Errors, Pagination, and Reliability

GraphQL errors

A GraphQL HTTP response can contain errors even when the transport request completed. Check both data and errors; do not treat HTTP 200 alone as application success.

Error class	Client response
Authentication	Refresh once when appropriate, otherwise sign out
Authorization	Stop the action and update the UI to reflect unavailable access
Validation	Preserve inputs and show the server message near the action or field
Not found	Remove stale selection and return to an available list
Rate limit	Disable repeated submission and retry only after the indicated window
Provider or temporary failure	Keep persisted Kralis state authoritative and offer a safe retry

REST errors

Use HTTP status and the documented response body. Handle invalid credentials, expired tokens, forbidden access, validation errors, rate limits, and server failures separately.

Cursor pagination

Kralis GraphQL lists commonly use Relay-style connections.

query ListStudents($first: Int!, $after: String) {
  students(first: $first, after: $after) {
    edges {
      node {
        pk
        username
        fullName
      }
    }
    pageInfo {
      hasNextPage
      endCursor
    }
    totalCount
  }
}

Never silently assume a fixed first page contains the whole school. Search selectors, event lists, students, recordings, and other growing datasets must support pagination.

Retry safety

Queries are generally safe to retry. Mutations may not be. Disable duplicate submission, retain operation state, and refetch after an uncertain response before repeating a create, payment, result, promotion, or recording action.

Changing data

Another Kralis Web user or custom client can change the same school data. Refetch after important mutations, use realtime or polling only where the product contract supports it, and avoid assuming cached permissions remain valid forever.

​GraphQL errors

​REST errors

​Cursor pagination

​Retry safety

​Changing data

GraphQL errors

REST errors

Cursor pagination

Retry safety

Changing data