{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://segment.com/schemas/segment/event.json",
  "title": "Segment Event",
  "description": "A Segment analytics event conforming to the Segment spec. Events flow through the Segment platform and are delivered to configured destinations. Every event must include a type and either a userId or anonymousId.",
  "type": "object",
  "required": ["type"],
  "properties": {
    "type": {
      "type": "string",
      "description": "The type of Segment call. Determines the structure and semantics of the event.",
      "enum": ["identify", "track", "page", "screen", "group", "alias"]
    },
    "userId": {
      "type": "string",
      "description": "Unique identifier for the user in your database. Required unless anonymousId is provided.",
      "minLength": 1
    },
    "anonymousId": {
      "type": "string",
      "description": "A pseudo-unique substitute for a user ID, typically assigned by the Segment library before a user is identified.",
      "minLength": 1
    },
    "event": {
      "type": "string",
      "description": "The name of the action a user performed. Required for track calls.",
      "minLength": 1
    },
    "name": {
      "type": "string",
      "description": "The name of the page or screen. Used in page and screen calls."
    },
    "groupId": {
      "type": "string",
      "description": "A unique identifier for the group or account. Required for group calls.",
      "minLength": 1
    },
    "previousId": {
      "type": "string",
      "description": "The previous user ID to merge with userId. Required for alias calls.",
      "minLength": 1
    },
    "properties": {
      "type": "object",
      "description": "A free-form dictionary of properties for the event. Used with track, page, and screen calls.",
      "additionalProperties": true
    },
    "traits": {
      "type": "object",
      "description": "A free-form dictionary of traits for the user or group. Used with identify and group calls.",
      "additionalProperties": true
    },
    "context": {
      "$ref": "#/$defs/Context"
    },
    "integrations": {
      "type": "object",
      "description": "A dictionary of destination names to boolean or object values that control which destinations receive this event.",
      "additionalProperties": true
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 date string for when the event originally occurred."
    },
    "sentAt": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 date string for when the event was sent from the client."
    },
    "receivedAt": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 date string for when Segment received the event."
    },
    "messageId": {
      "type": "string",
      "description": "A unique identifier for the message, used for deduplication."
    },
    "writeKey": {
      "type": "string",
      "description": "The source write key. Included in pixel tracking API calls."
    }
  },
  "anyOf": [
    { "required": ["userId"] },
    { "required": ["anonymousId"] }
  ],
  "if": {
    "properties": { "type": { "const": "track" } }
  },
  "then": {
    "required": ["event"]
  },
  "$defs": {
    "Context": {
      "type": "object",
      "description": "Contextual information that provides extra details about the event, such as device information, IP address, locale, and library version.",
      "properties": {
        "active": {
          "type": "boolean",
          "description": "Whether the user is currently active."
        },
        "ip": {
          "type": "string",
          "format": "ipv4",
          "description": "The IP address of the user."
        },
        "locale": {
          "type": "string",
          "description": "The locale of the user, such as en-US.",
          "pattern": "^[a-z]{2}(-[A-Z]{2})?$"
        },
        "userAgent": {
          "type": "string",
          "description": "The user agent string of the client."
        },
        "library": {
          "$ref": "#/$defs/Library"
        },
        "page": {
          "$ref": "#/$defs/PageContext"
        },
        "device": {
          "$ref": "#/$defs/Device"
        },
        "os": {
          "$ref": "#/$defs/OperatingSystem"
        },
        "screen": {
          "$ref": "#/$defs/Screen"
        },
        "campaign": {
          "$ref": "#/$defs/Campaign"
        },
        "referrer": {
          "type": "object",
          "description": "Referrer information.",
          "properties": {
            "type": {
              "type": "string",
              "description": "The referrer type."
            },
            "name": {
              "type": "string",
              "description": "The referrer name."
            },
            "url": {
              "type": "string",
              "format": "uri",
              "description": "The referrer URL."
            },
            "link": {
              "type": "string",
              "format": "uri",
              "description": "The referrer link."
            }
          }
        },
        "timezone": {
          "type": "string",
          "description": "The user's timezone, such as America/New_York."
        }
      },
      "additionalProperties": true
    },
    "Library": {
      "type": "object",
      "description": "Information about the Segment library that generated the event.",
      "properties": {
        "name": {
          "type": "string",
          "description": "The name of the Segment library."
        },
        "version": {
          "type": "string",
          "description": "The version of the Segment library."
        }
      }
    },
    "PageContext": {
      "type": "object",
      "description": "Information about the current web page.",
      "properties": {
        "path": {
          "type": "string",
          "description": "The path of the page URL."
        },
        "referrer": {
          "type": "string",
          "format": "uri",
          "description": "The referrer URL."
        },
        "search": {
          "type": "string",
          "description": "The search query string."
        },
        "title": {
          "type": "string",
          "description": "The page title."
        },
        "url": {
          "type": "string",
          "format": "uri",
          "description": "The full page URL."
        }
      }
    },
    "Device": {
      "type": "object",
      "description": "Information about the user's device.",
      "properties": {
        "id": {
          "type": "string",
          "description": "The device ID."
        },
        "advertisingId": {
          "type": "string",
          "description": "The advertising ID."
        },
        "adTrackingEnabled": {
          "type": "boolean",
          "description": "Whether ad tracking is enabled."
        },
        "manufacturer": {
          "type": "string",
          "description": "The device manufacturer."
        },
        "model": {
          "type": "string",
          "description": "The device model."
        },
        "name": {
          "type": "string",
          "description": "The device name."
        },
        "type": {
          "type": "string",
          "description": "The device type, such as ios or android."
        },
        "token": {
          "type": "string",
          "description": "The push notification token."
        }
      }
    },
    "OperatingSystem": {
      "type": "object",
      "description": "Information about the device operating system.",
      "properties": {
        "name": {
          "type": "string",
          "description": "The OS name."
        },
        "version": {
          "type": "string",
          "description": "The OS version."
        }
      }
    },
    "Screen": {
      "type": "object",
      "description": "Information about the device screen.",
      "properties": {
        "width": {
          "type": "integer",
          "description": "The screen width in pixels.",
          "minimum": 0
        },
        "height": {
          "type": "integer",
          "description": "The screen height in pixels.",
          "minimum": 0
        },
        "density": {
          "type": "number",
          "description": "The screen pixel density.",
          "minimum": 0
        }
      }
    },
    "Campaign": {
      "type": "object",
      "description": "Campaign attribution information from UTM parameters.",
      "properties": {
        "name": {
          "type": "string",
          "description": "The campaign name (utm_campaign)."
        },
        "source": {
          "type": "string",
          "description": "The campaign source (utm_source)."
        },
        "medium": {
          "type": "string",
          "description": "The campaign medium (utm_medium)."
        },
        "term": {
          "type": "string",
          "description": "The campaign term (utm_term)."
        },
        "content": {
          "type": "string",
          "description": "The campaign content (utm_content)."
        }
      }
    }
  }
}