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

# persist

> Remove the expiration from a key

## Description

Remove the existing timeout on a key, turning the key from volatile (a key with an expire set) to persistent (a key that will never expire as no timeout is associated).

## Method Signature

```typescript theme={null}
persist(key: string): Promise<0 | 1>
```

## Parameters

<ParamField path="key" type="string" required>
  The key to remove expiration from
</ParamField>

## Return Value

<ResponseField name="result" type="0 | 1">
  * `1` if the timeout was removed
  * `0` if key does not exist or does not have an associated timeout
</ResponseField>

## Examples

### Remove expiration from a key

```typescript theme={null}
await redis.set("mykey", "value");
await redis.expire("mykey", 100);

let ttl = await redis.ttl("mykey");
console.log(ttl); // ~100

const result = await redis.persist("mykey");
console.log(result); // 1

ttl = await redis.ttl("mykey");
console.log(ttl); // -1 (no expiration)
```

### Key without expiration

```typescript theme={null}
await redis.set("mykey", "value");
const result = await redis.persist("mykey");
console.log(result); // 0 (key has no timeout)
```

### Non-existent key

```typescript theme={null}
const result = await redis.persist("nonexistent");
console.log(result); // 0
```

### Make a temporary key permanent

```typescript theme={null}
// Set a key with expiration
await redis.set("session:user123", "data", { ex: 3600 });

// Later, decide to keep it permanently
await redis.persist("session:user123");

// Key will now never expire
const ttl = await redis.ttl("session:user123");
console.log(ttl); // -1
```

## See Also

* [expire](/api/commands/expire) - Set a key's time to live
* [ttl](/api/commands/ttl) - Get the time to live for a key