# JSON.NUMMULTBY

> Multiply JSON number.

Use `JSON.NUMMULTBY` to multiply the numeric values a path selects by a number.

The multiplier may be a fraction to scale values down, and the update is atomic. The reply is the new value of each match, and a match that is not a number returns an error. It is the multiplicative counterpart of [`JSON.NUMINCRBY`](/redis/commands/json/json-numincrby), useful for applying percentage changes such as a discount to every price in a document.

## Syntax

```redis
JSON.NUMMULTBY <key> <path> <value>
```

## Arguments

| Argument | Required | Repeatable | Description |
| --- | --- | --- | --- |
| `key` | Yes | No | JSON document key. |
| `path` | Yes | No | Path selecting numbers. |
| `value` | Yes | No | Numeric multiplier. |

## 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 | Bulk string containing a JSON number or array |
| RESP3 | Bulk string containing a JSON number or array |

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

## Examples

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

<AccordionGroup>

<Accordion title="Redis CLI" icon="terminal">

```bash
JSON.NUMMULTBY profile $.score 2
```

</Accordion>

<Accordion title="@upstash/redis" icon="node-js" iconType="brands">

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

const redis = Redis.fromEnv();

const newValue = await redis.json.nummultby("key", "$.path.to.value", 2);
```

</Accordion>

<Accordion title="upstash_redis" icon="python" iconType="brands">

```python
from upstash_redis import Redis

redis = Redis.from_env()
result = redis.json().nummultby("profile", "$.score", 2)
print(result)
```

</Accordion>

<Accordion title="ioredis" icon="node-js" iconType="brands">

```ts
import Redis from "ioredis";

const redis = new Redis(process.env.REDIS_URL!);
const result = await redis.call("JSON.NUMMULTBY", "profile", "$.score", "2");
console.log(result);
```

</Accordion>

<Accordion title="node-redis" icon="node-js" iconType="brands">

```ts
import { createClient } from "redis";

const client = await createClient({ url: process.env.REDIS_URL })
  .on("error", console.error)
  .connect();
const result = await client.json.numMultBy("profile", "$.score", 2);
console.log(result);
```

</Accordion>

<Accordion title="redis-py" icon="python" iconType="brands">

```python
import os
import redis

client = redis.from_url(os.environ["REDIS_URL"])
result = client.json().nummultby("profile", "$.score", 2)
print(result)
```

</Accordion>

<Accordion title="go-redis" icon="golang" iconType="brands">

```go
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.Do(context.Background(), "JSON.NUMMULTBY", "profile", "$.score", "2").Result()
    if err != nil {
        panic(err)
    }
    fmt.Println(result)
}
```

</Accordion>

<Accordion title="jedis" icon="java" iconType="brands">

```java
import java.net.URI;
import java.nio.charset.StandardCharsets;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.commands.ProtocolCommand;

ProtocolCommand command = () -> "JSON.NUMMULTBY".getBytes(StandardCharsets.UTF_8);
try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {
  Object result = jedis.sendCommand(command, "profile", "$.score", "2");
  System.out.println(result);
}
```

</Accordion>

<Accordion title="redis-rs" icon="rust" iconType="brands">

```rust
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("JSON.NUMMULTBY");
    command.arg("profile");
    command.arg("$.score");
    command.arg("2");
    let result: redis::Value = command.query(&mut connection)?;
    println!("{result:?}");
    Ok(())
}
```

</Accordion>

</AccordionGroup>