small"} -->
+                    <p class="has-small-font-size">Bedrooms</p>
+                    <!-- /wp:paragraph --></div>
+                <!-- /wp:column -->
+
+                <!-- wp:column {"width":"20%"} -->
+                <div class="wp-block-column" style="flex-basis:20%"><!-- wp:paragraph {"fontSize":"large"} -->
+                    <p class="has-large-font-size"><strong>{bathroom_count}</strong></p>
+                    <!-- /wp:paragraph -->
+
+                    <!-- wp:paragraph {"fontSize":"small"} -->
+                    <p class="has-small-font-size">Bathrooms</p>
+                    <!-- /wp:paragraph --></div>
+                <!-- /wp:column -->
+
+                <!-- wp:column {"width":"20%"} -->
+                <div class="wp-block-column" style="flex-basis:20%"><!-- wp:paragraph {"fontSize":"large"} -->
+                    <p class="has-large-font-size"><strong>{area}</strong></p>
+                    <!-- /wp:paragraph -->
+
+                    <!-- wp:paragraph {"fontSize":"small"} -->
+                    <p class="has-small-font-size">{area_measurement}</p>
+                    <!-- /wp:paragraph --></div>
+                <!-- /wp:column --></div>
+            <!-- /wp:columns -->
+
+            <!-- wp:separator {"className":"is-style-wide"} -->
+            <hr class="wp-block-separator is-style-wide"/>
+            <!-- /wp:separator -->
+
+            <!-- wp:paragraph -->
+            <p>{description}</p>
+            <!-- /wp:paragraph -->
+
+            <!-- wp:heading {"level":3} -->
+            <h3>Property Details</h3>
+            <!-- /wp:heading -->
+
+            <!-- wp:paragraph -->
+            <p>{property_details}</p>
+            <!-- /wp:paragraph -->
+
+            <!-- wp:list -->
+            <ul><li><strong>Year built:</strong> {year_built}</li><li><strong>Garage:</strong> {garage}</li><li><strong>Basement:</strong>
+                {basement}</li><li><strong>Heating:</strong> {heating}</li><li><strong>Cooling:</strong> {cooling}</li><li><strong>Appliances included:</strong>
+                {appliances}</li></ul>
+            <!-- /wp:list --></div>
+        <!-- /wp:column -->
+
+        <!-- wp:column {"width":"33.33%"} -->
+        <div class="wp-block-column" style="flex-basis:33.33%"><!-- wp:jetpack/map {"points":[{"placeTitle":"West Hill Court","title":"West Hill Court","caption":"West Hill Court, Cupertino, California 95014, United States","id":"address.958477920958366","coordinates":{"longitude":-122.0404674,"latitude":37.3072975}}],"zoom":14,"mapCenter":{"lng":-122.0404674,"lat":37.3072975},"markerColor":"#3366ff","mapHeight":400,"className":"is-style-default"} -->
+            <div class="wp-block-jetpack-map is-style-default" data-map-style="default" data-map-details="true" data-points="[{&quot;placeTitle&quot;:&quot;West Hill Court&quot;,&quot;title&quot;:&quot;West Hill Court&quot;,&quot;caption&quot;:&quot;West Hill Court, Cupertino, California 95014, United States&quot;,&quot;id&quot;:&quot;address.958477920958366&quot;,&quot;coordinates&quot;:{&quot;longitude&quot;:-122.0404674,&quot;latitude&quot;:37.3072975}}]" data-zoom="14" data-map-center="{&quot;lng&quot;:-122.0404674,&quot;lat&quot;:37.3072975}" data-marker-color="#3366ff" data-map-height="400" data-show-fullscreen-button="true"><ul><li><a href="https://www.google.com/maps/search/?api=1&amp;query=37.3072975,-122.0404674">West Hill Court</a></li></ul></div>
+            <!-- /wp:jetpack/map -->
+
+            <!-- wp:heading {"level":3} -->
+            <h3>Schedule a Private Showing</h3>
+            <!-- /wp:heading -->
+
+            <!-- wp:jetpack/contact-info -->
+            <div class="wp-block-jetpack-contact-info"><!-- wp:jetpack/email {"email":"{email}"} -->
+                <div class="wp-block-jetpack-email"><a href="mailto:{email}">{email}</a></div>
+                <!-- /wp:jetpack/email -->
+
+                <!-- wp:jetpack/phone {"phone":"{phone_display}"} -->
+                <div class="wp-block-jetpack-phone"><a href="tel:{phone}">{phone_display}</a></div>
+                <!-- /wp:jetpack/phone -->
+
+                <!-- wp:jetpack/address {"address":"{address_street}","city":"{address_city}","postal":"{address_postal}","country":"{address_region}"} -->
+                <div class="wp-block-jetpack-address"><div class="jetpack-address__address jetpack-address__address1">{address_street}</div><div><span class="jetpack-address__city">{address_city}</span>, <span class="jetpack-address__region"></span> <span class="jetpack-address__postal">{address_postal}</span></div><div class="jetpack-address__country">
+                    {address_region}</div></div>
+                <!-- /wp:jetpack/address --></div>
+            <!-- /wp:jetpack/contact-info --></div>
+        <!-- /wp:column --></div>
+    <!-- /wp:columns --></div>
+<!-- /wp:group -->
\ No newline at end of file
diff --git a/includes/templates/place/place.html b/includes/templates/place/place.html
new file mode 100644
index 00000000..763fcbca
--- /dev/null
+++ b/includes/templates/place/place.html
@@ -0,0 +1,47 @@
+{featured_image}
+<!-- wp:group {"className":"newspack-listings__business-pattern-1"} -->
+<div class="wp-block-group newspack-listings__business-pattern-1"><!-- wp:columns -->
+    <div class="wp-block-columns"><!-- wp:column {"width":"66.66%"} -->
+        <div class="wp-block-column" style="flex-basis:66.66%"><!-- wp:paragraph -->
+            <p>{description}</p>
+            <!-- /wp:paragraph --></div>
+        <!-- /wp:column -->
+        [tiled-gallery-shortcode images=asdfasdf]
+
+        <!-- wp:column {"width":"33.33%"} -->
+        <div class="wp-block-column" style="flex-basis:33.33%">
+            <!-- wp:jetpack/map {"mapCenter":{"lng":-122.41941550000001,"lat":37.7749295}} -->
+            <div class="wp-block-jetpack-map" data-map-style="default" data-map-details="true" data-points="[]"
+                 data-zoom="13" data-map-center="{&quot;lng&quot;:-122.41941550000001,&quot;lat&quot;:37.7749295}"
+                 data-marker-color="red" data-show-fullscreen-button="true"></div>
+            <!-- /wp:jetpack/map -->
+
+            <!-- wp:jetpack/contact-info -->
+            <div class="wp-block-jetpack-contact-info"><!-- wp:jetpack/email {"email":"{email}"} -->
+                <div class="wp-block-jetpack-email"><a href="mailto:{email}">{email}</a></div>
+                <!-- /wp:jetpack/email -->
+
+                <!-- wp:jetpack/phone {"phone":"{phone_display}"} -->
+                <div class="wp-block-jetpack-phone"><a href="tel:{phone}">{phone_display}</a></div>
+                <!-- /wp:jetpack/phone -->
+
+                <!-- wp:jetpack/address {"address":"{address_street}","city":"{address_city}","region":"{address_region}","postal":"{address_postal}"} -->
+                <div class="wp-block-jetpack-address">
+                    <div class="jetpack-address__address jetpack-address__address1">
+                        {address_street}
+                    </div>
+                    <div><span class="jetpack-address__city">{address_city}</span>, <span
+                            class="jetpack-address__region">{address_region}</span> <span
+                            class="jetpack-address__postal">{address_postal}</span></div>
+                </div>
+                <!-- /wp:jetpack/address --></div>
+            <!-- /wp:jetpack/contact-info -->
+
+            <!-- wp:separator {"className":"is-style-wide"} -->
+            <hr class="wp-block-separator is-style-wide"/>
+            <!-- /wp:separator -->
+
+            <!-- wp:jetpack/business-hours /--></div>
+        <!-- /wp:column --></div>
+    <!-- /wp:columns --></div>
+<!-- /wp:group -->
\ No newline at end of file
diff --git a/newspack-listings.php b/newspack-listings.php
index c4059e24..0ee47e0f 100644
--- a/newspack-listings.php
+++ b/newspack-listings.php
@@ -37,8 +37,26 @@
 require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/class-products.php';
 
 // CLI importer files.
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/contracts/contract-importer-mode.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/contracts/contract-listings-type-mapper.php';
 require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/importer-utils.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-import-mode.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-importer-mode.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-marketplace-type.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-listing-type.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-listings-type-mapper.php';
 require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-importer.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-newspack-listings-callable-importer.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/contracts/contract-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/contracts/contract-iterable-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/contracts/contract-csv-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-abstract-callable-pre-create.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-abstract-callable-post-create.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-abstract-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-abstract-iterable-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-json-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-csv-file.php';
+require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/importer/class-file-import-factory.php';
 
 // Migration utilities.
 require_once NEWSPACK_LISTINGS_PLUGIN_FILE . '/includes/migration/class-migration.php';