{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://dynamicfeed.ai/schemas/station-receipt-v1.json",
  "title": "DF-VERIFY/1 \u2014 station-receipt/v1 profile (We Sign Your Station)",
  "description": "A signed, tamper-evident record that a registered station REPORTED a reading at a moment, produced by POST /v1/station/reading. HONEST PROVENANCE: Dynamic Feed did NOT measure the value, the station operator did; the receipt states this in words (observation.measured_by and observation.source). SCOPE: attests what the station reported, NOT that the sensor is calibrated and NOT that the value is accurate; corroborate with an independent source where one exists. Detached Ed25519 signature over the object minus its `signature`, json-sorted-compact; independently time-stampable by an independent RFC 3161 authority via /v1/anchor. Advisory evidence, not a certification, never the money path.",
  "type": "object",
  "required": [
    "schema",
    "issuer",
    "witnessed_at",
    "station",
    "observation",
    "signature"
  ],
  "additionalProperties": true,
  "properties": {
    "schema": {
      "const": "station-receipt/v1"
    },
    "issuer": {
      "type": "string"
    },
    "witnessed_at": {
      "type": "string",
      "format": "date-time",
      "description": "when Dynamic Feed witnessed the station's report"
    },
    "station": {
      "type": "object",
      "required": [
        "station_id"
      ],
      "properties": {
        "station_id": {
          "type": "string",
          "pattern": "^stn_[0-9a-f]{16}$"
        },
        "name": {
          "type": [
            "string",
            "null"
          ]
        },
        "location": {
          "type": [
            "object",
            "null"
          ]
        }
      }
    },
    "observation": {
      "type": "object",
      "required": [
        "quantity",
        "value",
        "source",
        "measured_by"
      ],
      "properties": {
        "quantity": {
          "type": "string"
        },
        "value": {
          "type": "number"
        },
        "unit": {
          "type": [
            "string",
            "null"
          ]
        },
        "observed_at": {
          "type": "string",
          "description": "when the station reports it measured the value"
        },
        "source": {
          "const": "station-reported"
        },
        "measured_by": {
          "type": "string",
          "description": "states the station operator measured it, not Dynamic Feed"
        },
        "source_count": {
          "type": "integer",
          "description": "number of independent sources (1 when only the station reported)"
        },
        "single_source": {
          "type": "boolean",
          "description": "true unless an independent Dynamic Feed feed corroborated the quantity at the station's location"
        }
      }
    },
    "provenance": {
      "type": [
        "string",
        "null"
      ],
      "description": "station -> owner -> witnessed:dynamicfeed.ai"
    },
    "note": {
      "type": "string"
    },
    "signature": {
      "type": "object",
      "required": [
        "alg",
        "key_id",
        "sig"
      ],
      "properties": {
        "alg": {
          "const": "Ed25519"
        },
        "key_id": {
          "type": "string"
        },
        "sig": {
          "type": "string"
        }
      }
    },
    "concordance": {
      "type": "object",
      "description": "present when Dynamic Feed's own independent feed for the quantity at the station's location could cross-check the report; carries an honest agree/diverge/single_source/degraded verdict (concordance/v1). The station and Dynamic Feed are distinct provenance roots."
    }
  }
}