JSON.ARRTRIM - Upstash Documentation

Use JSON.ARRTRIM to keep only a range of elements in the arrays a path selects and discard the rest. Both start and stop are inclusive indexes and may be negative to count from the end of the array. Indexes outside the array are clamped, and a range that selects nothing leaves an empty array. The reply is the new length of each array the path matched. It is the JSON counterpart of LTRIM: combine it with JSON.ARRAPPEND to keep a capped list, such as the last N events, inside a document.

Syntax

JSON.ARRTRIM <key> <path> <start> <stop>

Arguments

Argument	Required	Repeatable	Description
`key`	Yes	No	JSON document key.
`path`	Yes	No	Path selecting arrays.
`start`	Yes	No	Inclusive first index to keep.
`stop`	Yes	No	Inclusive last index to keep.

Important points

Raw TCP examples pass JSON values as valid JSON text. Typed Upstash SDK helpers serialize native objects and values for you.
Paths beginning with $ use JSONPath and can match multiple values, so many JSON commands return an array of per-match results.

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	Array of integer lengths or null values, one per matched path
RESP3	Array of integer lengths or null values, one per matched path

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

JSON.ARRTRIM profile $.tags 0 9

@upstash/redis

import { Redis } from "@upstash/redis";

const redis = Redis.fromEnv();

const length = await redis.json.arrtrim("key", "$.path.to.array", 2, 10);

upstash_redis

from upstash_redis import Redis

redis = Redis.from_env()
result = redis.json().arrtrim("profile", "$.tags", 0, 9)
print(result)

ioredis

import Redis from "ioredis";

const redis = new Redis(process.env.REDIS_URL!);
const result = await redis.call("JSON.ARRTRIM", "profile", "$.tags", "0", "9");
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.json.arrTrim("profile", "$.tags", 0, 9);
console.log(result);

redis-py

import os
import redis

client = redis.from_url(os.environ["REDIS_URL"])
result = client.json().arrtrim("profile", "$.tags", 0, 9)
print(result)

go-redis

package main

import (
    "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.JSONArrTrimWithArgs(context.Background(), "profile", "$.tags", &redis.JSONArrTrimArgs{Start: 0, Stop: func() *int { stop := 9; return &stop }()}).Result()
    if err != nil {
        panic(err)
    }
    fmt.Println(result)
}

jedis

import java.net.URI;

import redis.clients.jedis.JedisPooled;

try (JedisPooled jedis = new JedisPooled(new URI(System.getenv("REDIS_URL")))) {
  Object result = jedis.jsonArrTrim("profile", new redis.clients.jedis.json.Path("$.tags"), 0, 9);
  System.out.println(result);
}

redis-rs

use redis::JsonCommands;

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: redis::Value = connection.json_arr_trim("profile", "$.tags", 0, 9)?;
    println!("{result:?}");
    Ok(())
}

​Syntax

​Arguments

​Important points

​Response

​Examples

Syntax

Arguments

Important points

Response

Examples