REST API访客购物车接口调用出现404错误咨询

Let's break down why you're hitting that 404 error with No such entity with cartId = null—the key clue here is that the API isn't receiving a valid cart ID at all, even though you think you're passing it. Here are the most likely fixes, ordered by how common they are:

1. You didn't replace the {cart-id} placeholder with the actual cart ID #

This is the #1 culprit for this exact error. When you copy the curl command from Swagger, it includes {cart-id} as a placeholder—you need to swap that out with the real ID you got from the POST /guest-cart/ response.

For example, if your create cart call returned abc123 as the cart ID, your curl command should look like this:

curl -X GET "http://website.com/default/rest/all/V1/guest-carts/abc123" -H "accept: application/json" -H "Authorization: Bearer {your-token}"

In Postman, double-check that you've filled in the path parameter field with the actual ID, not left it as the {cart-id} placeholder string.

2. You're extracting the wrong value from the create cart response #

Magento's POST /guest-cart/ returns an object containing the cart ID, not just a raw string. The response structure looks like this:

{
  "cartId": "abc123"
}

Make sure you're using the value of the cartId field, not the entire response body or some other unrelated field. It's easy to accidentally copy the whole JSON instead of just the ID string.

3. Your Authorization token has incorrect permissions (or is invalid) #

While you're including the Authorization header, verify two things:

• The token is valid: Test it with a simple API call like GET /rest/all/V1/store/storeViews—if that returns an error, your token is expired or invalid.
• The token has permissions to access guest carts: If you're using an admin token, ensure it has the Magento_Cart::manage permission. Note: Guest carts shouldn't require admin auth in most default setups, but some custom configurations might enforce it.

4. The API path has typos or incorrect store code #

• Double-check the path: Ensure it's /rest/all/V1/guest-carts/{cartId} (no missing s on carts, correct casing).
• Verify the default store code: If your Magento store uses a different code (e.g., en_us), replace default with your actual store code. Using the wrong code can route the request to a store where the cart doesn't exist.

5. The guest cart was automatically cleaned up #

Magento has a cron job that cleans up inactive guest carts (default is 30 days), but this shouldn't happen to a cart you just created. If all else fails, check if your cron tasks are running unexpectedly or if there's a custom module overriding cart cleanup behavior.

Quick Validation Step #

1. Re-run POST /guest-cart/ and copy the exact cartId from the response.
2. Paste that ID directly into your browser (or Postman) with the full API URL and valid headers—you should get a response like this for an empty cart:

{
  "items": [],
  "total_quantity": 0,
  "billing_address": null,
  "shipping_addresses": [],
  "payment_methods": [],
  "shipping_methods": []
}

内容的提问来源于stack exchange，提问作者Nico Shultz