APP API Reference
Complete reference for all APP API messages used to communicate with AppEndpoint.
Request Messages
Messages sent from your application to AppEndpoint.
| Code | Name | Description |
|---|---|---|
0x01 |
GET_ENDPOINT_INFO_REQUEST | Get information about the local endpoint |
0x02 |
GET_ATRS_INFO_REQUEST | Get list of all ATRs on this endpoint |
0x03 |
GET_VERSION_REQUEST | Get AppEndpoint version information |
0x04 |
REGISTER_APP_REQUEST | Register application with ATR |
0x05 |
SEND_APP_DATA_REQUEST | Send data to remote application |
GET_ENDPOINT_INFO_REQUEST (0x01)
Retrieves information about the local endpoint including name, ID, and status.
# Payload: opcode only (4 bytes)
payload = struct.pack("<L", 0x01)
packet = build_akm_header(len(payload)) + payload
sock.sendall(packet)GET_ATRS_INFO_REQUEST (0x02)
Retrieves information about all ATRs configured on this endpoint (up to 10).
# Payload: opcode only (4 bytes)
payload = struct.pack("<L", 0x02)
packet = build_akm_header(len(payload)) + payload
sock.sendall(packet)REGISTER_APP_REQUEST (0x04)
Registers your application with a specific ATR and App Value.
| Field | Type | Description |
|---|---|---|
| Opcode | U32 | 0x00000004 |
| ATR_ID | U16 | Abbreviated ATR ID |
| App_Value | U16 | Unique application identifier |
# Payload: opcode (4) + ATR_ID (2) + App_Value (2) = 8 bytes
payload = struct.pack("<LHH", 0x04, atr_id, app_value)
packet = build_akm_header(len(payload)) + payload
sock.sendall(packet)SEND_APP_DATA_REQUEST (0x05)
Sends data to a remote application through the encrypted channel.
| Field | Type | Description |
|---|---|---|
| Opcode | U32 | 0x00000005 |
| ATR_ID | U16 | Target ATR ID |
| Target_App_Value | U16 | Target application's App Value |
| Data | bytes[4046] | Data buffer (zero-padded) |
| Length | U32 | Actual data length |
MAX_APP_BUFFER_SIZE = 4046
FMT = f"<LHH{MAX_APP_BUFFER_SIZE}sL"
data = message.encode()
padded = data.ljust(MAX_APP_BUFFER_SIZE, b"\x00")
payload = struct.pack(FMT, 0x05, atr_id, target_app, padded, len(data))
packet = build_akm_header(len(payload)) + payload
sock.sendall(packet)Response Messages
Messages received from AppEndpoint.
| Code | Name | Description |
|---|---|---|
0x41 |
GET_ENDPOINT_INFO_RESPONSE | Endpoint information |
0x42 |
GET_ATRS_INFO_RESPONSE | ATR list (up to 10) |
0x43 |
GET_VERSION_RESPONSE | Version information |
0x44 |
REGISTER_APP_RESPONSE | Registration confirmation |
0x46 |
RECEIVE_APP_DATA_RESPONSE | Incoming data from remote app |
GET_ATRS_INFO_RESPONSE (0x42)
| Field | Type | Description |
|---|---|---|
| Opcode | U32 | 0x00000042 |
| Conf_Code | U32 | 0 = success |
| Num_ATRs | U32 | Number of ATRs (max 10) |
| ATR_Block | bytes[2240] | Array of 10 ATR structs (224 bytes each) |
REGISTER_APP_RESPONSE (0x44)
| Field | Type | Description |
|---|---|---|
| Opcode | U32 | 0x00000044 |
| Conf_Code | U32 | 0 = success, 1 = error |
| ATR_ID | U16 | Registered ATR ID |
| App_Value | U16 | Registered App Value |
RECEIVE_APP_DATA_RESPONSE (0x46)
Received asynchronously when data arrives from a remote application.
| Field | Type | Description |
|---|---|---|
| Opcode | U32 | 0x00000046 |
| ATR_ID | U16 | Source ATR ID |
| Source_App_Value | U16 | Sender's App Value |
| Data | bytes[4046] | Data buffer |
| Length | U32 | Actual data length |
Data Structures
ATR Structure (224 bytes)
| Offset | Size | Field |
|---|---|---|
| 16 | 20 | ATR Name |
| 36 | 2 | Abbreviated ID (U16) |
| 38 | 2 | Active Status (U16) |
| 40 | 4 | Category (U32: 0=Provisioning, 1=Operational) |
| 64 | 20 | Server Name |
| 120 | 20 | Client Name |