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

# Memory

> Persist data between conversations with configurable time-to-live (TTL) and file support

## Introduction

Memory lets you store variables that persist between conversations, workflows, and nodes. Unlike Context (which is only available during the current conversation), Memory keeps data available for future interactions with the user.

## Key features

| Feature              | Description                                            |
| -------------------- | ------------------------------------------------------ |
| **Configurable TTL** | Define the time-to-live of each variable in seconds    |
| **Multiple types**   | Supports primitives, JSON, and files                   |
| **File storage**     | Store images, videos, audio, and documents up to 10 MB |
| **Specific methods** | Differentiated API for each data type                  |

## Data types

| Type        | Max size       | TTL      | Max TTL            |
| ----------- | -------------- | -------- | ------------------ |
| **String**  | 255 characters | Optional | -                  |
| **Number**  | 15 digits      | Optional | -                  |
| **Boolean** | -              | Optional | -                  |
| **JSON**    | 15 KB          | Required | 86,400 s (1 day)   |
| **File**    | 10 MB          | Required | 604,800 s (1 week) |

<Note>
  **TTL (Time To Live):** Lifetime in seconds. Once the TTL elapses, the variable is automatically deleted. For example, `3600` = 1 hour, `86400` = 1 day.
</Note>

## Saving variables

### Using the Variable node

To save variables without code, use the **Variable** node inside the `Logic` section. In `Variable` enter the name and in `Value` what you want to save; it can be plain text, another variable, or a context value.

```md theme={null}
Variable: name
Value: {{$user.names}}
```

<Tip>
  The Variable node is ideal for saving primitives (string, number, boolean) quickly and visually.
</Tip>

<Note>
  Each Variable node allows a maximum of **20 variables**. If you need more, use multiple nodes or save the values from a code node.
</Note>

### Using code nodes

For greater control over TTL and complex data types, use the `$memory` methods in code nodes:

```javascript theme={null}
// Primitives (string, number, boolean) - TTL optional
$memory.set('name', 'John')
$memory.set('attempts', 3)
$memory.set('verified', true)

// Primitive with TTL (expires in 1 hour)
$memory.set('temporaryCode', 'ABC123', 3600)

// JSON - TTL required (maximum 1 day)
$memory.setJson('preferences', {
  language: 'en',
  notifications: true
}, 86400)

// File - async, TTL required, MIME required (maximum 1 week)
await $memory.setFile('receipt', base64String, 604800, 'application/pdf')
```

## Reading variables

### In any node

Inside any node you can access Memory with the syntax `{{$memory.variableName}}`. For example, if the variables in memory are:

```json theme={null}
{
  "name": "John",
  "lastOrder": { "id": "ORD-123", "status": "on the way" }
}
```

Then:

* `{{$memory.name}}` shows `John`
* `{{$memory.lastOrder.status}}` shows `on the way`

### In code nodes

Use the specific methods according to the data type:

```javascript theme={null}
// Primitives
const name = $memory.get('name')
const name = $memory.get('name', 'Guest') // with default value

// JSON
const prefs = $memory.getJson('preferences')
const prefs = $memory.getJson('preferences', {}) // with default value

// Files - returns FileHandle
const file = $memory.getFile('receipt')
```

## Working with files

When saving a file in Memory, you must provide the content in base64, the TTL, and the MIME type:

```javascript theme={null}
// Save a file
await $memory.setFile('document', base64Content, 604800, 'application/pdf')
```

When reading a file with `$memory.getFile()` you get a **FileHandle** with three methods to access the content:

| Method        | Description                     | Async |
| ------------- | ------------------------------- | ----- |
| `.toUrl()`    | Temporary URL for download (S3) | No    |
| `.toBase64()` | Content as a base-64 string     | Yes   |
| `.toRaw()`    | Buffer / Uint8Array             | Yes   |

```javascript theme={null}
// Get temporary URL
const url = $memory.getFile('receipt').toUrl()

// Get content in base64
const base64 = await $memory.getFile('receipt').toBase64()

// Get file content
const content = await $memory.getFile('receipt').toRaw()
```

### Allowed MIME types

| Category      | MIME types                                                              |
| ------------- | ----------------------------------------------------------------------- |
| **Text**      | `text/plain`                                                            |
| **JSON**      | `application/json`                                                      |
| **XML**       | `application/xml`, `text/xml`                                           |
| **Images**    | `image/jpeg`, `image/png`, `image/gif`                                  |
| **Videos**    | `video/mp4`, `video/ogg`, `video/webm`, `video/x-msvideo`, `video/mpeg` |
| **Audio**     | `audio/mpeg`, `audio/wav`, `audio/ogg`, `audio/aac`, `audio/flac`       |
| **Documents** | `application/pdf`                                                       |

<Warning>
  The methods `$memory.setFile()`, `$memory.getFile().toBase64()`, and `$memory.getFile().toRaw()` are **asynchronous**. You must use `await` when calling them.
</Warning>

## Deleting variables

You can delete variables before their TTL expires:

```javascript theme={null}
// Delete a variable
$memory.delete('temporary')

// Delete multiple variables
$memory.delete(['cache', 'session', 'temporary'])
```

## Security

<Warning>
  **Do not store sensitive data in Memory:**

  * Passwords or credit card numbers
  * Long-lived authentication tokens
  * Highly sensitive personally identifiable information (PII)

  For long-term persistence, use **[Datum](/guides/nodos/datum)**.
</Warning>