{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://aifitnessapi.com/schema/v1/unified-health-data.schema.json",
  "title": "Unified health-data record (aifitnessapi.com, v1)",
  "description": "A vendor-neutral shape for 9 common health records, each field mapped to HealthKit, Health Connect, the Google Health API and Wear OS Health Services at https://aifitnessapi.com/schema. Version 1.0.0. License: CC BY 4.0 (attribution: aifitnessapi.com).",
  "x-version": "1.0.0",
  "x-license": "CC-BY-4.0",
  "oneOf": [
    {
      "$ref": "#/$defs/HeartRate"
    },
    {
      "$ref": "#/$defs/Steps"
    },
    {
      "$ref": "#/$defs/SleepSession"
    },
    {
      "$ref": "#/$defs/Workout"
    },
    {
      "$ref": "#/$defs/BodyMass"
    },
    {
      "$ref": "#/$defs/BodyFat"
    },
    {
      "$ref": "#/$defs/Height"
    },
    {
      "$ref": "#/$defs/HeartRateVariability"
    },
    {
      "$ref": "#/$defs/OxygenSaturation"
    }
  ],
  "$defs": {
    "Source": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "platform",
        "nativeType"
      ],
      "properties": {
        "platform": {
          "type": "string",
          "enum": [
            "healthkit",
            "health-connect",
            "google-health-api",
            "wear-os"
          ],
          "description": "Where the record came from."
        },
        "nativeType": {
          "type": "string",
          "description": "The source's own type name (an HK identifier, a Health Connect class, a Google Health API data type)."
        },
        "sourceName": {
          "type": [
            "string",
            "null"
          ],
          "description": "The app or device that wrote it, when the source says."
        }
      }
    },
    "HeartRate": {
      "type": "object",
      "title": "Heart rate sample",
      "description": "One heart-rate reading at one instant, in beats per minute.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "beatsPerMinute"
      ],
      "properties": {
        "type": {
          "const": "heartRate"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "beatsPerMinute": {
          "type": "number",
          "minimum": 0,
          "x-unit": "count/min",
          "description": "Heart beats per minute."
        }
      }
    },
    "Steps": {
      "type": "object",
      "title": "Step count over an interval",
      "description": "The number of steps taken between two instants.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "startTime",
        "endTime",
        "count"
      ],
      "properties": {
        "type": {
          "const": "steps"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "startTime": {
          "type": "string",
          "format": "date-time",
          "description": "Start of the interval, RFC 3339 in UTC."
        },
        "endTime": {
          "type": "string",
          "format": "date-time",
          "description": "End of the interval, RFC 3339 in UTC."
        },
        "startUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the start as ±HH:MM; null when unknown."
        },
        "endUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the end as ±HH:MM; null when unknown."
        },
        "count": {
          "type": "integer",
          "minimum": 0,
          "x-unit": "count",
          "description": "Steps in the interval."
        }
      }
    },
    "SleepSession": {
      "type": "object",
      "title": "Sleep session with stages",
      "description": "One sleep period and the stages inside it, each stage an interval with one value from the unified stage vocabulary.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "startTime",
        "endTime",
        "stages"
      ],
      "properties": {
        "type": {
          "const": "sleepSession"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "startTime": {
          "type": "string",
          "format": "date-time",
          "description": "Start of the interval, RFC 3339 in UTC."
        },
        "endTime": {
          "type": "string",
          "format": "date-time",
          "description": "End of the interval, RFC 3339 in UTC."
        },
        "startUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the start as ±HH:MM; null when unknown."
        },
        "endUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the end as ±HH:MM; null when unknown."
        },
        "stages": {
          "type": "array",
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "startTime",
              "endTime",
              "stage"
            ],
            "properties": {
              "startTime": {
                "type": "string",
                "format": "date-time"
              },
              "endTime": {
                "type": "string",
                "format": "date-time"
              },
              "stage": {
                "type": "string",
                "enum": [
                  "awake",
                  "awakeInBed",
                  "outOfBed",
                  "inBed",
                  "asleep",
                  "light",
                  "deep",
                  "rem",
                  "restless",
                  "unknown"
                ]
              }
            }
          },
          "description": "Non-overlapping stage intervals inside the session; empty when the source has none."
        }
      }
    },
    "Workout": {
      "type": "object",
      "title": "Workout session",
      "description": "One exercise session: when it ran, what it was, and the totals where the source states them.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "startTime",
        "endTime",
        "activityType",
        "nativeActivityType"
      ],
      "properties": {
        "type": {
          "const": "workout"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "startTime": {
          "type": "string",
          "format": "date-time",
          "description": "Start of the interval, RFC 3339 in UTC."
        },
        "endTime": {
          "type": "string",
          "format": "date-time",
          "description": "End of the interval, RFC 3339 in UTC."
        },
        "startUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the start as ±HH:MM; null when unknown."
        },
        "endUtcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "UTC offset at the end as ±HH:MM; null when unknown."
        },
        "activityType": {
          "type": [
            "string",
            "null"
          ],
          "description": "The activity as this site's workout crosswalk key (Two constants share a crosswalk row only when their names are identical after removing a leading EXERCISE_TYPE_ (Health Connect's prefix, which the Google Health API also uses on EXERCISE_TYPE_UNSPECIFIED), lowercasing, and removing every character that is not a letter or a digit). null when the source value is not in the crosswalk data."
        },
        "nativeActivityType": {
          "type": "string",
          "description": "The source's own activity value, unchanged (an Objective-C constant, an Int as text, or an enum string)."
        },
        "energyKcal": {
          "type": [
            "number",
            "null"
          ],
          "minimum": 0,
          "x-unit": "kcal",
          "description": "Total energy for the session in kilocalories; null when the source carries none."
        },
        "distanceMeters": {
          "type": [
            "number",
            "null"
          ],
          "minimum": 0,
          "x-unit": "m",
          "description": "Total distance in meters; null when the source carries none."
        }
      }
    },
    "BodyMass": {
      "type": "object",
      "title": "Body mass (weight)",
      "description": "The user's weight at one instant, in kilograms.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "kilograms"
      ],
      "properties": {
        "type": {
          "const": "bodyMass"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "kilograms": {
          "type": "number",
          "minimum": 0,
          "x-unit": "kg",
          "description": "Body mass in kilograms."
        }
      }
    },
    "BodyFat": {
      "type": "object",
      "title": "Body fat percentage",
      "description": "Body fat as a percentage from 0 to 100.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "percent"
      ],
      "properties": {
        "type": {
          "const": "bodyFat"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "percent": {
          "type": "number",
          "minimum": 0,
          "maximum": 100,
          "x-unit": "%",
          "description": "Body fat, 0–100."
        }
      }
    },
    "Height": {
      "type": "object",
      "title": "Height",
      "description": "The user's height at one instant, in meters.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "meters"
      ],
      "properties": {
        "type": {
          "const": "height"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "meters": {
          "type": "number",
          "minimum": 0,
          "x-unit": "m",
          "description": "Height in meters."
        }
      }
    },
    "HeartRateVariability": {
      "type": "object",
      "title": "Heart rate variability",
      "description": "One HRV reading in milliseconds, tagged with the statistic it is. SDNN and RMSSD are different measures and never convert into each other.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "metric",
        "milliseconds"
      ],
      "properties": {
        "type": {
          "const": "heartRateVariability"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "metric": {
          "type": "string",
          "enum": [
            "sdnn",
            "rmssd"
          ],
          "description": "sdnn: standard deviation of heartbeat intervals. rmssd: root mean square of successive differences."
        },
        "milliseconds": {
          "type": "number",
          "minimum": 0,
          "x-unit": "ms",
          "description": "The value in milliseconds."
        }
      }
    },
    "OxygenSaturation": {
      "type": "object",
      "title": "Blood oxygen saturation (SpO2)",
      "description": "One SpO2 reading as a percentage from 0 to 100.",
      "additionalProperties": false,
      "required": [
        "type",
        "source",
        "time",
        "percent"
      ],
      "properties": {
        "type": {
          "const": "oxygenSaturation"
        },
        "source": {
          "$ref": "#/$defs/Source"
        },
        "time": {
          "type": "string",
          "format": "date-time",
          "description": "The instant of the reading, RFC 3339 in UTC (a trailing Z)."
        },
        "utcOffset": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^[+-]\\d{2}:\\d{2}$",
          "description": "The user's UTC offset at that instant as ±HH:MM; null when the source does not carry one."
        },
        "percent": {
          "type": "number",
          "minimum": 0,
          "maximum": 100,
          "x-unit": "%",
          "description": "Oxygen saturation, 0–100."
        }
      }
    }
  }
}