500 Internal Server Error on Webservice API (JSON output & Order Status update)

[Jay Chauhan]

Hello,
I am facing two main issues with the PrestaShop Webservice API while running PrestaShop in Docker container (local environment).
 

1. Authentication API with JSON format

• When I call the API with output_format=JSON, it returns 500 Internal Server Error.
• The same request works fine with XML format.
• Example request (API key hidden for security):
   

  Quote

  curl --location 'http://localhost:8080/api?output_format=JSON' \
  --header 'Authorization: Basic <API_KEY>'

   

• Response: 500 Internal Server Error
• Logs show no additional info (please guide where to check deeper logs if needed).
   

2. Updating Order Status

• My order flow is:
• Current status: Authorized
• I successfully updated to: Processing in Progress
• Next, when I try to update to: Shipped → I get 500 Internal Server Error.
• Same sequence works correctly when changing statuses inside the Back Office.
• API Request (simplified, key hidden):
   

  Quote

  curl -X PUT 'http://localhost:8080/api/orders/ORDER_ID' \
  -H 'Authorization: Basic <API_KEY>' \
  -H 'Content-Type: application/xml' \
  -d '<prestashop>...<current_state><![CDATA[4]]></current_state>...</prestashop>'

   

• Question: Is there a predefined sequence of allowed order status changes in the API?
• Or is this a bug with the Webservice, since the same transitions work in Back Office?
   

Steps to Reproduce

1. Run PrestaShop in Docker (local mode).
2. Create an order (status = Authorized).
3. Use API to change status → Processing in Progress (works).
4. Use API again to change status → Shipped (fails with 500).
5. Try API call with output_format=JSON → also fails with 500.

Environment

• PrestaShop Version: 9
• Running in: Docker image (local)
• Mode: Developer

Questions:

1. Why does the API fail with output_format=JSON while XML works?
2. Is there a required/predefined sequence of order status transitions when using the API (different from Back Office)?
    

Thank you in advance 🙏

Edited yesterday at 05:24 AM by Jay Chauhan (see edit history)