EVALSHA - Upstash Documentation

Use EVALSHA to run a script that is already in the server's script cache, identified by its SHA1 digest.

It behaves exactly like EVAL but sends only the 40-character digest instead of the script body, which keeps the request small when a script is called often. The digest is what SCRIPT LOAD returns, and it is also computed as a side effect of any EVAL call.

Locking behaviour comes from the cached script body, not from the call: the script takes the global lock unless its shebang sets the allow-key-locking flag, in which case only the keys passed in KEYS are locked. Because the flag lives in the body, changing it means loading a new script and calling the new digest. See Key-Based Locking.

When the script is not in the cache the server replies with a NOSCRIPT error, and the client is expected to fall back to EVAL. Most client libraries do this automatically. The cache does not survive a restart and is cleared by SCRIPT FLUSH, so applications must always be able to resend the script body.

Syntax#

EVALSHA <sha1> <numkeys> [<key> [<key> ...]] [<arg> [<arg> ...]]

Arguments#

Argument	Required	Repeatable	Description
`<sha1>`	Yes	No	SHA1 digest of a script cached with `SCRIPT LOAD`.
`<numkeys>`	Yes	No	Number of key arguments that follow.
`<key>`	No	Yes	Redis key targeted by the command.
`<arg>`	No	Yes	Additional argument, available to the script as `ARGV`.

Important points#

numkeys must equal the number of key arguments that immediately follow it; remaining arguments are available to the script or function as ordinary arguments.
The cached script takes the global lock unless its shebang sets the allow-key-locking flag. See Key-Based Locking.
A script queued inside a MULTI/EXEC transaction always runs under the global lock, even when it sets allow-key-locking. Call it directly if you want per-key locking.
Pass every key the script touches through KEYS whether or not allow-key-locking is set. A key built inside the script is read from disk under the lock when it is not in memory, and it is rejected outright when the flag is set. See Dynamic Keys and Latency.

Reply conversion#

redis.setresp() and the RESP2 and RESP3 conversions applied to redis.call replies work exactly as they do for EVAL.

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	Reply produced by the cached script
RESP3	Reply produced by the cached script

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

EVALSHA fb67a0c03b48ddbf8b4c9b011e779563bdbc28cb 0 value

@upstash/redis

import { Redis } from "@upstash/redis";const redis = Redis.fromEnv();const result = await redis.evalsha("fb67a0c03b48ddbf8b4c9b011e779563bdbc28cb", [], ["hello"]);console.log(result) // "hello"

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.evalsha("<sha1>", args=["value"])print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.evalsha("<sha1>", "0", "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.evalSha("<sha1>", { arguments: ["value"] });console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.evalsha("<sha1>", 0, "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.EvalSha(context.Background(), "<sha1>", nil, "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.evalsha("<sha1>", java.util.List.of(), java.util.List.of("value"));  System.out.println(result);}

redis-rs

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 mut command = redis::cmd("EVALSHA");    command.arg("<sha1>");    command.arg("1");    let result: redis::Value = command.query(&mut connection)?;    println!("{result:?}");    Ok(())}