Inventory System with Facebook Marketplace Sync

A used-guitar dealer sells one-of-a-kind items. There's one of each, and it can sell anywhere: at the counter, on the shop's website, on Reverb, or on Facebook Marketplace. When it sells in one place, every other listing has to come down, fast.

Facebook Marketplace was the hardest. It's where many local buyers look, but it gives small sellers no way to connect it to their own systems. Keeping it accurate meant scrolling through 150-plus listings and checking each one against the shop's records by hand. Sold guitars stayed up, buyers asked about instruments that were already gone, and some new stock never got listed at all.

Off-the-shelf retail software didn't fit either. It's built for products you reorder, not trade-ins and purchased lots, where every item has its own cost, condition, and price.

We built an inventory system around how the dealer actually works. Every item has one record: photos, specs, cost, price, where it's listed, and whether it has sold. That record drives the online shop, the in-store checkout, printed price tags, and sales reports. It also tracks what each purchased lot cost, so the shop knows its real margin on every item.

AI helps with the writing. From an item's rough title and notes, it drafts a clean sale title and a full description, which staff edit and approve before anything is listed.

Then we connected Facebook Marketplace. With no official way in, a sync tool signs in as the shop, reads its live listings, and compares them with inventory. It sorts every difference into a short list: items for sale that aren't on Facebook yet, Facebook listings that look like an unlinked item, linked listings that have disappeared (sold on Facebook, or taken down), and listings that aren't shop inventory at all.

Nothing changes without a yes. The tool walks through each difference one at a time and asks what to do. For new stock, it fills in Facebook's own listing form with the photos, title, price, category, condition, and description, then saves it as a draft for staff to check and post. It never publishes on its own.

The first run linked the shop's existing Facebook listings to inventory: 120 of 124 matched automatically, 4 went to a person to check, and none were mixed up. On a later live run of 526 inventory items against 154 Facebook listings, it confirmed 119 were in step and correctly picked out all 9 listings that weren't shop inventory, with no false matches.