LMOVE - Upstash Documentation

Use LMOVE to atomically take an element from one end of a list and push it onto one end of another list, returning the element.

The two directions are chosen independently: LEFT RIGHT takes from the head of the source and appends to the tail of the destination, which preserves order when transferring between queues, while LEFT LEFT behaves like moving between stacks. If the source is empty nothing happens and the reply is null. Source and destination may be the same key, in which case the list is rotated.

Because the element is never outside a list, LMOVE is the building block for reliable queues: a worker moves an item into a processing list, does the work, and removes it from there, so a crash leaves the item recoverable instead of lost. It replaces the deprecated RPOPLPUSH, and BLMOVE is the blocking form.

Syntax#

LMOVE <source> <destination> (LEFT | RIGHT) (LEFT | RIGHT)

Arguments#

Argument	Required	Repeatable	Description
`<source>`	Yes	No	Redis key used as source.
`<destination>`	Yes	No	Redis key used as destination.
`(LEFT \| RIGHT)`	Yes	No	Which end of the source list the element is taken from: `LEFT` (head) or `RIGHT` (tail).
`(LEFT \| RIGHT)`	Yes	No	Which end of the destination list the element is pushed onto: `LEFT` (head) or `RIGHT` (tail).

Response#

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.

Protocol	Reply
RESP2	Bulk string
RESP3	Bulk string

Note

Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.

Examples#

TCP examples use the TLS REDIS_URL from the Upstash console. REST examples use UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.

Redis CLI

LMOVE source-key destination-key LEFT LEFT

@upstash/redis

import { Redis } from "@upstash/redis";const redis = Redis.fromEnv();await redis.rpush("source", "a", "b", "c");const element = await redis.lmove("source", "destination", "left", "left");

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.lmove("source-key", "destination-key", "LEFT", "LEFT")print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.lmove("source-key", "destination-key", "LEFT", "LEFT");console.log(result);

node-redis

import { createClient } from "redis";const client = await createClient({ url: process.env.REDIS_URL })  .on("error", console.error)  .connect();const result = await client.lMove("source-key", "destination-key", "LEFT", "LEFT");console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.lmove("source-key", "destination-key", "LEFT", "LEFT")print(result)

go-redis

package mainimport (    "context"    "fmt"    "os"    "github.com/redis/go-redis/v9")func main() {    opts, err := redis.ParseURL(os.Getenv("REDIS_URL"))    if err != nil {        panic(err)    }    client := redis.NewClient(opts)    result, err := client.LMove(context.Background(), "source-key", "destination-key", "LEFT", "LEFT").Result()    if err != nil {        panic(err)    }    fmt.Println(result)}

jedis

import java.net.URI;import redis.clients.jedis.Jedis;try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {  Object result = jedis.lmove("source-key", "destination-key", redis.clients.jedis.args.ListDirection.LEFT, redis.clients.jedis.args.ListDirection.LEFT);  System.out.println(result);}

redis-rs

use redis::TypedCommands;fn main() -> redis::RedisResult<()> {    let url = std::env::var("REDIS_URL").expect("REDIS_URL is not set");    let client = redis::Client::open(url)?;    let mut connection = client.get_connection()?;    let result = connection.lmove("source-key", "destination-key", redis::Direction::Left, redis::Direction::Left)?;    println!("{result:?}");    Ok(())}