MSETNX - Upstash Documentation

Use MSETNX to set several keys at once, but only if none of them already exists.

The command is all or nothing: if even a single key is present, nothing is written and the reply is 0; otherwise every key is written and the reply is 1. Since the check and the writes are one atomic step, it can be used to claim a whole group of related keys, so that a partially initialized state can never be observed.

Syntax#

MSETNX <key> <value> [<key> <value> ...]

Arguments#

Argument	Required	Repeatable	Description
`<key> <value>`	Yes	Yes	Key and the value to store in it. Repeat to set several keys in one call.

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	Integer: `1` if all keys were set, `0` if no key was set
RESP3	Integer: `1` if all keys were set, `0` if no key was set

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

MSETNX key1 value1 key2 value2

@upstash/redis

import { Redis } from "@upstash/redis";const redis = Redis.fromEnv();redis.msetnx({  "key1": "value1",  "key2": "value2"})

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.msetnx({"my-key": "value"})print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.msetnx("my-key", "value");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.mSetNX({ "my-key": "value" });console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.msetnx({"my-key": "value"})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.MSetNX(context.Background(), "my-key", "value").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.msetnx("my-key", "value");  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.mset_nx(&[("my-key", "value")])?;    println!("{result:?}");    Ok(())}