HELLO
Selects RESP2 or RESP3 and reports connection and server information.
Connections · Example verified
Syntax covered here
HELLO 2 | HELLO 3The case switches to RESP3, successfully issues PING, then switches back to RESP2; clients must decode the negotiated reply format.
Tested example & replies
Requests below run in order against an empty database. Each connection authenticates with the fixture password first. Quoted values are strings; null is a nil reply; arrays preserve RESP order.
# connection: default
> HELLO 3
{"server":"lavik","version":"0.1.0-beta.1","proto":3,"id":64,"mode":"standalone","role":"master","modules":[]}
# connection: default
> PING
"PONG"
# connection: default
> HELLO 2
["server","lavik","version","0.1.0-beta.1","proto",2,"id",64,"mode","standalone","role","master","modules",[]]Test environment & reproducible evidence
Verified: 2026-09-21T11:06:06Z · Docker / Linux aarch64 · lavik 0.1.0-beta.1
Storage & connection: io_uring · temporary file, 2 workers, standalone, plaintext TCP, password authentication. This test does not measure NVMe performance.
Pinned source: 3955b98d43b312324aa8d52775df52cfb111c0d0
Binary SHA-256: 8306b37ddf05023f85166a6aa2192b7084757e8defd342b602e6470244aca887
Image: sha256:af0cfb11b78f184cb6cc49a774a49dc97a8e43a0bd3f4d63d83c8c9ef3282d6e
Lavik command registry · Valkey counterpart (support may differ)