About

Use the Merchant Callback API to handle shipping and tax information for your orders. This is required for multi-step checkout. Request and response schemas for every event are in the Merchant Callback reference.
Custom cart divisions have split shipping and tax enabled by default. On other platforms, reach out to your CSM to have it enabled.

Shipping API

  1. Implement the Shipping API endpoint on your server.
  2. Respond to Bolt’s order.shipping POST request from your Merchant Callback API.
  3. Verify the authenticity of the request by confirming that it originated from Bolt.

PHP Example


Tax API

The Tax API endpoint is called after a shopper has chosen a shipping option.
  1. Implement the Tax API endpoint on your server.
  2. Respond to Bolt’s order.tax POST request from your Merchant Callback API.
  3. Verify the authenticity of the request by confirming that it originated from Bolt.

PHP Example


Shipping & Tax API

The combined Shipping & Tax endpoint will eventually be deprecated. Bolt recommends using the new, decoupled endpoints for Shipping and Tax.
  1. Implement the shipping_and_tax Merchant Callback API on your server.
  2. Respond to Bolt’s order.shipping_and_tax POST request from your Merchant Callback API.
  3. Verify the authenticity of the request by confirming that it originated from Bolt.

PHP Example

Test the Endpoint

Use the following steps to test your Shipping and Tax API implementation:
  1. Navigate to your store.
  2. Open Bolt Checkout, enter an address, then continue to Shipping.
    • Bolt should hit your /shipping_and_tax endpoint.
    • The shipping and tax options from your response should appear in the Bolt Checkout modal.
  3. Try all shipping options.
  4. Ensure that the price of shipping and tax on the cart updates accurately.

Errors & Troubleshooting

To respond with specific errors in merchant api responses visit the error codes documentation.