JsRates

JsRates is a Shopify app that lets merchants define custom shipping rates using JavaScript. It provides full control over shipping logic, from simple flat rates to complex multi-carrier, multi-warehouse rules. Users can write, test, and deploy their rules in a robust environment that includes test payloads, AI-assisted code generation, and integration with third-party APIs.

Key Features

• JavaScript-based rules: Write shipping logic in a single script, handling products, couriers, zones, and exceptions.
• AI-assisted coding: Generate and explain JavaScript snippets with a built-in AI tool.
• Real checkout simulation: Test rules against realistic Shopify payloads before going live.
• Carrier integrations: Connect with major couriers like UPS, FedEx, and Canada Post via their APIs.
• Modular and reusable: Break logic into modules for regions or brands.
• Performance insights: Monitor script execution frequency and duration.
• Free demo and affordable full plan: Start testing with no risk; a paid plan unlocks live checkout.

Workflow

1. Write your shipping rules in JavaScript using the built-in editor.
2. Test with sample data to verify rates and conditions.
3. Activate by setting JsRates as your store’s shipping rate app in Shopify.

Who It’s For

• Shopify merchants with shipping rules too complex for standard apps.
• Developer agencies managing multiple Shopify stores.
• Teams that need total customisation and are comfortable with (or willing to learn) basic JavaScript.