# Use attributes in Amazon Connect to route based on number of contacts in a queue
<a name="attrib-system-metrics"></a>

Amazon Connect includes queue attributes that can help you define routing conditions in your flows based on real-time metrics about the queues and agents in your contact center. For example, here are some common usage scenarios:
+ Check the number of contacts or available agents in a queue, and how long the oldest contact has been in a queue, then route accordingly.
+ To route to the queue with the fewest contacts in it:

  1. Get metrics for multiple queues.

  1. Use a [Set contact attributes](set-contact-attributes.md) block to store the metric attributes for each queue.

  1. compare queue metric attributes using a [Check contact attributes](check-contact-attributes.md) block, and route the contact to the queue with the fewest calls in it, or to a callback if all queues are busy.

# Using a Check contact attributes block to route a contact to a queue


1. In Amazon Connect, choose **Routing**, **Contact flows**.

1. Open an existing flow or create a new one.

1. Optionally, under **Interact**, add a **Play prompt** block to the designer to play a greeting to your customers. Add a connector between the **Entry point** block and the **Play prompt** block.

1. Under **Set**, drag a **Get queue metrics** block to the designer, and connect the **Okay** branch of the **Play prompt** block to it.

1. Choose the title of the **Get queue metrics** block to open the properties for the block. By default, the block retrieves metrics for the current working queue. To retrieve metrics for a different queue, choose **Set queue**.

1. Choose **Select a queue**, then select the queue to retrieve metrics for from the drop-down, then choose **Save**.

   You can also determine which queue to retrieve metrics for using contact attributes.

1. Under **Check**, drag a **Check contact attributes** block to the designer.

1. Choose the title of the block to display the settings for the block. Then, under **Attribute to check**, select **Queue metrics** in the **Type** drop-down menu.

1. Under **Attribute**, choose **Contacts in queue**.

1. To use conditions to route the contact, choose **Add another condition**.

   By default, the **Check contact attributes** block includes a single condition, **No match**. The **No match** branch is followed when there are no matches for any of the conditions you define in the block.

1. Under **Conditions to check**, select **Is less than** as the operator for the condition in the drop-down menu, then in the value field enter 5.

1. Choose **Add another condition**, then choose **Is greater or equal** from the drop-down menu, and enter 5 in the value field.

1. Choose **Save**.

   You now see two new output branches for the **Check contact attributes** block.

You can now add additional blocks to the flow to route the contact as desired. For example, connect the < 5 branch to a **Transfer to queue** block to transfer calls to the queue when there are fewer than five calls currently in the queue. Connect the > 5 branch to a Set customer callback number block and then transfer the call to a callback queue using a **Transfer to queue** block so the customer doesn't have to stay on hold.

## Route contacts based on queue metrics
<a name="route-based-on-queue-metrics"></a>

Many contact centers route customers based on the number of contacts waiting in a queue. This topic explains how to configure a flow that looks similar to the following image. It shows the following three flow blocks connected by Success branches: **Set contact attributes**, **Get queue metrics**, and **Check contact attributes**.

![\[The flow designer with three flow blocks on it.\]](http://docs.aws.amazon.com/connect/latest/adminguide/images/get-metrics-specify-set-contact-attributes.png)


1. Add a [Set contact attributes](set-contact-attributes.md) block to your flow.

1. In the [Set contact attributes](set-contact-attributes.md), specify the channel. If you set a channel dynamically using text, for the attribute value enter **Voice** or **Chat**, as shown in the following image. This value is not case-sensitive.   
![\[The properties page of the Set contact attributes block. Namespace is set to User defined, Value set to chat.\]](http://docs.aws.amazon.com/connect/latest/adminguide/images/get-metrics-properties2.png)

1. Add a [Get metrics](get-queue-metrics.md) block to your flow. 

 In the Get queue metrics block, dynamic attributes can only return metrics for one channel

## Add a Check contact attributes block after the Get queue metrics block
<a name="get-metrics-tips2"></a>

After a **Get queue metrics** block, add a [Check contact attributes](check-contact-attributes.md) block to branch based on the returned metrics. Use the following steps:

1. After **Get queue metrics**, add a **Check contact attributes** block.

1. In the **Check contact attributes** block, set **Attribute to check** to **Queue metrics**.

1. In the **Attributes to check** dropdown box, you'll see that the following queue metrics are returned by the **Get queue metrics** block. Choose the metric that you want to use for the routing decision.   
![\[The properties page of the Check contact attributes block, Namespace is set to Queue metrics.\]](http://docs.aws.amazon.com/connect/latest/adminguide/images/get-metrics-block-returned-metrics.png)

1. Choose **Add a condition** to enter the comparison for your routing decision. The following image shows the block configured to check whether contacts in queue is greater than 5.  
![\[The Attribute to check section, the Conditions to check section.\]](http://docs.aws.amazon.com/connect/latest/adminguide/images/get-metrics-check-attributes-block.png)