Using the JsRates MCP Server with Your AI Assistant

The JsRates MCP server helps AI assistants such as ChatGPT and Claude answer JsRates questions and write shipping rate code using the official JsRates documentation. Connect it once, then describe your shipping rules in plain language to get code, examples, and explanations tailored to JsRates.

MCP stands for Model Context Protocol. It allows your AI assistant to use JsRates information during your conversation without you having to find and copy documentation yourself.

What You Can Do

Generate shipping rate code: Describe your rules for free shipping, weight-based rates, destination-based pricing, customer tags, or other conditions.
Update existing code: Paste your current shipping rate code and explain what you want to change.
Get examples: Ask for examples of courier integrations, delivery dates, product tags, and other JsRates features.
Check common mistakes: Ask the assistant to check your code using the JsRates code checker and explain any issues.
Understand JsRates: Ask how a feature works or how to use the built-in modules.

The JsRates MCP server is free and does not require a JsRates account, API key, or sign-in. Your AI provider's own subscription requirements and usage limits still apply.

What You Need

An AI assistant that supports remote MCP connections.
Access to add a custom MCP server, app, or connector in that assistant. Availability depends on your AI account and workspace permissions.
The JsRates server URL: https://mcp.jsrates.com/mcp.

Use JsRates as the connection name and select No authentication or No sign in if prompted. You do not need to enter your Shopify store details or JsRates API key. If your assistant asks for a connection type, choose Streamable HTTP.

Connecting to ChatGPT

Using Plugins

Open ChatGPT Plugins.
Select the + button, then Add custom MCP server.
Enter JsRates as the name and a description such as JsRates documentation and shipping code assistance.
Under Connection, enter https://mcp.jsrates.com/mcp as the server URL.
Choose No authentication, review the connection notice, and select I understand and want to continue.
Select Create as a plugin, review the discovered tools, and install the resulting plugin.
Start a new conversation, type @, and select JsRates before entering your request.

These steps follow OpenAI's current custom MCP connection instructions. Your account or workspace must allow custom MCP connections.

If Your Account Uses Apps or Connectors

If your ChatGPT interface shows Apps or Apps & Connectors, use the setup path below:

Open Settings → Apps or Apps & Connectors.
Under Advanced settings, enable Developer mode, if available.
Choose the option to create a custom app or connector.
Enter JsRates as the name and https://mcp.jsrates.com/mcp as the server URL.
Choose No authentication and complete the setup.
Start a new conversation and select JsRates from the available tools or apps.

Connecting to Claude

Use the remote connector option in Claude on the web or in Claude Desktop:

Open Customize → Connectors. In interfaces that show it under settings, open Settings → Connectors.
Click + Add, then Add custom connector.
Enter JsRates as the name.
Enter https://mcp.jsrates.com/mcp as the remote server URL and click Continue.
If asked about authentication, choose No sign in. No API key or other credentials are needed.
Finish by clicking Add.
Open a conversation, click the + button beside the message box, and select Connectors. Turn on JsRates for that conversation.

On a Team or Enterprise workspace, an owner or authorized administrator may need to add the connector before members can use it. See Claude's custom connector setup guide for current options.

Try Your First Request

Once connected, ask:

Use the JsRates tools to explain how shipping rate code works and show me a simple example.

The assistant should use the JsRates connection to look up the relevant information. You do not need to choose individual server tools yourself.

Example Prompts

Free shipping: "Using JsRates, give free shipping on orders over $100. Otherwise, offer standard shipping for $9.99 and express shipping for $19.99. Use my store's currency."
Weight-based rates: "Write JsRates shipping code with weight tiers: up to 1 kg costs $5, over 1 kg up to 5 kg costs $10, and over 5 kg costs $20."
Courier rates: "Show me how to get live UPS shipping rates in JsRates, with a fallback rate if UPS is unavailable."
Product tags: "Using JsRates, add one $15 surcharge to the order if any item has the oversized tag."
Customer rules: "Using JsRates, offer free express shipping to customers tagged VIP."
Code review: "Use the JsRates code checker to check the code below. Explain the issues and suggest corrections."

For better results, include the countries you ship to, weight units, prices, thresholds, and any exceptions. When updating existing code, paste the code and describe which behavior you want to keep.

Working with Detailed Shipping Requirements

For complex shipping rules, attach your requirements document to the AI conversation using a file type supported by your assistant, or paste the requirements directly into the chat. You can include rate tables, postcode lists, examples, and your existing shipping code. The assistant reads these materials and uses the JsRates tools to help turn your requirements into code.

Provide as much relevant detail as possible, including:

Destinations: Countries, shipping zones, postcode ranges, remote areas, and locations you do not deliver to.
Products and carts: Product tags, vendors, weights, dimensions, quantities, and how to handle carts containing products with different shipping rules.
Prices and thresholds: Currency, weight units, rate tables, minimum or maximum charges, and whether thresholds include discounts or taxes.
Special conditions: Customer groups, free shipping eligibility, surcharges, exclusions, and whether charges apply per item, package, or order.
Rule priority: Which rule wins when several apply, whether charges are combined, and when free shipping overrides other charges.
Delivery options: Service names, delivery estimates, courier requirements, and what should happen if a courier cannot return a rate.
Expected results: Example carts and destinations with the shipping options and prices you expect, including values exactly at a threshold.

You can use this prompt with your attachment:

I have attached our shipping requirements, rate tables, and example orders. Use the JsRates documentation and tools to help implement these rules. First, read all attachments and summarize the rules in a numbered checklist, including priorities, exceptions, and mixed-cart behavior. Identify missing details or conflicting rules and ask me to clarify them before generating code. Do not invent prices, thresholds, or business rules. Once we have clarified the requirements, generate the JsRates code, explain how each rule is covered, and check it with the JsRates code checker. Provide test cases with expected shipping options and prices so I can verify the results in JsRates. Flag anything that needs additional data or cannot be implemented as described.

Review the assistant's checklist before proceeding. If it cannot read part of an attachment, paste that section or provide a clearer version. For changes to existing code, also state which current rules must remain in place.

Testing and Using the Generated Code

Ask the assistant to explain the generated code and check it with the JsRates code checker.
Review the rules and confirm that they match your requirements.
Copy the code into the Editor page in JsRates.
Configure test data for different carts and delivery destinations, then use More Actions → Run to review the results. See Running Your Code for details.
Test important cases, including threshold amounts, excluded destinations, different customer types, and courier failures where applicable, before using the code for live shipping rates.

The MCP code checker identifies common mistakes but does not run your code or guarantee that the shipping rates are correct. Always test generated code in JsRates before using it at checkout.

Store Access and Privacy

The JsRates MCP server provides documentation, examples, and code checks. It does not connect to your JsRates or Shopify account, read your existing code or settings, or change your live shipping rates. Share the code you want help with in the conversation, then apply any changes yourself in JsRates.

Code submitted to the MCP code checker is checked and the result returned; it is not stored by the JsRates MCP server. Your AI provider handles the conversation according to its own privacy settings and policies. Keep API keys and other credentials out of shared code.

Using Other AI Assistants

You can also connect compatible tools such as Codex, Claude Code, Cursor, and VS Code. Add a remote MCP server using https://mcp.jsrates.com/mcp, select Streamable HTTP where required, and leave authentication disabled. The setup location varies by tool.

Troubleshooting

I Cannot Find the Option to Add a Connection

Check whether your AI account supports custom MCP connections and whether your workspace administrator allows them. Menu names may differ between accounts and versions.

The Connection Does Not Work

Confirm that the server URL is exactly https://mcp.jsrates.com/mcp, including the /mcp at the end. Use No authentication or No sign in, then try connecting again. This URL is intended for an MCP connection rather than a regular web page.

The Assistant Is Not Using JsRates

Make sure JsRates is enabled or selected for the current conversation. Mention JsRates in your request, or explicitly ask the assistant to use the JsRates tools. If needed, start a new conversation with the connection selected.

The Assistant Cannot See My Existing Shipping Code

The MCP server has no access to your store or saved JsRates code. Copy the relevant code into the conversation and explain what you want the assistant to do.