N · Not Found ​

Returned when the key didn't exist at the time of a release request (R), or when the token didn't match the one currently held. This isn't an error — it's returned as a "didn't exist" value.

token is the value the request carried, echoed back verbatim as a correlator — the client uses it to pin down which request this response belongs to (see Reply Matching Rules).

Byte notation: op is an ASCII character, token is binary (u64, big-endian), and key is UTF-8 text (variable-length, shown as N in the structure). The trailing \n is 0A. The fixed header is a binary value that may contain 0x0A, so it must be consumed by byte count first, before scanning for the newline.

Flow ​

Release is close to idempotent — sending R for a key the server already reclaimed via lease expiry, or one that was already released, gets you N. Since this is a normal branch of the flow, clients don't need to treat it as an error.