JsRates

JsRates is built specifically for Shopify stores with shipping rules that standard apps cannot express. Users write shipping logic in JavaScript, test it with built-in test payloads and test runs in the editor, and then enable JsRates as their shipping rate app so Shopify calls the script at checkout. A free Demo plan supports testing in checkout test mode, and a Full plan supports live checkout. The page states free setup help is available for non-technical merchants. It also mentions AI-assisted code generation, modular functionality, third-party API connectivity for courier rates, a dedicated API endpoint, debugging and validation tools, and performance tracking. The page claims 3.5M+ monthly checkout and API shipping rate requests processed, 99.9% uptime, and over 2 years of use, and includes merchant testimonials.

Key features

• JavaScript shipping logic editor
• Test payloads and test runs in the editor
• Returns Shopify-formatted shipping rates
• Checkout test mode activation (Demo plan)
• AI-assisted coding and code generation
• Custom OpenAI GPT integration
• VS Code integration
• Dedicated API endpoint
• Third-party API connectivity for courier rates
• Modular functionality for reusable logic
• Data and code import
• Debugging tools and script validation
• Performance tracking
• Real-time shipping rates
• Courier API links
• Free setup help for non-technical merchants

Best suited for

• Shopify merchants with complex shipping rules
• Shopify developer partners and dev agencies
• Stores using multiple couriers, warehouses, or product-specific rules
• Teams comfortable with JavaScript or working with a developer

Pricing

Demo: Free, with unlimited time, up to 1,000 requests, up to 500,000 AI characters, and checkout test mode. Full: $35/month, with unlimited requests, 5,000,000 AI characters monthly, and full checkout activation.