The Core API returns errors as JSON with a consistent shape. The code field is the HTTP status, repeated in the body for clients that don’t have easy access to the response status code.

Common error responses Permalink

{ "code": 401, "message": "Unauthorized" }

{ "code": 404, "message": "Not found" }

{
  "code": 422,
  "message": "Validation Error",
  "errors": [
    { "field": "start", "location": "body", "messages": ["is required"] }
  ]
}

Validation errors (422) Permalink

Validation failures return 422 with an errors array. Each entry has:

• field — the offending parameter name
• location — body, query, or params
• messages — array of human-readable validation messages; a single field can fail multiple rules at once

What about the Metrics API? Permalink

WebSocket errors are returned as JSON within the standard response frame format (see Metrics API overview). The shape mirrors the REST error format above — a code and a message, optionally an errors array for validation failures.