How to build price comparison in Bubble

Go to the Data tab and create two data types. Product with fields: name (text), description (text), image (image), and category (text). PriceEntry with fields: product (Product), source_name (text, e.g., Amazon, Walmart), price (number), url (text, link to the product on the source), currency (text), and last_updated (date). This structure separates the product identity from its prices across different sources.

Go to the Plugins tab and open the API Connector. Create a new API for each price source. For example, create an API called RetailerAPI with a call named GetPrice. Set the method to GET, enter the retailer's API URL with the product identifier as a parameter, and configure authentication (typically API key in header, marked Private). Initialize each call with a test product ID to map the response structure including price, product name, and URL fields.

Create a backend workflow called refresh_prices with parameter product_id (text). In it: look up the Product by ID, then call each retailer API with the product identifier. For each response, search for an existing PriceEntry (product = this product, source_name = this source). If it exists, update the price and last_updated. If not, create a new PriceEntry. Schedule this workflow to run daily for each product, or trigger it on demand when a user views a product page.

On your product detail page, add a Repeating Group with type PriceEntry and data source: Do a search for PriceEntries where product = Current Page Product, sorted by price ascending. In each cell, display: source_name, price (formatted with currency symbol), last_updated (formatted as a relative date like 2 hours ago), and a Visit Store button that opens the url in a new tab. The lowest price appears at the top since the list is sorted ascending.

Add a conditional to the first cell of the Repeating Group: When Current cell's index is 1, change the background color to light green and add a Best Price badge text element with conditional visibility (only visible when index is 1). For additional context, add a Text element showing the savings: max price minus min price, displayed as Save $X compared to the highest price. Calculate this using the PriceEntry search with sort descending first item's price minus ascending first item's price.

Create a data type called PriceAlert with fields: user (User), product (Product), target_price (number). Add an Alert Me button on the product page that opens a popup where users enter their target price. Create the PriceAlert on save. In the refresh_prices backend workflow, after updating prices, add a step: Search for PriceAlerts where product = this product and target_price >= the new lowest price. For each match, send an email notification to the user with the current best price and source link. For complex comparison platforms with many data sources, consider working with RapidDev for expert Bubble development.