Reference

Data type commands

Klyro implements 145 commands: 130 Redis-shaped commands plus the 15-command MEM.* family. Matching RESP reply shapes let standard client libraries decode the results.

Choose a language once and every tabbed example in the documentation follows that choice. The preference is stored only in this browser.

import { createClient } from "klyro-db";

const db = createClient();
// Run commands, then close with: await db.quit();

Generic (any type)

const exists = await db.exists("session:42");
await db.expire("session:42", 900);
const ttl = await db.ttl("session:42");

Command	Reply
PING [message]	PONG, or the message
ECHO message	The message
HELLO [protover]	Server info; HELLO 3 switches to RESP3
DEL key [key ...] / UNLINK key [key ...]	Number of keys removed
EXISTS key [key ...]	How many exist; a repeated key counts each time
EXPIRE key seconds / PEXPIRE key ms	1 if the TTL was set, 0 if the key is missing
EXPIREAT key unix-seconds / PEXPIREAT key unix-ms	1 or 0
PERSIST key	1 if a TTL was removed, else 0
TTL key / PTTL key	Time left, -1 no expiry, -2 missing
TYPE key	string, list, hash, set, zset, memory, or none
RENAME key newkey / RENAMENX key newkey	OK, or 1/0 for the NX form
COPY source destination [REPLACE]	1 if copied, else 0
RANDOMKEY	A key, or nil if the keyspace is empty
KEYS pattern	Array of matching keys
SCAN cursor [MATCH pattern] [COUNT count]	[next-cursor, [keys...]]
DBSIZE	Number of live keys
FLUSHDB / FLUSHALL	OK; one keyspace, so both do the same thing
INFO [section]	One text blob of # Section headers over key:value lines
CONFIG GET pattern [pattern ...]	Map of parameter to value
CONFIG SET parameter value	OK, or an error explaining the refusal
CONFIG RESETSTAT	OK; clears INFO's activity counters
SAVE	OK; writes the dump file immediately
QUIT / SHUTDOWN	OK, then closes the connection or stops the server

COPY is a deep copy: mutating the destination afterwards leaves the source untouched. RENAME and COPY both carry the TTL across.

Strings

await db.set("session:42", "active", "EX", 900);
await db.incr("metrics:requests");
const status = await db.get("session:42");

Command	Reply
SET key value [NX\|XX] [GET] [EX s\|PX ms\|EXAT ts\|PXAT ts\|KEEPTTL]	OK, or nil when NX/XX is not satisfied
SETNX key value	1 if written, else 0
SETEX key seconds value / PSETEX key ms value	OK
GET key	The value, or nil
GETSET key value	The previous value, or nil; clears any TTL
GETDEL key	The value, or nil; removes the key
GETEX key [EX s\|PX ms\|PERSIST]	The value, or nil; adjusts the TTL
MGET key [key ...]	Array of values, nil per missing key
MSET key value [key value ...]	OK
MSETNX key value [key value ...]	1 if all were written, 0 if any key existed
INCR / DECR / INCRBY / DECRBY key [n]	The new value
INCRBYFLOAT key n	The new value, as text
APPEND key value	The new length
STRLEN key	The length, 0 if missing
GETRANGE key start end / SUBSTR key start end	The substring; inclusive, negatives count from the end
SETRANGE key offset value	The new length; pads any gap with NUL bytes

The lock primitive

SET key value NX EX 30 takes the key only if nobody holds it, and the lease expires on its own. INCR, DECR, INCRBY, APPEND, and SETRANGE keep an existing TTL; SET without KEEPTTL, GETSET, and MSET clear it.

Lists

await db.lpush("jobs", "generate-report");
const job = await db.brpop("jobs", 5);

Command	Reply
LPUSH / RPUSH key value [value ...]	The new length
LPUSHX / RPUSHX key value [value ...]	The new length, or 0 if the key does not exist
LPOP / RPOP key [count]	One value or nil; with a count, an array
LLEN key	The length
LRANGE key start stop	Array of values
LINDEX key index	The value, or nil
LSET key index value	OK, or an error if the key or index is out of range
LINSERT key BEFORE\|AFTER pivot value	The new length, -1 if the pivot is absent, 0 if the key is
LREM key count value	How many were removed
LTRIM key start stop	OK; an empty range deletes the key
RPOPLPUSH source destination	The moved value, or nil
LMOVE source destination LEFT\|RIGHT LEFT\|RIGHT	The moved value, or nil

Hashes

await db.hset("user:42", { name: "Ari", plan: "pro" });
const profile = await db.hgetall("user:42");

Command	Reply
HSET key field value [field value ...]	Number of fields added
HSETNX key field value	1 if written, 0 if the field exists
HMSET key field value [field value ...]	OK
HGET key field	The value, or nil
HMGET key field [field ...]	Array of values, nil per missing field
HDEL key field [field ...]	Number of fields removed
HLEN key / HSTRLEN key field	The field count / the value's length
HEXISTS key field	1 or 0
HKEYS key / HVALS key	Array of fields, or of values
HGETALL key	Map of field to value
HINCRBY key field n / HINCRBYFLOAT key field n	The new value

Sets

await db.sadd("online-users", "42", "73");
const online = await db.sismember("online-users", "42");
const users = await db.smembers("online-users");

Command	Reply
SADD key member [member ...]	Number of members newly added
SREM key member [member ...]	Number removed
SISMEMBER key member	1 or 0
SMISMEMBER key member [member ...]	Array of 1/0, one per member
SCARD key / SMEMBERS key	The member count / the members
SPOP key [count]	Removes and returns one member or nil; with a count, a set
SRANDMEMBER key [count]	The same without removing; a negative count may repeat members
SMOVE source destination member	1 if moved, else 0
SINTER / SUNION / SDIFF key [key ...]	Set of members
SINTERSTORE / SUNIONSTORE / SDIFFSTORE dest key [key ...]	Size of the stored result

A missing key counts as an empty set. SDIFF subtracts every later set from the first, so it is not symmetric. A STORE variant whose result is empty deletes the destination.

Sorted sets

await db.zadd("leaderboard", 980, "user:42", 860, "user:73");
const leaders = await db.zrevrange("leaderboard", 0, 9, "WITHSCORES");

Command	Reply
ZADD key score member [score member ...]	Number of members newly added
ZSCORE key member / ZMSCORE key member [member ...]	The score, or nil
ZINCRBY key increment member	The new score; a missing member starts at 0
ZREM key member [member ...]	Number removed
ZCARD key	The member count
ZRANK / ZREVRANK key member	The 0-based rank, or nil
ZRANGE / ZREVRANGE key start stop [WITHSCORES]	Members by score
ZRANGEBYSCORE / ZREVRANGEBYSCORE key min max [WITHSCORES]	Members inside the score window
ZCOUNT key min max	How many fall inside the window
ZREMRANGEBYRANK / ZREMRANGEBYSCORE key start stop	Number removed
ZPOPMIN / ZPOPMAX key [count]	The popped members with their scores

Score bounds accept a plain number, -inf/+inf, or a ( prefix for an exclusive bound, as in ZCOUNT board (75 +inf.

Rules that apply everywhere

A command against a key holding a different type replies WRONGTYPE, for instance LPUSH on a key created by SET.
Removing the last element of a collection deletes the key, same as Redis.
Keys, values, fields, and members are arbitrary bytes: they may contain spaces, newlines, and NUL bytes. So are a memory record’s text and metadata.
Calling an unimplemented Redis command returns ERR unknown command. See limitations for what is missing.