Packet Format

Header

Every LOCO packet starts with a 22-byte little-endian header:

Offset  Size  Type    Field
0       4     u32     packet_id
4       2     i16     status_code
6       11    ASCII   method (null-padded)
17      1     u8      body_type
18      4     u32     body_length

Total header: 22 bytes.

Body

The body is BSON-encoded (Binary JSON). The body_length field specifies its exact size.

Example

A GETCONF request:

Header (22 bytes):
  packet_id:   01 00 00 00      (1)
  status_code: 00 00            (0)
  method:      47 45 54 43 4F 4E 46 00 00 00 00  ("GETCONF\0\0\0\0")
  body_type:   00               (0)
  body_length: 1A 00 00 00      (26)

Body (26 bytes):
  BSON document: {"os": "mac", "model": "mac"}

Method Names

Method names are ASCII strings, max 11 characters, null-padded. Common methods:

Packet ID

Sequential counter starting from 1. Responses carry the same packet_id as the request. Push messages (MSG, CHANGESVR) use server-assigned IDs.

Size Limits

• Maximum body size: 100 MB (enforced client-side)
• Maximum frame size: 100 MB (for encrypted frames)