memcached (text)

The ASCII line-based protocol that telnet and most older memcached clients speak.

Framing

• Every command starts on its own line and ends with \r\n.
• Storage commands are followed by a separate data block, also \r\n-terminated.
• Maximum line length: 4 KiB.
• Maximum payload length: 16 MiB.

exptime semantics

The exptime field on set, add, replace, cas, touch, gat, gats, and the meta T flag follows the standard memcached rules:

Value	Meaning
0	Never expires
1 … 2592000	Relative seconds from now (up to 30 days)
> 2592000	Absolute UNIX timestamp

The 30-day threshold is the memcached convention.

Flags

The flags field is a 32-bit opaque integer that the server stores verbatim and returns on get. fastcached never interprets it.

CAS

Every entry has a CAS token (64-bit, monotonically increasing per storage instance). cas and meta C(token) use it for compare-and-swap; gets, gats, and mg c return it to the client.

noreply

set, add, replace, append, prepend, cas, delete, incr, decr, touch, flush_all, cache_memlimit, and verbosity accept a trailing noreply token. When present, the response (including any error) is suppressed. Pipelines that use noreply lose visibility into failures.

Error tokens

Token	Meaning
ERROR	Unknown command
CLIENT_ERROR <msg>	The client sent a malformed command
SERVER_ERROR <msg>	The server hit an internal failure

Commands

See the Commands index for the full list.