# JSON.STRAPPEND

> Append to JSON string.

Use `JSON.STRAPPEND` to append text to the string values a path selects.

The value is JSON text, so the appended string must be quoted, as in `'"suffix"'`. The reply is the new length of each string the path matched, with an error for matches that are not strings. Appending in place avoids reading and rewriting the whole document just to extend one field.

## Syntax

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

## Arguments

| Argument | Required | Repeatable | Description |
| --- | --- | --- | --- |
| `key` | Yes | No | JSON document key. |
| `path` | Yes | No | Path selecting strings. |
| `value` | Yes | No | JSON-encoded string to append. |

## 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 | Integer, array of integer lengths or null values, or Null bulk string or null array |
| RESP3 | Integer, array of integer lengths or null values, or Null |

<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.STRAPPEND profile $.name '" Lovelace"'
```

</Accordion>

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

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

const redis = Redis.fromEnv();

await redis.json.strappend("key", "$.path.to.str", "abc");
```

</Accordion>

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

```python
from upstash_redis import Redis

redis = Redis.from_env()
result = redis.json().strappend("profile", "$.name", " Lovelace")
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.STRAPPEND", "profile", "$.name", "\" Lovelace\"");
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.strAppend("profile", " Lovelace", { path: "$.name" });
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().strappend("profile", " Lovelace", "$.name")
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.JSONStrAppend(context.Background(), "profile", "$.name", `" Lovelace"`).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.jsonStrAppend("profile", new redis.clients.jedis.json.Path("$.name"), " Lovelace");
  System.out.println(result);
}
```

</Accordion>

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

```rust
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_str_append("profile", "$.name", " Lovelace")?;
    println!("{result:?}");
    Ok(())
}
```

</Accordion>

</AccordionGroup>