{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://tiergauge.com/api/freshness.schema.json",
  "title": "TierGauge data-freshness feed",
  "description": "Schema for /api/freshness.json. Each tracked tool is bucketed by how long ago its last_verified field was set: fresh (within fresh_days), due (within stale_days), stale (older). Useful for monitoring scrape health.",
  "type": "object",
  "required": ["feed_version", "generated_at", "site", "license", "thresholds", "tools_tracked", "buckets", "tools"],
  "properties": {
    "$schema": { "type": "string", "format": "uri" },
    "feed_version": { "type": "string" },
    "generated_at": { "type": "string", "format": "date-time" },
    "site": { "type": "string", "format": "uri" },
    "license": { "type": "string" },
    "thresholds": {
      "type": "object",
      "required": ["fresh_days", "stale_days"],
      "properties": {
        "fresh_days": { "type": "integer", "minimum": 1 },
        "stale_days": { "type": "integer", "minimum": 1 }
      }
    },
    "tools_tracked": { "type": "integer", "minimum": 0 },
    "buckets": {
      "type": "object",
      "required": ["fresh", "due", "stale"],
      "properties": {
        "fresh": { "type": "integer", "minimum": 0 },
        "due": { "type": "integer", "minimum": 0 },
        "stale": { "type": "integer", "minimum": 0 }
      }
    },
    "tools": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["slug", "name", "primary_category", "last_verified", "age_days", "staleness"],
        "properties": {
          "slug": { "type": "string", "minLength": 1 },
          "name": { "type": "string", "minLength": 1 },
          "primary_category": { "type": "string", "minLength": 1 },
          "last_verified": { "type": "string", "format": "date-time" },
          "age_days": { "type": "integer", "minimum": 0 },
          "staleness": { "type": "string", "enum": ["fresh", "due", "stale"] }
        }
      }
    }
  }
}