# llReadKeyValue

*LSL function (requires an experience)*

```lsl
key key llReadKeyValue(string k);
```

- `string k`: Key of the key-value pair to read.

- Returns: `key`
- Energy: 10

Start an asynchronous transaction to read the value associated with the specified key (**k**) and the script's [Experience](/categories/experience/).

If the key does not exist the [dataserver](/events/dataserver/) will return a failure along with the error [XP_ERROR_KEY_NOT_FOUND](/constants/XP_ERROR_KEY_NOT_FOUND/).

Returns a [key](https://wiki.secondlife.com/wiki/key) that can be used to identify the corresponding [dataserver](/events/dataserver/) event to determine if this command succeeded or failed and the results.

```lsl title="How to use" frame="terminal"
key result = llReadKeyValue("");
```

## Examples

<details open>
<summary>Example 1</summary>

```lsl collapse={15-26}
key trans;
default
{
    state_entry()
    {
        trans = llReadKeyValue("FOO");
    }
    dataserver(key t, string value)
    {
        if (t == trans)
        {
            // our llReadKeyValue transaction is done
            if (llGetSubString(value, 0, 0) == "1")
            {
                // the key-value pair was successfully read
                llSay(0, "New key-value pair value: " + llGetSubString(value, 2, -1));
            }
            else
            {
                // the key-value pair failed to read
                integer error =  (integer)llGetSubString(value, 2, -1);
                llSay(0, "Key-value failed to read: " + llGetExperienceErrorMessage(error));
            }
        }
    }
}
```

</details>

## Shared wiki templates

The wiki article also includes shared templates whose conditional content is not reproduced here: [Template:Issues/BUG-8895](https://wiki.secondlife.com/wiki/Template:Issues/BUG-8895).

## See also

### Functions

- [llGetExperienceErrorMessage](/functions/llGetExperienceErrorMessage/)
- [llCreateKeyValue](/functions/llCreateKeyValue/)
- [llReadKeyValue](/functions/llReadKeyValue/)
- [llUpdateKeyValue](/functions/llUpdateKeyValue/)
- [llDeleteKeyValue](/functions/llDeleteKeyValue/)
- [llDataSizeKeyValue](/functions/llDataSizeKeyValue/)
- [llKeyCountKeyValue](/functions/llKeyCountKeyValue/)
- [llKeysKeyValue](/functions/llKeysKeyValue/)

---

*Source: [LlReadKeyValue](https://wiki.secondlife.com/wiki/LlReadKeyValue) on the Second Life Wiki. Content from the Second Life Wiki articles LlReadKeyValue (revision 1216653, 2024-05-13), Template:LSL Function/KeyValue (revision 1218517, 2025-11-17) and Template:LSL Function/Experience (revision 1210521, 2022-03-11), CC BY-SA 3.0.*

---

From lsl.dev: https://lsl.dev/functions/llReadKeyValue/