Encoding and Data Format

XSCP is a text-based protocol that enforces a strict structure to ensure predictable parsing and high performance.

Encoding

All data exchanged via XSCP must be encoded in UTF-8. This ensures universal compatibility across different operating systems and programming languages while maintaining a simple byte-to-character relationship for ASCII-range characters.

Framing and Delimiters

The protocol is line-oriented, meaning each PDU (Protocol Data Unit) is treated as a single, discrete line of text.

• PDU Terminator: Every message must end with the CRLF sequence (\r\n). Parsers should treat the arrival of \r\n as the signal to process the preceding buffer.
• Field Separator: Within a PDU, fields are separated by the pipe character (|).
• Structure: A typical PDU follows the pattern: FIELD1|FIELD2|PAYLOAD\r\n.

Formatting Constraints

To ensure integrity and prevent protocol smuggling, the following rules apply:

• Control Fields: The pipe character (|) and CRLF sequence are strictly forbidden within control fields (such as the source or command identifiers).
• Payload Flexibility: The pipe character (|) is allowed within the message payload section. The parser handles this by only splitting the PDU into a fixed number of structural segments, treating the remainder as the raw payload.
• Line Breaks: The CRLF sequence remains globally forbidden within any part of the PDU content to avoid premature message termination.