Creating a Fulfillment - Error "line_items_by_fulfillment_order":"expected Hash to be a Array"

[ChrisWHG]

I have set up a FulfillmentService, and can receive an AssignedFulfillmentOrder and Accept the request without a problem. But once the goods are shipped I need to create a Fulfillment.

I am working with /admin/api/2022-07/fulfillments.json and sending a POST request with

{
    "fulfillment":{
        "message":"The package was shipped this morning.",
        "line_items_by_fulfillment_order":[{
            "fulfillment_order_id":6171140030771
        }]
    }
}

Which is almost identical to the example in the API reference. I am not including tracking yet, I plan on updating that later. But the response I get is

{"errors":{"line_items_by_fulfillment_order":"expected Hash to be a Array"}}

I have tried for hours to solve this, tried many different variations. Hoping someone can help with this.

[ShopifyDevSup]

Hi @ChrisWHG 👋

The `line_items_by_fulfillment_order` in your payload is missing the `fulfillment_order_line_items` field. Properly formatted, it would look similar to the below. I'd recommend reviewing step 4 of this guide on how to create fulfillments.

{
    "fulfillment": {
        "message":"The package was shipped this morning.",
        "line_items_by_fulfillment_order": [{
            "fulfillment_order_id": "6171140030771",
            "fulfillment_order_line_items": [{
                "id": "9876543210",
                "quantity": "1"
            }]
        }]
    }
}

Hope that helps!

[ChrisWHG]

Hi,

Thanks for your reply. I did try it with the line items too. The API reference says it can be left undefined and then all items will be fulfilled. But even with them in I am getting the same error.

{
    "fulfillment":{
        "message":"The package was shipped this morning.",
        "line_items_by_fulfillment_order":[{
            "fulfillment_order_id":6171140030771,

            "fulfillment_order_line_items":[{

                "id":13686305358131,
                "quantity":1

            }]
        }]
    }
}

return is still {"errors":{"line_items_by_fulfillment_order":"expected Hash to be a Array"}}

This is the complete return. Hoping I can solve this as this is almost the final piece in the App.

{"headers":{"status":"HTTP\/2 400 \r","date":"Wed, 04 Jan 2023 20","content-type":"application\/json; charset=utf-8","x-sorting-hat-podid":"306","x-sorting-hat-shopid":"66804154675","referrer-policy":"origin-when-cross-origin","x-frame-options":"DENY","x-shopid":"66804154675","x-shardid":"306","x-stats-userid":"","x-stats-apiclientid":"20111261697","x-stats-apipermissionid":"423845101875","x-shopify-api-version":"2022-07","http_x_shopify_shop_api_call_limit":"1\/40","x-shopify-shop-api-call-limit":"1\/40","strict-transport-security":"max-age=7889238","x-shopify-stage":"production","content-security-policy":"default-src 'self' data","x-content-type-options":"nosniff","x-download-options":"noopen","x-permitted-cross-domain-policies":"none","x-xss-protection":"1; mode=block; report=\/xss-report?source%5Baction%5D=create&source%5Bapp%5D=Shopify&source%5Bcontroller%5D=admin%2Ffulfillments&source%5Bsection%5D=admin_api&source%5Buuid%5D=dafbe2db-04c7-4008-a5e1-075cea303053","x-dc":"gcp-australia-southeast1,gcp-us-east1,gcp-us-east1","x-request-id":"dafbe2db-04c7-4008-a5e1-075cea303053","cf-cache-status":"DYNAMIC","report-to":"{\"endpoints\"","nel":"{\"success_fraction\"","server-timing":"cfRequestDuration;dur=340.000153","server":"cloudflare","cf-ray":"7846bbf84e39a814-SYD","alt-svc":"h3=\""},"response":"{\"errors\":{\"line_items_by_fulfillment_order\":\"expected Hash to be a Array\"}}"}

[ShopifyDevSup · Accepted solution]

Thanks for sharing the X-Request-ID! 

Our logs show that the request resulted in a 400 error, suggesting that there maybe an issue with how your app is sending this request. I'd recommend testing with a curl request similar to the below instead. If the curl request to fulfill is successful, I would review how your app is making the request. I've seen similar errors when the header `Content-Type` isn't set to `application/json`, so that may be a good place to start. 

curl -L -X POST 'https://YOUR_STORE.myshopify.com/admin/api/2023-01/fulfillments.json' \
-H 'X-Shopify-Access-Token: YOUR_TOKEN' \
-H 'Content-Type: application/json' \
--data-raw '{
    "fulfillment": {
        "message": "The package was shipped this morning",
        "line_items_by_fulfillment_order": [
            {
                "fulfillment_order_id": 5580299141238,
                "fulfillment_order_line_items": [
                    {
                        "id": 1234,
                        "quantity": 1
                    }
                ]
            }
        ]
    }
}'

Hope that helps!

[ChrisWHG]

Thank you, you are right. I just made the request from Postman and the fulfillment was created. I am using a php curl function in my app so I need to revisit how the data is being sent.

[Swetha09]

Hi ChrisWHG, we are having the issue as above. Can you please let us know how u fixed the issue. We are getting the same error.

{"errors":{"line_items_by_fulfillment_order":"expected Hash to be a Array"}}

[ShopifyDevSup]

Hey @Swetha09, 

I took a closer look, and was able to replicate the error noted in your post. This error is returned for a syntax issue in the request body, specifically related to the line_items_by_fulfillment_order parameter. Below are some insights on the required formatting for a request body on the REST Fulfillment endpoint, and a simplified example with some comment notes that you are welcome work from:

{
 "fulfillment": {
   "line_items_by_fulfillment_order": [   // This should be an array, required.
     {
       "fulfillment_order_id": FULFILLMENT_ORDER_ID 
       "fulfillment_order_line_items": [   // This should be an array, required if included.
         {
           "id": ID,   // fulfillment_order.line_item.id 
           "quantity": QUANTITY 
         },
         // ...Additional line items go here...
       ]
     }
   ],
   "tracking_number": "TRACKING_NUMBER",
   "tracking_company": "TRACKING_COMPANY", 
   "location_id": LOCATION_ID 
 }
}

Note: both line_items_by_fulfillment_order and fulfillment_order_line_items should be arrays.

If the intention is to fulfill all line items in a fulfillment order, pass only the line_items_by_fulfillment_order array with a fulfillment_order_id. To fulfill specific line items, include the relevant details in the fulfillment_order_line_items array. For more information, refer to the Fulfillment API's documentation.

Hope this helps clarify why this error would be generated, and how to approach resolving it!

Cheers, 
@awwdam | Shopify Developer Support

[ChrisWHG]

Hi, I am sorry I can't help. I can't remember what I did to correct the problem.

Chris