Introduction to JsRates
What is JsRates?
JsRates is a powerful Shopify app that lets you define shipping rates using JavaScript. It gives merchants and developers full control and flexibility to build, manage, and maintain custom shipping logic. With JsRates, you can safely test, refine, and deploy shipping rates that adapt to your business as it grows.
What can I build with JsRates?
JsRates enables you to build anything from simple flat-rate shipping to highly complex, dynamic pricing logic that cannot be expressed using Shopify’s native shipping settings or standard shipping apps.
It is designed for rules that require custom logic, calculations, conditional flows, or external data, where configuration-based tools fall short.
Common use cases include:
- Flat or conditional shipping rates
- Shipping rules based on cart contents, weight, price, destination, or customer data
- Live rate calculations using courier or third-party APIs
- Promotional shipping logic (free shipping, discounts, surcharges, handling fees)
- Region-based, product-based, or customer-specific rates
- Shipping rules driven from spreadsheet data
- Multi-step or computed shipping logic maintained in code
If your shipping logic can be expressed in JavaScript, it can be implemented in JsRates.
Who is JsRates for?
JsRates is designed for Shopify merchants who want more control over how shipping rates are calculated and maintained. It is a strong fit for:
- Developers and technical teams
- Advanced eCommerce merchants
- Agencies and Shopify partners
- Businesses with evolving or complex shipping requirements
JsRates is often chosen not only because it can handle complex cases, but because it provides transparency, maintainability, and long-term flexibility.
What if I am not familiar with JavaScript?
You do not need to be an expert in JavaScript to use JsRates successfully.
JsRates provides:
- AI-assisted code generation and explanations
- Free setup support for complex configurations
- Hands-on help from our team when needed
If you need assistance, use the Contact Support option inside the app. Our team can help design and implement shipping logic that fits your business requirements.
Features
JsRates provides a comprehensive set of tools for building, testing, and maintaining shipping logic:
- Debugging tools for identifying and fixing issues
- Script validation to ensure code runs correctly
- Test input data for simulating checkout scenarios
- AI-assisted code generation, explanation, and completion
- Third-party API requests for dynamic pricing
- Modular architecture with reusable modules
- Data and code import and export
- Visual Studio Code extension for local editing
- Logs and performance analytics
- Cart item enrichment using metafields, tags, and attributes
- Real-time shipping rate calculation
- Courier and carrier API integrations
- Dedicated API endpoint for product pages, cart pages, or external systems
Carrier Integrations
If you use a shipping carrier that provides an online system or API for rate calculation, JsRates can integrate with it.
We can build a custom carrier integration at no additional cost. This allows JsRates to connect directly to your carrier’s system and retrieve live rates, which you can then adapt using your own business rules.
With JsRates, carrier rates are not a black box. You can:
- Add handling fees or surcharges
- Apply custom discounts
- Offer free shipping based on order value, destination, or customer type
JsRates supports integrations with carriers such as UPS, FedEx, Canada Post, DHL, Australia Post, and any other carrier that provides API access.
To discuss a custom carrier integration, contact us via Contact Support in the app or email support@jsrates.com.
Requirements
To apply JsRates at checkout, third-party carrier-calculated shipping must be enabled in your Shopify plan. This is a Shopify requirement for custom checkout rate providers.
If carrier-calculated shipping is not enabled, you can still use the JsRates API to display shipping rates on product and cart pages.
Carrier-Calculation Requirement: To apply JsRates at checkout, enable third-party carrier-calculated shipping on your Shopify plan. While this feature is a prerequisite for checkout usage, the JsRates API allows rate display on product and cart pages independently. For assistance in enabling carrier-calculated shipping, consult Shopify Support
Maximizing JsRates: Dive into our comprehensive help documentation, quick start guide, and tutorial series to unlock the full potential of JsRates.
Peek Into JsRates Editor Themes
Here's a glimpse of the JsRates editor in action:
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