{
  "id": "api/rest-api-rate-limit-header-missing",
  "signature": "429 Too Many Requests — Rate limit headers missing in response",
  "signature_zh": "429 请求过多 — 响应中缺少速率限制头",
  "regex": "429.*rate limit|rate limit.*exceeded|too many requests",
  "domain": "api",
  "category": "resource_error",
  "subcategory": null,
  "root_cause": "API server enforces rate limiting but does not include standard headers like X-RateLimit-Remaining or Retry-After, making client backoff impossible.",
  "root_cause_type": "generic",
  "root_cause_zh": "API 服务器强制执行速率限制，但未包含标准头部（如 X-RateLimit-Remaining 或 Retry-After），导致客户端无法进行退避。",
  "versions": [
    {
      "version": "REST API v2.1",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "nginx rate limiting module v1.24",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "AWS API Gateway v2",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Without Retry-After, the client may back off too long or too short, leading to wasted time or continued throttling.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "The issue is missing headers, not the limit value; increasing limit may not fix the client's inability to adapt.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Many APIs do not include retry info in the body; relying on it is fragile and non-standard.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Implement a fixed delay between requests (e.g., 1 second) to stay under the rate limit.",
      "success_rate": 0.8,
      "how": "Implement a fixed delay between requests (e.g., 1 second) to stay under the rate limit.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use a token bucket algorithm client-side to self-throttle.",
      "success_rate": 0.85,
      "how": "Use a token bucket algorithm client-side to self-throttle.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Implement a fixed delay between requests (e.g., 1 second) to stay under the rate limit.",
    "Use a token bucket algorithm client-side to self-throttle."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After",
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.82,
  "fix_success_rate": 0.75,
  "resolvable": "partial",
  "first_seen": "2024-01-20",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}