# JSON.MERGE

> Merge JSON values.

Use `JSON.MERGE` to merge a JSON value into a document at a path, following the JSON Merge Patch semantics of RFC 7386.

Objects are merged recursively: keys in the patch replace or create the matching keys in the target, keys set to `null` delete them, and any value that is not an object, arrays included, replaces the target outright instead of being merged element by element. The parent must already exist: merging into a missing child of an existing object creates it, but intermediate levels are not built along the way, and a key that does not exist yet can only be created by merging at the root.

This is the command for partial updates of an object, where [`JSON.SET`](/redis/commands/json/json-set) would replace the whole branch: one call can change a few fields, delete another, and leave the rest of the document untouched.

## Syntax

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

## Arguments

| Argument | Required | Repeatable | Description |
| --- | --- | --- | --- |
| `key` | Yes | No | JSON document key. |
| `path` | Yes | No | Path to merge into. |
| `value` | Yes | No | Valid JSON value containing the merge patch. |

## 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 | Simple string `OK` |
| RESP3 | Simple string `OK` |

<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.MERGE profile $ '{"active":true}'
```

</Accordion>

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

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

const redis = Redis.fromEnv();

await redis.json.merge("key", "$.path.to.value", {"new": "value"})
```

</Accordion>

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

```python
from upstash_redis import Redis

redis = Redis.from_env()
result = redis.json().merge("profile", "$", {"active": True})
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.MERGE", "profile", "$", "{\"active\":true}");
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.merge("profile", "$", { active: true });
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().merge("profile", "$", {"active": True})
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.JSONMerge(context.Background(), "profile", "$", `{"active":true}`).Result()
    if err != nil {
        panic(err)
    }
    fmt.Println(result)
}
```

</Accordion>

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

```java
import java.net.URI;

import redis.clients.jedis.JedisPooled;

try (JedisPooled jedis = new JedisPooled(new URI(System.getenv("REDIS_URL")))) {
  Object result = jedis.jsonMerge("profile", new redis.clients.jedis.json.Path("$"), java.util.Map.of("active", true));
  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.MERGE");
    command.arg("profile");
    command.arg("$");
    command.arg("{\"active\":true}");
    let result: redis::Value = command.query(&mut connection)?;
    println!("{result:?}");
    Ok(())
}
```

</Accordion>

</AccordionGroup>