If you want to have a true multi-vendor marketplace, you will need to purchase Enterprise Edition license which includes spree_multi_vendor gem providing full multi-vendor support.
Ability to invite and manage vendors, their products and orders
Full fledged vendor dashboard where vendors can self-serve orders, products, manage their team, etc.
White-label Shopify Sales Channel application allowing vendors to connect their Shopify stores, import products, shipping rates and receive orders to fulfill them like a regular order in their Shopify store.
White-label WooCommerce application allowing vendors to connect their WooCommerce stores, import products, shipping rates and receive orders to fulfill them like a regular order in their WooCommerce store
Stripe Connect integration allowing vendors to receive payments directly to their Stripe accounts, split payments between marketplace and vendors, automated payouts and more
Multi-party checkout allowing customers to checkout with multiple vendors, split payments between them and receive separate invoices for each vendor
Flexible permission system to tailor the marketplace to your needs (eg. disable/enable vendor panel features)
Vendor API endpoints to allow vendors to manage their products, orders, etc.