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

# Cache

> Brand-scoped key-value cache for backend scripts.

Backend scripts have access to a Redis-backed key-value cache via the `cache` global. Every key is automatically scoped to the current brand — scripts can never read or write keys belonging to another brand.

Values are JSON-serialised, so you can store strings, numbers, booleans, arrays, and plain objects.

## `cache.get(key)`

Retrieve a value from the cache.

```javascript theme={null}
var count = cache.get('page_views');
if (count !== null) {
  setVariable('views', count);
}
```

| Parameter | Type   | Description |
| --------- | ------ | ----------- |
| `key`     | string | Cache key   |

**Returns:** The stored value, or `null` if the key does not exist or has expired.

## `cache.set(key, value, ttlSeconds?)`

Store a value in the cache with an optional TTL.

```javascript theme={null}
cache.set('last_visit', new Date().toISOString(), 3600);
```

| Parameter    | Type   | Default | Description                      |
| ------------ | ------ | ------- | -------------------------------- |
| `key`        | string | —       | Cache key                        |
| `value`      | any    | —       | Value to store (JSON-serialised) |
| `ttlSeconds` | number | 3600    | Time-to-live in seconds          |

**Returns:** `true` on success, `false` if the brand key limit was reached or an error occurred.

## `cache.del(key)`

Delete a key from the cache.

```javascript theme={null}
cache.del('last_visit');
```

| Parameter | Type   | Description |
| --------- | ------ | ----------- |
| `key`     | string | Cache key   |

**Returns:** `true` on success.

## `cache.has(key)`

Check whether a key exists in the cache.

```javascript theme={null}
if (cache.has('onboarding_complete')) {
  redirect('/dashboard');
}
```

| Parameter | Type   | Description |
| --------- | ------ | ----------- |
| `key`     | string | Cache key   |

**Returns:** `true` if the key exists, `false` otherwise.

## `cache.setIfAbsent(key, value, ttlSeconds?)`

Write a value only if the key does **not** already exist. Useful for debouncing and deduplication.

```javascript theme={null}
var isNew = cache.setIfAbsent('email_sent:' + email, true, 86400);
if (isNew) {
  // First time — send the email
}
```

| Parameter    | Type   | Default | Description             |
| ------------ | ------ | ------- | ----------------------- |
| `key`        | string | —       | Cache key               |
| `value`      | any    | —       | Value to store          |
| `ttlSeconds` | number | 3600    | Time-to-live in seconds |

**Returns:** `true` if the value was written (key was absent), `false` if the key already existed.

## `cache.increment(key, amount?, ttlSeconds?)`

Atomically increment a numeric value. Creates the key with the given amount if it doesn't exist.

```javascript theme={null}
var views = cache.increment('page:home:views', 1, 86400);
setVariable('view_count', views);
```

| Parameter    | Type   | Default | Description                             |
| ------------ | ------ | ------- | --------------------------------------- |
| `key`        | string | —       | Cache key                               |
| `amount`     | number | 1       | Value to add (can be negative or float) |
| `ttlSeconds` | number | —       | Optional TTL to set/refresh             |

**Returns:** The new numeric value after incrementing.

<Note>
  **Limits per brand:**

  * **50,000 keys** maximum per brand
  * **512 bytes** maximum value size
  * **1-hour** maximum TTL
  * **20 cache operations** per script execution
</Note>

<Warning>
  Cache keys must match the pattern `[a-zA-Z0-9_.:-]` and be at most 200 characters long. Keys that don't match will throw an error.
</Warning>