Make (Integromat)

Create a New Scenario and Choose Trigger

Start a new scenario with a new order event as the starting point.

In Make, create a new Scenario, select the trigger module 'Watch New Orders' from the main sales app (e.g., Shopee or WooCommerce).

Run a test trigger with a test order first to ensure the returned data is in the desired format.

Add Router to Channel Workflow

Use the Router module to handle differently based on the originating channel of the order.

Add a Router immediately after the trigger, creating condition branches based on the 'order source' field (Shopee, Website, Facebook).

Give clear names to each branch (e.g., 'Shopee Branch', 'Website Branch') for easier maintenance later.

Update Centralized Inventory

Record the quantity sold into a centralized inventory data source.

In each branch, add a module to update Google Sheets or the central inventory database, subtracting the quantity sold.

Use the Aggregator module if you need to group many small orders before updating to reduce the number of writes to the sheet.

Sync Back to the Remaining Channels

Update the new inventory quantity back to the other sales channels to avoid double sales.

Add a module to call an API to update inventory for the remaining channels (e.g., update product quantities on Shopee after an order from the website).

Add a small delay between API calls if the target platform limits request frequency.

Add Error Handling and Activate Scenario

Ensure the scenario does not stop unexpectedly when a step encounters a temporary error.

Add an Error Handler for important API call modules, setting up automatic retries, then activate the scenario.

Monitor the execution history in the first few days to catch any unforeseen errors early.