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

# Make your first billable metric

> Billable metrics are a core feature that allows you to measure the usage events you send to Orb. These metrics power your usage-based pricing by tracking customer interactions and activities. This guide will walk you through creating your first billable metric in Orb and understanding its functions.

<iframe src="https://www.loom.com/embed/58e28a4b485f4bd2aef60b173765d65a?sid=13d112bb-9054-46e7-b22a-832b713caa36" title="Billable metric" className="w-full h-96 rounded-xl" />

## Step 1: What Are Billable Metrics?

Billable metrics in Orb help you measure and calculate usage data based on the events you send into the platform. For example:

* If you’re tracking **API calls**, the events for those API calls are sent to Orb, and the billable metric counts them.
* Beyond simple examples, billable metrics can handle more complex use cases, such as:
  * Measuring **storage** used by a customer on a VM.
  * Tracking **input and output tokens** for an AI model.

## Step 2: Creating a Billable Metric

To create your first metric, follow these steps:

1. **Navigate to the Billable Metrics Page** in test mode.
2. **Click on Create a New Metric**: You’ll have two options for how to define your metric:
   1. **Simple Event Filter**: Use this to quickly match events based on properties such as event name (e.g., API call).
   2. **Custom SQL Query**: For more advanced use cases, you can use SQL queries to define how your events should be processed.

## Step 3: Simple Event Filter

If you choose the simple event filter option:

* You can match events by their **event name**, such as `api_call`.
* This filter allows you to match additional fields within the event’s properties. For instance, if the event includes a key-value pair like `source`, you can add that to your filter.
  * Orb will autofill values into the input based on previous events you’ve sent, making it easier to set up the filter.

*Previewing Events:*

Once the filter is set, you can preview past events to confirm the metric captures the correct data.

## Step 4: Defining the Calculation

After filtering the events, decide what type of calculation you want to perform:

* For example, if you’re counting API calls, you can set up a **count** of events where the event name is `api_call` .
* For more advanced calculations, you can define your property with a "Computed Property" expression.

## Step 5: Finalizing the Metric

Once you’ve defined the calculation, follow these steps:

1. **Name the Metric**: Give it a clear, descriptive name (e.g., “Count API Calls”).
2. **Define an Item**: The item is the sellable entity for this metric. For instance, if you’re selling API calls, you can create an item called “API Calls.”
3. **Publish the Metric**: You can add an optional description before publishing the metric.

## Step 6: Debugging Your Metric

Orb provides tools for debugging your billable metrics:

* In the **debugging tab**, you can filter by customer or date range to test your metric against existing events.
* This allows you to confirm that the metric produces the expected results before deploying it live.

## Step 7: Managing Billable Metrics

* **Duplicate Metrics**: If you need to create a similar metric, you can duplicate an existing one instead of starting from scratch.
* **Edit or Archive Metrics**: You can edit the metric’s name and description or archive metrics that are no longer in use.
* **Copy to Live Mode**: Once you’ve tested and validated the metric in test mode, you can easily copy it to live mode for production use.

## Step 8: Using Custom SQL Queries

For more complex use cases, you can use **Custom SQL** to build highly tailored metrics. Custom SQL allows for powerful extensions, making it suitable for various unique usage patterns. You can see some sample SQL expressions [here](https://docs.withorb.com/guides/extensibility/advanced-metrics).

By following this guide, you can create and configure billable metrics in Orb to track customer usage, power your pricing models, and ensure accurate billing for your services.