> ## Documentation Index
> Fetch the complete documentation index at: https://upstash-dx-3009-array-sdk-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# ARSEEK

> Choose the index where the next append will write.

Moves only the append cursor; existing values are unchanged. The key must already exist.

## Arguments

<ParamField body="key" type="string" required>
  The array key.
</ParamField>

<ParamField body="index" type="number | string" required>
  The index where the next ARINSERT should write.
</ParamField>

## Response

<ResponseField type="0 | 1" required>
  TypeScript returns `1` if the cursor was set and `0` if the key does not exist. Python returns `True` or `False`, respectively.
</ResponseField>

<RequestExample>
  ```ts Example theme={"system"}
  await redis.arset("readings", 10, "existing");
  const nextIndex = await redis.arlen("readings");
  console.log(await redis.arseek("readings", nextIndex)); // 1
  console.log(await redis.arinsert("readings", "new")); // "11"
  console.log(await redis.arget("readings", 10)); // "existing"
  ```
</RequestExample>

See the [server command reference](/redis/commands/array/arseek) for protocol details.