Multi-seller marketplace for digital downloads

The challenge

The owner of a site selling downloadable web extensions and designs wanted to open it up to other sellers. Those sellers would upload and sell their own downloadable products, with the marketplace tracking seller transactions and payout details.

Most multi-seller tools are built around physical goods: shipping, stock limits and paid products. Here nearly everything was a download, some items were free, and the store owner wanted the marketplace added as a clean vQmod install on OpenCart 1.5.4 rather than as edits to core files that would complicate future updates.

What we did

• vQmod conversion. We took our own Multiseller extension and converted it to a vQmod package for OpenCart 1.5.4.x, so it could be installed and removed without overwriting core files. We set up demo stores so the client could test it before going live.
• Installation on the client's server. We installed the package, corrected the vQmod set-up and the placement of language files, and resolved a missing seller database table.
• Built for downloads. Products uploaded by sellers now default to no shipping and a download limit of 999, so buyers are not asked for delivery details and can re-download their purchases. We also enabled free (zero-price) downloadable products.
• Seller payouts. We restored the PayPal email field in the seller account so the marketplace has the details it needs to pay sellers.
• Fixes. We cleared an undefined-variable notice for the PayPal field and fixed division-by-zero errors in the seller transaction report, then uploaded the updated files to the client's server and sent the final extension package.

Tech stack

PHP, MySQL, OpenCart 1.5.4, vQmod, PayPal