Redis API reference

Implemented · some Planned

marekvs speaks RESP2 and RESP3. The tables below list the commands that are actually wired into the command dispatcher (crates/marekvs-engine/src/cmd/), so if a command is here, it runs. Commands that some tools assume exist but that marekvs does not implement are called out explicitly in Not implemented.

Note

Read guarantees are per connection: a connection sees its own writes and never reads backward in time. They are not cross-client — two clients on two nodes can briefly observe different values. See Consistency.

#Connection & server

Command	Notes
`PING` `ECHO`	Liveness / echo.
`HELLO`	Protocol handshake; selects RESP2/RESP3.
`AUTH`	Single-password auth when `MAREKVS_REQUIREPASS` is set.
`QUIT` `RESET`	Close / reset the connection state.
`SELECT`	Accepted (single logical keyspace).
`CLIENT` `COMMAND` `CONFIG` `INFO` `DBSIZE`	Introspection / runtime config.
`FLUSHALL` `FLUSHDB`	Clear data.
`TIME`	Server time.
`REPLICAOF` / `SLAVEOF`	Follow a real Redis master (live migration).
`SHUTDOWN` `DEBUG`	Lifecycle / debug helpers.

A few settings are live-reconfigurable via CONFIG SET: requirepass, lua-time-limit, and loglevel.

#Generic / keyspace

Command	Notes
`DEL` `UNLINK` `EXISTS` `TYPE` `TOUCH`	Standard key ops.
`TTL` `PTTL` `EXPIRETIME` `PEXPIRETIME`	Read expiry.
`EXPIRE` `PEXPIRE` `EXPIREAT` `PEXPIREAT` `PERSIST`	Set / clear expiry.
`KEYS` `SCAN` `RANDOMKEY`	Enumerate keys.
`RENAME` `RENAMENX`	Rename keys.
`EXPIREMEMBER` `EXPIREMEMBERAT` `PEXPIREMEMBERAT`	KeyDB-style per-member TTL.
`TTL key member`	Per-member TTL read (KeyDB extension).

#Strings

Command	Notes
`GET` `SET` `SETNX` `SETEX` `PSETEX`	Get / set with options.
`GETSET` `GETDEL` `GETEX`	Get-and-mutate.
`APPEND` `STRLEN` `SETRANGE` `GETRANGE` / `SUBSTR`	Substring ops.
`INCR` `DECR` `INCRBY` `DECRBY` `INCRBYFLOAT`	Counters (see below).
`MGET` `MSET` `MSETNX`	Multi-key get / set.

Done

INCR / DECR / INCRBY / DECRBY are backed by PN-counters: concurrent increments on different nodes are all preserved, never lost. An explicit SET resets the counter. See counters.

#Hashes

Command	Notes
`HSET` `HMSET` `HSETNX` `HGET` `HMGET` `HGETALL`	Field get / set.
`HDEL` `HEXISTS` `HLEN` `HKEYS` `HVALS` `HSTRLEN`	Field inspection.
`HINCRBY` `HINCRBYFLOAT`	Field arithmetic.
`HRANDFIELD` `HSCAN`	Sample / iterate.

#Sets

Command	Notes
`SADD` `SREM` `SCARD` `SISMEMBER` `SMISMEMBER`	Membership.
`SMEMBERS` `SPOP` `SRANDMEMBER` `SSCAN`	Read / sample / iterate.
`SMOVE`	Move a member between sets.
`SUNION` `SINTER` `SDIFF` (+ `STORE`) `SINTERCARD`	Set algebra.

Concurrent SADDs on different nodes both survive (ORSWOT merge).

#Sorted sets

Command	Notes
`ZADD` `ZINCRBY` `ZREM`	Add / mutate.
`ZSCORE` `ZMSCORE` `ZCARD` `ZRANK` `ZREVRANK` `ZCOUNT`	Inspect.
`ZRANGE` `ZRANGEBYSCORE` `ZREVRANGE` `ZREVRANGEBYSCORE`	Range queries.
`ZPOPMIN` `ZPOPMAX` `ZREMRANGEBYSCORE` `ZSCAN`	Pop / trim / iterate.

#Lists

Command	Notes
`LPUSH` `RPUSH` `LPUSHX` `RPUSHX`	Push.
`LPOP` `RPOP` `LLEN` `LRANGE` `LINDEX`	Pop / read.
`LSET` `LREM` `LTRIM` `LINSERT` `LPOS`	Mutate / search.
`LMOVE` `RPOPLPUSH`	Move between lists.
`BLPOP` `BRPOP` `BLMOVE` `BRPOPLPUSH`	Blocking variants.

Note

Lists are per-element position-keyed LWW registers. Blocking commands poll at ~50 ms and also wake on a replicated push. Concurrent cross-node pushes can collide on a position — see the list caveat.

#Streams

Command	Notes
`XADD` `XLEN` `XDEL` `XTRIM`	Append / size / trim.
`XRANGE` `XREVRANGE` `XREAD`	Read entries.

Warning

Consumer groups are not implemented — XGROUP, XREADGROUP, XACK, XCLAIM, XAUTOCLAIM, XPENDING, XSETID, and XINFO are absent. Streams provide raw, at-least-once entry operations only.

#HyperLogLog

Command	Notes
`PFADD` `PFCOUNT` `PFMERGE`	Convergent (per-register max) cardinality.

#Pub/Sub

Command	Notes
`SUBSCRIBE` `UNSUBSCRIBE` `PSUBSCRIBE` `PUNSUBSCRIBE`	Channel / pattern.
`PUBLISH` `PUBSUB`	Publish / introspect.

#Scripting

Command	Notes
`EVAL` `EVALSHA` `SCRIPT`	Lua 5.4; keys must co-locate. See Lua scripting.

#Transactions

Command	Notes
`MULTI` `EXEC` `DISCARD`	Queue and run sequentially.

Warning

Transactions are a convenience batch, not ACID: queued commands run sequentially with no atomicity beyond per-key shard serialization. WATCH / UNWATCH are rejected with an error — marekvs is AP and has no transactional compare-and-swap.

#Not implemented

These are not in the dispatch table, even though some clients or older design notes assume them. Calling one returns an error:

Keyspace: COPY, OBJECT, SORT, DUMP, RESTORE, MOVE
Sorted set: ZMPOP, ZRANDMEMBER, ZRANGESTORE, ZREMRANGEBYRANK, ZREMRANGEBYLEX, ZLEXCOUNT
List: LMPOP
Stream: XSETID, XINFO, consumer-group commands
Cluster / HA: WAIT, FAILOVER, CLUSTER, FUNCTION (no Redis Cluster protocol, no MOVED/ASK)
Modules / extras: GEO*, JSON*, bitfield/bit ops, CLIENT TRACKING (client-side caching)
Transport: no TLS.

#Cross-cutting semantics

Protocols: RESP2 and RESP3, negotiated with HELLO; inline commands are supported.
Atomicity: per-key only. A key's operations are serialized on one shard thread; there is no multi-key or cross-node atomicity.
Type errors: operating on the wrong structure returns WRONGTYPE.
Expiry: absolute deadlines decided at the origin, converging cluster-wide.
Counters: exact under concurrency (PN-counters).
Blocking commands: implemented via ~50 ms polling that also wakes on a replicated push.

#Where to go next

The structures behind these commands: Data model.
What "eventually consistent" means for reads: Consistency.
Scripting details and caveats: Lua scripting.