Errors

{
  "data": null,
  "errors": [
    {
      "message": "Human-readable error description",
      "locations": [{ "line": 2, "column": 3 }],
      "path": ["products", "edges", 0, "node"],
      "extensions": {
        "code": "ERROR_CODE",
        "requestId": "req_abc123"
      }
    }
  ]
}

{
  "data": {
    "products": {
      "edges": [
        { "node": { "id": "prod_abc123", "name": "Product A", "impactScore": { "co2Equivalent": 12.4 } } }
      ]
    }
  },
  "errors": [
    {
      "message": "Failed to load impact score for product prod_def456",
      "path": ["products", "edges", 1, "node", "impactScore"],
      "extensions": { "code": "CALCULATION_ERROR" }
    }
  ]
}

{
  "errors": [
    {
      "message": "Validation failed",
      "extensions": {
        "code": "VALIDATION_ERROR",
        "details": {
          "fields": [
            { "field": "quantity", "message": "Must be greater than 0" },
            { "field": "transportMethod", "message": "Invalid value. Allowed: TRUCK, RAIL, SHIP, AIR" }
          ]
        }
      }
    }
  ]
}