Weekly currency drift check on your Shopify market prices

Every Monday at 7am, check whether currency moves have quietly eaten the margin on my international Shopify prices. Treat this as advisory only: never write prices back to Shopify and never call any Shopify update or write operation, because I want to approve any repricing myself.

Let me declare my setup as workflow inputs, because Shopify does not reliably expose the manual conversion rate I configured for each market. I want to supply: my base currency, the list of markets I sell into with each market's currency code and the fixed conversion rate I set for it, my target margin percentage, the drift threshold as a percentage with a default of 1.5, and the Slack channel to post to.

Start by pulling my catalogue from Shopify with List Products, then use List Variants on each product to get the per-variant prices and SKUs. Page through the whole catalogue rather than stopping at the first page, and skip anything archived or in draft so I only see products that are actually live.

Then use Open Exchange Rates Get Latest Rates to fetch today's live rates. My plan is likely the free tier, which only supports a USD base and returns a 400 invalid_base error for anything else, so request the USD-based quotes and derive the cross rate for each market currency by dividing the two USD quotes. A single Get Latest Rates call covers every currency I need. Do not use Convert Amount or Get Time-Series, since those are gated to higher plans.

For each product in each market, work out the effective margin today. The storefront price in that market was set using my fixed conversion rate, so converting that same storefront price back into my base currency at today's live rate tells me what I actually realise per sale now. Compare that against what I realised when the fixed rate was set, and express the gap as a movement in margin percentage points, noting whether the drift runs against me or in my favour.

Flag only the products where the drift has moved margin by more than my threshold, 1.5 percent by default. For each flagged product, suggest a corrected price: the storefront price in that market's currency that would restore my original margin at today's live rate. Round each suggestion to a sensible retail price point rather than an exact decimal, and show the current price alongside it so the change is obvious.

Post the findings to my Slack channel using Slack Send a Message, grouped by market. Under each market heading, show the currency pair, the fixed rate I set, today's live rate, and the drift as a percentage. Below that, list the flagged products with SKU, current price, suggested price, and the margin movement. If a market has no products past the threshold, say so in a single line rather than dropping the market entirely, so I can see the check covered it. Use Slack formatting to keep the message scannable, and if nothing anywhere crossed the threshold, still post a short all-clear so I know the run happened.