Validation failures (418)

The Neo FX Hub provides different response status between an API request containing an invalid body structure (400), for example, the wrong type specified for a property, and a request with a valid structure that can't be processed due to invalid data (418), for example, missing a required value or referencing an item that can't be found.

The short rule is that a 400 response means that the request needs to be reviewed technically and a 418 means that the data of the request may need adjusting.

In addition, a 418 will always include a detailed response body of what needs adjusting, while a 400 may not, as it may not be possible to know why the body is invalid.

Example

If the API endpoint is documented to receive:

{
  "id": "string", // Length 8; alphanumeric
  "count": "number", // Must match length of items array
  "items": [ "string" ] // Between 1 and 10
}

The following request will give a 400 response with no body:

{
  "id": "abcd1234", // Okay
  "count": "some", // Invalid
  "items": "value" // Invalid
}

While the next request will give a 418 with a body:

{
  "id": "abcd*", // Too short and non-alphanumeric
  "count": 9, // Doesn't match items length
  "items": [ ] // Can't be empty
}

{
  "id": [
    {
      "error": "bad_length",
      "params": {
        "len": 8 // Expected length
      }
    },
    {
      "error": "invalid" // The value can't be used
    }
  ],
  "count": [
    {
      "error": "invalid",
      "params": {
        "len": 1 // Minimum value
      }
    }
  ],
  "items": [
    {
      "error": "invalid",
      "params": {
        "len": 1 // Minimum length
      }
    }
  ]
}

Endpoints should specify the possible list of error codes per field and their specific meaning. Many codes (such as "invalid") are overloaded based on scenario.

Validation failures (418)

Example#

Example