Errors

Mews Loyalty Partner API follows RFC 9457 (Problem Details for HTTP APIs) as the standard for error responses. Your API must return errors in this format.

Custom errors

Your API can return an error which isn't specified in this document (i.e. with different type URI), however, users will see only a generic error message.

Error properties

The error response object contains the following properties:

Property	Type	Contract	Description
type	string	required	URI identifying the top-level problem type.
status	integer	required	HTTP status code.
title	string	required	Short, human-readable summary of the problem type.
detail	string	optional	Human-readable explanation specific to this occurrence of the problem.
instance	string	optional	URI identifying this specific occurrence of the problem for tracing.
errors	array of objects	optional	Field-level validation errors related to the request payload.
errors[].type	string	required when errors is present	URI identifying the field-level error type.
errors[].pointer	string	required when errors is present	JSON Pointer to the affected field in URI fragment form (e.g., #/customer/email), formatted according to the RFC 6901 fragment representation rules.
errors[].detail	string	optional	Human-readable explanation of the field-level validation error.

Top-level errors

Top-level errors describe the general nature of the problem. The type URI identifies the error type and links to documentation describing it.

core/bad-request

HTTP status: 400. The request is syntactically invalid or missing required fields.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some of the customer data is either missing or is invalid.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/customer/email",
      "detail": "Email is required for customer enrollment."
    }
  ]
}

core/unauthorized

HTTP status: 401. Authentication is missing or invalid.

{
  "type": "https://purl.mews.com/problem/core/unauthorized",
  "title": "Unauthorized",
  "status": 401,
  "detail": "Bearer token is missing or invalid"
}

core/not-found

HTTP status: 404. The requested resource was not found.

{
  "type": "https://purl.mews.com/problem/core/not-found",
  "title": "Membership not found",
  "status": 404,
  "detail": "The requested membership with ID MEMB-845329-JK92A was not found in our system."
}

core/request-timeout

HTTP status: 408. The server timed out waiting for the request to complete.

{
  "type": "https://purl.mews.com/problem/core/request-timeout",
  "title": "Request Timeout",
  "status": 408,
  "detail": "The server timed out waiting for the member search request to complete."
}

core/unprocessable-entity

HTTP status: 422. The request is valid but cannot be processed due to business logic.

{
  "type": "https://purl.mews.com/problem/core/unprocessable-entity",
  "title": "Unprocessable Content",
  "status": 422,
  "detail": "The request could not be processed due to business validation rules.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/memberFilter",
      "detail": "At least one valid filter parameter must be provided for member search."
    }
  ]
}

core/too-many-requests

HTTP status: 429. The client has exceeded the rate limit.

{
  "type": "https://purl.mews.com/problem/core/too-many-requests",
  "title": "Too Many Requests",
  "status": 429,
  "detail": "Rate limit exceeded. Please wait before making additional requests."
}

core/internal-server-error

HTTP status: 500. An unexpected server-side error occurred.

{
  "type": "https://purl.mews.com/problem/core/internal-server-error",
  "title": "Internal Server Error",
  "status": 500,
  "detail": "An unexpected error occurred on the server. Please try again later."
}

loyalty/invalid-member-search-criteria

HTTP status: 400. The search payload is syntactically valid, but the combination of fields does not meet search requirements.

{
  "type": "https://purl.mews.com/problem/loyalty/invalid-member-search-criteria",
  "title": "Invalid search criteria",
  "status": 400,
  "detail": "First name and last name are required for member search.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/memberFilter/firstName",
      "detail": "First name is required for member search."
    },
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/memberFilter/lastName",
      "detail": "Last name is required for member search."
    }
  ]
}

Field-level errors

Field-level errors appear in the errors array of a top-level error response. They identify which specific field caused the validation failure using RFC 6901 (JSON Pointer) syntax in the pointer field.

core/field-required

The field is required but missing from the request.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some of the customer data is either missing or is invalid.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/customer/email",
      "detail": "Email is required for customer enrollment."
    },
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/customer/firstName",
      "detail": "First name is required for customer enrollment."
    }
  ]
}

core/field-invalid-format

The value has an invalid format for the expected field type.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some of the customer data has invalid format.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-invalid-format",
      "pointer": "#/customer/phoneNumber",
      "detail": "Phone number format is invalid. Expected format: [phone]"
    }
  ]
}

core/field-too-short

The value is shorter than the minimum allowed length.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some field values do not meet length requirements.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-too-short",
      "pointer": "#/customer/firstName",
      "detail": "First name must be at least 2 characters long."
    }
  ]
}

core/field-too-long

The value exceeds the maximum allowed length.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some field values exceed maximum length limits.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-too-long",
      "pointer": "#/customer/email",
      "detail": "Email address cannot exceed 254 characters."
    }
  ]
}

core/field-out-of-range

A numeric value is outside the acceptable range.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid membership data",
  "status": 400,
  "detail": "Some numeric values are outside acceptable ranges.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-out-of-range",
      "pointer": "#/membership/points",
      "detail": "Points value must be between 0 and 999999."
    }
  ]
}

core/field-invalid-type

The field has an unexpected or invalid data type.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid membership data",
  "status": 400,
  "detail": "Some fields have invalid data types.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-invalid-type",
      "pointer": "#/membership/active",
      "detail": "Active status must be a boolean value (true or false)."
    }
  ]
}

core/field-not-allowed-value

The value does not match the allowed enum values.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid membership data",
  "status": 400,
  "detail": "Some enum values are not allowed.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-not-allowed-value",
      "pointer": "#/membership/tier",
      "detail": "Tier must be one of: Bronze, Silver, Gold, Platinum"
    }
  ]
}

core/field-duplicate

A duplicate value was provided where uniqueness is required.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some values are duplicates where uniqueness is required.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-duplicate",
      "pointer": "#/customer/email",
      "detail": "Email address is already registered in our system."
    }
  ]
}

core/field-email-invalid

The email address format is invalid.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "Some email addresses have invalid format.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-email-invalid",
      "pointer": "#/customer/email",
      "detail": "The provided email address format is invalid."
    }
  ]
}

Array pointer examples

Field-level errors can reference elements within arrays using JSON Pointer notation. The array index is zero-based.

{
  "type": "https://purl.mews.com/problem/core/bad-request",
  "title": "Invalid customer data",
  "status": 400,
  "detail": "One or more customer records contain invalid data.",
  "errors": [
    {
      "type": "https://purl.mews.com/problem/core/field-email-invalid",
      "pointer": "#/customers/0/email",
      "detail": "The provided email address is not valid."
    },
    {
      "type": "https://purl.mews.com/problem/core/field-required",
      "pointer": "#/customers/2/firstName",
      "detail": "First name is required for customer enrollment."
    }
  ]
}