{
  "id": "python/fastapi-validation-error-field-required",
  "signature": "fastapi.exceptions.RequestValidationError: field required",
  "signature_zh": "fastapi.exceptions.RequestValidationError: 字段必填",
  "regex": "fastapi\\.exceptions\\.RequestValidationError:\\ field\\ required",
  "domain": "python",
  "category": "type_error",
  "subcategory": null,
  "root_cause": "A required field in the request body or query parameters is missing.",
  "root_cause_type": "generic",
  "root_cause_zh": "请求体或查询参数中缺少必填字段。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Providing field with None value",
      "why_fails": "FastAPI treats None as missing for required fields.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "Using wrong field name due to case sensitivity",
      "why_fails": "Field names are case-sensitive in Pydantic models.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Add default values or make fields optional",
      "success_rate": 0.9,
      "how": "class Item(BaseModel):\n    name: str = 'default'  # optional with default\n    price: float = 0.0",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use Pydantic's Field with alias",
      "success_rate": 0.85,
      "how": "class Item(BaseModel):\n    item_name: str = Field(..., alias='name')\n# Request uses 'name', model uses 'item_name'",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.87,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-04-12",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}