Issues with the Sendorders in n8n Foundation course exercise

Questions
1

Describe the problem/error/question

While sending Order to the n8n site, I get the below errors. I checked for spaces, calculations etc, but can’t find the error source. All my nodes are executing perfectly when done individually

What is the error message (if any)? Your request is invalid or could not be processed by the service. Your order totals are incorrect. Please ensure you are calculating the totals correctly.

Please share your workflow

{
  "nodes": [
    {
      "parameters": {
        "assignments": {
          "assignments": [
            {
              "id": "6e58682d-4337-46a8-a36f-a6047502bfe7",
              "name": "order_id",
              "value": "={{ $json.order_id }}",
              "type": "string"
            },
            {
              "id": "2a009df0-7d77-43e6-9e91-a70e004bb17f",
              "name": "customer_name",
              "value": "={{ $json.customer_name }}",
              "type": "string"
            },
            {
              "id": "c36c31fc-c9a7-4dcb-8002-c7434369ea78",
              "name": "region",
              "value": "={{ $json.region }}",
              "type": "string"
            },
            {
              "id": "a6ad9769-cf53-4e2d-b27f-8869ec1506d3",
              "name": "status",
              "value": "={{ $json.status }}",
              "type": "string"
            },
            {
              "id": "ea21f188-1793-4fbc-80b4-14d080492695",
              "name": "order_total",
              "value": "={{Math.round($json.quantity * $json.unit_price)}}",
              "type": "number"
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.set",
      "typeVersion": 3.4,
      "position": [
        16,
        -112
      ],
      "id": "e5206f2a-e49f-4f97-a253-f42bbdee3f20",
      "name": "SetOrderTotals"
    },
    {
      "parameters": {
        "aggregate": "aggregateAllItemData",
        "destinationFieldName": "orders",
        "options": {}
      },
      "type": "n8n-nodes-base.aggregate",
      "typeVersion": 1,
      "position": [
        608,
        -320
      ],
      "id": "f4a9b2b7-cbb5-4092-adae-82a31b6faadf",
      "name": "AggregateOrders"
    },
    {
      "parameters": {
        "select": "channel",
        "channelId": {
          "__rl": true,
          "value": "C0BEZ3AKS9E",
          "mode": "list",
          "cachedResultName": "test"
        },
        "text": "=\"Sales pipeline complete. 50 orders processed, 38 delivered.\"\n\"North Order Total :\" {{ $json.region[0].average_order_total }}\n\"South Order Total:\" {{ $json.region[2].average_order_total }}\n\"West Order Total:\" {{ $json.region[1].average_order_total }}\n\"East Order Total:\" {{ $json.region[3].average_order_total }}",
        "otherOptions": {}
      },
      "type": "n8n-nodes-base.slack",
      "typeVersion": 2.5,
      "position": [
        816,
        -416
      ],
      "id": "27fbb4f2-ab2a-4977-bef1-5350b8a52c03",
      "name": "SendToSlack",
      "webhookId": "5a4cba28-edf6-40b0-b14f-d68952cccf47",
      "credentials": {
        "slackApi": {
          "id": "JsMFdrKSTabhvlb7",
          "name": "Slack account"
        }
      }
    },
    {
      "parameters": {
        "method": "POST",
        "url": "https://learn.app.n8n.cloud/webhook/course/n8n101/process-orders",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            {
              "name": "x-assessment-id",
              "value": "dcaececa5196aa91d2a41fc5b5b53ec8"
            }
          ]
        },
        "sendBody": true,
        "bodyParameters": {
          "parameters": [
            {
              "name": "orders",
              "value": "={{ $json.orders }}"
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.4,
      "position": [
        816,
        -224
      ],
      "id": "2a053049-1a4b-46f0-abf1-3787c72a1297",
      "name": "SendOrders",
      "credentials": {
        "httpHeaderAuth": {
          "id": "Ga9QOladMz18EL6I",
          "name": "n8n Academy API Key"
        }
      }
    },
    {
      "parameters": {
        "fieldsToSummarize": {
          "values": [
            {
              "aggregation": "sum",
              "field": "order_total"
            },
            {
              "field": "order_total"
            },
            {
              "aggregation": "average",
              "field": "order_total"
            }
          ]
        },
        "fieldsToSplitBy": "region",
        "options": {}
      },
      "type": "n8n-nodes-base.summarize",
      "typeVersion": 1.1,
      "position": [
        208,
        -320
      ],
      "id": "91cd6ef5-16d0-4ea0-89a6-b5d2499b1681",
      "name": "SummarizebyRegion"
    },
    {
      "parameters": {
        "assignments": {
          "assignments": [
            {
              "id": "c271aab4-45e9-4cd8-bc1e-5fee1682718a",
              "name": "sum_order_total",
              "value": "={{ Math.round($json.sum_order_total *100)/100}}",
              "type": "number"
            },
            {
              "id": "8a43ca44-257c-4d5e-9240-396005282a88",
              "name": "count_order_total",
              "value": "={{ $json.count_order_total }}",
              "type": "number"
            },
            {
              "id": "4e9f85c6-ec6e-4a80-bd09-024fadd61c5f",
              "name": "average_order_total",
              "value": "={{ Math.round($json.average_order_total*100)/100 }}",
              "type": "number"
            }
          ]
        },
        "includeOtherFields": true,
        "options": {}
      },
      "type": "n8n-nodes-base.set",
      "typeVersion": 3.4,
      "position": [
        416,
        -320
      ],
      "id": "ea9206a9-c0e7-4836-9194-9a07c0826961",
      "name": "Edit Fields"
    }
  ],
  "connections": {
    "SetOrderTotals": {
      "main": [
        [
          {
            "node": "SummarizebyRegion",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "AggregateOrders": {
      "main": [
        [
          {
            "node": "SendToSlack",
            "type": "main",
            "index": 0
          },
          {
            "node": "SendOrders",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "SummarizebyRegion": {
      "main": [
        [
          {
            "node": "Edit Fields",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Edit Fields": {
      "main": [
        [
          {
            "node": "AggregateOrders",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {},
  "meta": {
    "templateCredsSetupCompleted": true,
    "instanceId": "7134812ff1766ac00dec6d0b790eac6d9b713a9539f0e1c05a87cf2a2442a32d"
  }
}

Your request is invalid or could not be processed by the service
Your order totals are incorrect. Please ensure you are calculating the totals correctly.

image
image1204×469 84.7 KB

Information on your n8n setup

  • n8n version: Community
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
  • Running n8n via (Docker, npm, n8n cloud, desktop app):
  • Operating system: Windows
2

Hi Venu,

The error “Your order totals are incorrect” almost always points to an issue with the JSON payload format in your SendOrders (HTTP Request) node.

When you use ={{ $json.orders }} in the value field, n8n often defaults to passing the data as a string, but the n8n Academy API endpoint specifically expects a JSON Object containing the array of orders.

Here is how to fix it:

  1. Change the Body Content Type: In your SendOrders node, ensure the Send Body option is enabled, but look for an option like “JSON” or “Body Parameters” and ensure it isn’t forcing the data into a string format.

  2. Use the Expression Editor correctly: In the Value field for your orders body parameter, try using an expression that forces the JSON object structure: ={{ JSON.stringify($json.orders) }} or, better yet, if the node supports it, change the Body Parameters type to JSON and use {{ $json.orders }} directly without quotes.

  3. Check your SetOrderTotals node: You are using Math.round($json.quantity * $json.unit_price). Double-check that your input data doesn’t have hidden strings or null values. If quantity or unit_price are being interpreted as strings, the math might be failing silently or producing unexpected types. Try wrapping them in Number(): ={{ Math.round(Number($json.quantity) * Number($json.unit_price)) }}

    To see exactly what the API is “seeing,” add a Webhook node or use a service like Webhook.site to inspect the exact outgoing payload from your SendOrders node. If the API returns a 400 error, it is almost certainly because it received a string instead of the expected JSON array.

    Let me know if that clears the validation error!

    Best, Swapnil swapnilailabs.com

3

Hi Swapnil

Thankyou for such a prompt response. Let me explain what I did before I posted this issue

  1. I checked all nodes if the data type for the order total is correct. it is set as numbers
  2. In the Send Node,
    1. In body, the Body content type is JSON
    2. Specify Fields :
      Name: orders
    3.     Value:  {{ $json.orders }}

All the nodes execute perfectly well without any errors.

I tried the Webhook too and there are no errors there.

The below is the webook result

{“orders”:[{“sum_order_total”:5348,“count_order_total”:16,“average_order_total”:334.25,“region”:“north”},{“sum_order_total”:2507,“count_order_total”:10,“average_order_total”:250.7,“region”:“west”},{“sum_order_total”:2353,“count_order_total”:14,“average_order_total”:168.07,“region”:“south”},{“sum_order_total”:2263,“count_order_total”:10,“average_order_total”:226.3,“region”:“east”}]}

4

Hi @venu_nair ,

You might need to compare your workflow with the instructions again, as I see your above branch has a bit more nodes than the previous time I did.

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image1688×595 57.5 KB

5

Hello All,

I am getting similar error for the same workflow which is share at the URL Course | n8n Platform

Following is my workflow and the error message.

Any help spotting the issue is much appreciated! :slight_smile:

Worklfow

image
image1577×506 56.4 KB

Workflow Code

Section 2 - Sales Data Pipeline.json (5.6 KB)

Error Obtained in the last Node - SendOrders

{
“errorMessage”: “Your request is invalid or could not be processed by the service”,
“errorDescription”: “Your order totals are incorrect. Please ensure you are calculating the totals correctly.”,
“errorDetails”: {
“rawErrorMessage”: [
“422 - “{\“error\”:\“Your order totals are incorrect. Please ensure you are calculating the totals correctly.\”}””
],
“httpCode”: “422”
},
“n8nDetails”: {
“nodeName”: “SendOrders”,
“nodeType”: “n8n-nodes-base.httpRequest”,
“nodeVersion”: 4.4,
“itemIndex”: 0,
“time”: “03/07/2026, 14:12:47”,
“n8nVersion”: “2.27.5 (Self Hosted)”,
“binaryDataMode”: “filesystem”,
“stackTrace”: [
“NodeApiError: Your request is invalid or could not be processed by the service”,
" at ExecuteContext.execute (C:\Users\Jaideep Satghare\AppData\Roaming\npm\node_modules\n8n\node_modules\n8n-nodes-base\nodes\HttpRequest\V3\HttpRequestV3.node.ts:869:16)“,
" at WorkflowExecute.executeNode (C:\Users\Jaideep Satghare\AppData\Roaming\npm\node_modules\n8n\node_modules\n8n-core\src\execution-engine\workflow-execute.ts:1067:8)”,
" at WorkflowExecute.runNode (C:\Users\Jaideep Satghare\AppData\Roaming\npm\node_modules\n8n\node_modules\n8n-core\src\execution-engine\workflow-execute.ts:1367:11)“,
" at C:\Users\Jaideep Satghare\AppData\Roaming\npm\node_modules\n8n\node_modules\n8n-core\src\execution-engine\workflow-execute.ts:1829:27”,
" at C:\Users\Jaideep Satghare\AppData\Roaming\npm\node_modules\n8n\node_modules\n8n-core\src\execution-engine\workflow-execute.ts:2521:11"
]
}
}

6

Hi @Jaideep_Satghare, please check the configuration of your “SetOrderTotals” node’s “order_total” field according to the instructions. I see it’s different.

Also, your issue is a bit different, so it’s worth opening another post so others can help you too, thanks.

7

@kristinker , thank you for your reply. :smiley:

I intentionally modified the “order_total” field using Math rounding function to force the integer conversion.

Nevertheless, I was able to find the issue it was a trailing space in the field name for order_total. I was using "order_total " instead of “order_total”. I corrected it and it has worked fine.

Thank you for asking me to take a relook at the node. :smiley:

This issue can be closed as far as I am concerned. I will open a new thread in the future for similar issues.