Your live stock and your supplier's cost or margin usually sit in a different feed from your main product feed — a warehouse export, an ERP feed, a supplier price list. Join that feed in with a lookup, matching each product on a shared key like a GTIN or SKU, so availability and prices refresh automatically on every import. The mechanics live in Joining another feed.
Why stock and prices belong in a separate feed#
Your product feed describes what a product is — title, images, description. It rarely carries the two things that change every day: how many are in stock, and what they cost right now. Those live in the systems that own them — a warehouse feed for availability, a supplier feed for cost or price.
For an agency, that split is a liability. Stale stock means you're paying to advertise sold-out products, and a wrong price gets products disapproved. Copying numbers over by hand doesn't survive the next import — the feed overwrites them. A lookup solves this properly: it joins the second feed to your catalog and re-runs the join on every import, so availability and prices are always as fresh as the source system.
The join, in one sentence#
A lookup takes a value your main feed already has — a barcode, a SKU — finds the matching row in the second feed, and hands back one column from that row into a field of yours. You add the second feed once as an Auxiliary feed, then point a field at it. That's the whole model; the dialog that wires it up is covered step by step in Joining another feed — this guide is about aiming it at the two jobs you'll do most.
Worked scenario: keep availability fresh from a warehouse feed#
Say your warehouse exports a feed keyed by GTIN, with an availability status per product — in stock or out of stock — and you want that driving your Availability field instead of the stale value in your main feed.
- On the catalog's Data sources tab, add the warehouse feed as an Auxiliary feed (choose Feed URL… and paste its URL).
- Open the value editor for your Availability field — on the Mapping tab, or in a Set field rule — and add a lookup against the warehouse feed.
- Match your product's GTIN against the warehouse feed's barcode column, and set that pair's matching mode to Barcode — the right mode for GTINs, EANs, and UPCs.
- Return the warehouse feed's availability column, and watch the live "matches N / M sampled" chip to confirm your products are actually finding their row.
- Publish the catalog. Nothing reprocesses until you publish, and "Import now" uses your last published configuration.
On every import from then on, Renable fetches the warehouse feed fresh and re-runs the join, so availability follows real stock without you touching it again.
If your warehouse feed carries a numeric stock count rather than a ready-made status, don't point it straight at Availability — a raw number like 42 or 0 isn't a valid availability value, and ad networks reject it. Return the count into a custom attribute instead, then convert it with a rule: when the count is at least 1, set Availability to in stock, otherwise out of stock. See Fixing your feed data with rules.
Worked scenario: pull the current price from a supplier feed#
A supplier price list works the same way. Add the supplier feed as an Auxiliary feed, add a lookup on your Price field, match on the key both feeds share, and return the supplier's price column. If the supplier keys on your SKU rather than a barcode, match on SKU — leave the mode on Smart (the default), or use Exact when you know both feeds format it identically.
You're not limited to price: point a lookup at any column the supplier carries — cost, RRP, lead time — and return it into a custom attribute you use for reporting or campaign segmentation.
Which key to match on#
The join is only as good as the key you match on:
- Matching on a GTIN, EAN, or UPC? Use Barcode mode.
- Matching on a SKU or your own product ID? Use Smart (the default), or Exact when both feeds format the value identically.
Joining another feed explains why barcodes need their own mode and how each mode compares values. When neither feed shares a single reliable key, you can match on two columns together — brand and MPN — or try one key and fall back to another; both are covered there too.
Or ask Aimée#
You don't have to wire this up by hand. Tell Aimée what you want — "pull live stock from my warehouse feed" or "match my products to the supplier price list on GTIN" — and she can add the auxiliary feed, build the lookup, test that it matches before saving, and publish once you approve.
FAQ#
The lookup only matches some of my products — why?
Your key columns probably don't line up, or you're matching barcodes without Barcode mode. Check the live "matches N / M sampled" chip as you build the lookup: a low number means the match isn't landing. See Joining another feed, and if stock or prices are still off after publishing, Prices or stock look wrong.
Do I need to re-import the warehouse feed on a schedule to keep stock fresh?
No. Renable fetches your auxiliary feeds at import time, so every import of your main feed pulls the latest data from the joined feed too. The join is always as current as your last import.
Related articles#
- Joining another feed — the full lookup dialog: match pairs, matching modes, and the return column.
- Prices or stock look wrong — when the joined values aren't what you expect.
- Mapping tables — a small table you fill in by hand, for translating one set of values onto another.