how do I track the cost of goods I sold on Shopify

Turn on cost tracking for the book and Talisk calculates cost of goods sold from the product costs already on your Shopify variants, posting COGS against the same period as the sale.

That's what makes your margin real. Without COGS, a P&L shows revenue and overheads but nothing for what the stock actually cost you, so it flatters your profit, sometimes badly.

Two things worth knowing:

• It's opt-in. Connecting a store doesn't silently switch it on: you turn it on from the offer card or from Setup, and it applies from that point forward.
• Missing costs are visible. Any variant sold without a cost on file is listed for you to fill in, rather than silently counted as free stock. You can edit them inline or import them.

Refunds reverse the COGS at the original cost, so returned stock doesn't leave a phantom cost behind.