Specification: APDU Transmit

Transmit series of APDU commands in hexadecimals. Each command with an specified ID. Commands will generate response passed from device to client on topic validators/apdu/receive with corresponding commandId.

APDU commands can be used to read or write specific values from travel cards or other NFC based devices.

transceiveId can be used to link transmit and receive events. eventTimestamp is the time the command transmit request is generated.

• Topic: validators/nfc/apdu/[deviceId]/transmit
• Direction: Consume (Outbound from client)
• JSON Schema: transmit.schema.json
• MQTT QoS: 1 (at least once)
• Trigger: Result from transmitted commands.

Hex and expected status

All commands should be represented as hex, starting with 0x. See examples. Expected status is optional. If result of executing command does not match expected status prefix, result is ommited in the receive event.

0xAF and continuation

Continuation on 0xAF is handled implicitly if expStatus is set as 0x00, depending on apdu type. See description below.

desfire (native)

• If expStatus=0x00 or empty and first bytes in response indicates more data (0xAF) the device should fetch all data until end and give result as concatinated byte array.
• If expStatus=0xAF is transmitted it is not handled automatically by the device.

Related

See related transmit topic: validators/nfc/apdu/receive.

Examples

{
  "traceId": "543070fe-ef32-11ed-a05b-0242ac120003",
  "deviceId": "flv202400004",
  "eventTimestamp": "2023-04-22T10:28:37.337Z",
  "transceiveId": "c28f206d-8016-4d22-b21b-70d8d6d2fea4",
  "apduType": "desfire",
  "command": [
    { "commandId": 1, "frame": "0x0080", "expStatus": "0x00" },
    { "commandId": 2, "frame": "0x000000100000", "expStatus": "0x00" },
    { "commandId": 3, "frame": "0x0180", "expStatus": "0x00" },
    { "commandId": 4, "frame": "0x07", "expStatus": "0x00" }
  ]
}

Additional information

Link to APDU-documentation.