
# Create a LangCache service

Redis Cloud

Redis LangCache provides vector search capabilities and efficient caching for AI-powered applications. This guide walks you through creating and configuring a LangCache service in Redis Cloud.

## Prerequisites

To create a LangCache service, you will need:

*   A Redis Cloud database. If you don't have one, see [Create a database](/docs/latest/operate/rc/databases/create-database/).
    
    Note:
    
    LangCache does not support the following databases during public preview:
    
    *   Databases with a [CIDR allow list](/docs/latest/operate/rc/security/cidr-whitelist/)
    *   [Active-Active](/docs/latest/operate/rc/databases/active-active/) databases
    *   Databases with the [default user](../../security/access-control/data-access-control/default-user/index.md) turned off
    
*   An API key for your embedding provider, if not using the default Redis embedding provider. LangCache supports [OpenAI](https://platform.openai.com/api-keys) and the Redis embedding provider during public preview.
    

## Create a LangCache service

From the [Redis Cloud console](https://cloud.redis.io/), select **LangCache** from the left-hand menu.

If you have not already created a LangCache service, you'll see a page with an introduction to LangCache. Otherwise, select **New service** to go to the LangCache introduction page.

[![The New service button.](/docs/latest/images/rc/langcache-new-service.png)](/docs/latest/images/rc/langcache-new-service.png)

From here:

*   Select **Quick create** to create a LangCache service with default settings using your Free 30MB database. If you haven't created a Free database yet, Redis Cloud will create one and set up the LangCache service for you.
    
    [![The Quick create button.](/docs/latest/images/rc/langcache-quick-create.png)](/docs/latest/images/rc/langcache-quick-create.png)
    
    After Redis Cloud creates your LangCache service, a window containing your LangCache service key will appear. Select **Copy** to copy the key to your clipboard.
    
    [![The LangCache service key window. Use the Copy button to save the service key to the clipboard.](/docs/latest/images/rc/langcache-service-key.png)](/docs/latest/images/rc/langcache-service-key.png)
    
    Warning:
    
    This is the only time the value of the user key is available. Save it to a secure location before closing the dialog box.  
      
    
    If you lose the service key value, you will need to [generate a new service key](/docs/latest/operate/rc/langcache/view-edit-cache/#replace-service-api-key) to be able to use the LangCache API.
    
    After your cache is created, you can [use the LangCache API](/docs/latest/operate/rc/langcache/use-langcache/) from your client app.
    
    You can also [view and edit the cache](/docs/latest/operate/rc/langcache/view-edit-cache/) and [monitor the cache's performance](/docs/latest/operate/rc/langcache/monitor-cache/).
    
*   If you want to customize your LangCache service, select **Create custom service**.
    
    [![The Create custom service button.](/docs/latest/images/rc/langcache-custom-service.png)](/docs/latest/images/rc/langcache-custom-service.png)
    
    This takes you to the **Create LangCache service** page. The page is divided into the following sections:
    
    1.  The [General settings](#general-settings) section defines basic properties of your service.
    2.  The [Embedding settings](#embedding-settings) section defines the embedding model used by your service.
    3.  The [Attributes settings](#attributes-settings) section allows you to define attributes for your service.

### General settings

The **General settings** section defines basic properties of your service.

[![The General settings section.](/docs/latest/images/rc/langcache-general-settings.png)](/docs/latest/images/rc/langcache-general-settings.png)

Setting name

Description

**Service name**

Enter a name for your LangCache service. We recommend you use a name that describes your service's purpose.

**Select database**

Select the Redis Cloud database to use for this service from the list.

**TTL**

The time to live (TTL) for cache entries, in milliseconds. Default: `No expiration` - items in the cache will remain until manually removed.

**User for this service**

The [database access user](/docs/latest/operate/rc/security/access-control/data-access-control/role-based-access-control/) to use for this service. LangCache only supports the [`default` user](../../security/access-control/data-access-control/default-user/index.md) during public preview.

### Embedding settings

The **Embedding settings** section defines the embedding model used by your service.

[![The Embedding settings section.](/docs/latest/images/rc/langcache-embedding-settings.png)](/docs/latest/images/rc/langcache-embedding-settings.png)

Required settings depend on the embedding provider you select.

Setting name

Description

**Embedding Provider**

The embedding provider to use for your service. Select between `Redis`, `OpenAI`, and `Bring your own`.  
Any embedding provider you use must support the [OpenAI embeddings API](https://platform.openai.com/docs/api-reference/embeddings).

**Embedding provider API key**

Enter your embedding provider's API key _(`OpenAI` and `Bring your own` embedding providers only)_

**Embedding provider URL**

Enter your embedding provider's API URL _(`Bring your own` embedding provider only)_

**Model**

Select or enter the embedding model to use for your service.

**Similarity threshold**

Set the minimum similarity score required to consider a cached response a match. Range: `0.5` to `1.0`. Default: `0.85`  
  
A higher value means more precise matches, but if it's too high, you will compromise on the number of matches and may lose relevant matches. A lower value means more matches, but may include less relevant matches. We recommend starting between `0.8` and `0.9` and then fine-tuning based on your results.

### Attributes settings

Attributes provide powerful scoping capabilities for your LangCache operations. Think of them as tags or labels that help you organize and manage your cached data with precision.

The **Attributes settings** section allows you to define attributes for your service. It is collapsed by default.

[![The Attributes settings section.](/docs/latest/images/rc/langcache-attribute-settings.png)](/docs/latest/images/rc/langcache-attribute-settings.png)

LangCache allows you to define up to 5 custom attributes that align with your specific use case. To add a new attribute:

1.  Select **Add attribute**.
    
    [![The Add attribute button.](/docs/latest/images/rc/langcache-add-attribute.png)](/docs/latest/images/rc/langcache-add-attribute.png)
2.  Give your custom attribute a descriptive name and select the check mark button to save it.
    
    [![The custom attributes section. Select the Confirm add attribute button to save your attribute.](/docs/latest/images/rc/langcache-custom-attributes.png)](/docs/latest/images/rc/langcache-custom-attributes.png)

After you save your custom attribute, it will appear in the list of custom attributes. Use the **Delete** button to remove it.

[![Select the Delete button to delete the selected attribute.](/docs/latest/images/rc/icon-delete-lb.png)](/docs/latest/images/rc/icon-delete-lb.png)

You can also select **Add attribute** again to add an additional attribute.

[![The Add attribute button.](/docs/latest/images/rc/langcache-add-attribute.png)](/docs/latest/images/rc/langcache-add-attribute.png)

### Create service

When you are done setting the details of your LangCache service, select **Create** to create it.

[![Use the Create button to create a LangCache service.](/docs/latest/images/rc/button-access-management-user-key-create.png)](/docs/latest/images/rc/button-access-management-user-key-create.png)

A window containing your LangCache service key will appear. Select **Copy** to copy the key to your clipboard.

[![The LangCache service key window. Use the Copy button to save the service key to the clipboard.](/docs/latest/images/rc/langcache-service-key.png)](/docs/latest/images/rc/langcache-service-key.png)

Warning:

This is the only time the value of the user key is available. Save it to a secure location before closing the dialog box.  
  

If you lose the service key value, you will need to [generate a new service key](/docs/latest/operate/rc/langcache/view-edit-cache/#replace-service-api-key) to be able to use the LangCache API.

You'll be taken to your LangCache service's **Configuration** page. You'll also be able to see your LangCache service in the LangCache service list.

[![The LangCache service in the LangCache service list.](/docs/latest/images/rc/langcache-service-list.png)](/docs/latest/images/rc/langcache-service-list.png)

If an error occurs, verify that:

*   Your database is active.
*   You have provided a valid OpenAI API key.
*   You have provided valid values for all the required fields.

For help, [contact support](https://redis.io/support/).

## Next steps

After your cache is created, you can [use the LangCache API](/docs/latest/operate/rc/langcache/use-langcache/) from your client app.

You can also [view and edit the cache](/docs/latest/operate/rc/langcache/view-edit-cache/) and [monitor the cache's performance](/docs/latest/operate/rc/langcache/monitor-cache/).

## On this page
