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

# Usage & Billing

> Monitor your token consumption, view per-model cost breakdowns, and manage prepaid credit billing from the Lilac dashboard in real time.

Lilac tracks usage per request at the token level. You can monitor consumption and costs from the dashboard.

## Viewing Usage

Navigate to **Billing** in the dashboard to see:

* **Token usage over time** — prompt and completion tokens, broken down by day
* **Per-model breakdown** — usage and estimated cost for each model
* **Per-key breakdown** — usage attributed to individual API keys

## How Usage is Calculated

Each request records:

| Metric            | Description                       |
| ----------------- | --------------------------------- |
| Prompt tokens     | Tokens in your input messages     |
| Completion tokens | Tokens generated by the model     |
| Total tokens      | Sum of prompt + completion tokens |

Your cost is calculated as:

```
cost = (prompt_tokens × input_price) + (completion_tokens × output_price)
```

See [Pricing](/inference/pricing) for current per-token rates.

## Invoices

Invoices are generated monthly and available in the **Billing** section of your dashboard. Each invoice includes a full breakdown of usage by model and API key.

## Managing Spend

* **Credit balance** — visible at the top of the Billing page
* **Auto top-up** — automatically add credits when your balance drops below a threshold
* **Per-key tracking** — create separate API keys for different projects or environments to track spend independently

## Enterprise billing

Enterprise customers can opt into monthly invoicing instead of prepaid credits. With monthly billing, you are invoiced at the end of each billing cycle for your usage — no need to maintain a credit balance.

To set up monthly invoicing, contact us at [contact@getlilac.com](mailto:contact@getlilac.com).