> ## 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

> Perform arbitrary bitfield operations.

Use `BITFIELD` to treat a string as an array of packed integers and run several operations on it in a single atomic call.

Every operation names an encoding and a bit offset. The encoding is `u<bits>` for unsigned integers (up to 63 bits) or `i<bits>` for signed integers (up to 64 bits). The offset is counted in bits from the start of the value or, when prefixed with `#`, in units of the encoding width, so `#2` with `u8` addresses the third 8-bit field. The string grows automatically with zero bits when an operation addresses an offset past its current end.

`GET` reads a field, `SET` writes one and returns its previous value, and `INCRBY` adds a possibly negative increment and returns the new value. `OVERFLOW` sets how the `SET` and `INCRBY` operations that follow it behave when a value does not fit the encoding: `WRAP` wraps around like modular arithmetic and is the default, `SAT` saturates at the minimum or maximum of the encoding, and `FAIL` leaves the field unchanged and returns null for that operation. The reply is an array with one entry per operation, in the order the operations were given.

Packing many small counters into a single key this way saves memory and keeps the whole update atomic, which makes it a good fit for rate limiters and compact per-user counters.

## Syntax

```redis theme={"system"}
BITFIELD <key>
  [GET <encoding> <offset> |
    [OVERFLOW WRAP | SAT | FAIL]
    (SET <encoding> <offset> <value> |
      INCRBY <encoding> <offset> <increment>)
    [GET <encoding> <offset> |
      [OVERFLOW WRAP | SAT | FAIL]
      (SET <encoding> <offset> <value> |
        INCRBY <encoding> <offset> <increment>)
      ...]]
```

## Arguments

| Argument                                                                                                                                  | Required | Repeatable | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ----------------------------------------------------------------------------------------------------------------------------------------- | -------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `<key>`                                                                                                                                   | Yes      | No         | Redis key targeted by the command.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| `(GET <encoding> <offset> \| [OVERFLOW WRAP \| SAT \| FAIL] (SET <encoding> <offset> <value> \| INCRBY <encoding> <offset> <increment>))` | No       | Yes        | An operation on a field of `<encoding>` (`u<bits>` unsigned up to 63 bits, or `i<bits>` signed up to 64 bits) at `<offset>` bits, or at `#<n>` to address the n-th field of that width: `GET` reads it, `SET` writes it and returns the previous value, and `INCRBY` adds an increment and returns the new value. `OVERFLOW` sets how the `SET` and `INCRBY` operations after it handle a value that does not fit: `WRAP` wraps around (the default), `SAT` saturates at the encoding's limits, and `FAIL` leaves the field unchanged and returns null. Repeat to run several operations in one atomic call. |

## 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 my-key GET u8 0
    ```
  </Accordion>

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

    const redis = Redis.fromEnv();
    const result = await redis.bitfield("my-key").get("u8", 0).exec();
    console.log(result);
    ```
  </Accordion>

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

    redis = Redis.from_env()
    result = redis.bitfield("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("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.bitField("my-key", [{ operation: "GET", 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("my-key").get("u8", 0).execute()
    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.BitField(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.bitfield("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");
        command.arg("my-key");
        let result: redis::Value = command.query(&mut connection)?;
        println!("{result:?}");
        Ok(())
    }
    ```
  </Accordion>
</AccordionGroup>


## Related topics

- [BITFIELD](/docs/redis/sdks/py/commands/bitmap/bitfield.md)
- [BITFIELD_RO](/docs/redis/commands/bitmap/bitfield-ro.md)
- [Features](/docs/redis/sdks/py/features.md)
- [Bitmap commands](/docs/redis/commands/bitmap/overview.md)
- [Overview](/docs/redis/sdks/py/commands/overview.md)