openapi: 3.1.1
info:
  title: BecknReportDescriptors — Telemetry Sidecar (v1.0)
  version: 1.0.0
  description: >
    Minimal, OpenADR 3.1.0-aligned sidecar declaring what telemetry a
    seller commits to providing under a contract. Each entry $ref-reuses
    OpenADR's `reportPayloadDescriptor` 1:1 (the same descriptor type
    used inside `BecknTimeSeries.payloadDescriptors`) and adds one
    DEG extension — `cardinality` — to disambiguate signals that are
    reported every interval (USAGE, POWER, SOC_END) from signals
    reported once per event (GPS_LAT, GPS_LON).

    Embedded as `inputs[seller].inputs.reportDescriptors` in DemandFlexBuyOffer
    (or any equivalent offer). The property is nullable: set to `null`
    when the contract requires no telemetry.

    For the actual report body, see BecknTimeSeries; the descriptors here
    declare the schema, the time-series carries the values.

components:
  schemas:

    BecknReportDescriptors:
      type: array
      minItems: 1
      description: >
        Sidecar array — one entry per signal the seller commits to report.
      items:
        $ref: "#/components/schemas/BecknReportPayloadDescriptor"

    BecknReportPayloadDescriptor:
      description: >
        OpenADR3 `reportPayloadDescriptor` augmented with a `cardinality`
        field. Required fields and value enums otherwise match OpenADR3.
      allOf:
        - $ref: "https://raw.githubusercontent.com/beckn/DEG/refs/heads/main/specification/external/openadr/3.1.0/openadr3.yaml#/components/schemas/reportPayloadDescriptor"
        - type: object
          properties:
            cardinality:
              type: string
              enum: [PER_INTERVAL, PER_EVENT]
              default: PER_INTERVAL
              description: |
                How often this payload is expected on the wire:

                  PER_INTERVAL  - reported in every interval of the
                                  BecknTimeSeries (default). Use for
                                  power-like signals (USAGE, BASELINE,
                                  POWER — KW per interval) and SOC_END
                                  (% at end of each interval).
                  PER_EVENT     - reported exactly once per event, on
                                  interval 0 of the BecknTimeSeries.
                                  Use for slow-changing or summary
                                  signals: GPS_LAT, GPS_LON (vehicle
                                  position at start of event).
              example: PER_INTERVAL

  # Canonical payloadType vocabulary used by demand-flex EV vendor
  # telemetry. Add to this list as new signals are introduced.
  #
  # | payloadType | units    | readingType  | cardinality   | meaning                                           |
  # |-------------|----------|--------------|---------------|---------------------------------------------------|
  # | BASELINE    | KW       | DIRECT_READ  | PER_INTERVAL  | Reference (vendor-rated) charge power             |
  # | USAGE       | KW       | DIRECT_READ  | PER_INTERVAL  | Measured charge power during the event            |
  # | POWER       | KW       | DIRECT_READ  | PER_INTERVAL  | Signed instantaneous power (charge=+, discharge=-)|
  # | SOC_END     | PERCENT  | DIRECT_READ  | PER_INTERVAL  | State of charge at end of each interval           |
  # | GPS_LAT     | DEGREES  | DIRECT_READ  | PER_EVENT     | Vehicle latitude at start of event                |
  # | GPS_LON     | DEGREES  | DIRECT_READ  | PER_EVENT     | Vehicle longitude at start of event               |