> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# BITFIELD_RO

> Read bitfield values.

Use `BITFIELD_RO` to read one or more bitfield values without modifying the key.

It is the read-only form of [`BITFIELD`](/docs/redis/commands/bitmap/bitfield) and accepts `GET` operations only, so it is safe to run on replicas and from read-only scripts. Each `GET` names an encoding, `u<bits>` for unsigned or `i<bits>` for signed integers, and a bit offset that can be written as `#<n>` to address the n-th field of that width. The reply holds one integer per `GET`, and any part of a field that lies past the end of the stored string reads as zero.

## Syntax

```redis theme={"system"}
BITFIELD_RO <key> [GET <encoding> <offset> [GET <encoding> <offset> ...]]
```

## Arguments

| Argument                  | Required | Repeatable | Description                                                                                            |
| ------------------------- | -------- | ---------- | ------------------------------------------------------------------------------------------------------ |
| `<key>`                   | Yes      | No         | Redis key targeted by the command.                                                                     |
| `GET <encoding> <offset>` | No       | Yes        | Read the value at `<offset>` using `<encoding>`, such as `u8` or `i16`. Repeat to read several fields. |

## 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 or null replies, one per subcommand |
| RESP3    | Array of integer or null replies, one per subcommand |

<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 theme={"system"}
    BITFIELD_RO my-key GET u8 0
    ```
  </Accordion>

  <Accordion title="@upstash/redis" icon="node-js" iconType="brands">
    <Note>
      This command is not supported yet in `@upstash/redis`.
    </Note>
  </Accordion>

  <Accordion title="upstash_redis" icon="python" iconType="brands">
    ```python theme={"system"}
    from upstash_redis import Redis

    redis = Redis.from_env()
    result = redis.bitfield_ro("my-key").get("u8", 0).execute()
    print(result)
    ```
  </Accordion>

  <Accordion title="ioredis" icon="node-js" iconType="brands">
    ```ts theme={"system"}
    import Redis from "ioredis";

    const redis = new Redis(process.env.REDIS_URL!);
    const result = await redis.bitfield_ro("my-key", "GET", "u8", "0");
    console.log(result);
    ```
  </Accordion>

  <Accordion title="node-redis" icon="node-js" iconType="brands">
    ```ts theme={"system"}
    import { createClient } from "redis";

    const client = await createClient({ url: process.env.REDIS_URL })
      .on("error", console.error)
      .connect();
    const result = await client.bitFieldRo("my-key", [{ encoding: "u8", offset: 0 }]);
    console.log(result);
    ```
  </Accordion>

  <Accordion title="redis-py" icon="python" iconType="brands">
    ```python theme={"system"}
    import os
    import redis

    client = redis.from_url(os.environ["REDIS_URL"])
    result = client.bitfield_ro("my-key", "u8", 0)
    print(result)
    ```
  </Accordion>

  <Accordion title="go-redis" icon="golang" iconType="brands">
    ```go theme={"system"}
    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.BitFieldRO(context.Background(), "my-key", "GET", "u8", 0).Result()
        if err != nil {
            panic(err)
        }
        fmt.Println(result)
    }
    ```
  </Accordion>

  <Accordion title="jedis" icon="java" iconType="brands">
    ```java theme={"system"}
    import java.net.URI;

    import redis.clients.jedis.Jedis;

    try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {
      Object result = jedis.bitfieldReadonly("my-key", "GET", "u8", "0");
      System.out.println(result);
    }
    ```
  </Accordion>

  <Accordion title="redis-rs" icon="rust" iconType="brands">
    ```rust theme={"system"}
    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("BITFIELD_RO");
        command.arg("my-key");
        let result: redis::Value = command.query(&mut connection)?;
        println!("{result:?}");
        Ok(())
    }
    ```
  </Accordion>
</AccordionGroup>


## Related topics

- [Features](/docs/redis/sdks/py/features.md)
- [BITFIELD](/docs/redis/commands/bitmap/bitfield.md)
- [EVALSHA_RO](/docs/redis/sdks/py/commands/scripts/evalsha_ro.md)